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. Sat, 20 Mar 2010 16:33:16 +0100 http://www.medworm.com/index.php?rid=3381651&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%3D20237773%26dopt%3DAbstract Authors: Shabbott BA, Sainburg RL Visuomotor adaptation is mediated by errors between intended and sensory-detected arm positions. However, it is not clear whether visual-based errors that are shown during the course of motion lead to qualitatively different or more efficient adaptation than errors shown after movement. For instance, continuous visual feedback mediates online error corrections, which may facilitate or inhibit the adaptation process. We addressed this question by manipulating the timing of visual error information and task instructions during a visuomotor adaptation task. Subjects were exposed to a visuomotor rotation, during which they received continuous visual feedback (CF) of hand position with instructions to correct or not correct online errors, or knowledge-of-re... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3381651 Wed, 17 Mar 2010 00:00:00 +0100 3381651 http://www.medworm.com/index.php?rid=3374535&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%3D20232062%26dopt%3DAbstract Authors: Fierro B, De Tommaso M, Giglia F, Giglia G, Palermo A, Brighina F Evidence by functional imaging studies suggests the role of left DLPFC in the inhibitory control of nociceptive transmission system. Pain exerts an inhibitory modulation on motor cortex, reducing MEP amplitude, while the effect of pain on motor intracortical excitability has not been studied so far. In the present study, we explored in healthy subjects the effect of capsaicin-induced pain and the modulatory influences of left DLPFC stimulation on motor corticospinal and intracortical excitability. Capsaicin was applied on the dorsal surface of the right hand, and measures of motor corticospinal excitability (test-MEP) and short intracortical inhibition (SICI) and facilitation (ICF) were obtained by paired-pulse ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3374535 Tue, 16 Mar 2010 00:00:00 +0100 3374535 http://www.medworm.com/index.php?rid=3374536&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%3D20229311%26dopt%3DAbstract Authors: Willigenburg NW, Kingma I, van Dieën JH Precision of limb control is associated with increased joint stiffness caused by antagonistic co-activation. The aim of this study was to examine whether this strategy also applies to precision of trunk postural control. To this end, thirteen subjects performed static postural tasks, aiming at a target object with a cursor that responded to 2D trunk angles. By manipulating target dimensions, different levels of precision were imposed in the frontal and sagittal planes. Trunk angle and electromyography (EMG) of abdominal and back muscles were recorded. Repeated measures ANOVAs revealed significant effects of target dimensions on kinematic variability in both movement planes. Specifically, standard deviation (SD) of trunk angle decrea... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3374536 Sun, 14 Mar 2010 00:00:00 +0100 3374536 http://www.medworm.com/index.php?rid=3374537&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%3D20229170%26dopt%3DAbstract Authors: Gorbet DJ, Mader LB, Staines WR PMID: 20229170 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3374537 Sat, 13 Mar 2010 00:00:00 +0100 3374537 http://www.medworm.com/index.php?rid=3362826&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%3D20221589%26dopt%3DAbstract Authors: Seizova-Cajic T, Azzi R Visual processing of basic perceptual attributes depends on attention. This has been well documented since the surprising initial report on attentional modulation of the visual motion aftereffect (Chaudhuri 1990). Here, we investigate proprioception and show for the first time that attention modulates adaptation to perceived limb movement. We used biceps vibration to induce illusory forearm extension in 10 participants and measured the aftereffect-perceived movement in the opposite direction. The aftereffect was largest when participants focused on the illusory extension during the adaptation period. To divert attention away from the illusory extension, a rapid serial visual presentation task was performed during the adaptation. The aftereffect was much... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3362826 Thu, 11 Mar 2010 00:00:00 +0100 3362826 http://www.medworm.com/index.php?rid=3355089&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%3D20217402%26dopt%3DAbstract Authors: Hesse C, Nakagawa TT, Deubel H Our study examined the effects of performing a pointing movement with the left hand on the kinematics of a simultaneous grasping movement executed with the right hand. We were especially interested in the question of whether both movements can be controlled independently or whether interference effects occur. Since previous studies suggested that eye movements may play a crucial role in bimanual movement control, the effects of different fixation strategies were also studied. Human participants were either free to move their eyes (Experiment 1) or they had to fixate (Experiment 2) while doing the task. The results show that bimanual movement control differed fundamentally depending on the fixation condition: if free viewing was allowed, participa... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3355089 Wed, 10 Mar 2010 00:00:00 +0100 3355089 http://www.medworm.com/index.php?rid=3355092&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%3D20217399%26dopt%3DAbstract This study investigates the cerebellar contribution to reactive grip control by examining differences between (22-48 years) subjects with focal cerebellar lesion due to ischaemic stroke (CL) and healthy subjects (HS). The subjects used a pinch grip to grasp and restrain an instrumented handle from moving when it was subject to unpredictable load forces of different rates (2, 4, 8, 32 N/s) or amplitudes (1, 2, 4 N). The hand ipsilateral to the lesion of the cerebellar subjects showed delayed and more variable response latencies, e.g., 278 +/- 162 ms for loads delivered at 2 N/s, compared to HS 180 +/- 53 ms (P = 0.005). The CL also used a higher pre-load grip force with the ipsilateral hand, 1.6 +/- 0.8 N, than the HS, 1.3 +/- 0.6 N (P = 0.017). In addition, the contralateral hand in subjec... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3355092 Tue, 09 Mar 2010 00:00:00 +0100 3355092 http://www.medworm.com/index.php?rid=3355091&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%3D20217400%26dopt%3DAbstract This study was designed to determine the effect of different frequencies of NMES applied over the common peroneal nerve on changes in CS excitability for the tibialis anterior (TA) muscle. We hypothesized that higher frequencies of stimulation would produce larger increases in CS excitability than lower frequencies. NMES was applied at 10, 50, 100, or 200 Hz during separate sessions held at least 48 h apart. The stimulation was delivered in a 20 s on, 20 s off cycle for 40 min using a 1 ms pulse width. The intensity of stimulation was set to evoke an M-wave in response to a single pulse that was 15% of the maximal M-wave. CS excitability was evaluated by the amplitude of motor-evoked potentials (MEPs) in TA evoked by transcranial magnetic stimulation. MEPs were recorded immediately before ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3355091 Tue, 09 Mar 2010 00:00:00 +0100 3355091 http://www.medworm.com/index.php?rid=3355090&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%3D20217401%26dopt%3DAbstract Authors: Papeo L, Longo MR, Feurra M, Haggard P The right temporoparietal junction (rTPJ) is a polysensory cortical area that plays a key role in perception and awareness. Neuroimaging evidence shows activation of rTPJ in intersensory and sensorimotor conflict situations, but it remains unclear whether this activity reflects detection or resolution of such conflicts. To address this question, we manipulated the relationship between touch and vision using the so-called mirror-box illusion. Participants' hands lay on either side of a mirror, which occluded their left hand and reflected their right hand, but created the illusion that they were looking directly at their left hand. The experimenter simultaneously touched either the middle (D3) or the ring finger (D4) of each hand. Participa... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3355090 Tue, 09 Mar 2010 00:00:00 +0100 3355090 http://www.medworm.com/index.php?rid=3355093&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%3D20213147%26dopt%3DAbstract This study was designed to examine the sensitivity of visual and haptic information alone and together for detecting curvature. When both visual and haptic information were present, temporal delays in signal onset were used to determine the effect of asynchronous sensory information on the interference of vision on the haptic estimate of curvature. Even under the largest temporal delays where visual and haptic information were clearly disparate, the presentation of visual information influenced the haptic perception of curvature. The uncertainty associated with the unimodal vision condition was smaller than that in the unimodal haptic condition, regardless of whether the haptic information was procured actively or under robot assistance for curvature detection. When both visual and haptic ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3355093 Sat, 06 Mar 2010 00:00:00 +0100 3355093 http://www.medworm.com/index.php?rid=3337210&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%3D20204608%26dopt%3DAbstract Authors: Thumser ZC, Adams NL, Lerner AJ, Stahl JS Humans may accomplish gaze shifts by eye-only saccades or combined eye-head saccades. The mechanisms that determine whether the head moves remain poorly understood. Many observations can be explained if phylogenetically ancient circuits generate eye-head saccades by default and frontal cerebral structures interrupt this synergy when eye-only saccades are preferable. Saccade-associated head movements have been reported to increase in the elderly. To test the hypothesis of frontal inhibition of head movements, we investigated whether the increase is associated with a decline in frontal cognitive function. We measured head movement tendencies and cognition in volunteers aged 61-80. Measures of head movement tendency included the customary... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3337210 Fri, 05 Mar 2010 00:00:00 +0100 3337210 http://www.medworm.com/index.php?rid=3337211&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%3D20204607%26dopt%3DAbstract Authors: Küng UM, Horlings CG, Honegger F, Allum JH Stabilising shifts of the centre of mass (COM) are observed during balance recovery when subjects simultaneously execute voluntary unilateral knee flexion or unilateral arm raising. Here, we examined whether voluntary lateral trunk bending provided more beneficial stabilising effects, and how motor programs of balance corrections are combined with those of the focal voluntary action. The upright balance of 24 healthy young subjects (19-33 years of age) was perturbed using multi-directional rotations of the support-surface. The perturbations consisted of combined pitch and roll rotations (7.5 degrees and 60 degrees /s) presented randomly in six different directions. Three conditions were tested: perturbation of stance only (PO); c... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3337211 Thu, 04 Mar 2010 00:00:00 +0100 3337211 http://www.medworm.com/index.php?rid=3330863&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%3D20198364%26dopt%3DAbstract Authors: Sklavos S, Anastasopoulos D, Bronstein A Shifting the direction of the line of sight in everyday life often involves rotations not only of the eyes and head but also of the trunk. Here, we investigated covariation patterns of eye-in-orbit, head-on-trunk and trunk-in-space angular horizontal displacements during whole-body rotations to targets of up to 180 degrees eccentricity performed by standing healthy human subjects. The spatial covariation was quantified statistically across various behavioral task conditions (unpredictable, memory driven predictable, visual feedback) and constraints (accuracy) by principal components (PC) analysis. Overall, the combined movement was stereotyped such that the first two PCs accounted for essentially the whole data variance of combined gaze... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3330863 Wed, 03 Mar 2010 00:00:00 +0100 3330863 http://www.medworm.com/index.php?rid=3330862&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%3D20198365%26dopt%3DAbstract Authors: Priot AE, Laboissière R, Sillan O, Roumes C, Prablanc C Telestereoscopic viewing provides a method to distort egocentric distance perception by artificially increasing the interpupillary distance. Adaptation to such a visual rearrangement is little understood. Two experiments were performed in order to dissociate the effects of a sustained increased vergence demand, from those of an active calibration of the vergence/distance mapping. Egocentric distances were assessed within reaching space through open-loop pointing to small targets in the dark. During the exposure condition of the first experiment, subjects were instructed to point to the targets without feedback, whereas in the second experiment, hand visual feedback was available, resulting in a modified relationship ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3330862 Wed, 03 Mar 2010 00:00:00 +0100 3330862 http://www.medworm.com/index.php?rid=3330866&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%3D20195847%26dopt%3DAbstract Authors: Caudron S, Nougier V, Guerraz M The described experiment investigated whether adaptation to successive Achilles tendon vibration depends on the postural challenge. In phase 1, thirty-six participants were divided into three groups, each with a different postural challenge. After being blindfolded, participants received 15 trials of Achilles tendon vibration (10 s-90 Hz) while standing upright in either a free-standing condition (FS group), a light finger touch condition (LFT group), or a restrained-standing condition (RS group) in which a dorsal stand prevented body displacement. In phase 2, all participants were freely standing and received 15 additional trials of vibration. Antero-posterior trunk tilt was measured at the level of the trunk (C7). Although there were limited p... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3330866 Sat, 27 Feb 2010 00:00:00 +0100 3330866 http://www.medworm.com/index.php?rid=3330865&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%3D20195848%26dopt%3DAbstract We examined how humans grasp a circular control knob in order to turn it in different directions and by different extents. To examine the processes involved in anticipatory planning of grasps, we manipulated advance information about the location of the control knob and the target of the knob-turn. The forearm orientation at the time of grasping depended strongly on the knob-turn, with the direction of the knob-turn having a stronger effect than the extent of the knob-turn. However, the variability of the forearm orientations after the knob-turn remained considerable. Anticipatory forearm orientations began early during the grasping movement. Advance information had no influence on the trajectory of the grasp but affected reaction times and the duration of the grasp. From the results, we c... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3330865 Sat, 27 Feb 2010 00:00:00 +0100 3330865 http://www.medworm.com/index.php?rid=3330864&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%3D20195849%26dopt%3DAbstract Authors: Gheysen F, Van Opstal F, Roggeman C, Van Waelvelde H, Fias W Implicit motor sequence learning refers to an important human ability to acquire new motor skills through the repeated performance of a motor sequence. This learning process is characterized by slow, incremental gains of motor performance. The present fMRI study was developed to better delineate the areas supporting these temporal dynamics of learning. By using the serial color matching paradigm, our study focused on the motor level of sequence learning and tracked the time course of learning-related neural changes. Imaging results showed a significant contribution of the left anterior hippocampus in an early sequence acquisition stage (first scanning session) as well as during a later stage with stabilized learning ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3330864 Sat, 27 Feb 2010 00:00:00 +0100 3330864 http://www.medworm.com/index.php?rid=3316395&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%3D20186399%26dopt%3DAbstract Authors: Rice CD, Weber SA, Waggoner AL, Jessell ME, Yates BJ During breathing, the diaphragm and abdominal muscles contract out of phase. However, during other behaviors (including vomiting, postural adjustments, and locomotion) simultaneous contractions are required of the diaphragm and other muscle groups including abdominal muscles. Recent studies in cats using transneuronal tracing techniques showed that in addition to neurons in the respiratory groups, cells in the inferior and lateral vestibular nuclei (VN) and medial pontomedullary reticular formation (MRF) influence diaphragm activity. The goal of the present study was to determine whether neurons in these regions have collateralized projections to both diaphragm motoneurons and the lumbar spinal cord. For this purpose, the tr... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3316395 Fri, 26 Feb 2010 00:00:00 +0100 3316395 http://www.medworm.com/index.php?rid=3316394&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%3D20186400%26dopt%3DAbstract Authors: Hidalgo-Lozano A, Fernández-de-Las-Peñas C, Alonso-Blanco C, Ge HY, Arendt-Nielsen L, Arroyo-Morales M Our aim was to describe the differences in the presence of trigger points (TrPs) in the shoulder muscles and to investigate the presence of mechanical hypersensitivity in patients with unilateral shoulder impingement and healthy controls. Twelve patients with strictly unilateral shoulder impingement and 10 matched controls were recruited. TrPs in the levator scapula, supraspinatus, infraspinatus, subscapularis, pectoralis major, and biceps brachii muscles were explored. TrPs were considered active if the local and referred pain reproduced the pain symptoms and the patient recognized the pain as a familiar pain. Pressure pain thresholds (PPT) were assessed over the l... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3316394 Fri, 26 Feb 2010 00:00:00 +0100 3316394 http://www.medworm.com/index.php?rid=3316393&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%3D20186401%26dopt%3DAbstract This study examined grip force development in individuals with hemiparesis following unilateral stroke. Eleven patients with chronic stroke with severe hand impairment and five age-matched neurologically intact subjects grasped an instrumented object between the index finger and thumb while fingertip forces, digit posture, and muscle electromyographic activity were recorded. We tested a range of different grip conditions with varying grip sizes, object stability, and grip force level. We found that fingertip force direction in the paretic digits deviated from the direction normal to the grip surface by more than twice as much as for asymptomatic digits. Additionally, the paretic thumb had, on average, 18% greater deviation of grip force direction than the paretic index finger. This large d... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3316393 Fri, 26 Feb 2010 00:00:00 +0100 3316393 http://www.medworm.com/index.php?rid=3316392&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%3D20186402%26dopt%3DAbstract This study investigated whether short-term modifications of gait could be induced in healthy adults and whether a combination of kinetic (a compliant force resisting deviation of the foot from the prescribed footpath) and visual guidance was superior to either kinetic guidance or visual guidance alone in producing this modification. Thirty-nine healthy adults, 20-33 years old, were randomly assigned to the three groups receiving six 10-min blocks of treadmill training requiring them to modify their footpath to match a scaled-down path. Changes of the footpath, specific joint events and joint moments were analyzed. Persons receiving combined kinetic and visual guidance showed larger modifications of their gait patterns that were maintained longer, persisting up to 2 h after intervening over... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3316392 Fri, 26 Feb 2010 00:00:00 +0100 3316392 http://www.medworm.com/index.php?rid=3316391&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%3D20186403%26dopt%3DAbstract Authors: Mirams L, Poliakoff E, Brown RJ, Lloyd DM Research suggests that attention has a significant effect on somatic perception in both healthy people and those who suffer from somatic disturbance. The current study investigates the effects of attending to the body on somatic awareness and a particular type of somatic disturbance: erroneous reports of touch sensation, as measured by the Somatic Signal Detection Task (SSDT). During the SSDT, participants are required to detect near-threshold tactile stimulation at their fingertip. Previous research has found that healthy participants erroneously report touch sensations in the absence of a stimulus on this task and that such false alarms are increased when a simultaneous light flash is presented next to their fingertip. Thirty-seven p... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3316391 Fri, 26 Feb 2010 00:00:00 +0100 3316391 http://www.medworm.com/index.php?rid=3316390&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%3D20186404%26dopt%3DAbstract Authors: Vanneste S, Plazier M, Ost J, van der Loo E, Van de Heyning P, De Ridder D Tinnitus is considered as an auditory phantom percept. Preliminary evidence indicates that transcranial direct current stimulation (tDCS) of the temporo-parietal area might reduce tinnitus. tDCS studies of the prefrontal cortex have been successful in reducing depression, impulsiveness and pain. Recently, it was shown that the prefrontal cortex is important for the integration of sensory and emotional aspects of tinnitus. As such, frontal tDCS might suppress tinnitus as well. In an open label study, a total of 478 tinnitus patients received bilateral tDCS on dorsolateral prefrontal cortex (448 patients anode right, cathode left and 30 anode left, cathode right) for 20 min. Treatment effects were assesse... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3316390 Fri, 26 Feb 2010 00:00:00 +0100 3316390 http://www.medworm.com/index.php?rid=3316389&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%3D20186405%26dopt%3DAbstract Authors: Galati G, Pelle G, Berthoz A, Committeri G We review human functional neuroimaging studies that have explicitly investigated the reference frames used in different cortical regions for representing spatial locations of objects. Beyond the general distinction between "egocentric" and "allocentric" reference frames, we provide evidence for the selective involvement of the posterior parietal cortex and associated frontal regions in the specific process of egocentric localization of visual and somatosensory stimuli with respect to relevant body parts ("body referencing"). Similarly, parahippocampal and retrosplenial regions, together with specific parietal subregions such as the precuneus, are selectively involved in a specific form of allocentric representation in which object lo... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3316389 Fri, 26 Feb 2010 00:00:00 +0100 3316389 http://www.medworm.com/index.php?rid=3303345&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%3D20174919%26dopt%3DAbstract In conclusion, our results reveal a concurrent interplay of two task-dependent modules of motor-cognitive processing: an adaptive control module and a 'protective' module that opposes potentially 'dangerous' (or cognitively costly) bimanual interactions. PMID: 20174919 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3303345 Sat, 20 Feb 2010 00:00:00 +0100 3303345 http://www.medworm.com/index.php?rid=3295076&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%3D20169337%26dopt%3DAbstract Authors: Gottschall PE, Ajmo JM, Eakin AK, Howell MD, Mehta H, Bailey LA The purpose of this study was to develop ELISAs for key neural proteins, three synaptic and one glial, that exist in different intracellular compartments, which would be used as a measure of synaptic phenotype. These assays would be valuable to neurologically phenotype transgenic mouse models of human disease and also human disease itself using minimal amounts of post-mortem tissue. We showed that supernatant from crude brain tissue homogenates extracted in RIPA buffer containing 0.1% SDS bind to synaptophysin, synaptosome-associated protein of 25 kDa (SNAP-25), post-synaptic density-95 (PSD-95), and glial fibrillary acidic protein (GFAP) antibody pairs with high affinity and selectivity. Overall, RIPA + 0.1% SDS ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3295076 Fri, 19 Feb 2010 00:00:00 +0100 3295076 http://www.medworm.com/index.php?rid=3295075&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%3D20169338%26dopt%3DAbstract Authors: Levy-Tzedek S, Krebs HI, Song D, Hogan N, Poizner H We tested 23 healthy participants who performed rhythmic horizontal movements of the elbow. The required amplitude and frequency ranges of the movements were specified to the participants using a closed shape on a phase-plane display, showing angular velocity versus angular position, such that participants had to continuously control both the speed and the displacement of their forearm. We found that the combined accuracy in velocity and position throughout the movement was not a monotonic function of movement speed. Our findings suggest that specific combinations of required movement frequency and amplitude give rise to two distinct types of movements: one of a more rhythmic nature, and the other of a more discrete nature. ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3295075 Fri, 19 Feb 2010 00:00:00 +0100 3295075 http://www.medworm.com/index.php?rid=3295074&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%3D20169339%26dopt%3DAbstract Authors: Tschopp-Junker C, Gentaz E, Viviani P An experiment contrasted the effect of four training schedules in a visual orientation reproduction task. Two selective schedules involved repeated presentation of a single target orientation. Two non-selective schedules involved targets covering the first quadrant either at fixed, equispaced orientations, or distributed randomly. In pre-training sessions, we observed the classical oblique effect (precision for vertical and horizontal stimuli higher than for oblique ones). Practice improved precision with both distributed schedules, but was ineffectual for non-selective schedules. However, a significant oblique effect persisted under all conditions. We argue that the pattern of results is compatible with the hypothesis that the oblique eff... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3295074 Fri, 19 Feb 2010 00:00:00 +0100 3295074 http://www.medworm.com/index.php?rid=3285869&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%3D20165838%26dopt%3DAbstract Authors: Walsh E, Haggard P When a weak shock is delivered to the finger immediately before a voluntary movement, or during a delay interval where subjects are prepared to make the movement, shock detection rates worsen progressively as the movement approaches. Further, we previously showed that shock detection improves again if a NoGo signal produces inhibition of a prepared response. Here, we used a somatosensory version of the stop-signal paradigm to investigate inhibitory processing during the 'horserace' period when motor excitation and inhibition processes may be simultaneously active. When subjects made a rapid keypress response to a go-signal, shock detection deteriorated in a time-dependent manner, replicating sensory suppression. However, when go-signals were followed by adap... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3285869 Thu, 18 Feb 2010 00:00:00 +0100 3285869 http://www.medworm.com/index.php?rid=3285868&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%3D20165839%26dopt%3DAbstract Authors: Putrino D, Mastaglia FL, Ghosh S To study the interlimb coordination of reaching and postural movements, chronically implanted microelectrodes were used to record single unit activity from the primary motor cortex (MI) of cats during performance of a trained reaching task. Recordings were made from both cerebral hemispheres to record neurons that modulated their activity during reaching (reach-related neurons) and supportive (posture-related neurons) movements of either forelimb. Evidence of temporal associations in the activities of simultaneously recorded reach- and posture-related neurons was evaluated using shuffle-corrected cross correlograms. The spike activity of approximately 34% of reach-related neurons was temporally correlated with the spike activity of simultaneous... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3285868 Thu, 18 Feb 2010 00:00:00 +0100 3285868 http://www.medworm.com/index.php?rid=3285867&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%3D20165840%26dopt%3DAbstract Authors: Kim JK, Zatorre RJ Shape is an inherent property of objects existing in both vision and touch but not audition. Can shape then be represented by sound artificially? It has previously been shown that sound can convey visual information by means of image-to-sound coding, but whether sound can code tactile information is not clear. Blindfolded sighted individuals were trained to recognize tactile spatial information using sounds mapped from abstract shapes. After training, subjects were able to match auditory input to tactually discerned shapes and showed generalization to novel auditory-tactile pairings. Furthermore, they showed complete transfer to novel visual shapes, despite the fact that training did not involve any visual exposure. In addition, we found enhanced tactile acu... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3285867 Thu, 18 Feb 2010 00:00:00 +0100 3285867 http://www.medworm.com/index.php?rid=3280268&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%3D20157699%26dopt%3DAbstract We examined the influence of the hand employed in sensorimotor learning on the acquired sequence knowledge in a serial reaction time task. Right-handed subjects trained either with the dominant or with the nondominant hand sequences of finger postures in response to a corresponding stimulus sequence. In the course of training, they were repeatedly asked to switch to the opposite hand, either responding to the original stimulus sequence with nonhomologues fingers or to the mirror-ordered sequence of stimuli with homologues fingers. When the right hand was used at acquisition, transfer to the same stimulus sequence increased with practice. In contrast, when the left hand was trained, transfer to the homologues finger sequence increased with practice. The results indicate qualitative differen... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3280268 Tue, 16 Feb 2010 00:00:00 +0100 3280268 http://www.medworm.com/index.php?rid=3280267&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%3D20157700%26dopt%3DAbstract Authors: van der Meer JN, Schouten AC, Bour LJ, de Vlugt E, van Rootselaar AF, van der Helm FC, Tijssen MA In dystonia, both sensory malfunctioning and an abnormal intermuscular low-frequency drive of 3-7 Hz have been found, although cause and effect are unknown. It is hypothesized that sensory processing is primarily disturbed and induces this drive. Accordingly, experimenter-controlled sensory input should be able to influence the frequency of the drive. In six genetically confirmed myoclonus-dystonia (MD) patients and six matched controls, the low-frequency drive was studied with intermuscular coherence analysis. External perturbations were applied mechanically to the wrist joint in small frequency bands (0-4, 4-8 and 8-12 Hz; 'angle protocol) and at single frequencies (1, 5, 7 and ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3280267 Tue, 16 Feb 2010 00:00:00 +0100 3280267 http://www.medworm.com/index.php?rid=3270040&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%3D20151301%26dopt%3DAbstract We examined the effect of exploring redundant solutions during practice in enhancing the ability to flexibly use them to achieve a task goal. Three groups used different degrees of path redundancy to perform a virtual interception task in which they attempted to hit a stationary target by moving around a stationary obstacle. The low-variability group always practiced with the same position of the obstacle on all trials. The medium-variability and high-variability groups practiced with the obstacle in different positions within a range of 1 and 2 cm respectively. After eight blocks of practice, all participants were transferred to two tests: (a) a fixed obstacle test where the condition was the same as that practiced by the low-variability group, and (b) a variable obstacle test where the c... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3270040 Fri, 12 Feb 2010 00:00:00 +0100 3270040 http://www.medworm.com/index.php?rid=3263310&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%3D20143050%26dopt%3DAbstract Authors: Albert F, Diemayr G, McIsaac TL, Gordon AM Studies on grasp control underlying manual dexterity in people with Parkinson disease (PD) suggest that anticipatory grasp control is mainly unaffected during discrete tasks using simple two-digit grasp. Nevertheless, impaired hand function during daily activities is one of the most disabling symptoms of PD. As many daily grasping activities occur during functional movements involving the whole body, impairments in anticipatory grasp control might emerge during a continuous dynamic task such as object transport during walking. In this case, grasp control must be coordinated along with multiple body segments. The present study investigated the effect of PD on anticipatory grasp control and intersegmental coordination during walking wit... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3263310 Tue, 09 Feb 2010 00:00:00 +0100 3263310 http://www.medworm.com/index.php?rid=3263309&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%3D20143051%26dopt%3DAbstract Authors: Au WL, Lei N, Oishi MM, McKeown MJ Parkinson's disease preferentially affects internally generated movements, e.g., movements recalled from memory, while externally cued movements are relatively preserved. However, L: -dopa may have effects on visually guided movements as well as error-related processing. Fourteen Parkinson's disease (PD) subjects (on and off L: -dopa medication) as well as ten normal controls performed a tracking task using a joystick. During discrete 30 s blocks, the visual feedback of the actual tracking errors were attenuated, amplified or unaltered. Second order dynamical system models, with the desired trajectory as the input and the actual motor performance as the output, were used to characterize the motor performance by the each subject under each con... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3263309 Tue, 09 Feb 2010 00:00:00 +0100 3263309 http://www.medworm.com/index.php?rid=3244968&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%3D20135099%26dopt%3DAbstract Authors: Vishton PM, Reardon KM, Stevens JA It is widely accepted that human motor control is anticipatory in nature. Previous studies have used electromyography (EMG) to examine muscle responses to falling objects and identified anticipatory muscle tensing (AMT) as a spike in activation that occurs prior to object impact. Some studies have suggested that humans use an internal model of gravity to mediate precisely timed AMT responses. The present study further examines predictive motor control through the analysis of AMT during an object catching task. For some trials, participants watched an object falling toward the hand; for other trials, their eyes were closed. For some trials, the object fell downward and impacted the hand; for other randomly selected trials, the object abruptly ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3244968 Fri, 05 Feb 2010 00:00:00 +0100 3244968 http://www.medworm.com/index.php?rid=3244967&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%3D20135100%26dopt%3DAbstract Authors: Mulavara AP, Feiveson AH, Fiedler J, Cohen H, Peters BT, Miller C, Brady R, Bloomberg JJ Astronauts returning from space flight and performing Earth-bound activities must rapidly transition from the microgravity-adapted sensorimotor state to that of Earth's gravity. The goal of the current study was to assess locomotor dysfunction and recovery of function after long-duration space flight using a test of functional mobility. Eighteen International Space Station crewmembers experiencing an average flight duration of 185 days performed the functional mobility test (FMT) pre-flight and post-flight. To perform the FMT, subjects walked at a self selected pace through an obstacle course consisting of several pylons and obstacles set up on a base of 10-cm-thick, medium-density foam fo... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3244967 Fri, 05 Feb 2010 00:00:00 +0100 3244967 http://www.medworm.com/index.php?rid=3244966&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%3D20135101%26dopt%3DAbstract Authors: Gorbet DJ, Mader LB, Richard Staines W Previous work suggests the presence of sex differences in the laterality of brain activity in the premotor-parietal network during the preparation of visually guided reaching movements. In the current study, electroencephalography was used to test the hypothesis that women would have higher amplitude potentials over frontal and parietal regions ipsilateral to arm movements, relative to men. Event-related slow cortical potentials (SCPs) were collected from 30 participants (15 men and 15 women) during the performance of two visually guided reaching conditions (eyes and arm moved to the same spatial location or moved in opposite directions). The results of the study demonstrate that the amplitudes of SCPs were significantly higher overlying ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3244966 Fri, 05 Feb 2010 00:00:00 +0100 3244966 http://www.medworm.com/index.php?rid=3244965&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%3D20135102%26dopt%3DAbstract Authors: Striemer CL, Yukovsky J, Goodale MA Previous research has suggested that the visuomotor system possesses an "automatic pilot" which allows people to make rapid online movement corrections in response to sudden changes in target position. Importantly, the automatic pilot has been shown to operate in the absence of visual awareness, and even under circumstances in which people are explicitly asked not to correct their ongoing movement. In the current study, we investigated the extent to which the automatic pilot could be "disengaged" by explicitly instructing participants to ignore the target jump (i.e., "NO-GO"), by manipulating the order in which the two tasks were completed (i.e., either "GO" or NO-GO first), and by manipulating the proportion of trials in which the target ju... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3244965 Fri, 05 Feb 2010 00:00:00 +0100 3244965 http://www.medworm.com/index.php?rid=3244969&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%3D20131046%26dopt%3DAbstract Authors: Aspell JE, Wattam-Bell J, Atkinson J, Braddick OJ Mid-level visual processes which integrate local orientation information for the detection of global structure can be investigated using global form stimuli of varying complexity. Several lines of evidence suggest that the identification of concentric and parallel organisations relies on different underlying neural substrates. The current study measured brain activation by concentric, horizontal parallel, and vertical parallel arrays of short line segments, compared to arrays of randomly oriented segments. Six subjects were scanned in a blocked design functional magnetic resonance imaging experiment. We compared percentage BOLD signal change during the concentric, horizontal and vertical blocks within early retinotopic areas, t... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3244969 Thu, 04 Feb 2010 00:00:00 +0100 3244969 http://www.medworm.com/index.php?rid=3221075&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%3D20107978%26dopt%3DAbstract Authors: Alstermark B, Hultborn H, Jankowska E, Pettersson LG PMID: 20107978 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3221075 Thu, 28 Jan 2010 00:00:00 +0100 3221075 http://www.medworm.com/index.php?rid=3221074&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%3D20107979%26dopt%3DAbstract This study quantitatively describes differences between participants with hemiparetic stroke and age-matched healthy participants in axial body segment and gait kinematics during a direction change task. Participants were required to change walking direction by 45 degrees , either to their left or right, at the midpoint of a 6-m path. Participants were visually cued either at the start of the walk (pre-planned) or one stride before they reached the turn point (reactive). The sequence and inter-segmental timing of axial orientation onset was preserved in participants with stroke. Analysis of a subgroup of stroke survivors indicated that participants with lesions affecting the basal ganglia (BG) took significantly longer time than control participants to initiate the reorientation synergy wh... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3221074 Thu, 28 Jan 2010 00:00:00 +0100 3221074 http://www.medworm.com/index.php?rid=3221073&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%3D20107980%26dopt%3DAbstract Authors: Darling WG, Pizzimenti MA, Rotella DL, Hynes SM, Ge J, Stilwell-Morecraft KS, Vanadurongvan T, McNeal DW, Solon-Cline KM, Morecraft RJ The purpose of this study was to determine if recovery of neurologically impaired hand function following isolated motor cortex injury would occur without constraint of the non-impaired limb, and without daily forced use of the impaired limb. Nine monkeys (Macaca mulatta) received neurosurgical lesions of various extents to arm representations of motor cortex in the hemisphere contralateral to the preferred hand. After the lesion, no physical constraints were placed on the ipsilesional arm/hand and motor testing was carried out weekly with a maximum of 40 attempts in two fine motor tasks that required use of the contralesional hand for successf... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3221073 Thu, 28 Jan 2010 00:00:00 +0100 3221073 http://www.medworm.com/index.php?rid=3213225&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%3D20101395%26dopt%3DAbstract Authors: Tjernström F, Fransson PA, Patel M, Magnusson M We investigated the possible consequences of two consecutive postural tasks on adaptation. Four groups (total number of 46 healthy subjects) were perturbed on two consecutive days with vibration stimulus to tibialis anterior or posterior calf muscles, or both in different orders. Postural movements were recorded with a force platform. There were three major results: (1) tibialis anterior vibration instigated postural adaptation during exposure to the vibration, but did not induce long-term adaptation from day to day, contrary to posterior calf vibration. (2) The long-term postural adaptation from day to day when the posterior calf was vibrated was not affected by prior or subsequent tibialis anterior vibration, which contras... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3213225 Tue, 26 Jan 2010 00:00:00 +0100 3213225 http://www.medworm.com/index.php?rid=3213224&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%3D20101396%26dopt%3DAbstract Authors: Galea JM, Sami SA, Albert NB, Miall RC Motor adaptation is impaired by the performance of a secondary task which divides cognitive resources. Additionally, we previously reported slowed adaptation when participants were required to switch from one visual displacement adaptation task to another. Here, we examined whether a dividing secondary task had a similar effect on adaptation as switching between opposing visual displacements. The resource-dividing task involved simultaneously adapting to a step-visual displacement whilst vocally shadowing an auditory stimulus. The switching task required participants to adapt to opposing visual displacements in an alternating manner with the left and right hands. We found that both manipulations had a detrimental effect on adaptation rate... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3213224 Tue, 26 Jan 2010 00:00:00 +0100 3213224 http://www.medworm.com/index.php?rid=3201199&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%3D20094882%26dopt%3DAbstract Authors: Maier ME, Steinhauser M, Hübner R To study the effect of response-set size on action monitoring processes, the error-related negativity (Ne/ERN), the correct-related negativity (Nc/CRN), and behavioral indicators of action monitoring were compared across three groups of participants performing a two-choice, a four-choice, or an eight-choice version of the flanker task. After controlling for differential contribution of stimulus-related activity to response-locked averages resulting from large differences in response times across conditions, response-set size had strong effects on Ne/ERN and Nc/CRN. With increasing response-set size, the Ne/ERN amplitude decreased, but the Nc/CRN amplitude increased. Moreover, post-error behavioral adjustments were impaired with an increas... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3201199 Fri, 22 Jan 2010 00:00:00 +0100 3201199 http://www.medworm.com/index.php?rid=3195654&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%3D20091300%26dopt%3DAbstract Authors: Balitsky Thompson AK, Henriques DY Does the brain use a separate internal model for cursor mechanics during visuomotor adaptation? We compared the amount of adaptation and transfer to the opposite arm when subjects reached the targets under different viewing conditions of the arm during reaching. If the brain forms separate models, we predict a difference in the amount of adaptation and transfer for each viewing condition. If the brain forms one model, we predict equivalent amounts of adaptation and transfer between the two hands for each viewing condition. Separate groups of subjects performed a reaching task with either a rotated view of cursor motion representing their unseen hand or a rotated view of their actual hand. The two groups were further divided so that the magnit... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3195654 Fri, 22 Jan 2010 00:00:00 +0100 3195654 http://www.medworm.com/index.php?rid=3195658&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%3D20087576%26dopt%3DAbstract Authors: Rothwell JC, Shadmehr R, Yates B PMID: 20087576 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3195658 Wed, 20 Jan 2010 00:00:00 +0100 3195658 http://www.medworm.com/index.php?rid=3195657&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%3D20087577%26dopt%3DAbstract Authors: Keniston LP, Henderson SC, Meredith MA Multisensory convergence is the first, requisite step in the process that generates neural responses to events involving more than one sensory modality. Although anatomical studies have documented the merging of afferents from different sensory modalities within a given area, they do not provide insight into the architecture of connectivity at the neuronal level that underlies multisensory processing. In fact, few anatomical studies of multisensory convergence at the neuronal level have been conducted. The present study used a combination of tract-tracing, immunocytochemistry, and confocal microscopic techniques to examine the connections related to crossmodal auditory cortical inputs to somatosensory area SIV. Axons labeled from auditory... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3195657 Wed, 20 Jan 2010 00:00:00 +0100 3195657 http://www.medworm.com/index.php?rid=3195656&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%3D20087578%26dopt%3DAbstract Authors: Valic M, Pecotic R, Pavlinac I, Valic Z, Peros K, Dogas Z Exposure to acute intermittent hypoxia (AIH) evokes persistent increase in respiratory activity that lasts up to 60 min after hypoxic episodes have ceased. This persistent increase in phrenic nerve activity (PNA) is known as phrenic long-term facilitation (LTF). AIH-induced phrenic LTF in anesthetized rats is serotonin dependant. The present study was performed to determine whether microinjection of methysergide (4 mM, 20 +/- 5 nl), a broad spectrum 5-HT receptor antagonist, into the caudal raphe nuclei influences phrenic LTF. Peak integrated PNA and respiratory frequency were recorded at 15, 30, and 60 min after five 3-min episodes of normocapnic hypoxia in urethane-anesthetized, vagotomized, paralyzed and ventilated m... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3195656 Wed, 20 Jan 2010 00:00:00 +0100 3195656 http://www.medworm.com/index.php?rid=3195655&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%3D20087579%26dopt%3DAbstract Authors: Näsi T, Kotilahti K, Noponen T, Nissilä I, Lipiäinen L, Meriläinen P The interaction of brain hemodynamics and neuronal activity has been intensively studied in recent years to yield better understanding of brain function. We investigated the relationship between visual-evoked hemodynamic responses (HDRs), measured with near-infrared spectroscopy (NIRS), and neuronal activity in humans, approximated with the stimulus train duration or with visual-evoked potentials (VEPs). Concentration changes of oxyhemoglobin (HbO(2)) and deoxyhemoglobin (HbR) in tissue and VEPs were recorded simultaneously over the occipital lobe of ten healthy subjects to 3, 6, and 12 s pattern-reversing checkerboard stimulus trains having a reversal frequency of 2 Hz. We found that the ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3195655 Wed, 20 Jan 2010 00:00:00 +0100 3195655 http://www.medworm.com/index.php?rid=3179272&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%3D20076951%26dopt%3DAbstract Authors: Patel M, Modig F, Magnusson M, Fransson PA Alcohol intoxication is the cause of many falls requiring emergency care. The control of upright standing balance is complex and comprises contributions from several partly independent mechanisms like coordination, feedback and feedforward control and adaptation. Analysis of the segmental body movement coordination offers one option to detect the severity of balance problems. The study aims were (1) to investigate whether alcohol intoxication at 0.06 and 0.10% blood alcohol concentration (BAC) affected the segmental movement pattern under unperturbed and perturbed standing; (2) whether alcohol affected the ability for movement pattern adaptation; (3) whether one's own subjective feeling of drunkenness correlated to the movement patter... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3179272 Thu, 14 Jan 2010 00:00:00 +0100 3179272 http://www.medworm.com/index.php?rid=3172671&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%3D20069285%26dopt%3DAbstract Authors: Kovacs AJ, Shea CH The purpose of the experiment was to determine the influence of Lissajous feedback on 1:1 bimanual coordination patterns (0 degrees , 90 degrees , and 180 degrees phase lags) when the movement amplitudes of the two limbs were different (30 degrees , 60 degrees ). The present data supports the notion that the lead-lag relationship as well as amplitude assimilation observed in the literature can be partially attributed to the visual-perceptual factors present in the testing environment. When participants are provided integrated feedback in the form of Lissajous plots much of the lead-lag and amplitude assimilation effects were eliminated, and relative phase error and variability were also greatly reduced after only 3 min of practice under each condition. P... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3172671 Wed, 13 Jan 2010 00:00:00 +0100 3172671 http://www.medworm.com/index.php?rid=3172672&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%3D20066404%26dopt%3DAbstract Authors: Dalrymple KA, Bischof WF, Cameron D, Barton JJ, Kingstone A Patients with simultanagnosia, which is a component of Bálint syndrome, have a restricted spatial window of visual attention and cannot see more than one object at a time. As a result, these patients see the world in a piecemeal fashion, seeing the local components of objects or scenes at the expense of the global picture. To directly test the relationship between the restriction of the attentional window in simultanagnosia and patients' difficulty with global-level processing, we used a gaze-contingent display to create a literal restriction of vision for healthy participants while they performed a global/local identification task. Participants in this viewing condition were instructed to identify the global and... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3172672 Tue, 12 Jan 2010 00:00:00 +0100 3172672 http://www.medworm.com/index.php?rid=3164595&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%3D20062982%26dopt%3DAbstract Authors: Lackner JR, Dizio P Individuals exposed to both an increase in magnitude and a rotation of the gravitoinerital acceleration vector experience changes in visual and auditory localization and apparent body orientation. These effects are known as the oculogravic, audiogravic and somatogravic illusions, respectively. In our main experiment, we measured the magnitude, direction, and time course of the audiogravic and oculogravic illusions in recumbent subjects (n = 6) exposed to an increase to 2 g and a simultaneous 60 degrees rotation of the gravitoinertial acceleration (GIA) vector in their azimuthal plane (around their z-axis) in the Brandeis slow rotation room. In separate runs, subjects used a pointer to indicate the apparent azimuthal location of auditory and visual targets a... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3164595 Sat, 09 Jan 2010 00:00:00 +0100 3164595 http://www.medworm.com/index.php?rid=3164596&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%3D20058151%26dopt%3DAbstract This study concerns the process by which agents select control laws. Participants adjusted their walking speed in a virtual environment in order to intercept approaching targets. Successful interception can be achieved with a constant bearing angle (CBA) strategy that relies on prospective information, or with a modified required velocity (MRV) strategy, which also includes predictive information. We manipulated the curvature of the target paths and the display condition of these paths. The curvature manipulation had large effects on the walking kinematics when the target paths were not displayed (informationally poor display). In contrast, the walking kinematics were less affected by the curvature manipulation when the target paths were displayed (informationally rich display). This indic... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3164596 Fri, 08 Jan 2010 00:00:00 +0100 3164596 http://www.medworm.com/index.php?rid=3149400&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%3D20049420%26dopt%3DAbstract Authors: Deller T, Jen JC PMID: 20049420 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3149400 Tue, 05 Jan 2010 00:00:00 +0100 3149400 http://www.medworm.com/index.php?rid=3149399&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%3D20049421%26dopt%3DAbstract Authors: Maclellan MJ, McFadyen BJ Anticipatory locomotor adjustments (ALAs) are used during locomotion to perform tasks, such as obstacle clearance, although not much is known as to how these ALAs are implemented by the central nervous system (CNS). The current study applied the planar law of intersegmental coordination to both leading and trailing limbs in a paradigm in which obstacle height and depth were manipulated to propose how ALAs are controlled. Ten healthy young adults stepped over nine obstacle conditions. Full-body 3D kinematic data were collected and elevation angles of the foot, shank, and thigh in the sagittal plane were calculated. For each limb within each trial, a principal component analysis was applied to limb segment trajectories. As well, a Fourier harmonic serie... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3149399 Tue, 05 Jan 2010 00:00:00 +0100 3149399 http://www.medworm.com/index.php?rid=3143053&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%3D20047089%26dopt%3DAbstract Authors: Klous M, Danna-Dos-Santos A, Latash ML We used the framework of the uncontrolled manifold hypothesis to quantify multi-muscle synergies stabilizing the moment of force about the frontal axis (M (Y)) and the shear force in the anterior-posterior direction (F (X)) during voluntary body sway performed by standing subjects. We tested a hypothesis whether the controller could stabilize both M (Y) and F (X) at the same time when the task and the visual feedback was provided only on one of the variables (M (Y)). Healthy young subjects performed voluntary body sway in the anterior-posterior direction while different loads were attached at the ankle level producing horizontal forces acting forward or backwards. Principal component analysis was used to identify three M-modes within the ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3143053 Tue, 05 Jan 2010 00:00:00 +0100 3143053 http://www.medworm.com/index.php?rid=3143052&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%3D20047090%26dopt%3DAbstract In this study, we compare enumeration of a set of spheres presented to one hand (unimanual) and enumeration of the same total number of spheres presented divided over the two hands (bimanual). Our results show that, like in vision, a combination of subitizing and counting is used to process numbers in active touch. This shows that numbers are processed in a modality-independent way. This suggests that there are not only interactions between perception of numbers and hand motor action, but rather that number representation is modality-independent. PMID: 20047090 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3143052 Tue, 05 Jan 2010 00:00:00 +0100 3143052 http://www.medworm.com/index.php?rid=3143051&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%3D20047091%26dopt%3DAbstract Authors: Planetta PJ, Servos P The motion aftereffect (MAE) refers to the apparent motion of a stationary stimulus following adaptation to a continuously moving stimulus. There is a growing consensus that the fast adapting (FA) rather than the slowly adapting (SA) afferent units mediate the tactile version of the MAE. The present study investigated which FA units underlie the tactile MAE by measuring its prevalence, duration, and vividness on different skin areas that vary in their composition of FA units. Specifically, the right cheek, volar surface of the forearm, and volar surface of the hand were adapted using a ridged cylindrical drum, which rotated at 60 rpm for 120 s. Although there was no difference in duration or vividness between the skin surfaces tested, the tactile MAE was ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3143051 Tue, 05 Jan 2010 00:00:00 +0100 3143051 http://www.medworm.com/index.php?rid=3137789&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%3D20044745%26dopt%3DAbstract Authors: Kamibayashi K, Nakajima T, Fujita M, Takahashi M, Ogawa T, Akai M, Nakazawa K We investigated the modulation of the soleus (Sol) Hoffmann (H-) reflex excitability by peripheral sensory inputs during passive stepping using a robotic-driven gait orthosis in healthy subjects and spinal cord-injured patients. The Sol H-reflex was evoked at standing and at six phases during passive stepping in 40 and 100% body weight unloaded conditions. The Sol H-reflex excitability was significantly inhibited during passive stepping when compared with standing posture at each unloaded condition. During passive stepping, the H-reflex amplitude was significantly smaller in the early- and mid-swing phases than in the stance phase, which was similar to the modulation pattern previously reported for n... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3137789 Fri, 01 Jan 2010 00:00:00 +0100 3137789 http://www.medworm.com/index.php?rid=3137788&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%3D20044746%26dopt%3DAbstract In conclusion, vision of the body can significantly and persistently affect the internal model of the body used for motor programming. PMID: 20044746 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3137788 Fri, 01 Jan 2010 00:00:00 +0100 3137788 http://www.medworm.com/index.php?rid=3135937&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%3D20043148%26dopt%3DAbstract Authors: Gorniak SL, Zatsiorsky VM, Latash ML We investigated strategies of adjustments in kinetic and kinematic patterns, and in multi-digit synergies during quick vertical transport of an instrumented handle that collapsed when the grasping force exceeded a certain magnitude (quantified with a fragility index). The collapse threshold of the object was set using a novel electromagnetic device. Moving a fragile object is viewed as a task with two constraints on the grip force defined by the slipping and crushing thresholds. When moving more fragile objects, subjects decreased object peak acceleration, increased movement time, showed a drop in the safety margin (SM) (extra force over the slipping threshold), and showed a tendency toward violating the minimum-jerk criterion. Linear regre... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3135937 Thu, 31 Dec 2009 00:00:00 +0100 3135937 http://www.medworm.com/index.php?rid=3135942&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%3D20041233%26dopt%3DAbstract Authors: Gredebäck G, Kochukhova O Eighteen- and 25-month-old human toddlers' ability to manually solve a puzzle and their ability to anticipate the goal during observation of similar actions were investigated. Results demonstrate that goal anticipation during action observation is dependent on manual ability, both on a group level (only 25-month-olds solved the manual task and anticipated the goal during observation) and individually within the older age group (r ( xy ) = 0.53). These findings suggests a connection between manual ability and the ability to anticipate the goal of others' actions in toddlers, in accordance with the direct matching hypothesis. PMID: 20041233 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3135942 Wed, 30 Dec 2009 00:00:00 +0100 3135942 http://www.medworm.com/index.php?rid=3135941&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%3D20041234%26dopt%3DAbstract We examined the role that these eye movements may play in generating visual illusions of self motion (or vection). Observers viewed radially expanding optic-flow displays while performing lateral translational head oscillations at 1 Hz. Simulated viewpoint changes in these displays were synchronized with head movements, either in an ipsilateral (minimal sensory conflict) or a contralateral (high sensory conflict) direction. In control conditions, the observer viewed purely radial displays. Vection-onset latency and overall vection strength ratings were recorded, as well as horizontal eye movements. Vection onsets and strength ratings were significantly greater when the observer's head movements were incorporated into the visual displays. However, vection strength ratings were very similar ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3135941 Wed, 30 Dec 2009 00:00:00 +0100 3135941 http://www.medworm.com/index.php?rid=3135940&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%3D20041235%26dopt%3DAbstract Authors: Shirai N, Imura T, Hattori Y, Adachi I, Ichihara S, Kanazawa S, Yamaguchi MK, Tomonaga M Visual radial expansion/contraction motion provides important visual information that is used to control several adaptive actions. We investigated radial motion perception in infant Japanese macaque monkeys using an experimental procedure previously developed for human infants. We found that the infant monkeys' visual preference for the radial expansion pattern was greater than that for the radial contraction pattern. This trend towards an "expansion bias" is similar to that observed in human infants. These results suggest that asymmetrical radial motion processing is a basic visual function common to primates, and that it emerges early in life. PMID: 20041235 [PubMed - as supplied by ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3135940 Wed, 30 Dec 2009 00:00:00 +0100 3135940 http://www.medworm.com/index.php?rid=3135939&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%3D20041236%26dopt%3DAbstract Authors: James C, Stathis A, Macefield VG We have previously shown that sinusoidal galvanic vestibular stimulation (sGVS), a means of a selectively modulating vestibular afferent input without affecting other inputs, can cause partial entrainment of muscle sympathetic nerve activity (MSNA). Given that motion sickness causes sweating and pallor, we tested the hypothesis that sGVS also entrains skin sympathetic nerve activity (SSNA), but that the optimal frequencies are closer to those associated with slow postural changes (0.2 Hz). SSNA was recorded via tungsten microelectrodes inserted into the common peroneal nerve in 11 awake-seated subjects. Bipolar binaural sinusoidal GVS (+/-2 mA, 200 cycles) was applied to the mastoid processes at frequencies of 0.2, 0.5, 0.8, 1.1, 1.4, 1.7 and 2... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3135939 Wed, 30 Dec 2009 00:00:00 +0100 3135939 http://www.medworm.com/index.php?rid=3135938&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%3D20041237%26dopt%3DAbstract Authors: Overvliet KE, Smeets JB, Brenner E In most haptic search tasks, tactile stimuli are presented to the fingers of both hands. In such tasks, the search pattern for some object features, such as the shape of raised line symbols, has been found to be serial. The question is whether this search is serial over all fingers irrespective of the hand, or whether it is serial over the fingers of each hand and parallel over the two hands. To investigate this issue, we determined the speed of static haptic search when two items are presented to two fingers of the same hand and when two items are presented to two fingers of different hands. We compared the results with predictions for parallel and serial search based on the results of a previous study using the same items and a similar task... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3135938 Wed, 30 Dec 2009 00:00:00 +0100 3135938 http://www.medworm.com/index.php?rid=3130219&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%3D20039023%26dopt%3DAbstract Authors: Slobounov SM, Zhang K, Pennell D, Ray W, Johnson B, Sebastianelli W Memory problems are one of the most common symptoms of sport-related mild traumatic brain injury (MTBI), known as concussion. Surprisingly, little research has examined spatial memory in concussed athletes given its importance in athletic environments. Here, we combine functional magnetic resonance imaging (fMRI) with a virtual reality (VR) paradigm designed to investigate the possibility of residual functional deficits in recently concussed but asymptomatic individuals. Specifically, we report performance of spatial memory navigation tasks in a VR environment and fMRI data in 15 athletes suffering from MTBI and 15 neurologically normal, athletically active age matched controls. No differences in performance w... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3130219 Tue, 29 Dec 2009 00:00:00 +0100 3130219 http://www.medworm.com/index.php?rid=3130218&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%3D20039024%26dopt%3DAbstract Authors: Benguigui N, Bennett SJ The present study examined for the first time both the ocular and manual responses in a prediction motion (PM) task requiring participants to estimate time-to-contact (TTC) of an accelerating object. Results showed that while the ocular response initially matched well the object motion, smooth pursuit decayed towards zero following object occlusion, during which participants exhibited a saccadic response that placed the eyes in the region of the point of contact. The primary saccade was completed in advance of the object reaching the point of contact, and was best predicted by a first-order estimate of TTC (TTC1). Participants then made their manual response, which was also best predicted by TTC1. Therefore, object acceleration was not taken into accoun... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3130218 Tue, 29 Dec 2009 00:00:00 +0100 3130218 http://www.medworm.com/index.php?rid=3130217&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%3D20039025%26dopt%3DAbstract Authors: Wing AM, Doumas M, Welchman AE The ability to synchronise actions with environmental events is a fundamental skill supporting a variety of group activities. In such situations, multiple sensory cues are usually available for synchronisation, yet previous studies have suggested that auditory cues dominate those from other modalities. We examine the control of rhythmic action on the basis of auditory and haptic cues and show that performance is sensitive to both sources of information for synchronisation. Participants were required to tap the dominant hand index finger in synchrony with a metronome defined by periodic auditory tones, imposed movements of the non-dominant index finger, or both cues together. Synchronisation was least variable with the bimodal metronome as predict... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3130217 Tue, 29 Dec 2009 00:00:00 +0100 3130217 http://www.medworm.com/index.php?rid=3130216&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%3D20039026%26dopt%3DAbstract The objective of this study was to determine the importance of every frequency component on total physiological tremor (PT) amplitude. We suspect that since high frequencies of PT are of lower amplitude in displacement, removing them will have little to no impact on PT amplitude. PT of the index finger was measured with a laser displacement sensor while the finger was held horizontally. Amplitude of tremor was calculated in displacement, velocity and acceleration. PT amplitude was also calculated within five frequency bands. Although displacement amplitude of oscillations within the 7.5-12.5 and 16.5-30 Hz frequency bands represent 24 and 10% of total PT oscillation amplitude, respectively, their removal reduced PT amplitude by less than 3%. Conversely, the removal of the oscillations with... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3130216 Tue, 29 Dec 2009 00:00:00 +0100 3130216 http://www.medworm.com/index.php?rid=3130215&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%3D20039027%26dopt%3DAbstract This study characterizes the angular and linear motion-sensitive response properties of PBN unit responses during off-vertical axis rotation (OVAR) and position trapezoid stimulation. The OVAR responses displayed a constant firing component which varied from the firing rate at rest. Nearly two-thirds of the units also modulated their discharges with respect to head orientation (re: gravity) during constant velocity OVAR stimulation. The modulated response magnitudes were equal during ipsilateral and contralateral OVARs, indicative of a one-dimensional accelerometer. These response orientations during OVAR divided the units into three spatially tuned populations, with peak modulation responses centered in the ipsilateral ear down, contralateral anterior semicircular canal down, and occiput ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3130215 Tue, 29 Dec 2009 00:00:00 +0100 3130215 http://www.medworm.com/index.php?rid=3130214&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%3D20039028%26dopt%3DAbstract Authors: Cowie D, Atkinson J, Braddick O Stepping down at a change of height is a fundamental part of human locomotion. At a novel step, this requires the transformation of visual information about a depth change into a stepping movement of appropriate size. However, little is known about this process or its development. We studied adults, 3- and 4-year-old children stepping down a single stair of variable height. We assessed how well stepping down was scaled to stair height using several kinematic measures. Of these, 'kneedrop' and 'toedrop' describe how far the leg has descended by the time it begins to 'swing in' in preparation for landing; and 'toeheight (speedpeak)' describes where the toe begins to decelerate. If visually controlled, their values should scale to the height of the... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3130214 Tue, 29 Dec 2009 00:00:00 +0100 3130214 http://www.medworm.com/index.php?rid=3130213&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%3D20039029%26dopt%3DAbstract Authors: Kammers MP, Kootker JA, Hogendoorn H, Dijkerman HC At present there is a debate on the number of body representations in the brain. The most commonly used dichotomy is based on the body image, thought to underlie perception and proven to be susceptible to bodily illusions, versus the body schema, hypothesized to guide actions and so far proven to be robust against bodily illusions. In this rubber hand illusion study we investigated the susceptibility of the body schema by manipulating the amount of stimulation on the rubber hand and the participant's hand, adjusting the postural configuration of the hand, and investigating a grasping rather than a pointing response. Observed results showed for the first time altered grasping responses as a consequence of the grip aperture of t... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3130213 Tue, 29 Dec 2009 00:00:00 +0100 3130213 http://www.medworm.com/index.php?rid=3122804&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%3D20035320%26dopt%3DAbstract Authors: Goodale MA, Lacquaniti F, Marzi CA PMID: 20035320 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3122804 Fri, 25 Dec 2009 00:00:00 +0100 3122804 http://www.medworm.com/index.php?rid=3122803&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%3D20035321%26dopt%3DAbstract We examined postural responses in lower limb muscles of nine human subjects. Baseline measures were obtained when subjects executed reaching movements to a target placed in front of them (R condition) and during postural responses to forward and backward support-surface perturbations (no reaching, P condition) during quiet stance. Perturbations were also given at different delays after the onset of reaching movements (RP conditions) as well as with the arm extended in the direction of the target, but not reaching (P/AE condition). Results showed that during perturbations to reaching (RP), the initial automatic postural response, occurring around 100 ms after the onset of perturbations, was relatively unchanged in latency or amplitude compared to control conditions (P and P/AE). However, lo... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3122803 Fri, 25 Dec 2009 00:00:00 +0100 3122803 http://www.medworm.com/index.php?rid=3122802&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%3D20035322%26dopt%3DAbstract This study consisted of two randomized sessions with an interval of 1 week in between each session. In one session, pressure pain threshold (PPT) and pressure threshold for eliciting referred pain (PTRP) were measured at an MTrP region in the brachioradialis muscle in one forearm. In another session, PPT was measured at a non-MTrP region in the brachioradialis muscle of the contralateral forearm at the time of pre-compression, 20 min following compression, and 10 min after decompression. The results showed that ICB, which mainly blocks large-diameter myelinated muscle afferents, was associated with an increase in PPT and PTRP (all P < 0.001) at MTrP regions but not at non-MTrP regions. These results suggest that large-diameter muscle afferents may be involved in pain and mechanical hype... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3122802 Fri, 25 Dec 2009 00:00:00 +0100 3122802 http://www.medworm.com/index.php?rid=3122801&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%3D20035323%26dopt%3DAbstract Authors: Pinsault N, Vuillerme N The purpose of this study was to investigate whether vestibular and neck somatosensory weighting could change in conditions of trunk extensor muscle fatigue during quiet standing. To achieve this goal, 20 young healthy adults were asked to stand as still as possible in two conditions of No fatigue and Fatigue of trunk extensor muscles. In Experiment 1 (n = 10), the postural task was executed in two head conditions: Neutral and Head tilted backwards, recognised to degrade vestibular and neck somatosensory information. In Experiment 2 (n = 10), the postural task was executed in two stimulation conditions: No tactile stimulation and Tactile stimulation of the neck provided by the application of strips of adhesive bandage to the skin over and around the nec... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3122801 Fri, 25 Dec 2009 00:00:00 +0100 3122801 http://www.medworm.com/index.php?rid=3122800&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%3D20035324%26dopt%3DAbstract Authors: Nishimura Y, Sugisaki K, Hattori N, Inokuchi Y, Komachi M, Nishimura Y, Ogawa M, Okada M, Okazaki Y, Taki W, Yamamoto T, Yoshida E, Ayano S Japanese is a free word-order language, and allows both subject-object-verb (SOV) and object-subject-verb (OSV) orders. Our previous study using near-infrared spectroscopy (NIRS) imaging revealed that OSV sentences induce more activation in the left frontal lobe than SOV sentences. The present study develops our previous experiment: (1) by adopting an event-related design, and (2) by using sentences involving the adverb naze 'why', which plays a prominent role in recent linguistic studies. The results of our new experiment indicated that the cerebral activation in OwhySV sentences was significantly larger than that in SwhyOV sentences, in ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3122800 Fri, 25 Dec 2009 00:00:00 +0100 3122800 http://www.medworm.com/index.php?rid=3120656&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%3D20033680%26dopt%3DAbstract Authors: Poston B, Christou EA, Enoka JA, Enoka RM The purpose of the study was to determine the contributions of endpoint variance and trajectory variability to the endpoint accuracy of goal-directed isometric contractions when the target force and contraction speed were varied. Thirteen young adults (25 +/- 6 years) performed blocks of 15 trials at each of 2 contraction speeds and 4 target forces. Subjects were instructed to match the peak of a parabolic force trajectory to a target force by controlling the abduction force exerted by the index finger. The time to peak force was either 150 ms (fast) or 1 s (slow). The target forces were 20, 40, 60, and 80% of the maximal force that could be achieved in 150 ms during an MVC. The same absolute forces were required for both contraction s... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3120656 Thu, 24 Dec 2009 00:00:00 +0100 3120656 http://www.medworm.com/index.php?rid=3120657&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%3D20033397%26dopt%3DAbstract Authors: Latash ML, Friedman J, Kim SW, Feldman AG, Zatsiorsky VM We used the framework of the equilibrium-point hypothesis (in its updated form based on the notion of referent configuration) to investigate the multi-digit synergies at two levels of a hypothetical hierarchy involved in prehensile actions. Synergies were analyzed at the thumb-virtual finger (VF) level (VF is an imaginary digit with the mechanical action equivalent to that of the four actual fingers) and at the individual finger level. The subjects performed very quick vertical movements of a handle into a target. A load could be attached off-center to provide a pronation or supination torque. In a few trials, the handle was unexpectedly fixed to the table and the digits slipped off the sensors. In such trials, the hand ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3120657 Wed, 23 Dec 2009 00:00:00 +0100 3120657 http://www.medworm.com/index.php?rid=3115538&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%3D20024650%26dopt%3DAbstract Authors: Allison RS, Schumacher J, Sadr S, Herpers R Sensitivity to many visual stimuli, and, in particular, image displacement, is reduced during a change in fixation (saccade) compared to when the eye is still. In these experiments, we studied the sensitivity of observers to ecologically relevant image translations of large, complex, real world scenes either during horizontal saccades or during fixation. In the first experiment, we found that such displacements were much less detectable during saccades than during fixation. Qualitatively, even when trans-saccadic scene changes were detectible, they were less salient and appeared slower than equivalent changes in the absence of a saccade. Two further experiments followed up on this observation and estimated the perceived magnitude of ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3115538 Sat, 19 Dec 2009 00:00:00 +0100 3115538 http://www.medworm.com/index.php?rid=3115537&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%3D20024651%26dopt%3DAbstract We report data in line with the use of an allocentric reference frame and discuss its relevance depending on available gravity-related cues. PMID: 20024651 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3115537 Sat, 19 Dec 2009 00:00:00 +0100 3115537 http://www.medworm.com/index.php?rid=3105672&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%3D20020113%26dopt%3DAbstract Authors: Yokoi I, Komatsu H Previous studies have shown that neurons in layer 6 of V1 are activated by visual stimuli that induce perceptual filling-in at the blind spot (BS). As the main target of layer 6 neurons is the lateral geniculate nucleus (LGN), we speculate that the cortico-geniculate projection is involved in mediating filling-in at BS. To begin to test that hypothesis, we examined whether there is an anatomical basis for integration of visual signals from both sides of BS by cortico-geniculate feedback neurons in V1. We injected an anterograde tracer into a site adjacent to the region representing BS. We observed that numerous axons traverse the neuron-free gap that retinotopically corresponds to BS within LGN. This indicates that visual signals from one side of BS are conv... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3105672 Fri, 18 Dec 2009 00:00:00 +0100 3105672 http://www.medworm.com/index.php?rid=3105671&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%3D20020114%26dopt%3DAbstract We examined PD patients' ability for sequence-unselective learning through the use of a 2 x 8 button-press task. In the first session, PD patients and subjects from the control group performed a sequential 2 x 8 task until the learning criterion was fulfilled (Session 1). After 1 month, they participated in other sessions: one involving the learned sequence (Session 2) and another involving the new sequence (Session 3). We found that PD patients made more errors than the normal control subjects only when learning the new sequence (Session 3) (P < 0.01). In Session 3, control subjects reached the learning target with fewer errors than in the Session 1 (normal sequence-unselective learning), whereas the PD patients did not exhibit such an improvement. Our results revealed a sequence-unsel... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3105671 Fri, 18 Dec 2009 00:00:00 +0100 3105671 http://www.medworm.com/index.php?rid=3067741&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%3D19967389%26dopt%3DAbstract Authors: Nadig KG, Jäncke L, Lüchinger R, Lutz K It has been shown that frontal cortical areas increase their activity during error perception and error processing. However, it is not yet clear whether perception of motor errors is processed in the same frontal areas as perception of errors in cognitive tasks. It is also unclear whether brain activity level is influenced by the magnitude of error. For this purpose, we conducted a study in which subjects were confronted with motor and non-motor errors, and had them perform a sensorimotor transformation task in which they were likely to commit motor errors of different magnitudes (internal errors). In addition to the internally committed motor errors, non-motor errors (external errors) were added to the feedback in some trials.... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3067741 Sun, 06 Dec 2009 00:00:00 +0100 3067741 http://www.medworm.com/index.php?rid=3067740&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%3D19967390%26dopt%3DAbstract We report contrasting effects of mirror box therapy, as well as a new treatment-prism adaptation therapy-that provided sustained pain relief and reduced disability. The benefits were contingent upon adapting with the affected limb. Other novel observations suggest that: (1) pain may be a consequence, not the cause, of a disturbance of body representation that gives rise to the syndrome; (2) immobilisation, not pain, may precipitate this reorganisation of somatomotor circuits in susceptible individuals; and (3) limitation of voluntary movement is neither due to pain nor to weakness but, rather, to derangement of body representation which renders certain postures from the repertoire of hand movements inaccessible. PMID: 19967390 [PubMed - as supplied by publisher] (Source: Experimental B... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3067740 Sun, 06 Dec 2009 00:00:00 +0100 3067740 http://www.medworm.com/index.php?rid=3067739&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%3D19967391%26dopt%3DAbstract Authors: Monaco S, Króliczak G, Quinlan DJ, Fattori P, Galletti C, Goodale MA, Culham JC Ren et al. (J Neurophysiol 96:1464-1477, 2006) found that saccades to visual targets became less accurate when somatosensory information about hand location was added, suggesting that saccades rely mainly on vision. We conducted two kinematic experiments to examine whether or not reaching movements would also show such strong reliance on vision. In Experiment 1, subjects used their dominant right hand to perform reaches, with or without a delay, to an external visual target or to their own left fingertip positioned either by the experimenter or by the participant. Unlike saccades, reaches became more accurate and precise when proprioceptive information was available. In Experiment 2, subjects ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3067739 Sun, 06 Dec 2009 00:00:00 +0100 3067739 http://www.medworm.com/index.php?rid=3067743&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%3D19967340%26dopt%3DAbstract Authors: Martin BC, Henriques DY The influence of a secondary task on speeded responses, and its effect on the outcome of more complex tasks has been studied in detail. However, the consequence of task interference on specific movement parameters other than speed and accuracy has been largely ignored. The current study examines how performing a secondary task impacts the drawing of an unseen shape. Without vision of the hand, 15 subjects traced a shape on a graphics tablet. The shape and cursor were projected onto a screen. The shape disappeared and the subject attempted to draw three consecutive identical shapes. In the visual single-task condition, hand positions were represented by a cursor, but the resultant drawings could not be seen; in another, there was no visual feedback. In f... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3067743 Sat, 05 Dec 2009 00:00:00 +0100 3067743 http://www.medworm.com/index.php?rid=3067742&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%3D19967341%26dopt%3DAbstract Authors: Lavoie BA, Barks A, Thornton AR A maximum length sequence (MLS) is a quasi-random sequence of clicks and silences that enables simultaneous recording of linear components and nonlinear temporal interaction components (NLTICs). NLTICs are produced when the stimulation rate is fast enough such that several stimuli occur within the memory length of the system. The present study was designed to characterise the NLTICs of auditory mid-latency responses (MLR). Forty normally hearing subjects (19-45-year-old) were tested at MLS rates between 20 and 120 clicks/s. Linear components could be identified at all rates. The NLTICs of the MLS-MLR were identified in only a few subjects. This suggests two possibilities: (1) there may not be strong nonlinear temporal interactions within the MLR... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3067742 Sat, 05 Dec 2009 00:00:00 +0100 3067742 http://www.medworm.com/index.php?rid=3057472&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%3D19956934%26dopt%3DAbstract This study investigated the ability to predict others' action in a group of children and adolescents with autism spectrum disorders (ASD) (n = 18). Their performance was compared with a group of children with mental retardation (n = 13) and a group of children with typical development (n = 19). Participants were presented with short incomplete videotaped movies showing an actor executing familiar and non-familiar actions. When asked to predict the outcome, participants with ASD produced fewer correct responses and their performance did not improve for familiar actions, as compared to both comparison groups. In addition, they committed a greater number of errors of temporal inversion. These results provide new evidence that an impaired means-end analysis process, leading to a diminished sen... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3057472 Thu, 03 Dec 2009 00:00:00 +0100 3057472 http://www.medworm.com/index.php?rid=3049327&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%3D19953229%26dopt%3DAbstract Authors: Mason AH, Bruyn JL, Lazarus JA An experiment was designed to investigate the temporal and spatial couplings of the transport and grasp components for bimanual movements performed by children. Thirty-one participants aged 4-6 (younger) and 7-10 (older) performed the unimanual task of reaching for, grasping, and lifting a small or large cylinder with the right or left hands or the bimanual task of reaching for, grasping and lifting two small cylinders, two large cylinders, or one small and one large cylinder with the right and left hands. Kinematic measures, relative timing differences between the hands, spatial plots and cluster analysis were used to quantify both temporal and spatial couplings of the limbs. While average kinematic results indicated that children in the 4-6 and... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3049327 Wed, 02 Dec 2009 00:00:00 +0100 3049327 http://www.medworm.com/index.php?rid=3049326&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%3D19953230%26dopt%3DAbstract Authors: Reuschel J, Drewing K, Henriques DY, Rösler F, Fiehler K Many studies demonstrated a higher accuracy in perception and action when using more than one sense. The maximum-likelihood estimation (MLE) model offers a recent approach on how perceptual information is integrated across different sensory modalities suggesting statistically optimal integration. The purpose of the present study was to investigate how visual and proprioceptive movement information is integrated for the perception of trajectory geometry. To test this, participants sat in front of an apparatus that moved a handle along a horizontal plane. Participants had to decide whether two consecutive trajectories formed an acute or an obtuse movement path. Judgments had to be based on information from a single mo... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3049326 Wed, 02 Dec 2009 00:00:00 +0100 3049326 http://www.medworm.com/index.php?rid=3049333&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%3D19949776%26dopt%3DAbstract Authors: Tijtgat P, Bennett SJ, Savelsbergh GJ, De Clercq D, Lenoir M The purpose of this experiment was to examine the effects of advance knowledge on the kinematics of one-handed catching. Balls were launched from a distance of 8.4 m by a ball-projection machine with adjustable launching speed. Fifteen skilled ball catchers caught 160 balls with their preferred hand under blocked-order (4 blocks, each comprising 20 trials at 1 of 4 different ball speeds) or random-order (4 blocks, each comprising 20 trials of 4 different ball speeds) conditions. By projecting balls with different ball speeds from a fixed position, it was possible to modify the temporal constraints of the catching task. In both the blocked-order and random-order conditions, catching performance (number of catches, tou... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3049333 Tue, 01 Dec 2009 00:00:00 +0100 3049333 http://www.medworm.com/index.php?rid=3049332&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%3D19949777%26dopt%3DAbstract Authors: Pettypiece CE, Goodale MA, Culham JC We investigated the contribution of haptic and visual information about object size to both perception and action. Kinematics of the right hand were measured while participants performed grasping actions or manual estimations under the guidance of haptic information from the left hand, binocular visual information, or both haptics and vision. The greatest uncertainty was observed with haptic information alone. Moreover, when visual and haptic sizes were congruent, performance was no different from that with vision alone. Although this gives the appearance that vision dominates, when information from the two senses was incongruent, an influence of haptic cues emerged for both tasks. Our paradigm also allowed us to demonstrate that haptic sen... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3049332 Tue, 01 Dec 2009 00:00:00 +0100 3049332 http://www.medworm.com/index.php?rid=3049331&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%3D19949778%26dopt%3DAbstract Authors: Bo J, Seidler RD In three experiments, we examined the effects of age and spatial processing on implicit sequence learning. In experiment 1, 48 older adults (OA) and 48 young adults (YA) performed the alternating serial reaction time task (ASRT) under one of four conditions in which spatial processing demands were either present or absent from stimulus presentation (spatial vs. symbolic cueing) and/or response execution (spatial manual vs. vocal responses). Surprisingly, OA exhibited more learning than YA in the two vocal response conditions. In two follow-up experiments, we increased the response selection demands of the sequence learning task by asking new groups of YA and OA participants to make word categorization responses with 1:1 stimulus-response mapping (experiment 2)... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3049331 Tue, 01 Dec 2009 00:00:00 +0100 3049331 http://www.medworm.com/index.php?rid=3049330&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%3D19949779%26dopt%3DAbstract Discussion focuses on the role of calibration and the implications of the present findings for existing models of visually guided interception. PMID: 19949779 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3049330 Tue, 01 Dec 2009 00:00:00 +0100 3049330 http://www.medworm.com/index.php?rid=3049329&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%3D19949780%26dopt%3DAbstract This study aimed to address this question. Twenty patients with hemiparesis after ischemic stroke in the middle cerebral artery territory (11 with a right and 9 with a left hemispheric lesion) were investigated. All subjects were trained using two different tasks during ten training sessions. In both tasks, the subjects stood on a force platform and were taught to change the position of the center of pressure (COP) presented as a cursor on a monitor screen in front of the patient. The subjects were instructed to align the COP with the target and then move the target by shifting the COP in the indicated direction. In the "Balls" task, the position of the target (a ball) varied randomly, so the subject had to learn a general strategy of voluntary COP control. In "Bricks", the subject always ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3049329 Tue, 01 Dec 2009 00:00:00 +0100 3049329 http://www.medworm.com/index.php?rid=3049328&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%3D19949781%26dopt%3DAbstract This study aimed at determining if and how arm movements play a functional role in balance recovery after a perturbation. We tripped young subjects using an obstacle that suddenly appeared from the floor at exactly mid-swing. We measured arm muscle EMG, quantified body rotations after tripping, and established the effects of arm movements by calculating how the body would have rotated without arms. Strong asymmetric shoulder muscle responses were observed within 100 ms after trip initiation. Significantly faster and larger responses were found in the contralateral arm abductors on the non-tripped (right) side. Mean amplitudes were larger in the ipsilateral retroflexors and contralateral anteflexors. The resulting asymmetric arm movements had a small effect on body rotation in the sagittal ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3049328 Tue, 01 Dec 2009 00:00:00 +0100 3049328 http://www.medworm.com/index.php?rid=3041835&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%3D19946771%26dopt%3DAbstract Authors: Hermens F, Zanker JM, Walker R When we fixate an object, our eyes are not entirely still, but undergo small displacements such as microsaccades. Here, we investigate whether these microsaccades are sensitive to the preparatory processes involved in programming a saccade. We show that the frequency of microsaccades depends in a specific manner on the intention where to move the eyes (towards a target location or away from it), when to move (immediately after the onset of the target or after a delay), and what type of cue is followed (a peripheral onset or a centrally presented symbolic cue). In particular, in the preparatory interval before and early after target onset, more microsaccades were found when a delayed saccade towards a peripheral target was prepared than when a sac... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3041835 Sat, 28 Nov 2009 00:00:00 +0100 3041835 http://www.medworm.com/index.php?rid=3037146&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%3D19943037%26dopt%3DAbstract Authors: Barlind A, Karlsson N, Björk-Eriksson T, Isgaard J, Blomgren K Radiation therapy is used to treat malignant tumors in the brain and central nervous system involvement of leukemia and lymphomas in children. However, ionizing radiation causes a number of adverse long-term side effects in the brain, including cognitive impairment. Hippocampal neurogenesis is important for place learning and has been shown to be decreased by irradiation (IR) in rats and mice. In the present study, 10-day-old male mice received 6-Gy IR to the brain on postnatal day 10. We used BrdU labeling of the granule cell layer (GCL) of the hippocampus to evaluate cell proliferation and survival. An unbiased, automated platform for monitoring of behavior in a group housing environment (IntelliCage) was us... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3037146 Fri, 27 Nov 2009 00:00:00 +0100 3037146 http://www.medworm.com/index.php?rid=3037145&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%3D19943038%26dopt%3DAbstract We examined the responses of this body observation network to static images of ordinary and contorted postures by using a repetition suppression design in functional neuroimaging. Participants were scanned whilst observing static images of a contortionist or a group of objects in either ordinary or unusual configurations, presented from different viewpoints. Greater activity emerged in EBA and FBA when participants viewed contorted compared to ordinary body postures. Repeated presentation of the same posture from different viewpoints lead to suppressed responses in the fusiform gyrus as well as three regions that are characteristically activated by observing moving bodies, namely STS, IFG and IPL. These four regions did not distinguish the image viewpoint or the plausibility of the posture... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3037145 Fri, 27 Nov 2009 00:00:00 +0100 3037145 http://www.medworm.com/index.php?rid=3037144&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%3D19943039%26dopt%3DAbstract Authors: Ehrlenspiel F, Wei K, Sternad D According to explicit monitoring theories, the phenomenon of choking under pressure is due to actors focusing their attention on the execution of the skill. This step-by-step perceptually guided control may then interfere with automatic execution. In order to examine the changes in control at the sensorimotor level, we examined the rhythmic task of ball bouncing which affords detailed quantification of indicators of control based on previous research. The hypothesis was that under psychological pressure perceptually guided control should lead to decreased performance due to over-emphasis on closed-loop control and decreased compensatory control. In two experiments of different difficulty psychological stress was induced via setting up a fake com... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3037144 Fri, 27 Nov 2009 00:00:00 +0100 3037144 http://www.medworm.com/index.php?rid=3037143&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%3D19943040%26dopt%3DAbstract Authors: Doesburg SM, Herdman AT, Ribary U, Cheung T, Moiseev A, Weinberg H, Liotti M, Weeks D, Grunau RE Local alpha-band synchronization has been associated with both cortical idling and active inhibition. Recent evidence, however, suggests that long-range alpha synchronization increases functional coupling between cortical regions. We demonstrate increased long-range alpha and beta band phase synchronization during short-term memory retention in children 6-10 years of age. Furthermore, whereas alpha-band synchronization between posterior cortex and other regions is increased during retention, local alpha-band synchronization over posterior cortex is reduced. This constitutes a functional dissociation for alpha synchronization across local and long-range cortical scales. We interpret... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3037143 Fri, 27 Nov 2009 00:00:00 +0100 3037143 http://www.medworm.com/index.php?rid=3034134&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%3D19940982%26dopt%3DAbstract Authors: Hickey C, van Zoest W, Theeuwes J Studies of eye-movements and manual response have established that rapid overt selection is largely exogenously driven toward salient stimuli, whereas slower selection is largely endogenously driven to relevant objects. We use the N2pc, an event-related potential index of covert attention, to demonstrate that this time course reflects an underlying pattern in the deployment of covert attention. We find that shifts of attention that occur soon after the onset of a visual search array are directed toward salient, task-irrelevant visual stimuli and are associated with slow responses to the target. In contrast, slower shifts are target-directed and are associated with fast responses. The time course of exogenous and endogenous control provides a f... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3034134 Thu, 26 Nov 2009 00:00:00 +0100 3034134 http://www.medworm.com/index.php?rid=3034133&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%3D19940983%26dopt%3DAbstract We examined the important question of whether this feedback is excitatory or inhibitory. Biotinylated dextran amine (BDA) was injected into the cMRF of M. fascicularis monkeys to anterogradely label reticulotectal terminals and retrogradely label tectoreticular neurons. BDA labeled profiles in the ipsi- and contralateral intermediate gray layer (SGI) were examined electron microscopically. Postembedding GABA immunochemistry was used to identify putative inhibitory profiles. Nearly all (94.7%) of the ipsilateral BDA labeled terminals were GABA positive, but profiles postsynaptic to these labeled terminals were exclusively GABA negative. In addition, BDA labeled terminals were observed to contact BDA labeled dendrites, indicating the presence of a monosynaptic feedback loop connecting the cM... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3034133 Thu, 26 Nov 2009 00:00:00 +0100 3034133 http://www.medworm.com/index.php?rid=3034132&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%3D19940984%26dopt%3DAbstract Authors: Meskers CG, Schouten AC, Rich MM, de Groot JH, Schuurmans J, Arendzen JH The long latency M2 electromyographic response of a suddenly stretched active muscle is stretch duration dependent of which the nature is unclear. We investigated the influence of the group II afferent blocker tizanidine on M2 response characteristics of the m. flexor carpi radialis (FCR). M2 response magnitude and eliciting probability in a group of subjects receiving 4 mg of tizanidine orally were found to be significantly depressed by tizanidine while tizanidine did not affect the significant linear relation of the M2 response to stretch duration. The effect of tizanidine on the M2 response of FCR is supportive of a group II afferent contribution to a compound response of which the stretch duration dep... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3034132 Thu, 26 Nov 2009 00:00:00 +0100 3034132 http://www.medworm.com/index.php?rid=3034135&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%3D19937320%26dopt%3DAbstract Authors: Ocampo B, Kritikos A It has been argued that through a process of internal 'simulation', we automatically map observed actions directly onto our motor system to facilitate imitation. Instead, here we show that observed actions influence the kinematic parameters of manual responses in a dynamic, context-dependent fashion. Participants observed object-directed hand actions in imitative and complementary action contexts, and performed identical (same grip-type) and non-identical (opposite grip-type) responses to a similar object, respectively. In imitative contexts, identical actions were performed optimally. In complementary contexts, however, non-identical actions were enhanced relative to identical actions. A further experiment using arrow cues instead of hand actions confirme... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3034135 Wed, 25 Nov 2009 00:00:00 +0100 3034135 http://www.medworm.com/index.php?rid=3034138&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%3D19937230%26dopt%3DAbstract Authors: Parkinson J, Dyson BJ, Khurana B The perception of written letters reflects the action sequences that produce them. Faster recognition is observed for letters presented as sequences of strokes in a temporal order consistent with letter writing, compared to an inconsistent order. During a speeded letter identification task, parietal event-related potential (ERP) components were analysed separately for each stroke-frame in action-consistent and inconsistent stimulus sequences, during both passive and active (task-engaged) viewing. Electrophysiological data provided unique insights into stroke order priming by comparing local neural organisation during early, response-independent stages with later response-dependent stages. ERPs over posterior scalp areas revealed speeded visual ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3034138 Tue, 24 Nov 2009 00:00:00 +0100 3034138 http://www.medworm.com/index.php?rid=3034137&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%3D19937231%26dopt%3DAbstract Authors: Hesse C, Deubel H It has been observed that grip opening is delayed when participants are asked to execute complex grasping movements, such as passing over an obstacle or a via-position (Haggard and Wing 1998; Alberts et al. 2002). This finding was proposed to indicate a shift toward sequential performance, meaning that complex movements are carried out in independent motor steps. In our experiments we investigated which aspects of a grasping task determine whether a movement is executed holistically or sequentially. Therefore, participants had to perform different types of curved movements in order to reach and grasp a target object. When only the complexity of the transport paths was varied, no indication of sequential movement execution was found. However, when participants... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3034137 Tue, 24 Nov 2009 00:00:00 +0100 3034137 http://www.medworm.com/index.php?rid=3034136&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%3D19937232%26dopt%3DAbstract Authors: Green AM, Angelaki DE The vestibular system is vital for motor control and spatial self-motion perception. Afferents from the otolith organs and the semicircular canals converge with optokinetic, somatosensory and motor-related signals in the vestibular nuclei, which are reciprocally interconnected with the vestibulocerebellar cortex and deep cerebellar nuclei. Here, we review the properties of the many cell types in the vestibular nuclei, as well as some fundamental computations implemented within this brainstem-cerebellar circuitry. These include the sensorimotor transformations for reflex generation, the neural computations for inertial motion estimation, the distinction between active and passive head movements, as well as the integration of vestibular and proprioceptive i... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3034136 Tue, 24 Nov 2009 00:00:00 +0100 3034136 http://www.medworm.com/index.php?rid=3034139&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%3D19936722%26dopt%3DAbstract In this study, we examined the effect of timing constraints on repetitive unimanual force production sequences. Ten healthy participants produced a series of pinch grip forces in time to a metronome and to visually specified force amplitudes. Either visual feedback of force produced or the auditory metronome removed 10 s into the experimental trial, with participants performing continued responses for the remaining 20 s. In the continuation trials, a negative lag-1 autocorrelation in the inter-response intervals (IRIs) was observed as is commonly seen in motor timing tasks. However, removal of visual feedback resulted in a systematic increase in mean force output through the course of the trial, resulting in positive lag-1 autocorrelation values. An interaction was found between mean IRI a... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3034139 Fri, 20 Nov 2009 00:00:00 +0100 3034139 http://www.medworm.com/index.php?rid=3009348&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%3D19924408%26dopt%3DAbstract In this study, we have explored whether the impact of visual information on postural reactions is due to the same perceptual mechanisms that produce vection. Pitch motion of the visual field was presented at varying velocities to eight healthy subjects (29.9 +/- 2.8 years) standing quietly on a stationary base of support or receiving a 3 degrees toes-up tilt of the base of support. An infrared motion system recorded markers placed on body segments to record angular displacement of head and ankle and calculate whole body center of mass. Onset of the visual field motion and base of support movement were synchronized in all trials. We found that in the first 2 s following onset of visual field motion, both direction and amplitude of the linear displacement of whole body center of mass and ang... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3009348 Thu, 19 Nov 2009 00:00:00 +0100 3009348 http://www.medworm.com/index.php?rid=3009350&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%3D19921158%26dopt%3DAbstract Authors: Jones SA, Cressman EK, Henriques DY The present study examined the accuracy of proprioceptive localization of the hand using two paradigms. In our proprioceptive estimation paradigm, participants judged the position of a target hand relative to visual references, or their body's midline. Placement of the target hand was active (participants pushed a robot manipulandum along a constrained path) or passive (the robot manipulandum positioned participants' target hand). In our proprioceptive-guided reaching paradigm, participants reached to the unseen location of a hand; both the left and right hands served as the target hand and the reaching hand. In both paradigms, subjects were relatively good at estimating the location of each hand (i.e. relative to a reference marker or using... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3009350 Wed, 18 Nov 2009 00:00:00 +0100 3009350 http://www.medworm.com/index.php?rid=3009349&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%3D19921159%26dopt%3DAbstract Authors: McNeely ME, Earhart GM After stepping in place on a rotating treadmill, individuals exhibit involuntary turning in the direction opposite treadmill rotation when stepping in place on a stationary surface without vision. This response is called podokinetic after-rotation (PKAR). It remains unclear where the control center for PKAR is located and whether separate, independent podokinetic control centers exist for each lower limb. To better understand neural mechanisms underlying locomotor trajectory adaptation, this study asked whether PKAR transfers between lower limbs. Thirteen healthy adults underwent separate 15-min sessions where one (trained) leg or both legs stepped on the rotating surface. Afterward, all subjects exhibited PKAR during one-legged hopping on a stationary s... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3009349 Wed, 18 Nov 2009 00:00:00 +0100 3009349 http://www.medworm.com/index.php?rid=3009351&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%3D19921157%26dopt%3DAbstract In conclusion, announced short-term enriched housing has a high and long-lasting counteracting efficacy on stress-induced alterations of hippocampal synaptic plasticity. This information is important for counteracting the consequences of chronic stress in both human and captive rats. PMID: 19921157 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3009351 Tue, 17 Nov 2009 00:00:00 +0100 3009351 http://www.medworm.com/index.php?rid=3003627&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%3D19916006%26dopt%3DAbstract Authors: Huestegge L, Koch I Temporal gaps between the offset of a central fixation stimulus and the onset of an eccentric target typically reduce saccade latencies (saccadic gap effect). Here, we test whether temporal gaps also affect perceptual performance in peripheral vision. In Experiment 1, subjects executed saccades to briefly presented peripheral target letters and reported letter identity afterwards. A central fixation stimulus either remained visible throughout the trial (overlap) or disappeared 200 ms before letter onset (gap). Experiment 2 tested perceptual performance without saccade execution, whereas Experiment 3 tested saccade execution without perceptual demands. Peripheral letter perception performance was enhanced in gap as compared to overlap conditions (perceptual ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3003627 Sun, 15 Nov 2009 00:00:00 +0100 3003627 http://www.medworm.com/index.php?rid=3003626&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%3D19916007%26dopt%3DAbstract Authors: Campolo D, Formica D, Guglielmelli E, Keller F In this work, we tested the hypothesis that intrinsic kinematic constraints such as Donders' law are adopted by the brain to solve the redundancy in pointing at targets with the wrist. Ten healthy subjects were asked to point at visual targets displayed on a monitor with the three dof of the wrist. Three-dimensional rotation vectors were derived from the orientation of the wrist acquired during the execution of the motor task and numerically fitted to a quadratic surface to test Donders' law. The thickness of the Donders' surfaces, i.e., the deviation from the best fitting surface, ranged between 1 degrees and 2 degrees , for angular excursions from +/-15 degrees to +/-30 degrees . The results support the hypothesis under test, in... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3003626 Sun, 15 Nov 2009 00:00:00 +0100 3003626 http://www.medworm.com/index.php?rid=3003628&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%3D19915828%26dopt%3DAbstract In conclusion, the fact that during dual task performance transient bias in one task was not associated with concurrent improvement of performance in the other task indicates that alternation of supervisory control or attentional resources from one to the other task does not mediate the observed dual task costs. Resources of the central executive are not re-allocated or 'switched' from one to the other task. Dual task costs may result from mechanisms effective within each trial such as the demands of response selection. PMID: 19915828 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=3003628 Sat, 14 Nov 2009 00:00:00 +0100 3003628 http://www.medworm.com/index.php?rid=2992943&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%3D19908034%26dopt%3DAbstract Authors: Eysel UT, Hoffmann KP PMID: 19908034 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2992943 Thu, 12 Nov 2009 00:00:00 +0100 2992943 http://www.medworm.com/index.php?rid=2985578&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%3D19904528%26dopt%3DAbstract Authors: Rossit S, Szymanek L, Butler SH, Harvey M According to Milner and Goodale's model (The visual brain in action, Oxford University Press, Oxford, 2006) areas in the ventral visual stream mediate visual perception and off-line actions, whilst regions in the dorsal visual stream mediate the on-line visual control of action. Strong evidence for this model comes from a patient (DF), who suffers from visual form agnosia after bilateral damage to the ventro-lateral occipital region, sparing V1. It has been reported that she is normal in immediate reaching and grasping, yet severely impaired when asked to perform delayed actions. Here we investigated whether this dissociation would extend to saccade execution. Neurophysiological studies and TMS work in humans have shown that the poster... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2985578 Wed, 11 Nov 2009 00:00:00 +0100 2985578 http://www.medworm.com/index.php?rid=2985576&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%3D19904529%26dopt%3DAbstract Authors: Radulescu PV, Adam JJ, Fischer MH, Pratt J Fitts's Law for the timing of targeted movements states that, when target width is held constant, movement time (MT) will increase as the travelled distance increases. Even imagined movements, mentally simulated actions without actual actions, obey Fitts's Law. Recently, a violation of Fitts's Law has been reported; when targets occur in a structured array, MT to the farthest target is shorter than that predicted by Fitts's Law. We conducted two experiments to determine if the violation also occurs for imagined movements. Results showed a close correspondence between real and imaginary MTs across target locations, including the Fitts's violation for the farthest target. We conclude that the violation of Fitts's Law occurs in motor ima... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2985576 Wed, 11 Nov 2009 00:00:00 +0100 2985576 http://www.medworm.com/index.php?rid=2985574&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%3D19904530%26dopt%3DAbstract Authors: Morris G, Schmidt R, Bergman H The reinforcement learning hypothesis of dopamine function predicts that dopamine acts as a teaching signal by governing synaptic plasticity in the striatum. Induced changes in synaptic strength enable the cortico-striatal network to learn a mapping between situations and actions that lead to a reward. A review of the relevant neurophysiology of dopamine function in the cortico-striatal network and the machine reinforcement learning hypothesis reveals an apparent mismatch with recent electrophysiological studies. It was found that in addition to the well-described reward-related responses, a subpopulation of dopamine neurons also exhibits phasic responses to aversive stimuli or to cues predicting aversive stimuli. Obviously, actions that lead to ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2985574 Wed, 11 Nov 2009 00:00:00 +0100 2985574 http://www.medworm.com/index.php?rid=2985586&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%3D19902192%26dopt%3DAbstract Authors: Sülzenbrück S, Heuer H We studied adaptation to the visuo-motor transformation of a virtual and a real two-sided sliding lever. In a previous study (Sülzenbrück and Heuer in Exp Brain Res 195:153-165, 2009) we had found essentially no differences. However, adaptation had been restricted to a simplified symmetry approximation of the transformation. In the present study practice conditions were designed to facilitate adaptation (e.g., terminal rather than continuous visual feedback). In visual open-loop tests, differences between the effects of practice with a virtual and a real lever were found for curvature of hand movements, whereas movement end positions were not different. Curved hand movements induced by the use of the real lever persisted in subsequent... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2985586 Tue, 10 Nov 2009 00:00:00 +0100 2985586 http://www.medworm.com/index.php?rid=2985584&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%3D19902193%26dopt%3DAbstract Authors: Curtze C, Otten B, Postema K What happens to the mental representation of our body when the actual anatomy of our body changes? We asked 18 able-bodied controls, 18 patients with a lower limb amputation and a patient with rotationplasty to perform a laterality judgment task. They were shown illustrations of feet in different orientations which they had to classify as left or right limb. This laterality recognition task, originally introduced by Parsons in Cognit Psychol 19:178-241, (1987), is known to elicit implicit mental rotation of the subject's own body part. However, it can also be solved by mental transformation of the visual stimuli. Despite the anatomical changes in the body periphery of the amputees and of the rotationplasty patient, no differences in their ability t... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2985584 Tue, 10 Nov 2009 00:00:00 +0100 2985584 http://www.medworm.com/index.php?rid=2985583&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%3D19902194%26dopt%3DAbstract Authors: Schlicker K, Schmidt M The medial terminal nucleus (MTN) of the mammalian accessory optic system controls vertical compensatory eye movements. It consists of two neuronal populations which respond best either to upward or to downward visual image shifts. The two cell classes are located spatially separate in the dorsal or in the ventral subdivision of the MTN, respectively. Pronounced GABAergic pathways have been described to exist between neurons in the two MTN subdivisions indicating that inhibitory interactions play a significant role for the generation of MTN cell response properties. Yet, the types of GABA receptors which mediate these inhibitory interactions are unknown. Functionally, it is of particular interest to know whether GABA(C) receptors, as in other subcortical... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2985583 Tue, 10 Nov 2009 00:00:00 +0100 2985583 http://www.medworm.com/index.php?rid=2985582&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%3D19902195%26dopt%3DAbstract Authors: Rand MK, Lemay M, Squire LM, Shimansky YP, Stelmach GE The present project was aimed at investigating how two distinct and important difficulties (coordination difficulty and pronounced dependency on visual feedback) in Parkinson's disease (PD) affect each other for the coordination between hand transport toward an object and the initiation of finger closure during reach-to-grasp movement. Subjects with PD and age-matched healthy subjects made reach-to-grasp movements to a dowel under conditions in which the target object and/or the hand were either visible or not visible. The involvement of the trunk in task performance was manipulated by positioning the target object within or beyond the participant's outstretched arm to evaluate the effects of increasing the complexity of i... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2985582 Tue, 10 Nov 2009 00:00:00 +0100 2985582 http://www.medworm.com/index.php?rid=2985580&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%3D19902196%26dopt%3DAbstract Authors: Ortiz JA, Wright BA Training-induced improvements on perceptual skills can be attributed to at least two learning types: learning of general aspects of the trained condition (conceptual learning) and learning of specific feature values of the stimulus used in training (stimulus learning). Here we asked whether conceptual and stimulus learning on interaural time difference (ITD) discrimination emerge along different time courses. Conceptual learning was clearly evident 10 h after training, when performance on a target ITD condition was equivalent following training on that condition or on a non-target condition differing only in the stimulus, and was better in both cases than immediately after training. In contrast, stimulus learning emerged 24 h after training. At that time, p... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2985580 Tue, 10 Nov 2009 00:00:00 +0100 2985580 http://www.medworm.com/index.php?rid=2968555&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%3D19894039%26dopt%3DAbstract Authors: Fleming MK, Stinear CM, Byblow WD The aim of this study was to investigate the involvement of the parietal cortex during motor imagery (MI). In experiment one, participants imagined a sequence of upper limb movements during FMRI scanning. Statistical parametric mapping revealed a network of activation consistent with previous MI research, including activation in right and left inferior and superior parietal cortex. In experiment two, participants imagined a sequence of upper limb movements while real or sham single-pulse TMS was delivered over the scalp area corresponding to each individual's left or right superior parietal cortex. At the end of each trial, participants moved their upper limbs to the position that would result from executing the sequence of movements. TMS degr... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2968555 Fri, 06 Nov 2009 00:00:00 +0100 2968555 http://www.medworm.com/index.php?rid=2968557&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%3D19888566%26dopt%3DAbstract This study tests the hypothesis of an oriented spatial representation as the privileged way of mentally organizing serial information, by looking for stimulus-response compatibility effects in the processing of a newly acquired arbitrary sequence. Here we report an association between ordinal position of the items and spatial response preference for both order-relevant and order-irrelevant tasks. These results suggest that any ordered information, even when order is not intrinsically relevant to it, is spontaneously mapped in the representational space. This spatial representation is likely to acquire a left-to-right orientation, at least in western cultures. PMID: 19888566 [PubMed - as supplied by publisher] (Source: Experimental Brain Research) Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2968557 Wed, 04 Nov 2009 00:00:00 +0100 2968557 http://www.medworm.com/index.php?rid=2968556&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%3D19888567%26dopt%3DAbstract Authors: Kasamatsu T, Miller R, Zhu Z, Chang M, Ishida Y Modulation of single-cell responses by compound stimuli (target plus flankers) extending outside the cell's receptive field (RF) may represent an early neural mechanism for encoding objects in visual space, enhancing their perceptual saliency. The spatial extent of contextual modulation is wide. The size of the RF is known to be dynamically variable. It has been suggested that RF expansion when target contrast decreases is the real cause of effects attributed to modulation by flankers. This is not the case. We directly compared, in the same cells, the extent of RF size changes when stimulus contrast decreased with that revealed by systematically changing the target-and-collinear-flankers separation. We found that RF expansion at ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2968556 Wed, 04 Nov 2009 00:00:00 +0100 2968556 http://www.medworm.com/index.php?rid=2963430&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%3D19885653%26dopt%3DAbstract Authors: Turner CP, Debenedetto D, Ware E, Stowe R, Lee A, Swanson J, Walburg C, Lambert A, Lyle M, Desai P, Liu C Brain injury during the last trimester to the first 1-4 years in humans is now thought to trigger an array of intellectual and emotional problems later in life, including disorders such as schizophrenia. In adult schizophrenic brains, there is a specific loss of neurons that co-express glutamic acid decarboxylase-parvalbumin (GAD67-PV). Loss of this phenotype is thought to occur in mature animals previously exposed to N-methyl-D: -aspartate receptor (NMDAR) antagonists during late gestation or at postnatal day 7 (P7). However, in similarly treated animals, we have previously shown that GAD67 and PV are unaltered in the first 24 h. To more precisely define when changes in t... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2963430 Tue, 03 Nov 2009 00:00:00 +0100 2963430 http://www.medworm.com/index.php?rid=2963429&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%3D19885654%26dopt%3DAbstract Authors: Werner S, Bock O, Gizewski ER, Schoch B, Timmann D The aim of the present study was to elucidate the contribution of the superior and posterior inferior cerebellum to adaptive improvement and aftereffects in a visuomotor adaptation task. Nine patients with ischemic lesions within the territory of the posterior inferior cerebellar artery (PICA), six patients with ischemic lesions within the territory of the superior cerebellar artery (SCA) and 17 age-matched controls participated. All subjects performed center-out reaching movements under 60 degrees rotation of visual feedback. For the assessment of aftereffects, we tested retention of adaptation and de-adaptation under 0 degrees visual rotation. From this data we also quantified five measures of motor performance. Cerebellar l... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2963429 Tue, 03 Nov 2009 00:00:00 +0100 2963429 http://www.medworm.com/index.php?rid=2963434&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%3D19882147%26dopt%3DAbstract This study investigates if there are age- and falls-risk related differences in the length of time individuals need following fixation of a stepping target in order to step accurately onto it. This aim was achieved by manipulating the timing and location of stepping target presentation and comparing the effects on stepping performance between young adults, older adults characterised as having a low risk of falling and older adults characterised as having increased risk of falling (N = 10 in each group). Eye and lower limb kinematics were recorded using an eye tracker interfaced with a 3D motion analysis system. Temporal and spatial characteristics of eye and stepping movements were analysed and compared between groups and conditions in which participants had either <1, 2 or 3 s, followi... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2963434 Sat, 31 Oct 2009 00:00:00 +0100 2963434 http://www.medworm.com/index.php?rid=2963433&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%3D19882148%26dopt%3DAbstract Authors: Neely KA, Heath M In the visuomotor mental rotation (VMR) paradigm, participants execute a center-out reaching movement to a location that deviates from a visual cue by a predetermined instruction angle. Previous work has demonstrated a linear increase in reaction time (RT) as a function of the amplitude of the instruction angle (Georgopoulos and Massey in Exp Brain Res 65:361-370, 1987). In contrast, we recently reported a RT advantage for an instruction angle of 180 degrees relative to a 90 degrees angle (Neely and Heath in Neurosci Lett 463:194-198, 2009). It is possible, however, that perceptual expertise with the cardinal axes, which are perceptually familiar reference frames, influenced the results of our previous investigation. To address this issue, we employed a VMR p... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2963433 Sat, 31 Oct 2009 00:00:00 +0100 2963433 http://www.medworm.com/index.php?rid=2963432&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%3D19882149%26dopt%3DAbstract Authors: Mathôt S, Theeuwes J When attending an object in visual space, perception of the object remains stable despite frequent eye movements. It is assumed that visual stability is due to the process of remapping, in which retinotopically organized maps are updated to compensate for the retinal shifts caused by eye movements. Remapping is predictive when it starts before the actual eye movement. Until now, most evidence for predictive remapping has been obtained in single cell studies involving monkeys. Here, we report that predictive remapping affects visual attention prior to an eye movement. Immediately following a saccade, we show that attention has partly shifted with the saccade (Experiment 1). Importantly, we show that remapping is predictive and affects the locus of atte... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2963432 Sat, 31 Oct 2009 00:00:00 +0100 2963432 http://www.medworm.com/index.php?rid=2963431&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%3D19882150%26dopt%3DAbstract Authors: Zago M, Iosa M, Maffei V, Lacquaniti F It is known that arbitrary target accelerations along the horizontal generally are extrapolated much less accurately than target speed through a visual occlusion. The extent to which vertical accelerations can be extrapolated through an occlusion is much less understood. Here, we presented a virtual target rapidly descending on a blank screen with different motion laws. The target accelerated under gravity (1g), decelerated under reversed gravity (-1g), or moved at constant speed (0g). Probability of each type of acceleration differed across experiments: one acceleration at a time, or two to three different accelerations randomly intermingled could be presented. After a given viewing period, the target disappeared for a brief, variable pe... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2963431 Sat, 31 Oct 2009 00:00:00 +0100 2963431 http://www.medworm.com/index.php?rid=2944492&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%3D19862508%26dopt%3DAbstract Authors: Walz C, Elßner-Beyer B, Schubert D, Gottmann K Following initial contact formation, glutamatergic synapses in cortical neurons undergo pronounced functional maturation. These maturational events, occurring both pre- and postsynaptically, have been well described in the developing hippocampus. In this paper, we characterized glutamatergic synapses in immature layer Vb pyramidal neurons of the mouse somatosensory cortex during early postnatal development. At postnatal day 7, a significant subpopulation of glutamatergic synapses exhibited a low release probability that was accompanied by strong paired-pulse facilitation of AMPA EPSCs (paired-pulse ratio >/= 2). Increasing extracellular Ca(2+) concentration increased release probability and led to paired-pulse depression. ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2944492 Wed, 28 Oct 2009 00:00:00 +0100 2944492 http://www.medworm.com/index.php?rid=2927924&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%3D19856177%26dopt%3DAbstract Authors: Hilti LM, Brugger P Two apparently disparate phenomena of defective body integrity are reviewed. The first concerns dysmelia, characterized by the congenital absence or deformation of limbs, and the focus of the review is on phantom sensations of people with this kind of physical integrity disorder. The second phenomenon consists of non-psychotic individuals' desire to have a healthy limb amputated, which is interpreted as a mismatch between the physical integrity of a particular limb and its representation in multimodal cortical areas of the brain. We outlined commonalities and differences between the two conditions and note the absence, in both areas of research, of a unified theory that would account for the reported phenomenology. Phantom limbs in dysmelia and the desire f... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2927924 Sun, 25 Oct 2009 00:00:00 +0100 2927924 http://www.medworm.com/index.php?rid=2924409&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%3D19851758%26dopt%3DAbstract Authors: Buckingham G, Carey DP, Colino FL, Degrosbois J, Binsted G It is far more difficult to detect a small tactile stimulation on a finger that is moving compared to when it is static. This suppression of tactile information during motion, known as tactile gating, has been examined in some detail during single-joint movements. However, the existence and time course of this gating has yet to be examined during visually guided multi-joint reaches, where sensory feedback may be paramount. The current study demonstrated that neurologically intact humans are unable to detect a small vibratory stimulus on one of their index fingers during a bimanual reach toward visual targets. By parametrically altering the delay between the visual target onset and the vibration, it was demonstrated tha... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2924409 Fri, 23 Oct 2009 00:00:00 +0100 2924409 http://www.medworm.com/index.php?rid=2924408&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%3D19851759%26dopt%3DAbstract Authors: Hung YC, Charles J, Gordon AM Previously we found that children with hemiplegic cerebral palsy (CP) have impaired bimanual coordination compared to typically developing children during a functional drawer-opening task. However, performance of the task under time constraints (fast-as-possible) facilitated better bimanual coordination for these children. Accuracy is another important task constraint that could influence the coordination of the two hands during such tasks. The effect of accuracy constraints on bimanual coordination in children with hemiplegic CP is not well understood. In the present study, children were asked to reach forward and open a drawer with one hand and then activate a light switch inside the drawer with the contralateral hand. Task accuracy constraints ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2924408 Fri, 23 Oct 2009 00:00:00 +0100 2924408 http://www.medworm.com/index.php?rid=2924407&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%3D19851760%26dopt%3DAbstract Authors: Sugano Y, Keetels M, Vroomen J Previous research has shown that the timing of a sensor-motor event is recalibrated after a brief exposure to a delayed feedback of a voluntary action (Stetson et al. 2006). Here, we examined whether it is the sensory or motor event that is shifted in time. We compared lag adaption for action-feedback in visuo-motor pairs and audio-motor pairs using an adaptation-test paradigm. Participants were exposed to a constant lag (50 or 150 ms) between their voluntary action (finger tap) and its sensory feedback (flash or tone pip) during an adaptation period (~3 min). Immediately after that, they performed a temporal order judgment (TOJ) task about the tap-feedback test stimulus pairings. The modality of the feedback stimulus was either the same as the a... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2924407 Fri, 23 Oct 2009 00:00:00 +0100 2924407 http://www.medworm.com/index.php?rid=2924406&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%3D19851761%26dopt%3DAbstract Authors: Campbell KL, Al-Aidroos N, Fatt R, Pratt J, Hasher L The present study had two aims. First, to determine if bimodal audio-visual targets allow for greater inhibition of visual distractors, which in turn may lead to greater saccadic trajectory deviations away from those distractors. Second, to determine if bimodal targets can reduce age differences in the ability to generate deviations away, as older adults tend to benefit more from multisensory integration than younger adults. The results show that bimodal targets produced larger deviations away than unimodal targets, but only when the distractor preceded the target, and this effect was comparable across age groups. Furthermore, in contrast to previous research, older adults in this study showed similar deviations away from di... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2924406 Fri, 23 Oct 2009 00:00:00 +0100 2924406 http://www.medworm.com/index.php?rid=2924405&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%3D19851762%26dopt%3DAbstract Authors: Cohen RG, Biddle JC, Rosenbaum DA Moving around obstacles requires balancing the need to avoid collisions with the need to minimize biomechanical costs. We investigated this tradeoff by studying the effects of visual uncertainty, motor noise, and practice on clearance over obstacles in a manual positioning task. Participants moved a manipulandum back and forth over a stationary obstacle. We varied visual uncertainty by placing the obstacle at different heights relative to participants' eyes, and we varied motor noise by having participants hold the object to be moved at different positions relative to the range of motion of the arm joints. Clearance was larger in conditions of higher visual uncertainty than in conditions of lower visual uncertainty, larger in the higher motor ... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2924405 Fri, 23 Oct 2009 00:00:00 +0100 2924405 http://www.medworm.com/index.php?rid=2924402&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%3D19851763%26dopt%3DAbstract Authors: Rein R, Davids K, Button C The identification of attractors is one of the key tasks in studies of neurobiological coordination from a dynamical systems perspective, with a considerable body of literature resulting from this task. However, with regards to typical movement models investigated, the overwhelming majority of actions studied previously belong to the class of continuous, rhythmical movements. In contrast, very few studies have investigated coordination of discrete movements, particularly multi-articular discrete movements. In the present study, we investigated phase transition behavior in a basketball throwing task where participants were instructed to shoot at the basket from different distances. Adopting the ubiquitous scaling paradigm, throwing distance was manipu... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2924402 Fri, 23 Oct 2009 00:00:00 +0100 2924402 http://www.medworm.com/index.php?rid=2920627&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%3D19847407%26dopt%3DAbstract Authors: D'Ausilio A, Brunetti R, Delogu F, Santonico C, Belardinelli MO Music performance is characterized by complex cross-modal interactions, offering a remarkable window into training-induced long-term plasticity and multimodal integration processes. Previous research with pianists has shown that playing a musical score is affected by the concurrent presentation of musical tones. We investigated the nature of this audio-motor coupling by evaluating how congruent and incongruent cross-modal auditory cues affect motor performance at different time intervals. We found facilitation if a congruent sound preceded motor planning with a large Stimulus Onset Asynchrony (SOA -300 and -200 ms), whereas we observed interference when an incongruent sound was presented with shorter SOAs (-200, -... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2920627 Wed, 21 Oct 2009 23:00:00 +0100 2920627 http://www.medworm.com/index.php?rid=2920628&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%3D19844697%26dopt%3DAbstract Authors: Stani TM, Burchiel KJ, Hart MJ, Lenar DP, Anderson VC Deep brain stimulation (DBS) of the ventrolateral thalamus is a highly effective procedure for the treatment of essential tremor (ET). The regularity of repetitive, self-paced finger tapping is known to be abnormal in patients with ET and improved following DBS. However, the more complex timing that underlies force development in the hands in ET and after DBS has not been evaluated. In this pilot study, we assessed precision grip performance in seven ET subjects before and after 5 months of DBS. Ten healthy controls were also studied. ET subjects showed a significant increase in preload duration (235 +/- 145 vs. 82 +/- 49 ms) and peak negative load (-0.524 +/- 0.35 vs. -0.174 +/- 0.14 N) during grip-lift compared with healt... Experimental Brain Research journals http://www.medworm.com/rss/comments.php?id=2920628 Tue, 20 Oct 2009 23:00:00 +0100 2920628