MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Experimental Brain Research' source. Tue, 07 Feb 2012 07:05:43 +0100 http://www.medworm.com/index.php?rid=5640004&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22278107%26dopt%3DAbstract Authors: Muise SB, Lam CK, Bent LR Abstract Sensory afferent information from the skin of the foot sole and information from the vestibular system converge within the central nervous system; however, their mode of interaction remains unknown. The purpose of this study was to investigate the effect of reduced cutaneous foot sole information on the ability of the vestibular system to evoke short latency (SL) and medium latency (ML) lower limb muscle reflex responses. Galvanic vestibular stimulation (GVS; bipolar; binaural; 25 ms; 2 mA square-wave pulse) was applied to standing human subjects (four women, eight men, average age 21.1 ± 3.0 years) both before and after cooling the foot soles in 1°C ice water (15 min initially, followed by 5 min between blocks of 200 GVS pulses)... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5640004 Thu, 26 Jan 2012 05:00:00 +0100 5640004 http://www.medworm.com/index.php?rid=5640003&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22278108%26dopt%3DAbstract In conclusion, vision-to-event coordination dominates unimanual action coordination. The quality of performance is influenced by perceptual processes based on differential processing of the horizontal and vertical axis, and based on Gestalt principles. PMID: 22278108 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5640003 Thu, 26 Jan 2012 05:00:00 +0100 5640003 http://www.medworm.com/index.php?rid=5640002&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22278109%26dopt%3DAbstract This study examined the influence of time gain on the visual-motor control of isometric force. Time gain denotes the spatial length on the computer screen representing the unit of elapsed time of the force output, through which the time properties of the visually perceived force output can be compressed or extended. Five time gains and three force target waveforms (sinewave, brown noise, and straight line) with different time-dependent properties were tested in the experiment. The results revealed that time gain influenced task performance nonlinearly in a way that was dependent on the predictability of the target waveforms. In the sinewave target condition, there was a U-shaped modulation of time gain on the mean and variability of force error, and an inverted U-shaped modulation on the t... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5640002 Thu, 26 Jan 2012 05:00:00 +0100 5640002 http://www.medworm.com/index.php?rid=5640001&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22278110%26dopt%3DAbstract Authors: van der Kamp J, de Wit MM, Masters RS Abstract We investigated whether the control of movement of the left hand is more likely to involve the use of allocentric information than movements performed with the right hand. Previous studies (Gonzalez et al. in J Neurophys 95:3496-3501, 2006; De Grave et al. in Exp Br Res 193:421-427, 2009) have reported contradictory findings in this respect. In the present study, right-handed participants (N = 12) and left-handed participants (N = 12) made right- and left-handed grasps to foveated objects and peripheral, non-foveated objects that were located in the right or left visual hemifield and embedded within a Müller-Lyer illusion. They were also asked to judge the size of the object by matching their hand aperture to its length. ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5640001 Thu, 26 Jan 2012 05:00:00 +0100 5640001 http://www.medworm.com/index.php?rid=5640000&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22278111%26dopt%3DAbstract Authors: Sülzenbrück S, Heuer H Abstract We investigated the impact of enhanced mechanical transparency during practice on closed-loop performance as well as on the acquisition of an internal representation of the visuo-motor transformation of a lever. Three groups of participants controlled a cursor on a monitor by moving the effort arm of a sliding two-sided lever. The level of mechanical transparency was manipulated by varying the amount of conceptual knowledge about the tool the participants were using as well as by the visualization of the effective part of the tool on the monitor. While for groups cursor- and cursor+ only a cursor representing the tip of the load arm of the lever was visible, group shaft was additionally provided with a representation of the load arm on the... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5640000 Thu, 26 Jan 2012 05:00:00 +0100 5640000 http://www.medworm.com/index.php?rid=5640005&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22271193%26dopt%3DAbstract Authors: Massen C, Sattler C Abstract Research on bimanual coordination has shown that the efficiency of programming an action is determined by the way the action is cognitively represented. In tool use, actions can be represented with respect to the spatial goal of the action (e.g., the nail that is to be hit by a hammer) or with respect to the tool and its transformation (i.e., the function that maps external target locations onto corresponding bodily movements). We investigated whether the way of cuing bimanual actions with tools affects their cognitive representation and the efficiency with which they are programmed. In one group of participants, tool transformations were specified by symbolic cues, whereas the targets were indicated by direct spatial cues. In another group of ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5640005 Tue, 24 Jan 2012 05:00:00 +0100 5640005 http://www.medworm.com/index.php?rid=5623050&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22252738%26dopt%3DAbstract Authors: Liang J, Yin J, Chen T, Chen H, Ding X, Shen M Abstract The same numerical magnitude can be manifested in different physical notations. However, how the numbers with distinct notations are mentally represented is still unclear. Here, we hypothesized that how the number is mentally represented is influenced by the numerical processing level of the tasks. If the task only needed a low-level processing, the representation would be dependent on the surface forms of the numbers, exhibiting a numerical notation-dependent effect. By contrast, if the task required a deeper magnitude processing, the processing would utilize an abstract numerical format whose effects are notation independent. To test this hypothesis, we manipulated the notation type and the numerical processing leve... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5623050 Wed, 18 Jan 2012 05:00:00 +0100 5623050 http://www.medworm.com/index.php?rid=5602184&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22249434%26dopt%3DAbstract Authors: Kanemaru N, Watanabe H, Taga G Abstract In the field of motor development, a question exists whether spontaneous activity in early infancy serves as a precursor to later-emerging goal-directed behaviors. To answer this question, it is necessary to investigate in detail the properties of spontaneous movements in individual infants. In the current study, we longitudinally examined the spontaneous movements of the end points of the limbs in 6 infants aged 2-4 months. Examinations were carried out every week by using a motion analysis system, and the number of recordings performed for each infant varied from 6 to 9 times. Our major finding was that there was an age-related increase in the velocity and position correlation between arms and between legs, whereas there was no si... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5602184 Sun, 15 Jan 2012 05:00:00 +0100 5602184 http://www.medworm.com/index.php?rid=5602185&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22246105%26dopt%3DAbstract Authors: Latash ML Abstract Motor control is an area of natural science exploring how the nervous system interacts with other body parts and the environment to produce purposeful, coordinated actions. A central problem of motor control-the problem of motor redundancy-was formulated by Nikolai Bernstein as the problem of elimination of redundant degrees-of-freedom. Traditionally, this problem has been addressed using optimization methods based on a variety of cost functions. This review draws attention to a body of recent findings suggesting that the problem has been formulated incorrectly. An alternative view has been suggested as the principle of abundance, which considers the apparently redundant degrees-of-freedom as useful and even vital for many aspects of motor behavior. Over... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5602185 Sat, 14 Jan 2012 05:00:00 +0100 5602185 http://www.medworm.com/index.php?rid=5602186&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22246104%26dopt%3DAbstract Authors: Barthélemy D, Alain S, Grey MJ, Nielsen JB, Bouyer LJ Abstract Force field adaptation of locomotor muscle activity is one way of studying the ability of the motor control networks in the brain and spinal cord to adapt in a flexible way to changes in the environment. Here, we investigate whether the corticospinal tract is involved in this adaptation. We measured changes in motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) in the tibialis anterior (TA) muscle before, during, and after subjects adapted to a force field applied to the ankle joint during treadmill walking. When the force field assisted dorsiflexion during the swing phase of the step cycle, subjects adapted by decreasing TA EMG activity. In contrast, when the force field resiste... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5602186 Fri, 13 Jan 2012 05:00:00 +0100 5602186 http://www.medworm.com/index.php?rid=5602187&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22237940%26dopt%3DAbstract Authors: Dalecki M, Dräger T, Mierau A, Bock O Abstract We have shown before that subjects exposed to a changed gravitoinertial environment produce exaggerated manual forces. From the observed pattern of findings, we argued that initial forces were exaggerated because of abnormal vestibular activity and peak forces because of degraded proprioceptive feedback. If so, only peak but not initial forces should be affected by water immersion, an environment that influences proprioceptive feedback but not vestibular activity. The present study was undertaken to scrutinize this prediction. Twelve subjects sat in a chair once immersed in water and once on dry land, while producing pre-trained isometric forces with a joystick. In a control experiment, subjects performed a four-choice reacti... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5602187 Thu, 12 Jan 2012 05:00:00 +0100 5602187 http://www.medworm.com/index.php?rid=5602189&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22234434%26dopt%3DAbstract Authors: van Dokkum L, Mottet D, Bonnin-Koang HY, Metrot J, Roby-Brami A, Hauret I, Laffont I Abstract We investigated the visual perception of biological movement by people post-stroke, using minimal kinematic displays. A group of twenty patients and a group of twelve age-matched healthy controls were asked to judge movement fluency. The movements to judge were either displayed as an end-point dot or as a stick-figure of the arm and trunk. It was found that the perception of movement fluency was preserved post-stroke, however, with an increase in the variability of judgment. Moreover, the end-point dot representation ameliorated what was perceived and judged, presumably by directing attention to the important kinematic cues: smoothness and directness of the trajectory. We conclude... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5602189 Wed, 11 Jan 2012 05:00:00 +0100 5602189 http://www.medworm.com/index.php?rid=5602188&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22234435%26dopt%3DAbstract Authors: Tsutsumi R, Hanajima R, Hamada M, Shirota Y, Matsumoto H, Terao Y, Ohminami S, Yamakawa Y, Shimada H, Tsuji S, Ugawa Y Abstract In mild cognitive impairment (MCI), the corpus callosum is known to be affected structurally. We evaluated callosal function by interhemispheric inhibition (IHI) using transcranial magnetic stimulation (TMS) in MCI patients. We investigated 12 amnestic MCI patients and 16 healthy age-matched control subjects. The IHI was studied with a paired-pulse TMS technique. The conditioning TMS was given over the right primary motor cortex (M1) and the test TMS over the left M1. Motor evoked potentials were recorded from the relaxed first dorsal interosseous muscle. We also studied other motor cortical circuit functions; short-latency afferent inhibition (SA... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5602188 Wed, 11 Jan 2012 05:00:00 +0100 5602188 http://www.medworm.com/index.php?rid=5578419&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22231560%26dopt%3DAbstract Authors: Ong NT, Larssen BC, Hodges NJ Abstract The presence of after-effects in adaptation tasks implies that an existing internal model has been updated. Previously, we showed that although observers adapted to a visuomotor perturbation, they did not show after-effects. In this experiment, we tested 2 further observer groups and an actor group. Observers were now actively engaged in watching (encouraged through imagery and movement estimation), with one group physically practising for 25% of the trials (mixed). Participants estimated the hand movements that produced various cursor trajectories and/or their own hand movement from a preceding trial. These trials also allowed us to assess the development of explicit knowledge as a function of the three practice conditions. The pure ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578419 Tue, 10 Jan 2012 05:00:00 +0100 5578419 http://www.medworm.com/index.php?rid=5578420&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22227856%26dopt%3DAbstract Authors: Christel MI, Jeannerod M, Weiss PH Abstract To examine the mechanisms of functional bimanual synchronization in goal-directed movements, we studied the movement kinematics of motorically unimpaired subjects while they performed repetitive prehension movements (either unimanually or bimanually) to small food items. Compared to unimanual conditions, bimanual movement execution yielded a significantly prolonged mouth contact phase. We hypothesized that this threefold prolongation led to a proper functional synchronization of the movement onsets of both hands at the beginning of each new movement cycle. That these temporal adjustments occurred in the movement phase with maximal haptic input points to the importance of sensory feedback for bimanual coordination. These results a... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578420 Sat, 07 Jan 2012 05:00:00 +0100 5578420 http://www.medworm.com/index.php?rid=5578422&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22218499%26dopt%3DAbstract Authors: Adamo DE, Scotland S, Martin BJ Abstract While asymmetries in upper limb force matching have been observed, the mechanisms underlying asymmetry in the sense of effort have not been conceptualized. The aim of this study was to investigate asymmetries in the perception and reproduction of grasp force. Forty-two young adults, 22 right-handed (RH) and 20 left-handed (LH), were, respectively, divided into three groups according to differences between their right and left-hand strength (left stronger than right, right stronger than left and right & left equivalent). A reference force, representing 20% of the maximal voluntary contraction (MVC) produced by the right or left hand, was matched with same hand (Ipsilateral Remembered-IR) or opposite (Contralateral Remembered-CR) ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578422 Thu, 05 Jan 2012 05:00:00 +0100 5578422 http://www.medworm.com/index.php?rid=5578421&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22218500%26dopt%3DAbstract This study sought to determine whether modulation of voltage-gated sodium channels could induce V (th) hyperpolarization. Whole-cell patch-clamp recordings were made from antidromically identified lumbar spinal motoneurones in an isolated neonatal rat spinal cord preparation. Recordings were made with and without the bath application of veratridine, a plant alkaloid neurotoxin that acts as a sodium channel modulator. As seen in HEK 293 cells expressing Nav1.2 channels, veratridine-modified channels demonstrated a hyperpolarizing shift in their voltage-dependence of activation and a slowing of inactivation that resulted in an enhanced inward current in response to voltage ramp stimulations. In the native rat motoneurones, veratridine-modified sodium channels induced a hyperpolariz... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578421 Thu, 05 Jan 2012 05:00:00 +0100 5578421 http://www.medworm.com/index.php?rid=5578424&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22210117%26dopt%3DAbstract Authors: Schorer J, Jaitner T, Wollny R, Fath F, Baker J Abstract Research suggests an external focus of attention positively affects motor learning more than an internal focus; however, little research has considered this relationship in motor control situations. The present study examined the role of varying focus of attention conditions on dart throwing performance. Experts (n = 6) and novices (n = 6) performed 84 throws under two internal and one external conditions and in the presence and absence of knowledge of results (KR). Results indicated clear differences between experts and novices on both performance and motor control outcomes. Further, there was some evidence that movement execution was slowed in experts but not in novices, although results were somewhat inconclus... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578424 Sun, 01 Jan 2012 05:00:00 +0100 5578424 http://www.medworm.com/index.php?rid=5578423&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22210118%26dopt%3DAbstract Authors: Chang CH, Pan WW, Tseng LY, Stoffregen TA Abstract Research has confirmed that console video games give rise to motion sickness in many adults. During exposure to console video games, there are differences in postural activity (movement of the head and torso) between participants who later experience motion sickness and those who do not, confirming a prediction of the postural instability theory of motion sickness. Previous research has not addressed relations between video games, movement and motion sickness in children. We evaluated the nauseogenic properties of a commercially available console video game in both adults and 10-year-old children. Individuals played the game for up to 50 min and were instructed to discontinue immediately if they experienced any symptoms o... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578423 Sun, 01 Jan 2012 05:00:00 +0100 5578423 http://www.medworm.com/index.php?rid=5578425&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22207361%26dopt%3DAbstract Authors: Machulla TK, Di Luca M, Froehlich E, Ernst MO Abstract Recent studies show that repeated exposure to an asynchrony between auditory and visual stimuli shifts the point of subjective simultaneity. Usually, the measurement stimuli used to assess this aftereffect are interleaved with short re-exposures to the asynchrony. In a first experiment, we show that the aftereffect declines during measurement in spite of the use of re-exposures. In a second experiment, we investigate whether the observed decline is either due to a dissipation of the aftereffect with the passage of time, or the result of using measurement stimuli with a distribution of asynchronies different from the exposure stimulus. To this end, we introduced a delay before measuring the aftereffects and we compared ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578425 Fri, 30 Dec 2011 05:00:00 +0100 5578425 http://www.medworm.com/index.php?rid=5578427&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22205232%26dopt%3DAbstract In this study, we aim to investigate whether motor commands, emanating from movement planning, are customized to movement orientation relative to gravity from the first trial on. Participants made fast point-to-point elbow flexions and extensions in the transverse plane. We compared movements that had been practiced in reclined orientation either against or with gravity with the same movement relative to the body axis made in the upright orientation (neutral compared to gravity). For each movement type, five rotations from reclined to upright orientation were made. For each rotation, we analyzed the first trial in upright orientation and the directly preceding trial in reclined orientation. Additionally, we analyzed the last five trials of a 30-trial block in upright position and compared ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578427 Thu, 29 Dec 2011 05:00:00 +0100 5578427 http://www.medworm.com/index.php?rid=5578426&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22205233%26dopt%3DAbstract Authors: Aoki M, Sakaida Y, Tanaka K, Mizuta K, Ito Y Abstract There is little definitive evidence of the clinical significance of the vestibular-cardiovascular reflex in humans, despite the fact that the vestibular system is known to contribute to cardiovascular control in animals. The present study involved 248 dizzy patients (127 male patients and 121 female patients) aged 65 years and younger. We classified all participants into three groups based on their vestibular evoked myogenic potential (VEMP) responses; absent VEMP, asymmetry VEMP and normal VEMP. To investigate the effect of the otolith disorder, which was estimated by the VEMP, on the orthostatic blood pressure responses, the subjects' systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate were m... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5578426 Thu, 29 Dec 2011 05:00:00 +0100 5578426 http://www.medworm.com/index.php?rid=5550334&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198575%26dopt%3DAbstract Authors: Mohapatra S, Krishnan V, Aruin AS Abstract The purpose of the study was to investigate the role of altered proprioception on anticipatory (APAs) and compensatory (CPAs) postural adjustments and their interaction. Nine healthy adults were exposed to external perturbations induced at the shoulder level while standing with intact or altered proprioception induced by bilateral Achilles tendon vibration. Visual information was altered (eyes open or closed) in both the conditions. Electrical activity of eight trunk and leg muscles and center of pressure (COP) displacements were recorded and quantified within the time intervals typical for APAs and CPAs. The results showed that when proprioceptive information was altered in eyes-open conditions, anticipatory muscle activity was d... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5550334 Sun, 25 Dec 2011 05:00:00 +0100 5550334 http://www.medworm.com/index.php?rid=5550340&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198529%26dopt%3DAbstract Authors: Gilster R, Hesse C, Deubel H Abstract We investigated the choice of contact points during multidigit grasping of different objects. In Experiment 1, cylinders were grasped and lifted. Participants were either instructed as to the number of fingers they should use, ranging from a two-finger grasp to a five-finger grasp, or could grasp with their preferred number of fingers. We found a strong relationship between the position of the fingertips on the object and the number of fingers used. In general, variability in the choice of contact points was low within- as well as between participants. The virtual finger, defined as the geometric mean position of fingers opposing the thumb, was in almost perfect opposition to the thumb, suggesting the formation of a functional unit usi... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5550340 Sat, 24 Dec 2011 05:00:00 +0100 5550340 http://www.medworm.com/index.php?rid=5550339&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198530%26dopt%3DAbstract Authors: Magalhães FH, Kohn AF Abstract Optimal levels of noise stimulation have been shown to enhance the detection and transmission of neural signals thereby improving the performance of sensory and motor systems. The first series of experiments in the present study aimed to investigate whether subsensory electrical noise stimulation applied over the triceps surae (TS) in seated subjects decreases torque variability during a force-matching task of isometric plantar flexion and whether the same electrical noise stimulation decreases postural sway during quiet stance. Correlation tests were applied to investigate whether the noise-induced postural sway decrease is linearly predicted by the noise-induced torque variability decrease. A second series of experiments was conducted to i... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5550339 Sat, 24 Dec 2011 05:00:00 +0100 5550339 http://www.medworm.com/index.php?rid=5550338&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198531%26dopt%3DAbstract Authors: Babinsky E, Braddick O, Atkinson J Abstract It has been shown that infants over the age of 6 months will reach for an object in complete darkness. This experiment measured the reaching movements of 9- to 16-month-old infants and adults under several different conditions of illumination to investigate the role of vision and stored visual representations in reach control. In one condition, participants reached for an object with the lights on. In a second condition, participants reached for an object glowing in the dark (glowing condition). This allowed us to measure the effects of vision of the arm and vision of the reach space. We also looked at the effect of removing vision of the object on reach control: in the final two conditions, participants reached for an object in... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5550338 Sat, 24 Dec 2011 05:00:00 +0100 5550338 http://www.medworm.com/index.php?rid=5550337&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198532%26dopt%3DAbstract Authors: Salomonczyk D, Henriques DY, Cressman EK Abstract Previous studies have demonstrated that after reaching with misaligned visual feedback of the hand, one adapts his or her reaches and partially recalibrates proprioception, such that sense of felt hand position is shifted to match the seen hand position. However, to date, this has only been demonstrated in the right (dominant) hand following reach training with a visuomotor distortion in which the rotated cursor distortion was introduced gradually. As reach adaptation has been shown to differ depending on how the distortion is introduced (gradual vs. abrupt), we sought to examine proprioceptive recalibration following reach training with a cursor that was abruptly rotated 30° clockwise relative to hand motion. Furthermore,... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5550337 Sat, 24 Dec 2011 05:00:00 +0100 5550337 http://www.medworm.com/index.php?rid=5550336&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198533%26dopt%3DAbstract Authors: Piotrkiewicz M, Kudina L Abstract This paper deals with the analysis of changes in motoneuron (MN) firing evoked by repetitively applied stimuli aimed toward extracting information about the underlying synaptic volleys. Spike trains were obtained from computer simulations based on a threshold-crossing model of tonically firing MN, subjected to stimulation producing postsynaptic potentials (PSPs) of various parameters. These trains were analyzed as experimental results, using the output measures that were previously shown to be most effective for this purpose: peristimulus time histogram, raster plot and peristimulus time intervalgram. The analysis started from the effects of single excitatory and inhibitory PSPs (EPSPs and IPSPs). The conclusions drawn from this analysis a... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5550336 Sat, 24 Dec 2011 05:00:00 +0100 5550336 http://www.medworm.com/index.php?rid=5550335&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22198534%26dopt%3DAbstract Authors: Uysal H, Kızılay F, Inel SE, Ozen H, Pek G Abstract The H reflex obtained from the flexor carpi radialis muscle by median nerve stimulation is a well-known monosynaptic reflex. However, the origin of the late responses is still contentious. Radial nerve stimulation was performed through the spiral groove, and EMG recording was obtained from the flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles. An M response followed by an F response was achieved from the ECR by radial nerve stimulation; the antagonistic FCR muscle elicited a late response. A total of 25 cases were included in this study. In 22 of these cases, a response with a latency of 40.97 ± 5.35 ms was obtained from the FCR by radial nerve stimulation. When extension of the hand was restrict... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5550335 Sat, 24 Dec 2011 05:00:00 +0100 5550335 http://www.medworm.com/index.php?rid=5535147&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22186962%26dopt%3DAbstract Authors: Wessel JR, Haider H, Rose M Abstract Implicit learning, i.e. knowledge acquisition in incidental learning situations, is a fundamental feature of the human mind. The extraction of (and subsequent adaptation to) regular patterns in the environment facilitates everyday actions. The cognitive and neural processes accompanying the transition from subconscious (implicit) to verbally reportable (explicit) knowledge about task contingencies are of high interest to the cognitive neurosciences, since they indicate a process that generates awareness for learned associations. Previous studies indicated an important role of high-frequency coupling (gamma-band) for the process that initiates the emergence of awareness for an implicitly learned task-underlying structure. It is unclear, ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5535147 Wed, 21 Dec 2011 05:00:00 +0100 5535147 http://www.medworm.com/index.php?rid=5535149&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22183754%26dopt%3DAbstract Authors: Case LK, Wilson RC, Ramachandran VS Abstract Individuals with anorexia nervosa (AN) experience pronounced body image distortion in combination with a pernicious desire to maintain a dangerously low body weight. Relatively little is known, however, about the mechanism underlying body image distortion in AN. Despite having normal visual perception, individuals with AN both feel and see themselves as large-bodied and show deficits in interoception and haptic perception, suggesting a potential deficit in visual and tactile integration. The size-weight illusion (SWI) arises when two objects of equal weight but different sizes are held. Typical individuals experience a strong and robust illusion that the smaller object feels much heavier than the larger object because of an impl... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5535149 Tue, 20 Dec 2011 05:00:00 +0100 5535149 http://www.medworm.com/index.php?rid=5535148&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22183755%26dopt%3DAbstract In this study, we examine eye movements made in the context of demanding natural behavior, while playing squash. We show that prediction is a pervasive component of gaze behavior in this context. We show in addition that these predictive movements are extraordinarily precise and operate continuously in time across multiple trajectories and multiple movements. This suggests that prediction is based on complex dynamic visual models of the way that balls move, accumulated over extensive experience. Since eye, head, arm, and body movements all co-occur, it seems likely that a common internal model of predicted visual state is shared by different effectors to allow flexible coordination patterns. It is generally agreed that internal models are responsible for predicting future sensory state for... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5535148 Tue, 20 Dec 2011 05:00:00 +0100 5535148 http://www.medworm.com/index.php?rid=5535152&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22179527%26dopt%3DAbstract Authors: Bexander CS, Hodges PW Abstract People with whiplash-associated disorders (WAD) not only suffer from neck/head pain, but commonly report deficits in eye movement control. Recent work has highlighted a strong relationship between eye and neck muscle activation in pain-free subjects. It is possible that WAD may disrupt the intricate coordination between eye and neck movement. Electromyographic activity (EMG) of muscles that rotate the cervical spine to the right (left sternocleidomastoid, right obliquus capitis inferior (OI), right splenius capitis (SC) and right multifidus (MF)) was recorded in nine people with chronic WAD. Cervical rotation was performed with five gaze conditions involving different gaze directions relative to cervical rotation. The relationship between ey... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5535152 Sat, 17 Dec 2011 05:00:00 +0100 5535152 http://www.medworm.com/index.php?rid=5535151&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22179528%26dopt%3DAbstract This article will review the physiological function of APP and its proteolytic products, especially Aβ and AICD, in regulating lipid homeostasis and which lipid species modulate APP processing. Furthermore, we summarize the alterations in lipid metabolism observed in AD patients and AD mouse models. PMID: 22179528 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5535151 Sat, 17 Dec 2011 05:00:00 +0100 5535151 http://www.medworm.com/index.php?rid=5535150&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22179529%26dopt%3DAbstract Authors: Beurskens R, Bock O Abstract Earlier work suggests that the area of space from which useful visual information can be extracted (useful field of view, UFoV) shrinks in old age. We investigated whether this shrinkage, documented previously with a visual search task, extends to a bimanual tracking task. Young and elderly subjects executed two concurrent tracking tasks with their right and left arms. The separation between tracking displays varied from 3 to 35 cm. Subjects were asked to fixate straight ahead (condition FIX) or were free to move their eyes (condition FREE). Eye position was registered. In FREE, young subjects tracked equally well at all display separations. Elderly subjects produced higher tracking errors, and the difference between age groups increased with ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5535150 Sat, 17 Dec 2011 05:00:00 +0100 5535150 http://www.medworm.com/index.php?rid=5513605&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22169978%26dopt%3DAbstract Authors: Finley JM, Dhaher YY, Perreault EJ Abstract The nervous system can regulate the mechanical properties of the human ankle through feed-forward mechanisms such as co-contraction and rapid feedback mechanisms such as stretch reflexes. Though each of these strategies may contribute to joint stability, it is unclear how their relative contribution varies when ankle stability is threatened. We addressed this question by characterizing co-contraction and stretch reflexes during balance of an inverted pendulum simulated by a rotary motor configured as an admittance servo. The stability of this haptic environment was manipulated by varying the stiffness of a virtual spring supporting the pendulum. We hypothesized that co-contraction and stretch reflex amplitude would increase as th... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513605 Thu, 15 Dec 2011 05:00:00 +0100 5513605 http://www.medworm.com/index.php?rid=5513608&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22159560%26dopt%3DAbstract Authors: Riley MA, Mitra S, Saunders N, Kiefer AW, Wallot S Abstract Three experiments examined interactions between posture control in upright stance and a concurrent location memory task. Healthy young participants stood upright and memorized the locations of dots presented on a computer screen. In the retrieval phase, they indicated whether arrows presented on the screen would pass through any of the memorized locations. Postural sway variability was measured either during the retention period or during retrieval. Relative to not performing the memory task, postural sway variability increased in the retention period when the eyes were closed, but remained unaffected when the eyes were open. During retrieval, postural sway variability was reduced relative to the no-memory-task co... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513608 Tue, 13 Dec 2011 05:00:00 +0100 5513608 http://www.medworm.com/index.php?rid=5513609&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22159550%26dopt%3DAbstract Authors: Zhang L, Xin Z, Li F, Wang Q, Ding C, Li H Abstract The aim of this study was to examine how adults processed common fractions with common numerators under two distinct conditions. Whereas participants were presented with only common fractions in a "simple" condition, a "complex" condition involved the random presentation of common fractions as well as decimal fractions. In both conditions, participants were required to assess whether various "target" fractions were larger than or smaller than a "standard" common fraction (1/5). Behavioral results indicated that under both conditions, participants mentally processed the fractions componentially in terms of their constituent parts rather than holistically in terms of the numerical value of the fraction as a whole. The data ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513609 Sat, 10 Dec 2011 05:00:00 +0100 5513609 http://www.medworm.com/index.php?rid=5513606&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22159639%26dopt%3DAbstract Authors: Raw RK, Wilkie RM, Culmer PR, Mon-Williams M Abstract Handedness, a preference towards using the right or left hand, is established in early childhood. Such specialisation allows a higher level of skill to be maintained in the preferred hand on specific tasks through continuous practice and performance. Hand asymmetries might be expected to increase with age because of the time spent practising with the preferred hand. However, neurophysiological work has suggested reduced hemispheric function lateralisation in the ageing brain, and behavioural studies have found reduced motor asymmetries in older adults (Przybyla et al., in Neurosci Lett 489:99-104, 2011). We therefore tested the predictions of behavioural change from reduced hemispheric function by measuring tracing perf... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513606 Fri, 09 Dec 2011 05:00:00 +0100 5513606 http://www.medworm.com/index.php?rid=5513607&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22159588%26dopt%3DAbstract Authors: Casellato C, Tagliabue M, Pedrocchi A, Papaxanthis C, Ferrigno G, Pozzo T Abstract Many studies showed that both arm movements and postural control are characterized by strong invariants. Besides, when a movement requires simultaneous control of the hand trajectory and balance maintenance, these two movement components are highly coordinated. It is well known that the focal and postural invariants are individually tightly linked to gravity, much less is known about the role of gravity in their coordination. It is not clear whether the effect of gravity on different movement components is such as to keep a strong movement-posture coordination even in different gravitational conditions or whether gravitational information is necessary for maintaining motor synergism. We thus... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513607 Thu, 08 Dec 2011 05:00:00 +0100 5513607 http://www.medworm.com/index.php?rid=5513614&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22143868%26dopt%3DAbstract Authors: Semrau JA, Daitch AL, Thoroughman KA Abstract The use of vision allows us to guide and modify our movements by appropriately transforming external sensory information into proper motor commands. We investigated how people learned visuomotor transformations in different visual feedback environments. These environments presented perturbations of visual sense of movement direction. Across experiments and testing days, we altered the likelihood of visual perturbation occurrence and the distribution of sign and strength of visual perturbation angles. We then observed how transformation of sensed error into incremental adaptation depended on visual perturbation angle and on environmental experience. We found that environmental context affected adaptive responses within a day and... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513614 Tue, 06 Dec 2011 05:00:00 +0100 5513614 http://www.medworm.com/index.php?rid=5513613&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22143869%26dopt%3DAbstract Generalization properties of a "saccadic-like" hand-reaching adaptation along a single degree of freedom. Exp Brain Res. 2011 Dec 6; Authors: Laurent D, Sillan O, Prablanc C Abstract Visuomotor-adaptation experiments devoted to the study of plasticity are also used to indirectly test hypotheses about how the brain encodes the spatio-temporal characteristics of arm movement directed at a visual target. A current major theory, the vectorial coding hypothesis, postulates that arm movements are processed differentially for direction and amplitude. This approach, at first developed in an extrinsic Cartesian frame of references, has been also adopted in an intrinsic joint space. In the present paper, we report an experiment that corroborates this last point of view. Subjects perf... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513613 Tue, 06 Dec 2011 05:00:00 +0100 5513613 http://www.medworm.com/index.php?rid=5513612&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22143870%26dopt%3DAbstract Authors: Hogan MJ, Kenney JP, Roche RA, Keane MA, Moore JL, Kaiser J, Lai R, Upton N Abstract The current study examined the EEG of young, old and old declined adults performing a visual paired associate task. In order to examine the effects of encoding context and stimulus repetition, target pairs were presented on either detailed or white backgrounds and were repeatedly presented during both early and late phases of encoding. Results indicated an increase in P300 amplitude in the right parietal cortex from early to late stages of encoding in older declined adults, whereas both younger adults and older controls showed a reduction in P300 amplitude in this same area from early to late phase encoding. In the right hemisphere, stimuli encoded with a white background had larger P300 a... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513612 Tue, 06 Dec 2011 05:00:00 +0100 5513612 http://www.medworm.com/index.php?rid=5513611&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22143871%26dopt%3DAbstract Authors: Dessing JC, Rey FP, Beek PJ Abstract Novice and expert jugglers employ different visuomotor strategies: whereas novices look at the balls around their zeniths, experts tend to fixate their gaze at a central location within the pattern (so-called gaze-through). A gaze-through strategy may reflect visuomotor parsimony, i.e., the use of simpler visuomotor (oculomotor and/or attentional) strategies as afforded by superior tossing accuracy and error corrections. In addition, the more stable gaze during a gaze-through strategy may result in more accurate movement planning by providing a stable base for gaze-centered neural coding of ball motion and movement plans or for shifts in attention. To determine whether a stable gaze might indeed have such beneficial effects on juggling,... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513611 Tue, 06 Dec 2011 05:00:00 +0100 5513611 http://www.medworm.com/index.php?rid=5513610&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22143872%26dopt%3DAbstract Authors: Hasan A, Hamada M, Nitsche MA, Ruge D, Galea JM, Wobrock T, Rothwell JC Abstract Animal studies using polarising currents have shown that induction of synaptic long-term potentiation (LTP) and long-term depression (LTD) by bursts of patterned stimulation is affected by the membrane potential of the postsynaptic neurone. The aim of the present experiments was to test whether it is possible to observe similar phenomena in humans with the aim of improving present protocols of inducing synaptic plasticity for therapeutic purposes. We tested whether the LTP/LTD-like after effects of transcranial theta-burst stimulation (TBS) of human motor cortex, an analogue of patterned electrical stimulation in animals, were affected by simultaneous transcranial direct-current stimulation (t... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5513610 Tue, 06 Dec 2011 05:00:00 +0100 5513610 http://www.medworm.com/index.php?rid=5475478&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22138667%26dopt%3DAbstract Authors: Carlsen AN, Almeida QJ, Franks IM Abstract In reaction time (RT) tasks where fast ballistic movements are required, the requisite action is generally preplanned to enable the quickest responses. When a loud acoustic stimulus (e.g., >120 dB) that elicits a startle response is presented during the preplanning phase, the movement is triggered involuntarily and at a sufficiently short enough latency to discount normal cortical initiation processes. It has been suggested that the startle triggers the action by providing sufficient additional activation to surpass the initiation threshold. It is unclear, however, whether similar RT shortening due to startle would occur in the absence of an excitatory motor output. Thus, in the current study, participants performed a flexion ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475478 Sat, 03 Dec 2011 05:00:00 +0100 5475478 http://www.medworm.com/index.php?rid=5475481&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22130779%26dopt%3DAbstract Authors: Hoover AE, Harris LR, Steeves JK Abstract Some blind people are better at locating sounds than people with normal vision indicating cross-modal plasticity. People who have lost one eye have a unique form of visual deprivation that reduces visual afferent signals by half and can potentially also lead to cross-modal (as well as intra-modal) plasticity. To look for evidence of auditory-visual cross-modal compensation, we measured binaural and monaural sound localization in one-eyed people and compared them with normally sighted controls. One-eyed people showed significantly better binaural sound localization than controls in the central region of space (±78° from straight ahead), but they mislocalized sounds in the far periphery (on both the blind and intact side) by up to ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475481 Thu, 01 Dec 2011 05:00:00 +0100 5475481 http://www.medworm.com/index.php?rid=5475480&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22130780%26dopt%3DAbstract This study extends our knowledge of the observed decline in MEP amplitude following certain tasks. Our results suggest that central initiation of motor programs may induce a change in MEP amplitude, even in the absence of objective fatigue. PMID: 22130780 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475480 Thu, 01 Dec 2011 05:00:00 +0100 5475480 http://www.medworm.com/index.php?rid=5475479&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22130781%26dopt%3DAbstract Authors: Park J, Singh T, Zatsiorsky VM, Latash ML Abstract We used two methods to address two aspects of multi-finger synergies and their changes after fatigue of the index finger. Analytical inverse optimization (ANIO) was used to identify cost functions and corresponding spaces of optimal solutions over a broad range of task parameters. Analysis within the uncontrolled manifold (UCM) hypothesis was used to quantify co-variation of finger forces across repetitive trials that helped reduce variability of (stabilized) performance variables produced by all the fingers together. Subjects produced steady-state levels of total force and moment of force simultaneously as accurately as possible by pressing with the four fingers of the right hand. Both before and during fatigue, the subje... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475479 Thu, 01 Dec 2011 05:00:00 +0100 5475479 http://www.medworm.com/index.php?rid=5475482&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22124803%26dopt%3DAbstract Authors: Emery K, Côté JN Abstract Neck/shoulder pain has previously been linked to repetitive work and muscle fatigue. We have shown that asymptomatic people performing repetitive upper limb tasks display signs of shoulder fatigue and of whole-body compensatory strategies. However, the role played by the proprioceptive system in the production of these compensatory strategies has not been studied. A group of asymptomatic adults (n = 18) performed a repetitive pointing task at shoulder height to fatigue. Before and after fatigue, they performed two position sense tasks, eyes closed: a single-joint task where they abducted their shoulder to the perceived horizontal and a multi-joint task, where they stood and placed their finger at the perceived location of a target in front of ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475482 Tue, 29 Nov 2011 05:00:00 +0100 5475482 http://www.medworm.com/index.php?rid=5475486&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22120156%26dopt%3DAbstract Authors: Prox J, Rittger A, Saftig P Abstract Alzheimer's disease causing mutations in the amyloid precursor protein (APP) or in the Presenilin 1 (PS1) or Presenilin 2 (PS2) genes increase the production of amyloid peptides (Aβ) that precipitate in amyloid plaques. Since amyloid plaques are also a prominent feature of sporadic Alzheimer's disease (AD), abnormal proteolysis of APP and the generation of amyloid beta (Aβ) are key events in the pathogenesis of AD. The proteases (secretases) that cleave APP are therefore important therapeutic targets, both for the rare familial forms but likely also for the sporadic forms of AD. The identification and understanding of the (neuro)biological functions of the α-, β-, and presenilin/γ-secretase (complexes) is important for the developm... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475486 Sun, 27 Nov 2011 05:00:00 +0100 5475486 http://www.medworm.com/index.php?rid=5475485&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22120157%26dopt%3DAbstract Authors: Brennan AA, Bakdash JZ, Proffitt DR Abstract People have a lifetime of experience in which to calibrate their self-produced locomotion with the resultant optical flow. Contrary to walking across the ground, however, walking on a treadmill produces minimal optical flow, and consequentially, a perceptual-motor aftereffect results. We demonstrate that the magnitude of this perceptual-motor aftereffect-measured by forward drift while attempting to march in-place following treadmill walking-decreases as experience walking on a treadmill is acquired over time. Experience with treadmill walking enables walking in this context to become sufficiently distinguished from walking in other contexts. Consequently, two distinct perceptual-motor calibration states are maintained, each lin... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475485 Sun, 27 Nov 2011 05:00:00 +0100 5475485 http://www.medworm.com/index.php?rid=5475484&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22120158%26dopt%3DAbstract Authors: Weiler J, Heath M Abstract The latency of a prosaccade is increased when completed following an antisaccade (the prior-antisaccade effect). This finding has been attributed to the inhibition of the oculomotor networks necessary for an antisaccade engendering a persistent response set that delays a to-be-executed prosaccade. The goal of the present investigation was to determine whether the prior-antisaccade effect influences not only the planning but also the control of an unfolding prosaccade trajectory. To accomplish that objective, we employed a task-switching paradigm wherein participants alternated between pro- and antisaccades on every second trial (i.e., AABB paradigm). Importantly, trajectory control was evaluated by computing the proportion of variance (R ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475484 Sun, 27 Nov 2011 05:00:00 +0100 5475484 http://www.medworm.com/index.php?rid=5475483&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22120159%26dopt%3DAbstract Authors: Kida T, Kaneda T, Nishihira Y Abstract The amplitudes of the event-related brain potentials (ERPs) have been associated with the amount of attentional resources. The present study investigated whether force production type (increasing or decreasing force) in a visuomotor force tracking task modulates the ERPs elicited in a somatosensory oddball task performed simultaneously, whether stimulus-response coupling assessed by a single-trial analysis of P300 latency is modulated by the concurrent performance of the tasks, and whether dynamic visuomotor coordination rather static coordination is sensitive to the ERP modulation. In the dual-task condition, the subjects tracked a target line moving on the display with another line representing the force generated by the grip of the... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475483 Sun, 27 Nov 2011 05:00:00 +0100 5475483 http://www.medworm.com/index.php?rid=5475489&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22120106%26dopt%3DAbstract Authors: Katsumata H, Russell DM Abstract Debate exists as to whether humans use prospective or predictive control to intercept an object falling under gravity (Baurès et al. in Vis Res 47:2982-2991, 2007; Zago et al. in Vis Res 48:1532-1538, 2008). Prospective control involves using continuous information to regulate action. τ, the ratio of the size of the gap to the rate of gap closure, has been proposed as the information used in guiding interceptive actions prospectively (Lee in Ecol Psychol 10:221-250, 1998). This form of control is expected to generate movement modulation, where variability decreases over the course of an action based upon more accurate timing information. In contrast, predictive control assumes that a pre-programmed movement is triggered at an appropriate ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475489 Sat, 26 Nov 2011 05:00:00 +0100 5475489 http://www.medworm.com/index.php?rid=5475488&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22120107%26dopt%3DAbstract Authors: Boyles J, Panzer S, Shea CH Abstract An experiment was conducted to determine whether multi-frequency continuous bimanual circling movements of varying difficulty (1:2. 2:3, 3:4, and 4:5) could be effectively performed following relatively little practice when on-line continuous relative velocity feedback is provided. The between-subjects results indicate extremely effective bimanual multi-frequency performance for all coordination patterns with relatively stable and continuous movements of both limbs. The findings suggest that the previous performance effects using Lissajous feedback with reciprocal movement can be extended to circling movements using on-line relative velocity feedback. Contrary to the long-held position that these coordination patterns result in increasi... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475488 Sat, 26 Nov 2011 05:00:00 +0100 5475488 http://www.medworm.com/index.php?rid=5475487&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22120108%26dopt%3DAbstract Authors: Planetta PJ, Servos P Abstract The tactile motion aftereffect (tMAE) is a perceptual illusion in which a stationary stimulus feels as though it is moving when presented following adaptation to a unidirectionally moving tactile stimulus. Using functional magnetic resonance imaging (fMRI), we localized the brain areas responsive to tactile motion and then investigated whether these areas underlie the tMAE. Tactile stimulation was delivered to the glabrous surface of the right hand by means of a plastic cylinder with a square-wave patterned surface. In the tactile motion localizer, we contrasted periods in which the cylinder rotated at 15 rpm with periods of rest (stationary contact). Activation was observed in the contralateral (left) thalamus, postcentral gyrus, and pariet... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475487 Sat, 26 Nov 2011 05:00:00 +0100 5475487 http://www.medworm.com/index.php?rid=5475490&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22116400%26dopt%3DAbstract Authors: Bennett SJ, Elliott D, Rodacki A Abstract The current study examined the movement kinematics of older adults when aiming to vertically oriented targets. Late middle-age and early old-age participants completed 20 trials to a small target located downward or upward by 0.16 m from a home position at shoulder height. Aiming direction had a significant effect, resulting in more submovements, which were mostly reflective of undershooting when aiming to the downward compared to upward target. In trials containing a submovement, both groups exhibited shorter total movement time, concomitant with a decrease in duration of the primary movement and an increase in submovement amplitude, when aiming to the downward target. Measures of dispersion also differed in accord with the ampli... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475490 Fri, 25 Nov 2011 05:00:00 +0100 5475490 http://www.medworm.com/index.php?rid=5475491&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22113487%26dopt%3DAbstract Authors: Przybyla A, Good DC, Sainburg RL Abstract Our previous studies of interlimb asymmetries during reaching movements have given rise to the dynamic-dominance hypothesis of motor lateralization. This hypothesis proposes that dominant arm control has become optimized for efficient intersegmental coordination, which is often associated with straight and smooth hand-paths, while non-dominant arm control has become optimized for controlling steady-state posture, which has been associated with greater final position accuracy when movements are mechanically perturbed, and often during movements made in the absence of visual feedback. The basis for this model of motor lateralization was derived from studies conducted in right-handed subjects. We now ask whether left-handers show simi... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475491 Thu, 24 Nov 2011 05:00:00 +0100 5475491 http://www.medworm.com/index.php?rid=5475493&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22108701%26dopt%3DAbstract Authors: Vlaskamp BN, Schubö A Abstract Looking at actions of others activates representations of similar own actions, that is, the action resonates. This may facilitate or interfere with the actions that one intends to make. We asked whether people promote or block those effects by making eye movements to or away from the actions of others. We investigated gaze behavior with a cup-clinking task: An actor shown on a video grabbed a cup and moved it toward the participant who next grabbed his own cup in the 'same' or in a different, 'complementary', way. In the 'same' condition, participants mostly looked at the place where the actor held the cup. In the 'complementary' condition, gaze behavior was similar at the start of the actor's action. To our surprise, as the action reached c... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475493 Wed, 23 Nov 2011 05:00:00 +0100 5475493 http://www.medworm.com/index.php?rid=5475492&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22108702%26dopt%3DAbstract Authors: Yen SC, Schmit BD, Landry JM, Roth H, Wu M Abstract Treadmill training has been used as a promising technique to improve overground walking in patients with spinal cord injury (SCI). Previous findings showed that a gait pattern may adapt to a force perturbation during treadmill training and show aftereffects following removal of the force perturbation. We hypothesized that aftereffects would transfer to overground walking to a greater extent when the force perturbation was resisting rather than assisting leg swing during treadmill training. Ten subjects with incomplete SCI were recruited into this study for two treadmill training sessions: one using swing resistance and the other using swing assistance during treadmill stepping. A controlled resistance/assistance was provi... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475492 Wed, 23 Nov 2011 05:00:00 +0100 5475492 http://www.medworm.com/index.php?rid=5475495&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22105335%26dopt%3DAbstract Authors: Moro SS, Steeves JK Abstract Previous research has shown that people with one eye have enhanced spatial vision implying intra-modal compensation for their loss of binocularity. The current experiments investigate whether monocular blindness from unilateral eye enucleation may lead to cross-modal sensory compensation for the loss of one eye. We measured speeded detection and discrimination of audiovisual targets presented as a stream of paired objects and familiar sounds in a group of individuals with monocular enucleation compared to controls viewing binocularly or monocularly. In Experiment 1, participants detected the presence of auditory, visual or audiovisual targets. All participant groups were equally able to detect the targets. In Experiment 2, participants discrimi... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475495 Tue, 22 Nov 2011 05:00:00 +0100 5475495 http://www.medworm.com/index.php?rid=5475494&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22105336%26dopt%3DAbstract Authors: Jaekl P, Soto-Faraco S, Harris LR Abstract The retinal image of an object does not contain information about its actual size. Size must instead be inferred from extraretinal cues for which distance information makes an essential contribution. Asynchronies in the arrival time across visual and auditory sensory components of an audiovisual event can reliably cue its distance, although this cue has been largely neglected in vision research. Here we demonstrate that audio-visual asynchronies can produce a shift in the apparent size of an object and attribute this shift to a change in perceived distance. In the present study participants were asked to match the perceived size of a test circle paired with an asynchronous sound to a variable-size probe circle paired with a simult... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475494 Tue, 22 Nov 2011 05:00:00 +0100 5475494 http://www.medworm.com/index.php?rid=5475497&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22101568%26dopt%3DAbstract Authors: Teng S, Puri A, Whitney D Abstract Echolocating organisms represent their external environment using reflected auditory information from emitted vocalizations. This ability, long known in various non-human species, has also been documented in some blind humans as an aid to navigation, as well as object detection and coarse localization. Surprisingly, our understanding of the basic acuity attainable by practitioners-the most fundamental underpinning of echoic spatial perception-remains crude. We found that experts were able to discriminate horizontal offsets of stimuli as small as ~1.2° auditory angle in the frontomedial plane, a resolution approaching the maximum measured precision of human spatial hearing and comparable to that found in bats performing similar tasks. Fur... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475497 Sun, 20 Nov 2011 05:00:00 +0100 5475497 http://www.medworm.com/index.php?rid=5475496&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22101569%26dopt%3DAbstract This study tests for the first time the electrophysiological correlates of the effects of proprioceptive information on tactile-attentional mechanisms in the space behind the back. Observers were blindfolded and tactually cued to detect infrequent tactile targets on either their left or right hand and to respond to them either vocally or with index finger movements. We measured event-related potentials to tactile probes on the hands in order to explore tactile-spatial attention when the hands were either held close together or far apart behind the observer's back. Results show systematic effects of arm posture on tactile-spatial attention different from those previously found for front space. While attentional selection is typically more effective for hands placed far apart than close toge... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475496 Sun, 20 Nov 2011 05:00:00 +0100 5475496 http://www.medworm.com/index.php?rid=5475501&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22101492%26dopt%3DAbstract Authors: Valle MS, Eian J, Bosco G, Poppele RE Abstract We recorded from over 280 single cortical neurons throughout the medial anterior lobe of the cat cerebellum during passive movements of the hindlimbs resembling stepping on a moving treadmill. We used three stepping patterns, unilateral stepping of either the ipsilateral or contralateral leg and bipedal stepping in an alternating gait pattern. We found that over 60% of the neurons, mostly Purkinje cells, responded to stepping of one or both legs, and over 40% to more than one type of stepping pattern. Responsive cells were distributed throughout the five anterior lobules, and the highest concentration was found in traditional hindlimb areas in lobules 2 and 3. A comparison of response waveforms showed that they are similar for... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475501 Sat, 19 Nov 2011 05:00:00 +0100 5475501 http://www.medworm.com/index.php?rid=5475500&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22101493%26dopt%3DAbstract Authors: Iida T, Sakayanagi M, Svensson P, Komiyama O, Hirayama T, Kaneda T, Sakatani K, Kawara M Abstract Using functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS), we examined the role of periodontal afferent inputs on cerebral activation pattern evoked by masticatory muscle activity in twenty-two subjects. Statistical comparisons were used to identify brain regions with significant activation after subtraction of baseline activity from sham teeth-tapping (no periodontal input) and teeth-tapping (periodontal input) activity in an fMRI (N = 14) and NIRS study (N = 8). Both sham teeth-tapping and teeth-tapping significantly activated bilateral sensorimotor cortex and supplementary motor area in the fMRI study. NIRS revealed that oxygenated hemoglo... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475500 Sat, 19 Nov 2011 05:00:00 +0100 5475500 http://www.medworm.com/index.php?rid=5475499&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22101494%26dopt%3DAbstract Authors: Plessow F, Kiesel A, Kirschbaum C Abstract Goals are often at the basis of human actions. As an essential mechanism of behavioural adaptation, individuals need to be able to flexibly implement new task goals so as to alter their actions (switch tasks) in response to contextual changes. The present study investigated the effect of acute psychosocial stress on cognitive control processes of flexible task-goal implementation with temporal focus on the occurrence interval of the hypothalamus-pituitary-adrenal (HPA) stress response. For this, forty-eight healthy volunteers were either challenged with a standardised stress-induction protocol (the Trier Social Stress Test) or underwent a standardised control situation. Subsequently, they were exposed to a task-switching procedure... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475499 Sat, 19 Nov 2011 05:00:00 +0100 5475499 http://www.medworm.com/index.php?rid=5475498&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22101495%26dopt%3DAbstract Authors: Al-Janabi S, Finkbeiner M Abstract The purpose of the present study was to establish whether the validity effect produced by masked eye gaze cues should be attributed to strictly reflexive mechanisms or to volitional top-down mechanisms. While we find that masked eye gaze cues are effective in producing a validity effect in a central cueing paradigm, we also find that the efficacy of masked gaze cues is sharply constrained by the experimental context. Specifically, masked gaze cues only produced a validity effect when they appeared in the context of unmasked and predictive gaze cues. Unmasked gaze cues, in contrast, produced reliable validity effects across a range of experimental contexts, including Experiment 4 where 80% of the cues were invalid (counter-predictive). Tak... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475498 Sat, 19 Nov 2011 05:00:00 +0100 5475498 http://www.medworm.com/index.php?rid=5475504&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22094713%26dopt%3DAbstract Authors: Shi G, Liu Y, Liu T, Yan W, Liu X, Wang Y, Shi J, Jia L Abstract It is increasingly clear that microRNAs (miRNAs) play an important role in controlling cell survival. However, the functional significance of miRNAs in ischemic brain injury remains poorly understood. In the present study, we assayed the expression levels of miR-29b after ischemic brain injury, and defined the target genes and biological functions of miR-29b. We found that the miR-29b levels were significantly increased in rat brain after transient middle cerebral artery occlusion and neurons after oxygen-glucose deprivation. Moreover, ectopic expression of miR-29b promoted neuronal cell death, whereas its repression decreased cell death. Furthermore, we verified that miR-29b directly targeted and inhibited B... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475504 Fri, 18 Nov 2011 05:00:00 +0100 5475504 http://www.medworm.com/index.php?rid=5475503&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22094714%26dopt%3DAbstract Authors: Jung CK, Herms J Abstract The amyloid precursor protein (APP) is transported in high amounts to the presynaptic endings where its function is still unknown. Several studies indicate that lack of APP or its overexpression affects the number of dendritic spines, the postsynaptic compartment of excitatory synapses. Since synapse loss has been identified as one of the most important structural correlates of cognitive decline in Alzheimer's diseases (AD), the physiological function of APP at synapses, specifically at dendritic spines, has come into focus in AD research. This review intends to give an overview of the very controversial results on APP expression on dendritic spine number in the mouse brain. PMID: 22094714 [PubMed - as supplied by publisher] (Source: Experimen... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475503 Fri, 18 Nov 2011 05:00:00 +0100 5475503 http://www.medworm.com/index.php?rid=5475502&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22094715%26dopt%3DAbstract This study investigates the effects of eccentric exercise and delayed onset muscle soreness (DOMS) of the quadriceps on agonist-antagonist activity during a range of motor tasks. Ten healthy volunteers (age, mean ± SD, 24.9 ± 3.2 years) performed maximum voluntary contractions (MVC) and explosive isometric contractions of the knee extensors followed by isometric contractions at 2.5, 5, 10, 15, 20, and 30% MVC at baseline, immediately after and 24 h after eccentric exercise of the quadriceps. During each task, force of the knee extensors and surface EMG of the vasti and hamstrings muscles were recorded concurrently. Rate of force development (RFD) was computed from the explosive isometric contraction, and the coefficient of variation of the force (CoV) signal was estimated from the ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5475502 Fri, 18 Nov 2011 05:00:00 +0100 5475502 http://www.medworm.com/index.php?rid=5421178&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22086493%26dopt%3DAbstract Authors: Kögel D, Deller T, Behl C Abstract The roles of amyloid precursor protein (APP) family members in normal brain function are poorly understood. Under physiological conditions the majority of APP appears to be processed along the non-amyloidogenic pathway leading to the formation of the secreted N-terminal APP fragment sAPPα. This cleavage product of APP has been implicated in several physiological processes such as neuroprotection, synaptic plasticity, neurite outgrowth and synaptogenesis. In this review we focus on the role of APP family members in neuroprotection and summarize the cellular and molecular mechanisms which are believed to mediate this effect. We propose that a reduction of APP processing along the non-amyloidogenic pathway during brain aging could result i... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421178 Wed, 16 Nov 2011 05:00:00 +0100 5421178 http://www.medworm.com/index.php?rid=5421177&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22086494%26dopt%3DAbstract Authors: Li Z, Durgin FH Abstract Proprioception of hand orientation (orientation production using the hand) is compared with manual matching of visual orientation (visual surface matching using the hand) in two experiments. In experiment 1, using self-selected arm postures, the proportions of wrist and elbow flexion spontaneously used to orient the pitch of the hand (20 and 80%, respectively) are relatively similar across both manual matching tasks and manual orientation production tasks for most participants. Proprioceptive error closely matched perceptual biases previously reported for visual orientation perception, suggesting calibration of proprioception to visual biases. A minority of participants, who attempted to use primarily wrist flexion while holding the forearm horizon... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421177 Wed, 16 Nov 2011 05:00:00 +0100 5421177 http://www.medworm.com/index.php?rid=5421179&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22083094%26dopt%3DAbstract This study examines the interactions between such gaze-evoked blinks and gaze shifts in monkeys. Blink probability increases with gaze amplitude and at a faster rate for head-unrestrained movements. Across animals, blink likelihood is inversely correlated with the average gaze velocity of large-amplitude control movements. Gaze-evoked blinks induce robust perturbations in eye velocity. Peak and average velocities are reduced, duration is increased, but accuracy is preserved. The temporal features of the perturbation depend on factors such as the time of blink relative to gaze onset, inherent velocity kinematics of control movements, and perhaps initial eye-in-head position. Although variable across animals, the initial effect is a reduction in eye velocity, followed by a reacceleration tha... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421179 Tue, 15 Nov 2011 05:00:00 +0100 5421179 http://www.medworm.com/index.php?rid=5421181&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22080150%26dopt%3DAbstract Authors: Tabata H, Yoshinaga S, Nakajima K Abstract During cerebral neocortical development, excitatory neurons are generated from radial glial cells in the ventricular zone (VZ) or from secondary progenitor cells in the subventricular zone (SVZ); these neurons then migrate toward the pial surface. We have observed that post-mitotic neurons generated directly in the VZ accumulated just above the VZ with a multipolar morphology, while secondary progenitor cells having a long ascending process left the VZ faster than the post-mitotic neurons. Recent observations of human developing neocortex have revealed the existence of radial glia-like progenitors (oRG cells) in the SVZ. This type of progenitor was first thought to be human specific; however, similar cells have also been found in ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421181 Sun, 13 Nov 2011 05:00:00 +0100 5421181 http://www.medworm.com/index.php?rid=5421180&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22080151%26dopt%3DAbstract Authors: Kuroki S, Watanabe J, Mabuchi K, Tachi S, Nishida S Abstract Tactile motion provides critical information for perception and manipulation of objects in touch. Perceived directions of tactile motion are primarily defined in the environmental coordinate, which means they change drastically with body posture even when the same skin sensors are stimulated. Despite the ecological importance of this perceptual constancy, the sensory processing underlying tactile directional remapping remains poorly understood. The present study psychophysically investigated the mechanisms underlying directional remapping in human tactile motion processing by examining whether finger posture modulates the direction of the tactile motion aftereffect (MAE) induced by inter-finger apparent motions. ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421180 Sun, 13 Nov 2011 05:00:00 +0100 5421180 http://www.medworm.com/index.php?rid=5421183&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22080104%26dopt%3DAbstract This study investigated the extent to which the decline in touch perception affects adults throughout their working life. In addition, the influence of work-related expertise on tactile and haptic perception was examined in an attempt to determine whether expertise, in the form of the frequent use of the fingers, affects perception and counters age-related losses. The study was conducted with subjects from three age groups (18-25, 34-46, and 54-65 years) with two levels of expertise. Expertise was classified by the subjects' occupations. Five sensory tasks of touch perception were conducted. The results confirmed age-related changes in tactile perception over the span of one's working life. Older workers were proven to have lower tactile performance than younger adults. However, middle-ag... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421183 Sat, 12 Nov 2011 05:00:00 +0100 5421183 http://www.medworm.com/index.php?rid=5421182&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22080105%26dopt%3DAbstract Authors: Scattina E, Huber A, Menzocchi M, Paoletti G, Carli G, Manzoni D, Santarcangelo EL Abstract It has been shown that, in subjects with high hypnotizability (Highs), imagined somatosensory stimulation can involuntarily activate the neural circuits involved in the modulation of reflex action. In this vein, aim of the study was to investigate whether the imagery of nociceptive stimulation in one leg may produce both subjective experience of pain and congruent postural adjustments during normal upright stance. The displacement of the centre of pressure (CoP) was studied during imagery of leg pain (LP) and during the control conditions of imagery of tactile stimulation of the same leg and of throat pain (TP) in 12 Highs and 12 low hypnotizable subjects (Lows). The results showed ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421182 Sat, 12 Nov 2011 05:00:00 +0100 5421182 http://www.medworm.com/index.php?rid=5421189&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22076403%26dopt%3DAbstract Authors: Jedlicka P, Owen M, Vnencak M, Tschäpe JA, Hick M, Müller UC, Deller T Abstract The amyloid precursor protein (APP) plays a crucial role in the pathogenesis of Alzheimer's disease. Here, we studied whether the lack of APP affects the synaptic properties in the dentate gyrus by measuring granule cell field potentials evoked by perforant path stimulation in anesthetized 9-11-month-old APP-deficient mice in vivo. We found decreased paired-pulse facilitation, indicating altered presynaptic short-term plasticity in the APP-deficient dentate gyrus. In contrast, excitatory synaptic strength and granule cell firing were unchanged in APP knockout mice. Likewise, long-term potentiation (LTP) induced by a theta-burst stimulation protocol was not impaired in the absence of APP. Thes... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421189 Fri, 11 Nov 2011 05:00:00 +0100 5421189 http://www.medworm.com/index.php?rid=5421188&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22076404%26dopt%3DAbstract Authors: Ohtsuka H, Sasada S, Nakajima T, Futatsubashi G, Shimizu E, Komiyama T Abstract Voluntary contraction of a muscle generates electromyographic (EMG) activity in the homologous muscle on the opposite side (mirror-like activity), not only in pathological states and in infants but also in healthy adults. Few studies have examined whether the cutaneous reflexes during the preparatory period of a reaction time task are affected by mirror-like activity. In the present study, we investigated the modulation of the cutaneous reflexes in the left first interosseous (FDI) muscle in 9 healthy subjects while they performed a quick abduction of the right index finger during a reaction time task. Cutaneous reflexes were elicited by applying non-noxious electrical stimulation to the left i... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421188 Fri, 11 Nov 2011 05:00:00 +0100 5421188 http://www.medworm.com/index.php?rid=5421187&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22076405%26dopt%3DAbstract Authors: Meng X, Mao W, Sun W, Zhang X, Han C, Lu C, Huang Z, Wang Y Abstract Field dependence/independence (FD/FI) is an important dimension of personality and cognitive styles. Different ability in mobilizing and/or allocating mental-attentional capacity was considered to be the most possible explanation for the FDI cognitive style. Many studies on characterizing the functional neuroanatomy of attentional control indicated the existence of a dissociable sub-process of conflict-monitoring and "cognitive control" system. However, little was known about it. We might dissociate "cognitive control" system from conflict processing by taking advantage of the variable of the FDI cognitive style. In addition, essentially cognitive styles (FDI) are often widely studied in psychological and... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421187 Fri, 11 Nov 2011 05:00:00 +0100 5421187 http://www.medworm.com/index.php?rid=5421186&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22076406%26dopt%3DAbstract Authors: Wang W, Johnson T, Sainburg RL, Dounskaia N Abstract Directional preferences during center-out horizontal shoulder-elbow movements were previously characterized for the dominant arm. These preferences were attributed to a tendency to actively accelerate one joint, while exploiting largely passive motion at the other joint. Since the non-dominant arm is known for inefficient coordination of inter-segmental dynamics, here we hypothesized that directional preferences would differ between the arms. A center-out free-stroke drawing task was used that allowed freedom in the selection of movement directions. The task was performed both with and without a secondary cognitive task that has been shown to increase directional biases of the dominant arm. Mirror-symmetrical directional... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421186 Fri, 11 Nov 2011 05:00:00 +0100 5421186 http://www.medworm.com/index.php?rid=5421185&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22076407%26dopt%3DAbstract Authors: Dilda V, Macdougall HG, Curthoys IS, Moore ST Abstract Although imaging studies suggest activation of cortical areas by vestibular input, there is little evidence of an adverse effect of non-veridical vestibular input on cognitive function. To test the hypothesis that degraded vestibular afferent input adversely affects cognition, we compared performance on a cognitive test battery in a group undergoing suprathreshold bilateral bipolar Galvanic vestibular stimulation (GVS) with a control group receiving no GVS or subthreshold stimulation. The battery consisted of six cognitive tests as follows: reaction time, dual tasking, Stroop, mental rotation, perspective-taking and matching-to-sample, as well as a simple visuomotor (manual tracking) task. Subjects performed the test b... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421185 Fri, 11 Nov 2011 05:00:00 +0100 5421185 http://www.medworm.com/index.php?rid=5421184&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22076408%26dopt%3DAbstract Authors: Jombik P, Spodniak P, Bahyl V PMID: 22076408 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421184 Fri, 11 Nov 2011 05:00:00 +0100 5421184 http://www.medworm.com/index.php?rid=5421192&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22071683%26dopt%3DAbstract Authors: Bertrand JA, Lassonde M, Robert M, Nguyen DK, Bertone A, Doucet ME, Bouthillier A, Lepore F Abstract How the brain processes visual stimuli has been extensively studied using scalp surface electrodes and magnetic resonance imaging. Using these and other methods, complex gratings have been shown to activate the ventral visual stream, whereas moving stimuli preferentially activate the dorsal stream. In the current study, a first experiment assessed brain activations evoked by complex gratings using intracranial electroencephalography in 10 epileptic patients implanted with subdural electrodes. These stimuli of intermediate levels of complexity were presented in such a way that transformational apparent motion (TAM) was perceived. Responses from both the ventral and the dorsa... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421192 Thu, 10 Nov 2011 05:00:00 +0100 5421192 http://www.medworm.com/index.php?rid=5421191&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22071684%26dopt%3DAbstract Authors: Wu YH, Zatsiorsky VM, Latash ML Abstract We studied static prehension of a horizontally oriented object. Specific hypotheses were explored addressing such issues as the sharing patterns of the total moment of force across the digits, presence of mechanically unnecessary digit forces, and trade-off between multi-digit synergies at the two levels of the assumed control hierarchy. Within the assumed hierarchy, at the upper level, the task is shared between the thumb and virtual finger (an imagined finger producing a wrench equal to the sum of the wrenches of individual fingers). At the lower level, action of the virtual finger is shared among the four actual fingers. The subjects held statically a horizontally oriented handle instrumented with six-component force/torque senso... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421191 Thu, 10 Nov 2011 05:00:00 +0100 5421191 http://www.medworm.com/index.php?rid=5421190&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22071685%26dopt%3DAbstract Authors: Niu CM, Corcos DM, Shapiro MB Abstract Simple movements can be seen as building blocks for complex action sequences, and neural control of an action sequence can be expected to preserve some control features of its constituent blocks. It was previously found that during single-joint elbow movements to a single target, the proprioceptive feedback control is initially suppressed, and we tested this feedback suppression in a two-segment sequence during which subjects momentarily slowed down at an intermediate target at a 30° distance (first segment) and then immediately moved another 30° to the final target (second segment). Either the first or second segment was unexpectedly perturbed; the latency of the earliest response to the perturbation in the muscle surface electromy... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421190 Thu, 10 Nov 2011 05:00:00 +0100 5421190 http://www.medworm.com/index.php?rid=5421194&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22064931%26dopt%3DAbstract Authors: Weissman-Fogel I, Brayer-Zwi N, Defrin R Abstract The spatial resolution of the pain system has not been studied in depth, and results are contradictory regarding the gradient of spatial resolution. Microneurographic recordings have revealed smaller receptive fields and higher density of nociceptors in more distal than proximal leg regions, whereas histological studies report higher density of C-fibers in more proximal than distal body regions. Due to this controversy, we conducted various psychophysical tests in order to examine the nociceptive spatial resolution and its gradient. Heat-pain threshold (HPT), perceived pain intensity, spatial summation (SS) of pain, two-point discrimination (2PD) of pain, and pain localization were measured in four body regions: upper back,... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421194 Tue, 08 Nov 2011 05:00:00 +0100 5421194 http://www.medworm.com/index.php?rid=5421193&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22064932%26dopt%3DAbstract We examined whether developmental dyslexic adults suffer from sluggish attentional shifting (SAS; Hari and Renvall in Trends Cogn Sci 5:525-532, 2001) by measuring their shifting of attention in a visual search task with dynamic cluttered displays (Van der Burg et al. in J Exp Psychol Human 34:1053-1065, 2008). Dyslexics were generally slower than normal readers in searching a horizontal or vertical target among oblique distracters. However, the addition of a click sound presented in synchrony with a color change of the target drastically improved their performance up to the level of the normal readers. These results are in line with the idea that developmental dyslexics have specific problems in disengaging attention from the current fixation, and that the phasic alerting by a sound can c... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421193 Tue, 08 Nov 2011 05:00:00 +0100 5421193 http://www.medworm.com/index.php?rid=5421196&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22057780%26dopt%3DAbstract Authors: Bowling AC, Hindman EA, Donnelly JF Abstract The relations among spatial memory, Stroop-like colour-word subtests, and errors on antisaccade and memory-guided saccadic eye-movement trials for older and younger adults were tested. Two types of errors in the antisaccade task were identified: short latency prosaccade errors that were immediately corrected and longer latency uncorrected prosaccade errors. The age groups did not differ on percentages of either corrected or uncorrected errors, but the latency and time to correct prosaccade errors were shorter for younger than older adults. Uncorrected prosaccade errors correlated significantly with spatial memory accuracy and errors on the colour-word subtests, but neither of these neuropsychological indices correlated with corr... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421196 Sun, 06 Nov 2011 04:00:00 +0100 5421196 http://www.medworm.com/index.php?rid=5421195&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22057781%26dopt%3DAbstract In conclusion, in the more demanding condition of reproducing an obtuse angle, the Highs' reproduction was more accurate and more independent of cognitive load than that of the Lows. PMID: 22057781 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5421195 Sun, 06 Nov 2011 04:00:00 +0100 5421195 http://www.medworm.com/index.php?rid=5379941&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22052188%26dopt%3DAbstract We examined performance in a sustained attention to response task (SART) (Experiment 1) and a more traditionally formatted vigilance task (Experiment 2) using novel word stimuli (text-speak) and normally spelt words. This enabled us to address whether the SART is a better measure of sustained attention or of response strategy, and to investigate the cognitive demands of text-speak processing. In Experiment 1, 72 participants completed a subset (text-speak) and a word SART, as well as a self-reported text experience questionnaire. Those who reported more proficiency and experience with text-speak made more errors on the subset SART, but this appeared to be due to their increase in response speed. This did not occur in the word SART. In Experiment 2, 14 participants completed high No-Go, low... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379941 Fri, 04 Nov 2011 04:00:00 +0100 5379941 http://www.medworm.com/index.php?rid=5379942&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22048319%26dopt%3DAbstract Authors: Gaissert N, Wallraven C Abstract Although the hands are the most important tool for humans to manipulate objects, only little is known about haptic processing of natural objects. Here, we selected a unique set of natural objects, namely seashells, which vary along a variety of object features, while others are shared across all stimuli. To correctly interact with objects, they have to be identified or categorized. For both processes, measuring similarities between objects is crucial. Our goal is to better understand the haptic similarity percept by comparing it to the visual similarity percept. First, direct similarity measures were analyzed using multidimensional scaling techniques to visualize the perceptual spaces of both modalities. We find that the visual and the hapt... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379942 Thu, 03 Nov 2011 04:00:00 +0100 5379942 http://www.medworm.com/index.php?rid=5379944&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22045298%26dopt%3DAbstract Authors: Egsgaard LL, Buchgreitz L, Wang L, Bendtsen L, Jensen R, Arendt-Nielsen L Abstract To investigate the effects of homotopic and heterotopic conditioning pain modulation (CPM) on short-term cortical plasticity. Glutamate (tonic pain) or isotonic saline (sham) was injected in the upper trapezius (homotopic) and in the thenar (heterotopic) muscles. Intramuscular electrical stimulation was applied to the trapezius at pain threshold intensities, and somatosensory evoked potentials were recorded with 128 channel EEG. Pain ratings were obtained during glutamate and sham pain injection. Short-term cortical plasticity to electrical stimulation was investigated before, during, and after homotopic and heterotopic CPM versus control. Peak latencies at N100, P200, and P300 were extracte... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379944 Wed, 02 Nov 2011 04:00:00 +0100 5379944 http://www.medworm.com/index.php?rid=5379943&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22045299%26dopt%3DAbstract Authors: Shea CH, Boyle J, Kovacs AJ Abstract The experiment was designed to replicate and extend to an integrated feedback condition the pattern of movement time results found by Kelso et al. (J Exp Psychol Hum Percept Perform 5:229-238, 1979a, Science 204:1029-1031, 1979b) where the simultaneous movement of one hand to a low ID target and the other to a higher ID target indicated "a tight coordinate coupling between the hands" (p. 229). In the present experiment, a control group was provided feedback that depicted the independent movement of the two limbs under low and higher indexes of difficulty (ID). A Lissajous group was provided integrated feedback in the form of a Lissajous plot. The results indicated a pattern of results for the control and Lissajous groups similar to that... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379943 Wed, 02 Nov 2011 04:00:00 +0100 5379943 http://www.medworm.com/index.php?rid=5379952&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22038712%26dopt%3DAbstract Authors: Torres EB Abstract This work investigated whether fundamental differences emerged between segments of complex movement sequences performed at different instructed speeds. To this end, we tested 5 novices and 1 karate expert as they performed beginner's martial arts routines. We found that if one blindly took these segments and separated them according to the variability of trajectory parameters, one could unambiguously group two classes of movements between the same two space regions: one type that remained quite conserved despite speed changes and another type that changed with speed level. These groups corresponded to functionally different movements (strike segments explicitly directed to a set of goals and spontaneously retracting segments supplementing the goals). The... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379952 Sat, 29 Oct 2011 04:00:00 +0100 5379952 http://www.medworm.com/index.php?rid=5379949&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22038715%26dopt%3DAbstract This article reviews the multifunctional roles of an APP orthologue, the C. elegans APL-1. Understanding the function of APL-1 may provide insights into the functions and signaling pathways of human APP. In addition, the physiological effects of introducing human β-amyloid peptide into C. elegans are also reviewed. The C. elegans system provides a powerful genetic model to identify genes regulating the molecular mechanisms underlying intracellular β-amyloid peptide accumulation. PMID: 22038715 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379949 Sat, 29 Oct 2011 04:00:00 +0100 5379949 http://www.medworm.com/index.php?rid=5379948&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22038716%26dopt%3DAbstract Authors: Teo WP, Rodrigues JP, Mastaglia FL, Thickbroom GW Abstract Transcranial magnetic stimulation has been used to study changes in central excitability associated with motor tasks. Recently, we reported that a finger flexion-extension task performed at a maximal voluntary rate (MVR) could not be sustained and that this was not due to muscle fatigue, but was more likely a breakdown in central motor control. To determine the central changes that accompany this type of movement task, we tracked motor-evoked potential (MEP) amplitude from the first dorsal interosseous (FDI) and abductor pollicis brevis (APB) muscles of the dominant hand in normal subjects for 20 min after a 10 sec index finger flexion-extension task performed at MVR and at a moderate sustainable rate (MSR) and ha... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379948 Sat, 29 Oct 2011 04:00:00 +0100 5379948 http://www.medworm.com/index.php?rid=5379947&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22038718%26dopt%3DAbstract In this study, we used an imitation-matching task, which is previously used in behavioral experiments for infants, and fMRI to reveal the neural basis for imitation of multiple representations of observed actions. In our experiment, two video footages showing a pen being grasped and placed into one of two cups were sequentially presented. The participants judged whether an actor's action in the first movie was correctly imitated by an imitator in the second movie, regarding the following four aspects: action goal, a means of manipulation, an effector used, and movement trajectory. Although identical sets of stimuli were presented, different brain regions were activated, depending on the matching judgments made by subjects between the two actions. The current study indicates that distinct b... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379947 Sat, 29 Oct 2011 04:00:00 +0100 5379947 http://www.medworm.com/index.php?rid=5379945&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22038720%26dopt%3DAbstract This study investigated the importance of binocular vision to foot placement accuracy when stepping onto a floor-based target during gait initiation. Starting from stationary, participants placed alternate feet onto targets sequentially positioned along a straight travel path with the added constraint that the initial target (target 1) could move in the medio-lateral (M-L) direction. Repeated trials when target 1 remained stationary or moved laterally at the instant of lead-limb toe-off (TO) or 200 ms after TO (early swing) were undertaken under binocular and monocular viewing. Catch trials when target 1 shifted medially were also undertaken. Foot-reach kinematics, foot trajectory corrections and foot placement accuracy for the step onto target 1 were determined via 3D motion analyses. Pe... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379945 Sat, 29 Oct 2011 04:00:00 +0100 5379945 http://www.medworm.com/index.php?rid=5379953&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22028052%26dopt%3DAbstract Authors: Lim SC, Kyung KU, Kwon DS Abstract Two vibrations with slightly different frequencies induce the beats phenomenon. In tactile perception, when two pins of different frequencies stimulate the fingertips, an individual perceives a beats caused by a summation stimulus of the two vibrations. The present study demonstrates experimentally that humans can perceive another vibration based on the beats phenomenon when two tactile stimuli with slightly different frequencies are stimulated on the finger pad with a small contactor in different locations at the same time. Moreover, we examined the amplitude of the detection threshold to be able to perceive beats phenomenon on the index finger with 5 carrier frequency (63.1, 100, 158.5, 251.2, and 398.1 Hz) and 4 beats frequency (2.5, ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379953 Tue, 25 Oct 2011 04:00:00 +0100 5379953 http://www.medworm.com/index.php?rid=5379951&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22038713%26dopt%3DAbstract In conclusion, short-term cortical plasticity can be induced by a mismatch between visual input and location of tactile stimulation in men. The present study suggests that gender differences exist in the perception of the mirror box illusion. PMID: 22038713 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379951 Tue, 25 Oct 2011 04:00:00 +0100 5379951 http://www.medworm.com/index.php?rid=5379950&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22038714%26dopt%3DAbstract This study not only confirms a recently described bilateral fronto-parieto-cerebellar network for manipulation of increasingly unstable objects, but critically extends our understanding by describing its differentiated modulation with both force magnitude and instability requirements. Our results, therefore, expose a previously unrecognized and context-sensitive system of brain regions that enable dexterous manipulation for different force magnitude and instability requirements of the task. PMID: 22038714 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379950 Tue, 25 Oct 2011 04:00:00 +0100 5379950 http://www.medworm.com/index.php?rid=5379946&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22038719%26dopt%3DAbstract This study investigated the motion required to carry a cup filled with water without spilling it, which is a common human dexterous task. This task requires the individual to dampen hand vibration while walking. We hypothesize that a reduction in hand jerk and a constant cup angle are required to achieve this task. We measured movements while human subjects carried a cup with water (WW task) and with stones (WS task) using a three-dimensional position measurement system and then analyzed joint coordination. We empirically confirmed that the value of hand jerk and the variance in cup angle in the WW task were smaller than those in the WS task. We used uncontrolled manifold (UCM) analysis to quantify joint coordination corresponding to the motor synergy required to reduce the hand jerk and v... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5379946 Tue, 25 Oct 2011 04:00:00 +0100 5379946 http://www.medworm.com/index.php?rid=5345730&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22009129%26dopt%3DAbstract Authors: Michael GA, Dupuy MA, Deleuze A, Humblot M, Simon B, Naveteur J Abstract Visual input and attention enhance tactile perception. But do they influence the perception of spontaneous sensations (SPS) arising in the absence of any external stimulus? We have investigated this by requiring subject to focus attention on each hand while orienting overtly toward it (convergent focusing) or away (divergent focusing) and to subsequently describe the properties of the SPS they felt. Subjects performed this task under free viewing conditions or while blindfolded. Enhanced perception of SPS was found under convergent focusing and also under free viewing conditions. However, the effects of focusing were different whether visual input was available or not. When visual input was available,... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345730 Wed, 19 Oct 2011 04:00:00 +0100 5345730 http://www.medworm.com/index.php?rid=5345734&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22006270%26dopt%3DAbstract Authors: Korte M, Herrmann U, Zhang X, Draguhn A Abstract APP, APLP1, and APLP2 form a family of mammalian membrane proteins with unknown function. APP, however, plays a key role in the molecular pathology of Alzheimer's disease (AD), indicating that it is somehow involved in synaptic transmission, synaptic plasticity, memory formation, and maintenance of neurons. At present, most of our knowledge about the function of APP comes from consequences of AD-related mutations. The native role of APP, and even more of APLP1/2, remains largely unknown. New genetic knockout and knockin models involving several members of the APP/APLP family may yield better insight into the synaptic and systemic functions of these proteins. Here, we summarize recent results from such transgenic animals with... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345734 Tue, 18 Oct 2011 04:00:00 +0100 5345734 http://www.medworm.com/index.php?rid=5345733&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22006271%26dopt%3DAbstract Authors: Al-Hashmi AM, Kramer DJ, Mullen KT Abstract Achromatic visual function in primates is distributed between two pathways from retina to cortex, the parvocellular and the magnocellular. The relative contribution of these to human achromatic vision is controversial and largely unknown. Here, we use an optic neuritis (ON) model to investigate the effects of a severe loss of parvocellular function on human contrast sensitivity. In our first experiment, we use Gabor stimuli (0.5 cpd, 2 Hz) to show that, compared to normal control eyes, ON causes selective deficits in the two chromatic, cone opponent pathways, with L/M cone opponency affected more than S cone opponency, and a relative sparing of achromatic function. Since L/M cone opponency is carried exclusively by the midget g... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345733 Tue, 18 Oct 2011 04:00:00 +0100 5345733 http://www.medworm.com/index.php?rid=5345732&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22006272%26dopt%3DAbstract Authors: Jürgens R, Becker W Abstract We investigated the relative weighting of vestibular, optokinetic and podokinetic (foot and leg proprioceptive) cues for the perception of self-turning in an environment which was either stationary (concordant stimulation) or moving (discordant stimulation) and asked whether cue weighting changes if subjects (Ss) detect a discordance. Ss (N = 18) stood on a turntable inside an optokinetic drum and turned either passively (turntable rotating) or actively in space at constant velocities of 15, 30, or 60°/s. Sensory discordance was introduced by simultaneous rotations of the environment (drum and/or turntable) at ±{5, 10, 20, 40, 80}% of self-turning velocity. In one experiment, Ss were to detect these rotations (i.e. the sensory discordance)... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345732 Tue, 18 Oct 2011 04:00:00 +0100 5345732 http://www.medworm.com/index.php?rid=5345731&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22006273%26dopt%3DAbstract Authors: Goble DJ, Mousigian MA, Brown SH Abstract Perceiving the positions and movements of one's body segments (i.e., proprioception) is critical for movement control. However, this ability declines with older age as has been demonstrated by joint angle matching paradigms in the absence of vision. The aim of the present study was to explore the extent to which reduced working memory and attentional load influence older adult proprioceptive matching performance. Older adults with relatively HIGH versus LOW working memory ability as determined by backward digit span and healthy younger adults, performed memory-based elbow position matching with and without attentional load (i.e., counting by 3 s) during target position encoding. Even without attentional load, older adults with LOW... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345731 Tue, 18 Oct 2011 04:00:00 +0100 5345731 http://www.medworm.com/index.php?rid=5345736&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22002633%26dopt%3DAbstract Authors: Shen D, Alain C Abstract Attentional blink (AB) refers to a phenomenon where the correct identification of a first target (i.e., target) impairs the processing of a second target (i.e., probe) nearby in time. In the present study, we investigate the influence of temporal attention on auditory AB by means of scalp-recorded event-related potentials. Participants were instructed to focus their attention on a particular time interval following the target (i.e., short, middle, or long temporal position) in order to detect the occurrence of the probe in a rapid series of distractor sounds. We found a large probe processing deficit when the probe occurred immediately after the target. This AB decreased as the time interval between the target and the probe increased and coincided ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345736 Sat, 15 Oct 2011 04:00:00 +0100 5345736 http://www.medworm.com/index.php?rid=5345735&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22002634%26dopt%3DAbstract Authors: Green AL, Helton WS Abstract High-angle climbing is a physically and cognitively challenging activity. Whilst researchers have examined the physiological demands of climbing, the cognitive demands have been relatively neglected. In this experiment, we examined the performance of climbers when required to perform a dual climbing and word memory task, relative to single-task performance (word memory or climbing alone). Whilst there was no significant decrease in climbing distance during the dual-task condition, climbing efficiency was impaired, as was word recall. Participants' Energetic Arousal, Tense Arousal and Task-unrelated Thoughts (TUTs) all changed dependent on the condition, with arousal increasing after the climbing conditions, and TUTs decreasing after the memory-... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345735 Sat, 15 Oct 2011 04:00:00 +0100 5345735 http://www.medworm.com/index.php?rid=5345740&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21997329%26dopt%3DAbstract Authors: Albert MV, Kording KP Abstract The measurement of body and limb posture is important to many clinical and research studies. Current approaches either directly measure posture (e.g., using optical or magnetic methods) or more indirectly measure it by integrating changes over time (e.g., using gyroscopes and/or accelerometers). Here, we introduce a way of estimating posture from movements without requiring integration over time and the resulting complications. We show how the almost imperceptible tremor of the hand is affected by posture in an intuitive way and therefore can be used to estimate the posture of the arm. We recorded postures and tremor of the arms of volunteers. By using only the minor axis in the covariance of hand tremor, we could estimate the angle of the fo... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345740 Fri, 14 Oct 2011 04:00:00 +0100 5345740 http://www.medworm.com/index.php?rid=5345739&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21997330%26dopt%3DAbstract Authors: Forgaard CJ, Maslovat D, Carlsen AN, Franks IM Abstract In a choice reaction time (RT) paradigm, providing partial advance information (a precue) about the upcoming response has been shown to decrease RT, presumably due to preprogramming of the precued parameters. When advance information about a particular aspect of a movement is provided (precued), several different strategies might be used to prepare the motor system during the foreperiod. For example, in studies where response preparation time was manipulated, precues were provided specifying the required arm and direction but movement amplitude was left uncertain. In this case it was shown that a default movement was preprogrammed whose amplitude was intermediate between the alternatives (Favilla et al. in Exp Brain R... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345739 Fri, 14 Oct 2011 04:00:00 +0100 5345739 http://www.medworm.com/index.php?rid=5345738&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21997331%26dopt%3DAbstract Authors: Chen N, Fang F Abstract Using psychophysical methods, the present study aims to investigate whether orientation discrimination learning can modify the visual cortex and how the modification is related to the development of perceptual learning (performance improvement). In Experiment 1, subjects were trained with an orientation discrimination task at the orientation of 15° right tilted from the vertical. The training not only improved subjects' orientation discrimination performance, but also shifted their perceived vertical toward the trained orientation, which resembles a well-known visual illusion-tilt aftereffect. Interestingly, the change of perceived vertical and performance improvement had different dynamics. Subjects' performance levels were maintained at a constan... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345738 Fri, 14 Oct 2011 04:00:00 +0100 5345738 http://www.medworm.com/index.php?rid=5345737&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21997332%26dopt%3DAbstract Authors: Straube B, Wolk D, Chatterjee A Abstract Inferring causality is a fundamental feature of human cognition that allows us to predict outcomes in everyday events. Here, we use direct current stimulation (tDCS) to investigate the role of the right parietal lobe in the perception of causal events. Based on the results of a previous fMRI investigation, we hypothesized that the right parietal lobe plays a specific role in the processing of spatial attributes that contribute to judgments of causality. In line with our hypothesis, we found polarization-dependent modulation of causal judgments and corresponding reaction times (RTs) for trials with increasing violation of spatial contiguity in launching events. This effect was further modulated by temporal violations, as the effect o... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5345737 Fri, 14 Oct 2011 04:00:00 +0100 5345737 http://www.medworm.com/index.php?rid=5313199&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21989847%26dopt%3DAbstract Authors: Jacobson L, Koslowsky M, Lavidor M Abstract In vivo effects of transcranial direct current stimulation (tDCS) have attracted much attention nowadays as this area of research spreads to both the motor and cognitive domains. The common assumption is that the anode electrode causes an enhancement of cortical excitability during stimulation, which then lasts for a few minutes thereafter, while the cathode electrode generates the opposite effect, i.e., anodal-excitation and cathodal-inhibition effects (AeCi). Yet, this dual-polarity effect has not been observed in all tDCS studies. Here, we conducted a meta-analytical review aimed to investigate the homogeneity/heterogeneity of the effect sizes of the AeCi dichotomy in both motor and cognitive functions. The AeCi effect was fou... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5313199 Wed, 12 Oct 2011 04:00:00 +0100 5313199 http://www.medworm.com/index.php?rid=5313204&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986667%26dopt%3DAbstract Authors: Rohbanfard H, Proteau L Abstract Observation of an expert or novice model promotes the learning of a motor skill. In two experiments, we determined the effects of a mixed observation schedule (a combination of expert and novice models) on the learning of a sequential timing task. In Experiment 1, participants observed a novice, expert, or both novice and expert models. The results of retention/transfer tests revealed that all observation groups and a physical practice group learned the task and outperformed a control group. However, observing a novice model was not as effective as observing expert and mixed models. Importantly, a mixed schedule of novice and expert observation resulted in a more stable movement time and better generalization of the imposed relative timing ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5313204 Tue, 11 Oct 2011 04:00:00 +0100 5313204 http://www.medworm.com/index.php?rid=5313203&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986668%26dopt%3DAbstract Authors: Viviani P, Figliozzi F, Lacquaniti F Abstract Four experiments investigated the perception of visible speech. Experiment 1 addressed the perception of speech rate. Observers were shown video-clips of the lower face of actors speaking at their spontaneous rate. Then, they were shown muted versions of the video-clips, which were either accelerated or decelerated. The task (scaling) was to compare visually the speech rate of the stimulus to the spontaneous rate of the actor being shown. Rate estimates were accurate when the video-clips were shown in the normal direction (forward mode). In contrast, speech rate was underestimated when the video-clips were shown in reverse (backward mode). Experiments 2-4 (2AFC) investigated how accurately one discriminates forward and backward... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5313203 Tue, 11 Oct 2011 04:00:00 +0100 5313203 http://www.medworm.com/index.php?rid=5313202&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986669%26dopt%3DAbstract Authors: Scotto Di Cesare C, Bringoux L, Bourdin C, Sarlegna FR, Mestre DR Abstract In order to accurately localize an object, human observers must integrate multiple sensory cues related to the environment and/or to the body. Such multisensory integration must be repeated over time, so that spatial localization is constantly updated according to environmental changes. In the present experimental study, we examined the multisensory integration processes underlying spatial updating by investigating how gradual modifications of gravitoinertial cues (i.e., somatosensory and vestibular cues) and visual cues affect target localization skills. These were assessed by using a continuous pointing task toward a body-fixed visual target. The "single" rotation of the gravitoinertial vector (pr... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5313202 Tue, 11 Oct 2011 04:00:00 +0100 5313202 http://www.medworm.com/index.php?rid=5313201&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986670%26dopt%3DAbstract In conclusion, this study presents predictive pursuit performance in a large sample of apparently healthy individuals. Surprisingly, predictive pursuit was weakly if at all related to closed-loop pursuit or other oculomotor and cognitive tasks, supporting the usefulness of this phenotype in the study of frontal lobe integrity in normal and patient populations. PMID: 21986670 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5313201 Tue, 11 Oct 2011 04:00:00 +0100 5313201 http://www.medworm.com/index.php?rid=5313200&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21986671%26dopt%3DAbstract Authors: Kattoulas E, Evdokimidis I, Stefanis NC, Avramopoulos D, Stefanis CN, Smyrnis N Abstract Smooth pursuit eye movement dysfunction is considered to be a valid schizophrenia endophenotype. Recent studies have tried to refine the phenotype in order to identify the specific neurophysiological deficits associated with schizophrenia. We used a variation of the smooth eye pursuit paradigm, during which the moving target is occluded for a short period of time and subjects are asked to continue tracking. This is designed to isolate the predictive processes that drive the extraretinal signal, a process previously reported to be defective in schizophrenia patients as well as their healthy relatives. In the current study, we investigated the relationship between predictive pursuit perf... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5313200 Tue, 11 Oct 2011 04:00:00 +0100 5313200 http://www.medworm.com/index.php?rid=5313205&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21984054%26dopt%3DAbstract Authors: Bernardin BJ, Mason AH Abstract Task-switching paradigms have generally been used to investigate cognitive processes involved in decision making or allocating attention. This work extended the task-switching paradigm into the motor domain in order to investigate the consequences of an unexpected environmental perturbation on reaction time and movement time. Typically, task-switching paradigms have investigated consequences of rearranging task sets from one trial to the next; this work explored rearranging planned movements within the context of a single trial. Of particular interest was how the motor system reorganizes coordination patterns when reaching amplitude congruency is manipulated between the two hands. Results for Experiment 1 and the far distance in Experiment 2... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5313205 Sun, 09 Oct 2011 04:00:00 +0100 5313205 http://www.medworm.com/index.php?rid=5297699&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21969209%26dopt%3DAbstract This study demonstrates that an early-life environmental intervention may induce morphological changes in a structure involved with several functions, including the stress response. The results of the current study suggest that neonatal handling may influence the animals' responses to environmental adversities later in life. PMID: 21969209 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5297699 Tue, 04 Oct 2011 04:00:00 +0100 5297699 http://www.medworm.com/index.php?rid=5297698&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21969210%26dopt%3DAbstract Authors: Endres K, Fahrenholz F Abstract The amyloid precursor protein (APP) has a pivotal role in pathogenesis of Alzheimer's disease (AD) via its beta- and gamma-secretase-derived cleavage products-the A-beta peptides. An alternative processing pathway provided by the alpha-secretase prevents formation of those toxic peptides and gives rise to the neurotrophic and neuroprotective cleavage product APPs-alpha. The molecular identity of the alpha-secretase has been confirmed recently, and there is consistency about ADAM10 being the most relevant and physiological enzyme of this class. It is not clear to what extent a deficiency in the catalytic activity of ADAM10 contributes to AD pathology and whether a decline occurs in aging humans. Nevertheless, ADAM10 has been suggested as a va... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5297698 Tue, 04 Oct 2011 04:00:00 +0100 5297698 http://www.medworm.com/index.php?rid=5297700&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21964890%26dopt%3DAbstract Authors: Doeltgen SH, Ridding MC Abstract To investigate whether priming stimulation influences the responses of intracortical inhibitory and facilitatory motor circuits to a subsequent plasticity-inducing inhibitory theta burst TMS paradigm. Using standard transcranial magnetic stimulation (TMS) procedures, MEP amplitude, short-interval intracortical inhibition (SICI), and short-interval intracortical facilitation (SICF) were assessed at baseline and 5, 20 and 30 min following continuous theta burst stimulation (cTBS), intermittent TBS (iTBS), and iTBS-primed cTBS. SICI was assessed using paired-pulse TMS at inter-stimulus intervals (ISI) of 3 ms (SICI(3)) and the latency corresponding to the latency at which SICF was minimal in each individual. SICF was assessed at ISIs corresp... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5297700 Sun, 02 Oct 2011 04:00:00 +0100 5297700 http://www.medworm.com/index.php?rid=5297702&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21964867%26dopt%3DAbstract This study aimed to determine whether: (1) there was differential activation across locations of the first dorsal interosseous (FDI) muscle during a given task, (2) the differential activation was related to directional requirements and/or end goal of the task, and (3) there was an anatomical pattern to the differential activation. Twenty-six healthy right-handed participants carried out isometric finger/hand contractions in sitting while surface EMG was collected from 4 bipolar sites on the FDI muscle simultaneously. The tasks included: abduction, flexion, diagonal, 30% abduction + 30% flexion, 30% flexion + 30% abduction, key pinch, and power grasp. Mean peak integrated EMG for each task was normalized to site and task specific mean M waves. Differential activation was evident across... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5297702 Sat, 01 Oct 2011 04:00:00 +0100 5297702 http://www.medworm.com/index.php?rid=5297701&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21964868%26dopt%3DAbstract Authors: Zaehle T, Beretta M, Jäncke L, Herrmann CS, Sandmann P Abstract Transcranial direct current stimulation (tDCS) can systematically modify behavior by inducing changes in the underlying brain function. Objective electrophysiological evidence for tDCS-induced excitability changes has been demonstrated for the visual and somatosensory cortex, while evidence for excitability changes in the auditory cortex is lacking. In the present study, we applied tDCS over the left temporal as well as the left temporo-parietal cortex and investigated tDCS-induced effects on auditory evoked potentials after anodal, cathodal, and sham stimulation. Results show that anodal and cathodal tDCS can modify auditory cortex reactivity. Moreover, auditory evoked potentials were differentially modulate... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5297701 Sat, 01 Oct 2011 04:00:00 +0100 5297701 http://www.medworm.com/index.php?rid=5281219&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21960299%26dopt%3DAbstract Authors: Brunholz S, Sisodia S, Lorenzo A, Deyts C, Kins S, Morfini G Abstract Over two decades have passed since the original discovery of amyloid precursor protein (APP). While physiological function(s) of APP still remain a matter of debate, consensus exists that the proteolytic processing of this protein represents a critical event in the life of neurons and that abnormalities in this process are instrumental in Alzheimer's disease (AD) pathogenesis. Specific molecular components involved in APP proteolysis have been identified, and their enzymatic activities characterized in great detail. As specific proteolytic fragments of APP are identified and novel physiological effects for these fragments are revealed, more obvious becomes our need to understand the spatial organization ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281219 Fri, 30 Sep 2011 04:00:00 +0100 5281219 http://www.medworm.com/index.php?rid=5281221&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21952790%26dopt%3DAbstract Authors: Baumkötter F, Wagner K, Eggert S, Wild K, Kins S Abstract The amyloid precursor protein (APP) is one of the key proteins in Alzheimer's disease (AD), as it is the precursor of amyloid β (Aβ) peptides accumulating in amyloid plaques. The processing of APP and the pathogenic features of especially Aβ oligomers have been analyzed in detail. Remarkably, there is accumulating evidence from cell biological and structural studies suggesting that APP and its mammalian homologs, the amyloid precursor-like proteins (APLP1 and APLP2), participate under physiological conditions via trans-cellular dimerization in synaptogenesis. This offers the possibility that loss of synapses in AD might be partially explained by dysfunction of APP/APLPs cell adhesion properties. In this review, ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281221 Wed, 28 Sep 2011 04:00:00 +0100 5281221 http://www.medworm.com/index.php?rid=5281220&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21952791%26dopt%3DAbstract Authors: Jacobs JV, Yaguchi C, Kaida C, Irei M, Naka M, Henry SM, Fujiwara K Abstract It is becoming increasingly evident that people with chronic, recurrent low back pain (LBP) exhibit changes in cerebrocortical activity that associate with altered postural coordination, suggesting a need for a better understanding of how the experience of LBP alters postural coordination and cerebrocortical activity. To characterize changes in postural coordination and pre-movement cerebrocortical activity related to the experience of acutely induced LBP, 14 healthy participants with no history of LBP performed sit-to-stand movements in 3 sequential conditions: (1) without experimentally induced LBP; NoPain1, (2) with movement-associated LBP induced by electrocutaneous stimulation; Pain, and (3) ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281220 Wed, 28 Sep 2011 04:00:00 +0100 5281220 http://www.medworm.com/index.php?rid=5281225&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21947171%26dopt%3DAbstract Authors: Horslen BC, Carpenter MG Abstract There is mounting evidence to suggest that emotional state can influence postural control. Emotions are often qualified using dimensions such as valence (pleasantness) and arousal. While affective pictures have been used to detail the effects of valence on postural control, the influence of arousal independently, or in combination with valence, has yet to be investigated. This is an important oversight because there are multiple sensory and neuromuscular mechanisms that are known to be sensitive to arousal and to contribute to postural control. As such, the current study is the first to independently manipulate valence and arousal through affective pictures and to examine their independent effects on postural control. Subjects stood quietl... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281225 Tue, 27 Sep 2011 04:00:00 +0100 5281225 http://www.medworm.com/index.php?rid=5281224&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21947172%26dopt%3DAbstract Authors: Zago M, La Scaleia B, Miller WL, Lacquaniti F Abstract Vision of human actions can affect several features of visual motion processing, as well as the motor responses of the observer. Here, we tested the hypothesis that action observation helps decoding environmental forces during the interception of a decelerating target within a brief time window, a task intrinsically very difficult. We employed a factorial design to evaluate the effects of scene orientation (normal or inverted) and target gravity (normal or inverted). Button-press triggered the motion of a bullet, a piston, or a human arm. We found that the timing errors were smaller for upright scenes irrespective of gravity direction in the Bullet group, while the errors were smaller for the standard condition of norm... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281224 Tue, 27 Sep 2011 04:00:00 +0100 5281224 http://www.medworm.com/index.php?rid=5281223&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21947173%26dopt%3DAbstract Authors: Wei M, Lin N, Newlands SD Abstract Translational motion induces retinal image slip which varies with object distance. The brain must know binocular eye position in real time in order to scale eye movements so as to minimize retinal slip. Two potential sources of eye position information are orbital proprioception and an internal representation of eye position derived from central ocular motor signals. To examine the role of orbital proprioceptive information, the position of the left eye was perturbed by microstimulation of the left abducens nerve during translational motion to the right or left along the interaural axis in two rhesus macaques. Microstimulation rotated the eye laterally, activating eye muscle proprioceptors, while keeping central motor commands undisturbed... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281223 Tue, 27 Sep 2011 04:00:00 +0100 5281223 http://www.medworm.com/index.php?rid=5281222&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21947174%26dopt%3DAbstract Authors: Conson M, Mazzarella E, Trojano L Abstract Several studies showed that mental rotation of body parts is interfered with by manipulation of the subjects' posture. However, the experimental manipulations in such studies, e.g., to hold one arm flexed on one's own chest, activated not only proprioceptive but also self-tactile information. Here, we tested the hypothesis that the combination of self-touch and proprioception is more effective than proprioception alone in interfering with motor imagery. In Experiment 1 right- and left-handers were required to perform the hand laterality task, while holding one arm (right or left) flexed with the hand in direct contact with their chest (self-touch condition, STC) or with the hand placed on a wooden smooth surface in correspondence ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281222 Tue, 27 Sep 2011 04:00:00 +0100 5281222 http://www.medworm.com/index.php?rid=5281227&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21947084%26dopt%3DAbstract Authors: Wagner T, Pietrzik CU Abstract In this review, we will primarily focus on the role of members of the low-density lipoprotein receptor (LDL-R) family that are involved in trafficking and processing of the amyloid precursor protein (APP). We will discuss the role of the LDL-receptor family members, low-density lipoprotein receptor-related protein 1 (LRP1), LRP1b, apolipoprotein E receptor 2, sortilin-related receptor (SorLA/LR11) and megalin/LRP2 on the physiological function of APP and its cellular localization. Additionally, we will focus on adaptor proteins that have been shown to influence the physiological function of LDL-R family members in combination with APP processing. The results in this review emphasize that the physiological function of APP cannot be explained b... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281227 Fri, 23 Sep 2011 04:00:00 +0100 5281227 http://www.medworm.com/index.php?rid=5281226&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21947132%26dopt%3DAbstract In this study, two experiments were devised to examine the control strategy used by individuals when performing sequential aiming movements. Of particular interest was the aiming behavior displayed when task difficulty was changed midway through a sequence of movements. In Experiment 1, target size was manipulated, as the targets were made either larger or smaller, between the 8th and 12th movement of the sequence. In Experiment 2, the amplitude between the two targets was similarly changed while the target size remained constant. Results revealed that in Experiment 1, individuals took two movements following the perturbation to target size, to re-tune their movement times in order to correspond with the new task difficulty. Conversely for Experiment 2, movement time changed immediately an... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5281226 Fri, 23 Sep 2011 04:00:00 +0100 5281226 http://www.medworm.com/index.php?rid=5247194&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21938544%26dopt%3DAbstract Authors: Seegelke C, Hughes CM, Schack T Abstract Manual asymmetries in the control of movements have been investigated in a variety of experimental paradigms. Initial studies demonstrated that the dominant right hand has advantages over the non-dominant left hand in many aspects of motor control. However, more recent studies have shown that the presence and extent of these asymmetries depends on the task context and accuracy demands. Typically, manual asymmetries on a motor planning and motor execution level are examined separately. However, given that recent research has demonstrated that specific task constraints do not influence both levels equally, the purpose of the present experiment was to investigate manual asymmetries in motor planning and execution. To this end, initial ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5247194 Thu, 22 Sep 2011 04:00:00 +0100 5247194 http://www.medworm.com/index.php?rid=5247198&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21931982%26dopt%3DAbstract Authors: Dommett EJ, Rostron CL Abstract The spontaneously hypertensive rat (SHR) is the most commonly used model of attention-deficit hyperactivity disorder (ADHD), displaying the main symptoms of the disorder which are responsive to psychostimulant treatments. Research to date has focused on behavioural tests investigating functioning of the striatum or prefrontal cortex in these rats. However, there is now evidence that the superior colliculus, a structure associated with head and eye movements, may also be dysfunctional in ADHD. Therefore, the aim of this study was to investigate whether the SHR demonstrated impairment in collicular-dependent behaviour. To this end, we examined air righting behaviour, which has previously been shown to be modulated in a height-dependent manner ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5247198 Tue, 20 Sep 2011 04:00:00 +0100 5247198 http://www.medworm.com/index.php?rid=5247197&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21931983%26dopt%3DAbstract In this study, we adapted a framework from the dual-task paradigm, well suited to reveal bottlenecks in mental processing, to study how information is processed across sequential saccades. The pattern of RTs allowed us to distinguish among three forms of trans-saccadic processing (no trans-saccadic processing, trans-saccadic visual processing and trans-saccadic visual processing and saccade planning models). Using a cued double-step saccade task, we show that even though saccade execution is a processing bottleneck, limiting access to incoming visual information, partial visual and motor processing that occur prior to saccade execution is used to guide the next eye movement. These results provide insights into how the oculomotor system is designed to process information across multiple fix... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5247197 Tue, 20 Sep 2011 04:00:00 +0100 5247197 http://www.medworm.com/index.php?rid=5247196&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21931984%26dopt%3DAbstract In this study, participants were required to locomote in the dark to a lit target in three different conditions: monocular vision/target with image size, binocular vision/target with image size, and binocular vision/point-light target (without image size). In task one, participants brought their eyes to the target. In task two, participants brought their outstretched hand to the target. Movement trajectories for both tasks were analyzed. Results show that participants were significantly more accurate when binocular information was present. In both tasks, participants were found to use a proportional rate control strategy rather than a constant [Formula: see text] strategy. In the walk-to-reach task, they used monocular and/or binocular τ information to guide the head and then switched to ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5247196 Tue, 20 Sep 2011 04:00:00 +0100 5247196 http://www.medworm.com/index.php?rid=5247195&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21931985%26dopt%3DAbstract Authors: Aydin D, Weyer SW, Müller UC Abstract The amyloid precursor protein (APP) plays a key role in the pathogenesis of Alzheimer's disease (AD), as proteolytical cleavage of APP gives rise to the β-amyloid peptide which is deposited in the brains of Alzheimer patients. During the past years, intense research efforts have been directed at elucidating the physiological function(s) of APP and the question of whether a perturbation of these functions contributes to AD pathogenesis. Indeed, a growing body of evidence has accumulated supporting a role of APP and the two closely related homologues APLP1 and APLP2 in various aspects of nervous system development and function, in particular, for synapse formation and function. This review summarizes recent insights into the in vivo ro... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5247195 Tue, 20 Sep 2011 04:00:00 +0100 5247195 http://www.medworm.com/index.php?rid=5247199&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21927826%26dopt%3DAbstract Authors: Aznar-Casanova A, Keil MS, Moreno M, Supèr H Abstract In a three-dimensional (3-D) environment, sensory information is projected on a 2-D retina with the consequence that the visual system needs space information for accurately reconstructing the visual world. However, the 3-D environment is not accurately represented in the brain; in particular, the perception of distances in depth is imprecise. It has been argued that the visual system has an intrinsic bias of visual space where targets located on the ground floor are perceived on an implicit elevated surface. We studied how such an intrinsic bias of visual space affects shape constancy. We found that the projected shape of a semicircle can be explained taking into account a differential implicit slant surface. The dept... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5247199 Sat, 17 Sep 2011 04:00:00 +0100 5247199 http://www.medworm.com/index.php?rid=5231494&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21922279%26dopt%3DAbstract Authors: Li WL, Fraser JL, Yu SP, Zhu J, Jiang YJ, Wei L Abstract Ischemic stroke is a major cause of mortality and morbidity worldwide but effective treatments are limited. Strategies to enhance neurovascular remodeling following stroke provide promising opportunities to improve tissue repair and functional recovery. We have previously demonstrated that whisker activity promotes central angiogenesis in rodent models of whisker-barrel cortex stroke. However, the mechanisms involved in the regulation of neurovascular plasticity by peripheral stimulation are not well-defined. Here, we report that angiogenesis and neurogenesis occur concurrently after cerebral ischemia and whisker stimulation in mice. We show that neuroblasts expressing vascular endothelial growth factor receptor 2 (V... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5231494 Fri, 16 Sep 2011 04:00:00 +0100 5231494 http://www.medworm.com/index.php?rid=5231497&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21915669%26dopt%3DAbstract In this study, we investigated the effects of the model's handedness and the observer's viewpoint on the learning of a complex spatiotemporal task. Four groups of right-handed participants observed, from either a first- or third-person viewpoint, right- or left-handed models performing the task. Observation resulted in significant learning. More importantly, observation of same-handed models resulted in improved learning as compared with observation of opposite-handed models, regardless of the observer's viewpoint. This suggests that the action observation network (AON) is more sensitive to the model's handedness than to the observer's viewpoint. Our results are consistent with recent studies that suggest that the AON is linked to or involves sensorimotor regions of the brain that simulate... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5231497 Wed, 14 Sep 2011 04:00:00 +0100 5231497 http://www.medworm.com/index.php?rid=5231496&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21915670%26dopt%3DAbstract Authors: Hurt CP, Rosenblatt NJ, Grabiner MD Abstract A compensatory stepping response (CSR) is a common strategy to restore dynamic stability in response to a postural disturbance. Currently, few studies have investigated the CSR to laterally directed disturbances delivered to subjects during quiet standing. The purpose of this study was to characterize the CSR of younger adults following exposure to a series of similar laterally directed disturbances for which no instructions were given with regard to the recovery response. We hypothesized that in the absence of externally applied constraints to the recovery response, subjects would be equally as likely to perform a crossover step as a sidestep sequence (SSS). We further hypothesized that there would be an asymmetry in arm abduct... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5231496 Wed, 14 Sep 2011 04:00:00 +0100 5231496 http://www.medworm.com/index.php?rid=5231495&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21915671%26dopt%3DAbstract Authors: Murzin V, Fuchs A, Kelso JA Abstract Neural activity as measured non-invasively using electroencephalography (EEG) or magnetoencephalography (MEG) originates in the cortical gray matter. In the cortex, pyramidal cells are organized in columns and activated coherently, leading to current flow perpendicular to the cortical surface. In recent years, beamforming algorithms have been developed, which use this property as an anatomical constraint for the locations and directions of potential sources in MEG data analysis. Here, we extend this work to EEG recordings, which require a more sophisticated forward model due to the blurring of the electric current at tissue boundaries where the conductivity changes. Using CT scans, we create a realistic three-layer head model consisting... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5231495 Wed, 14 Sep 2011 04:00:00 +0100 5231495 http://www.medworm.com/index.php?rid=5219170&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21912927%26dopt%3DAbstract Authors: Borich MR, Kimberley TJ Abstract Sleep has been shown to benefit memory consolidation for certain motor skills, but it remains unclear if this relationship exists for motor skills with direct rehabilitation applications. We aimed to determine the neurobehavioral relationship between finger-tracking skill development and sleep following skill training in young, healthy subjects. Forty subjects received tracking training in the morning (n = 20) or the evening (n = 20). Measures of tracking skill and cortical excitability were collected before and after training. Following training, tracking skill and measures of cortical excitability were assessed at two additional follow-up visits (12 and 24 h post-training) for each subject following an episode of sleep or waking acti... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5219170 Tue, 13 Sep 2011 04:00:00 +0100 5219170 http://www.medworm.com/index.php?rid=5219169&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21912928%26dopt%3DAbstract Authors: Poeck B, Strauss R, Kretzschmar D Abstract Amyloid precursor proteins (APPs) are evolutionary conserved from nematodes to man (Jacobsen and Iverfeldt in Cell Mol Life Sci 66:2299-2318, 2009) suggesting an important physiological function of these proteins. Human APP is a key factor in the pathogenesis of Alzheimer's Disease because its proteolytic processing results in the production of the neurotoxic Aβ-peptide, which accumulates in the amyloid plaques characteristic for this disease (Selkoe in Physiol Rev 81(2):741-766, 2001). However, the processing also leads to the production of several other fragments and the role of these products, as well as the function of the full-length protein is so far not well understood. The functional analysis of APP in vertebrates has bee... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5219169 Tue, 13 Sep 2011 04:00:00 +0100 5219169 http://www.medworm.com/index.php?rid=5219168&cid=s_37323_168_f&fid=37323&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21912929%26dopt%3DAbstract Authors: Vogler JN, Titchener K Abstract Previous research examining cross-modal conflicts in object recognition has often made use of animal vocalizations and images, which may be considered natural and ecologically valid, thus strengthening the association in the congruent condition. The current research tested whether the same cross-modal conflict would exist for man-made object sounds as well as comparing the speed and accuracy of auditory processing across the two object categories. Participants were required to attend to a sound paired with a visual stimulus and then respond to a verification item (e.g., "Dog?"). Sounds were congruent (same object), neutral (unidentifiable image), or incongruent (different object) with the images presented. In the congruent and neutral condit... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=5219168 Tue, 13 Sep 2011 04:00:00 +0100 5219168