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 'Developmental Psychobiology' source. Thu, 09 Feb 2012 02:31:43 +0100 http://www.medworm.com/index.php?rid=5669681&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21018 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5669681 Thu, 09 Feb 2012 07:05:51 +0100 5669681 http://www.medworm.com/index.php?rid=5669686&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21012 AbstractIn humans, maternal cues guide newborns to the maternal breast, and transitional cues may be present in maternal–fetal fluids. The aim of the present study was to determine the consistent presence of sensorial cues in three maternal–fetal fluids—amniotic fluid, colostrum, and milk—and test the ability of these cues to produce appetitive responses in newborns. In the analytical study, gas chromatography‐mass spectrometry (GC‐MS) detected eight fatty acids consistently present in the amniotic fluid, colostrum, and milk from 12 healthy volunteers, but we do not find a mammalian pheromone, identified in another mammalian species (rabbits), in another 30 volunteers. In the behavioral study, we explored the ability of amniotic fluid or its fatty acids to produce appetitive re... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5669686 Tue, 07 Feb 2012 05:00:00 +0100 5669686 http://www.medworm.com/index.php?rid=5669685&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21009 AbstractMany vertebrates rely extensively on social information, but the value of information produced by other individuals will vary across contexts and habitats. Social learning may thus be optimized by the use of developmental or current cues to determine its likely value. Here, we show that a developmental cue, early maternal care, correlates with social learning propensities in adult rodents. The maternal behavior of rats Rattus norvegicus with their litters was scored over the first 6 days postpartum. Rat dams show consistent individual differences in the rate they lick and groom (LG) pups, allowing them to be categorized as high, low, or mid‐LG mothers. The 100‐day old male offspring of high and low‐LG mothers were given the opportunity to learn food preferences for novel diet... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5669685 Tue, 07 Feb 2012 05:00:00 +0100 5669685 http://www.medworm.com/index.php?rid=5669684&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21008 AbstractDiurnal patterns of salivary alpha amylase (sAA) in pregnant women have not previously been described. The current study employed ecological momentary assessment to examine the association between the diurnal sAA, obstetric history, maternal demographics, and mood during pregnancy. Saliva was self‐collected by 83 pregnant women (89% White, age 25.3–43.0 years; mean gestational age 21.9 weeks, range 6–37 weeks; gravida 1–6) at home over three days. Results indicated that current pregnancy (gestational age and fetal sex) and maternal demographics were not related to diurnal sAA. In contrast, a history of previous miscarriage (Parameter = −.17; SE = .05; p < .05) was associated with an atypical diurnal pattern. Even after accounting for obstetric history, trai... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5669684 Tue, 07 Feb 2012 05:00:00 +0100 5669684 http://www.medworm.com/index.php?rid=5669683&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21007 AbstractExperimental animal findings suggest that early stress and glucocorticoid exposure may program the function of the hypothalamic–pituitary–adrenal (HPA) axis in the offspring. The extension of these findings to human development is not yet clear. A prospective longitudinal study was conducted on 125 mothers and their normally developing children. Amniotic fluid was obtained at, on average, 17.2 weeks gestation; infant behavior and cortisol response to a separation–reunion stress was assessed at 17 months. Amniotic fluid cortisol predicted infant cortisol response to separation–reunion stress: infants who were exposed to higher levels of cortisol in utero showed higher pre‐stress cortisol values and blunted response to stress exposure. The association was independent of pre... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5669683 Tue, 07 Feb 2012 05:00:00 +0100 5669683 http://www.medworm.com/index.php?rid=5669682&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21006 This study supports a relationship between the parent child relationship during the first 2 years of life and later cortisol response to stress in youth at genetic risk for asthma. © 2012 Wiley Periodicals, Inc. Dev Psychobiol (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5669682 Tue, 07 Feb 2012 05:00:00 +0100 5669682 http://www.medworm.com/index.php?rid=5600284&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21010 AbstractBehavioral effects of different prenatal stress (PNS) schedules were examined in prepubertal “depressive/anxious‐like” WKY and control Wistar rats. Pregnant dams received 1 hr daily restraint stress on gestational days 14–20 or on 7 randomly scheduled days, or remained undisturbed. Offspring were tested during postnatal days 29–35 in social play, forced swim‐test, open field, and novelty tests. PNS induced an increase in anxiety‐like behaviors in WKY, particularly in females, while seemingly reducing depressive‐like behavior in the swim test. However, very high post‐stress corticosterone levels were found, suggesting that the reductions in swim‐test immobility reflect an extremely over‐responsive HPA axis, rather than normalization in stress reactivity leadi... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5600284 Wed, 18 Jan 2012 07:48:20 +0100 5600284 http://www.medworm.com/index.php?rid=5600285&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21011 In this study, we analyzed US‐PE in preweanling rats along with the role of the training context in this effect in terms of conditioned taste aversion preparation. Pre‐exposure to LiCl before conditioning retarded the acquisition of taste aversion. The US‐PE was observed in preweanling rats when, during pre‐exposure, subjects were exposed to the conditioning context, and this effect was not attenuated either by the administration of the US in a familiar environment (Experiment 1a), or by the presence of an alternative, more salient context during pre‐exposure (Experiment 1b). Additionally, the US‐PE was still observed when the route by which the US was administered was changed between the pre‐exposure and conditioning phases (Experiment 2a) as well as when the injection cues ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5600285 Tue, 17 Jan 2012 05:00:00 +0100 5600285 http://www.medworm.com/index.php?rid=5546353&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21003 AbstractAmong mammals, odor‐based communication between females and infants is decisive for neonatal survival. So far, the nature of odor substrates involved in the localization of the mother and their nipples is unknown in mice. The present study aims: (1) to evaluate the specific attractive value of lactating females to newborn mice, (2) to localize the abdominal region that is most attractive to pups, and (3) to identify odor substrates that support such attraction. Results showed that 5–6‐day‐old mice roam preferentially over the abdomen of lactating females than the abdomen of non‐lactating females. In lactating females, pups are more attracted to abdominal areas comprising nipples. The blend of odor substrates from nipples, as well as separate sources presumed to compose it... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5546353 Wed, 28 Dec 2011 23:33:55 +0100 5546353 http://www.medworm.com/index.php?rid=5546358&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20624 AbstractA major advantage of sheep models in experimental studies of neurodevelopmental disorders (e.g., with prenatal neurotoxicant exposure) is that the equivalent of all three trimesters of human brain development occurs in sheep entirely in utero. However, studies of learning and memory in sheep are limited. The goal of this study was to extend the analysis of spatial learning and memory in adolescent sheep using several traditional T‐maze tasks. Both 9‐ and 14‐week‐old lambs acquired a delayed nonmatching‐to‐place task, but the older lambs learned the task significantly faster. In contrast, acquisition of a matching‐to‐place task was significantly more difficult. Lambs, like rodents, appear to have a predisposition toward learning “win‐shift” spatial problems in ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5546358 Tue, 27 Dec 2011 05:00:00 +0100 5546358 http://www.medworm.com/index.php?rid=5546357&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21004 AbstractEpisodic memory endows us with the ability to reflect on our past and plan for our future. Most theorists argue that episodic memory emerges during the preschool period and that its emergence might herald the end of childhood amnesia. Here, we show that both 3‐ and 4‐year‐old children form episodic memories, but that 3‐year‐old children fail to retain those memories following a delay (Experiments 1 and 2). In contrast, 4‐year‐old children retained episodic memories over delays of 24 hr (Experiment 1) and 1 week (Experiment 3). This marked change in the retention of episodic memories between 3 and 4 years of age suggests that it is our ability to retain, rather than to form, an episodic memory that limits our ability to recall episodes from early childhood. © 2011 W... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5546357 Tue, 27 Dec 2011 05:00:00 +0100 5546357 http://www.medworm.com/index.php?rid=5546356&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21002 AbstractThe current study builds on the emerging autism spectrum disorder (ASD) literature that associates autonomic nervous system activity with social function, and examines the link between respiratory sinus arrhythmia (RSA) and both social behavior and cognitive function. The RSA response pattern was assessed in 23 4‐ to 7‐year‐old children diagnosed with an ASD. Higher baseline RSA amplitudes were associated with better social behavior (i.e., more conventional gestures, more instances of joint attention) and receptive language abilities. Similar to reports of typically developing children, ASD children with higher RSA amplitude at baseline showed greater RSA and HP reactivity during an attention‐demanding task. These results highlight the importance of studying RSA as a marker... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5546356 Tue, 27 Dec 2011 05:00:00 +0100 5546356 http://www.medworm.com/index.php?rid=5546355&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21001 AbstractThe unconditioned stimulus preexposure effect (US‐PE) is defined as an attenuation of the conditioned response after preexposure to the US prior to conditioning. Evidence exists that this effect can be weakened or eliminated by the presence of a signal predicting the US during the preexposure phase. This evidence has been found consistently across a variety of procedures in adult rats. The aim of the present study was to evaluate whether, in infant rats, signaling the US (LiCl) during preexposure with a salient cue (almond odor) attenuates the US‐PE. During the preexposure phase, preweanling rats received three (Experiment 1) or one (Experiment 2) preexposures to LiCl, preceded by exposure to almond odor. Appropriate control groups were also included in these experiments. After... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5546355 Tue, 27 Dec 2011 05:00:00 +0100 5546355 http://www.medworm.com/index.php?rid=5546354&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.21000 AbstractThe development of separation response behaviors in infant rhesus macaques across the first 6 months of life was assessed. Seventeen infants underwent a neonatal assessment at 7, 14, 21, and 30 days of age which included a brief period of social isolation. At 3 and 6 months of age these same monkeys and four additional subjects were again subjected to a period of brief social isolation and also exposed to a novel environment with their sedated mother. Results indicate a developmental increase followed by a steady decline in the frequency of separation vocalizations. A modest relationship between early‐infancy locomotor profiles and separation responses was also observed at several time points suggesting a possible relationship between these measures. However, stable inter‐indiv... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5546354 Tue, 27 Dec 2011 05:00:00 +0100 5546354 http://www.medworm.com/index.php?rid=5460975&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20618 AbstractDrawing on emotional security theory, this study examined linkages between interparental aggression, infant self‐regulatory behaviors, and patterns of physiological and behavioral stress responses in a diverse sample of 735 infants residing in predominately low‐income, non‐metropolitan communities. Latent profile analysis revealed four classes of adrenocortical and behavioral stress‐response patterns at 7 months of age, using assessments of behavioral and cortisol reactivity to an emotion eliciting challenge, as well as global ratings of the child's negative affect and basal cortisol levels. The addition of covariates within the latent profile model suggested that children with more violence in the home and children who used less caregiver‐oriented regulation strategies w... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5460975 Thu, 01 Dec 2011 05:00:00 +0100 5460975 http://www.medworm.com/index.php?rid=5460979&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20621 This study investigated this ontogenetic effect further and reports three findings: First, the CPFE is absent on PND 19 but emerges modestly in rats given exposure on PND 21. Second, the absence of the CPFE on PND 17 does not reflect inability to consolidate the context‐shock association established on the training day. Lastly, the CPFE on PND 24 requires exposure to the combined features of the context. These results are the first to show that the early development of contextual fear conditioning depends on conjunctive representations and that processes underlying the CPFE begin to emerge around PND 21 in the rat. © 2011 Wiley Periodicals, Inc. Dev Psychobiol (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5460979 Tue, 29 Nov 2011 05:00:00 +0100 5460979 http://www.medworm.com/index.php?rid=5460978&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20620 In conclusion, handling in the neonatal period induces the activation of the angiotensinergic system, as well as modulates its mRNA receptor expression. The oxidative stress balance system seems not to be involved. © 2011 Wiley Periodicals, Inc. Dev Psychobiol (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5460978 Tue, 29 Nov 2011 05:00:00 +0100 5460978 http://www.medworm.com/index.php?rid=5460977&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20619 AbstractEarly development of visual behavior was examined in hand‐reared (HR) and parentally reared (PR) common marmosets (Callithrix jacchus). On the day of birth, most of the marmosets exhibited sensitivity to light and sound: they closed their eyes in response to light and oriented to the sound sources. The behavior of tracking moving visual stimuli was exhibited at around 10 days postnatally in PR marmosets, but the onset of this behavior was delayed to the age of 16 days in HR marmosets. The delay occurred possibly because of the poor input of optical flow under the HR environment. The onset age of head‐cocking was about 2 weeks in both groups of marmosets, and the HR marmosets began head‐cocking and visual tracking simultaneously. Both groups of marmosets exhibited sensitivity ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5460977 Tue, 29 Nov 2011 05:00:00 +0100 5460977 http://www.medworm.com/index.php?rid=5460976&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20623 AbstractStereotypic behavior in captive animals has been hypothesized to emerge from thwarted natural behavior patterns and is thought to be more common in captive‐reared animals. However, data on the early stages of developing stereotypies are currently scarce. We compared the development of stereotypic route‐tracing and somersaulting in hand‐reared and wild‐caught starlings placed in individual cages for the first time. We found that wild‐caught birds were less active but showed more escape motivation and more evidence of route‐tracing behavior. Furthermore, somersaulting was only observed in wild‐caught birds. Development of somersaulting was predicted by subtle differences in behavior during the first few days in cages and developed in individuals with low levels of route... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5460976 Tue, 29 Nov 2011 05:00:00 +0100 5460976 http://www.medworm.com/index.php?rid=5391685&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20608 AbstractThe current study examined the moderating effect of children's cardiac vagal suppression on the association between maternal socialization of negative emotions (supportive and nonsupportive responses) and children's emotion regulation behaviors. One hundred and ninety‐seven 4‐year‐olds and their mothers participated. Mothers reported on their reactions to children's negative emotions and children's regulatory behaviors. Observed distraction, an adaptive self‐regulatory strategy, and vagal suppression were assessed during a laboratory task designed to elicit frustration. Results indicated that children's vagal suppression moderated the association between mothers' nonsupportive emotion socialization and children's emotion regulation behaviors such that nonsupportive reaction... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5391685 Thu, 10 Nov 2011 20:34:07 +0100 5391685 http://www.medworm.com/index.php?rid=5391687&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20613 AbstractAdverse early experiences are associated with a range of deleterious health outcomes in humans, including higher risk for affective disorders. Studies using a long‐standing model of nonhuman primate model of early adversity have demonstrated that nursery‐reared (NR) monkeys exhibit alterations in multiple aspects of biobehavioral development; however, few studies have evaluated the persistence of socioaffective behavioral changes through adulthood. We evaluated the effects of early rearing experience on adult animals' response to a well‐validated assessment of anxiety‐like behavior, the human intruder paradigm (HIP). We tested 22 rhesus monkeys who were either nursery‐reared (NR) or reared with their mothers (mother‐reared; MR). NR monkeys were inhibited in their behavi... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5391687 Wed, 09 Nov 2011 05:00:00 +0100 5391687 http://www.medworm.com/index.php?rid=5391686&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20616 AbstractThe current study examined developmental changes in fear learning and generalization in 40 healthy 8–13 year‐olds using an aversive conditioning paradigm adapted from Lau et al. [Lau et al. [2008] Journal of the American Academy of Child and Adolescent Psychiatry 47:94–102]. In this task, the conditioned stimuli (CS+/CS−) are two neutral female faces, and the unconditioned stimulus is a fearful, screaming face. The second phase of the study also included a generalization stimulus (GS): a 50% blend of the CS± faces. The eye‐blink startle reflex was utilized to measure defensive responding. Patterns of fear learning and generalization were qualified by child age. Older children demonstrated greater fear learning (i.e., larger startle during CS+ than CS−) than younger chi... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5391686 Wed, 09 Nov 2011 05:00:00 +0100 5391686 http://www.medworm.com/index.php?rid=5339305&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20602 In this study, an ecologically relevant approach was used to document daily self‐reports of stress in adolescents and an emerging adult comparison group. Participants visited the laboratory twice: once each when they endorsed a high and low level of stress, where they performed a risky decision‐making task and a response inhibition task. In both groups, participants showed greater risky decision‐making under high (vs. low) stress conditions but no stress‐related effects on response inhibition. The dissociation between decision‐making and response inhibition under stress suggests that, across development, individuals show greater vulnerability to contextual influence in decision‐making domains. © 2011 Wiley Periodicals, Inc. Dev Psychobiol (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5339305 Sun, 23 Oct 2011 08:24:50 +0100 5339305 http://www.medworm.com/index.php?rid=5326361&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20617 AbstractUpon awakening from sleep, combined processes of deactivation of the hippocampus and activation of suprachiasmatic nucleus result in a marked increase in cortisol release from structures within the hypothalamic–pituitary–adrenal axis. This phenomenon, termed the cortisol awakening response (CAR), has been studied extensively in adults. In the current study, we examine this phenomenon for the first time in infancy. Saliva samples were collected by 32 mothers from themselves and their infants (13 males; 7.8–17.4 months of age) at the infant's AM waking (and 30 min later), and upon waking from the infant's first nap (and 30 min later). In contrast to what has been observed with the CAR in adults, cortisol levels declined from AM waking to 30 min post‐waking. Moreover, co... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5326361 Wed, 19 Oct 2011 05:37:52 +0100 5326361 http://www.medworm.com/index.php?rid=5326363&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20612 AbstractIndividual differences in observed and maternal‐rated fear behaviors and frontal electroencephalogram (EEG) asymmetry were examined in normally developing 10‐month‐old infants. EEG was recorded during resting baseline, as well as during stranger approach, mask presentation, and toy spider presentation. Mothers completed the Infant Behavior Questionnaire. For mask presentation, baseline and task right frontal EEG asymmetry as well as maternal ratings predicted fear behavior during the mask task. For stranger approach, task‐related right frontal EEG asymmetry predicted fear behavior during stranger approach after controlling for baseline asymmetry. There was a trend for task‐related right frontal EEG asymmetry to predict fear during presentation of a toy spider after contro... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5326363 Mon, 17 Oct 2011 04:00:00 +0100 5326363 http://www.medworm.com/index.php?rid=5326362&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20615 AbstractThe current study investigated the effects of neonatal infection with Chlamydia muridarum bacteria on glucocorticoid (GR) and mineralocorticoid (MR) receptors in the adult mouse hippocampus. In male adults infected at birth, circulating corticosterone was significantly increased when compared to same sex controls; while neonatal infection resulted in female adults with significantly increased GR mRNA compared to same sex controls. When comparing males and females after neonatal infection, males had significantly less GR protein than females. Interestingly, after control treatment, males had significantly more GR mRNA, MR mRNA, and GR protein with significantly lower corticosterone than females. Neonatal respiratory infection significantly impacts adult hippocampal GR and MR, and ci... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5326362 Mon, 17 Oct 2011 04:00:00 +0100 5326362 http://www.medworm.com/index.php?rid=5307005&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20603 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5307005 Wed, 12 Oct 2011 19:36:08 +0100 5307005 http://www.medworm.com/index.php?rid=5264104&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20600 AbstractEyeblink classical conditioning in pre‐weanling rabbits was examined in the present study. Using a custom lightweight headpiece and restrainer, New Zealand white littermates were trained once daily in 400 ms delay eyeblink classical conditioning from postnatal days (PD) 17–21 or PD 24–28. These ages were chosen because eyeblink conditioning emerges gradually over PD 17–24 in rats [Stanton et al., (1992) Behavioral Neuroscience, 106(4):657–665], another altricial species with neurodevelopmental features similar to those of rabbits. Consistent with well‐established findings in rats, rabbits trained from PD 24–28 showed greater conditioning relative to littermates trained from PD 17–21. Both age groups displayed poor retention of eyeblink conditioning at retraining 1... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264104 Tue, 27 Sep 2011 04:00:00 +0100 5264104 http://www.medworm.com/index.php?rid=5264103&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20599 We examined whether robust CARs exist in 2‐ to 4‐year‐old children and if sleep restriction, wake timing, and napping influence the CAR (n = 7). During a 25‐day in‐home protocol, researchers collected four salivary cortisol samples (0, 15, 30, 45 min post‐wake) following five polysomnographic sleep recordings on nonconsecutive days after 4 hr (morning nap), 7 hr (afternoon nap), 10 hr (evening nap), 13 hr (baseline night), and 16 hr (sleep restriction night) of wakefulness (20 samples/child). The CAR was robust after nighttime sleep, diminished after sleep restriction, and smaller but distinct after morning and afternoon (not evening) naps. Cortisol remained elevated 45 min after morning and afternoon naps. © 2011 Wiley Periodicals, Inc. Dev Psychobiol (Sourc... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264103 Tue, 27 Sep 2011 04:00:00 +0100 5264103 http://www.medworm.com/index.php?rid=5264102&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20610 AbstractThe extent to which characteristic adolescent behaviors are associated with pubertal changes or driven by more general, puberty‐independent developmental alterations is largely unknown. Using physiological and hormonal markers of puberty, this experiment characterized pubertal timing across adolescence and examined the relationships among these variables and novelty‐directed behaviors. Males and females were tested for response to novelty at P28, P32, P36, P40, P44, P48, and P75, and examined for balano‐preputial skinfold separation and sperm presence (males) or vaginal opening (females), followed by blood collection for hormonal assessments. Despite earlier pubertal maturation in females, with maturation generally completed by P36 in females and P44 in males, novelty‐direc... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264102 Tue, 27 Sep 2011 04:00:00 +0100 5264102 http://www.medworm.com/index.php?rid=5264101&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20609 AbstractEarly attachment disruption is thought to promote later onset of depressive illness through a process involving sensitization. Maternal separation in guinea pig pups produces depressive‐like behavior and core body temperature fluctuations that appear to be mediated by proinflammatory activity. In pups near the age of weaning (∼20 days of age), these responses are increased during repeated separations occurring over several days. Here, enhanced depressive‐like behavior and core body temperature responses were observed during repeated separations in guinea pigs from ∼10 to 30 days of age. The sensitization lasted for more than a week, with the greatest temperature response occurring during the final separation. These results demonstrate persisting sensitization of behavioral ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264101 Tue, 27 Sep 2011 04:00:00 +0100 5264101 http://www.medworm.com/index.php?rid=5264100&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20607 This study aimed to (1) identify a stable, trait‐like component to cortisol and its circadian rhythm, and (2) investigate individual differences in developmental trajectories of HPA‐axis maturation. Multiple salivary cortisol samples were collected longitudinally across four assessments from age 9 (3rd grade) through age 15 (9th grade) in a community sample of children (N = 357). Sophisticated statistical models examined cortisol levels and its rhythm over time; effects of age, puberty and gender were primarily considered. In addition to situation‐specific and stable short‐term or epoch‐specific cortisol components, there is a stable, trait‐like component of cortisol levels and circadian rhythm across multiple years covering the transition from childhood into adolescence. Y... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264100 Tue, 27 Sep 2011 04:00:00 +0100 5264100 http://www.medworm.com/index.php?rid=5264099&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20606 AbstractThis longitudinal prospective study examined the relation between maternal anxiety during pregnancy and specific aspects of children's cognitive functioning at age five. Antenatal maternal state‐anxiety was measured around the 16th week of pregnancy. Children's neurocognitive functioning was examined using a simple reaction time (RT) task, and a choice RT task. Multiple regression analyses in the total sample (N = 922) showed that antenatal anxiety was positively related to children's intra‐individual variability in RT in the simple task. In a subsample (n = 100) of women with state‐anxiety scores above the 90th percentile, antenatal anxiety was positively associated with mean RT and intra‐individual variability in RT in the incompatible trials of the choice RT task... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264099 Tue, 27 Sep 2011 04:00:00 +0100 5264099 http://www.medworm.com/index.php?rid=5264098&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20605 AbstractThis analysis examined the relative contributions of sex, age, body mass index (BMI), and puberty (Tanner) stage on salivary melatonin amplitude. Sixty‐nine children and adolescents (30 females; 9.6–17.8 years) were examined for Tanner stage. Serial salivary melatonin samples were collected in controlled conditions, from which these melatonin amplitude measures were derived: area under the curve (AUC) and maximum value (MAX). AUC declined with advancing Tanner stage. This melatonin decline was similar between boys and girls, but girls secreted more melatonin compared to boys. Tanner stage and sex explained AUC variability, but age and BMI did not; similar results emerged for MAX. These results indicate that puberty stage may either mediate the decline of melatonin, or the decre... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264098 Tue, 27 Sep 2011 04:00:00 +0100 5264098 http://www.medworm.com/index.php?rid=5264097&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20604 AbstractKinematic studies of reaching in human infants using two‐dimensional (2‐D) and three‐dimensional (3‐D) recordings have complemented behavioral studies of infant handedness by providing additional evidence of early right asymmetries. Right hand reaches have been reported to be straighter and smoother than left hand reaches during the first year. Although reaching has been a popular measure of handedness in primates, there has been no systematic comparison of left and right hand reach kinematics. We investigated reaching in infant rhesus monkeys using the 2‐D motion analysis software MaxTRAQ Lite+ (Innovision Systems). Linear mixed‐effects models revealed that left hand reaches were smoother, but not straighter, than right hand reaches. An early left bias matches previous... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264097 Tue, 27 Sep 2011 04:00:00 +0100 5264097 http://www.medworm.com/index.php?rid=5264096&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20596 This study was conducted to compare how newborns of depressed mothers and newborns of nondepressed mothers gather tactile information about texture. Spontaneous manual activity on objects with a smooth or rough texture was recorded in 20 newborns born of mothers with a high risk of depression or a low risk of depression. An important result of the present study is that texture‐based modulation of hand‐pressing frequency was observed in both neonates born of depressed mothers and neonates born of nondepressed mothers. Moreover, hand‐pressing frequency did not depend on the pressure exerted on the object, since all neonates displayed comparable pressure on the held object. Lastly, the results revealed that newborns of depressed mothers held the rough object twice as long as newborns of... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264096 Tue, 27 Sep 2011 04:00:00 +0100 5264096 http://www.medworm.com/index.php?rid=5277111&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20601 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5277111 Thu, 01 Sep 2011 04:00:00 +0100 5277111 http://www.medworm.com/index.php?rid=5264095&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20614 AbstractCompromised respiratory sinus arrhythmia (RSA, i.e., low cardiac vagal control) frequently characterizes clinically depressed adults and also has been detected in infants of depressed mothers; however, its existence has not been established in older at‐risk offspring. We investigated developmental patterns of RSA in a sample of 163 5‐ to 14‐year‐old children, who were either at high risk for depression (due to having a parent with a childhood‐onset mood disorder) or low‐risk for depression. We hypothesized that high‐risk children have lower resting RSA than do low‐risk children, which could reflect atypical developmental trajectories. Children's RSA was assessed during resting baseline periods on multiple occasions, typically 1‐year apart. Linear growth modeling i... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5264095 Thu, 01 Sep 2011 04:00:00 +0100 5264095 http://www.medworm.com/index.php?rid=5149756&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20574 AbstractWe aim to stimulate an ontogenetic approach to personalities. We explain the importance of studying development for understanding proximate and ultimate aspects of personality and critically discuss, partly by perhaps provocative statements, our current lack of knowledge and potential approaches to the study of personality development. We first clarify some terminology and argue for a difference between behavioral profiles (BP; at the descriptive level) and personality (at the explanatory level). We then focus on the issue of temporal stability of personality, arguing that based on evolutionary theory, neurophysiological knowledge, and recent findings, personality is probably less stable than often thought. Next we consider the potential influence of genes, discussing gene by envir... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149756 Wed, 24 Aug 2011 21:39:13 +0100 5149756 http://www.medworm.com/index.php?rid=5149755&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20553 AbstractThe mouse, including countless lines of transgenic and knockout mice, has become the most prominent model organism in biomedical research. Behavioral characterization is often conducted in batteries of short tests on locomotion, anxiety, learning and memory, etc. In such tests, any individual differences within groups are usually considered to be disturbing variance. In order to reduce variance in experimental animal research enormous efforts of standardization have been made. While a substantial reduction of variability has been reached compared to the earlier years of experimental animal studies a considerable amount of inter‐individual differences still seems to escape standardization. This effect is demonstrated and evaluated by re‐analyzing data from two experiments conduc... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149755 Wed, 24 Aug 2011 21:39:12 +0100 5149755 http://www.medworm.com/index.php?rid=5149754&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20586 AbstractAnimal personality has been extensively studied from a functional and evolutionary point of view. Less attention has been paid to the development of personality, its phenotypic plasticity, and the influence of manipulation of early environmental factors. Here we describe the effects of manipulating the sex ratio of the litter, at postnatal day (pnd) 3, in wild‐type rats, on personality traits in adulthood. We measured the treatment effects on aggression, defensive burying, and open field behavior at pnd 90 and 120, as well as on their contextual generality, and stability over time (differential and structural consistency). Main effects of litter composition were found on open field behavior at pnd 120 but not on the other behaviors. Since correlations between behaviors changed ov... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149754 Wed, 24 Aug 2011 21:39:11 +0100 5149754 http://www.medworm.com/index.php?rid=5149753&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20522 AbstractFeatures of an individual's early development are frequently reported to alter the postnatal ontogeny in litter‐bearing mammals with respect to various physiological parameters. We hypothesized that such effects might also apply to the ontogeny of personality types. On the one hand, litter size effects by means of more contacts with littermates, might lead to the development of more offensive types. On the other hand, smaller and less developed young from larger litters might be less offensive due to their lower physical capabilities to deal with challenging situations. We studied these contrasting hypotheses in young rats, which we tested in a battery of emotionality tests. There were clear indications for the existence of distinct behavioral types by means of consistencies in b... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149753 Wed, 24 Aug 2011 21:39:10 +0100 5149753 http://www.medworm.com/index.php?rid=5149752&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20547 We present data on behavior of European rabbits from a field enclosure study. These data clearly show that aggressiveness is higher in young from smaller litters than in young from larger litters, and smaller litters are usually born during the early breeding season. Moreover, our data suggest that behavioral types of the young rabbits are stable over time, at least during their subadult life. We suggest, that changes in mean litter size over the course of the breeding season may not only be a product of mothers' age or food availability, but may also have an adaptive function by preparing offspring characteristics for adulthood in a social environment undergoing predictable density changes within the season. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:585–591, 2011. (Source: Devel... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149752 Wed, 24 Aug 2011 21:39:09 +0100 5149752 http://www.medworm.com/index.php?rid=5149751&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20535 AbstractAlthough most mammals grow up in the company of same or different age sibs (or half sibs), surprisingly little attention has been given to how relations among them might influence the development of individual differences in morphology, physiology, and behavior. Here we review evidence from our work on domestic and wild European rabbits, and more recently on laboratory rats, mice, and domestic cats, supporting the proposition that in mammals early sibling relations contribute to the development of individual differences in these three domains and thereby to long‐term behavioral differences of the kind we might consider part of an animal's behavioral style or personality. First we report a consistent and marked negative relation between litter size and individuals' body mass at bi... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149751 Wed, 24 Aug 2011 21:39:08 +0100 5149751 http://www.medworm.com/index.php?rid=5149750&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20594 AbstractTemperament is usually considered biologically based and largely inherited, however, the environment can shape the development of temperament. Allelic variation may confer differential sensitivity to early environment resulting in variations in temperament. Here we explore the relationship between measures of temperament in mothers and their first‐born offspring and the role of genetic sensitivity in establishing the strength of these associations. Temperament ratings were conducted on 3‐ to 4‐month‐old rhesus monkeys after a 25‐hr biobehavioral assessment. Factor analysis revealed a four‐factor structure of temperament. Females assessed as infants have reproduced and their offspring have also been evaluated through the standardized testing paradigm. Canonical correlati... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149750 Wed, 24 Aug 2011 21:39:07 +0100 5149750 http://www.medworm.com/index.php?rid=5149749&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20578 This article describes research exemplifying these forms of continuity in humans, and suggests potential implications for animal personality investigations. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:510–520, 2011. (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149749 Wed, 24 Aug 2011 21:39:05 +0100 5149749 http://www.medworm.com/index.php?rid=5149748&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20573 AbstractInterest has been growing among behavioral biologists in individual differences in animal behavior of the kind that can be considered to reflect differences in personality. Once considered the exclusive domain of human psychology, biologists have found evidence for personality across a wide range of species, while behavioral ecologist and theoretical biologists recognize the likely evolutionary origins and contribution to fitness of such. However, until recently most work has concentrated on ultimate questions of fitness and thus on adult animals, with little attention given to proximate, developmental origins. This is now changing, as approaches to studying animal personality broaden and methodologies are developed enabling this to be studied across periods of near continuous and ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149748 Wed, 24 Aug 2011 21:39:04 +0100 5149748 http://www.medworm.com/index.php?rid=5149744&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20598 This study investigated adrenocortical activity in response to different challenging and positive affect emotional contexts in child–mother dyads, as function of attachment security (children's secure base behaviors and mothers' attachment representations). Fifty‐one children ranging in age from 18 to 26 months and their mothers participated in this study. Secure children showed significant increases in their cortisol levels after fear episodes and significant decreases, after positive affect ones. No significant changes were found for frustration/anger episodes. Insecure children did not show significant differences in cortisol levels in any of the episodes, which suggests that insecure attachment may be related to hypothalamic–pituitary–adrenal axis suppression in response to cha... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149744 Wed, 24 Aug 2011 21:38:42 +0100 5149744 http://www.medworm.com/index.php?rid=5149747&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20591 AbstractAdult rats sweep their large facial whiskers (macrovibrissae) back and forth in a rhythmic pattern known as “whisking”. Here we examine how these whisker movements develop in relation to other aspects of exploratory behavior, particularly locomotion. We analyzed 963 high‐speed video recordings of neonatal rats, from P1 (Post‐natal day 1) to P21, and measured the emergence of whisker control and of head, body, and limb movements. Prior to P11, whisker movements were largely limited to unilateral retractions accompanying head turns. Between P11 and P13 bilateral whisking emerged alongside increased forward locomotion and improved control of the head. Contact‐induced modulations of whisking symmetry, synchrony, and whisker spread emerge shortly thereafter but continue to dev... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149747 Mon, 22 Aug 2011 23:00:00 +0100 5149747 http://www.medworm.com/index.php?rid=5149746&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20597 AbstractThe majority of children who are born very preterm escape major impairment, yet more subtle cognitive and attention problems are very common in this population. Previous research has linked infant focused attention during exploratory play to later cognition in children born full‐term and preterm. Infant focused attention can be indexed by sustained decreases in heart rate (HR). However there are no preterm studies that have jointly examined infant behavioral attention and concurrent HR response during exploratory play in relation to developing cognition. We recruited preterm infants free from neonatal conditions associated with major adverse outcomes, and further excluded infants with developmental delay (Bayley Mental Development Index [MDI < 70]) at 8 months corrected ag... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149746 Mon, 22 Aug 2011 23:00:00 +0100 5149746 http://www.medworm.com/index.php?rid=5149745&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20595 AbstractMotor overflow is extraneous movement in a limb not involved in a motor action. Typically, overflow is observed in people with neurological impairments and in healthy children and adults during strenuous and attention‐demanding tasks. In the current study, we found that young infants produce vast amounts of motor overflow, corroborating claims of symmetry being the default state of the motor system. While manipulating an object with one hand, all 27 of the typically developing 4.5‐ to 7.5‐month‐old infants who we observed displayed overflow movements of the free hand (on 4/5 of unimanual actions). Mirror‐image movements of the hands occurred on 1/8 of unimanual actions, and the hands and legs moved in synchrony on 1/3 of unimanual acts. Motor overflow was less frequent wh... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5149745 Mon, 22 Aug 2011 23:00:00 +0100 5149745 http://www.medworm.com/index.php?rid=5090529&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20593 AbstractThis longitudinal study of 27 infants examined the development of pulling‐to‐stand (PTS). In general, infants began PTS using a two‐leg strategy and transitioned to a half‐kneel strategy. As a group, infants showed no preference for either strategy at the onset of PTS, switching between strategies until half‐kneeling became the dominant pattern about 1 month after the onset of PTS. Examination of individual developmental trajectories revealed variability in age at PTS onset, time between PTS onset and half‐kneel strategy onset, duration of the two‐leg strategy as the dominant pattern, time until the half‐kneel strategy became the dominant pattern, shape of the transition between strategies (gradual vs. abrupt), and timing of PTS relative to onset of other motor mile... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5090529 Tue, 02 Aug 2011 23:00:00 +0100 5090529 http://www.medworm.com/index.php?rid=5090528&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20592 AbstractTo discover whether the accumulation of life's experiences, adverse and enriching, inform, and serve the following generation by inheritance we examine whether stress to a weanling female will influence her future offspring, whether prereproductive enrichment to the dam, or postweaning enrichment to the offspring, can reverse the transgenerational effects of stress, and whether, like adversity, enrichment might have transgenerational effects. Female rats were exposed to stressors when they were 27–29 days old. Half of these females and their controls were then raised in an enriched environment from weaning until mating at 60 days to examine whether preproduction enrichment reverses the effects of preproduction stress on offspring. Half of the offspring of each group were raised i... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5090528 Tue, 02 Aug 2011 23:00:00 +0100 5090528 http://www.medworm.com/index.php?rid=5043674&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20589 AbstractPrenatal aluminum exposure may affect the development of the embryo and alter the capacity for learning and memory in adults. The chick embryo is a good experimental model to study the effect of prenatal toxin exposure on cognitive defects in offspring, because it eliminates maternal confounding variables. In the present study, we applied a one‐trial passive avoidance‐learning task in day‐old chicks to examine the effects of prenatal aluminum chloride injections (2, 20, and 200 mM in 200 µl per egg, daily over a period of 4 successive days) on memory consolidation. The data suggest that chicks injected with aluminum chloride (20 mM) daily from E12 to E15 had significantly impaired short‐term memory, intermediate‐term memory, and long‐term memory (LTM) after train... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5043674 Tue, 19 Jul 2011 23:00:00 +0100 5043674 http://www.medworm.com/index.php?rid=5032591&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20586 AbstractAnimal personality has been extensively studied from a functional and evolutionary point of view. Less attention has been paid to the development of personality, its phenotypic plasticity, and the influence of manipulation of early environmental factors. Here we describe the effects of manipulating the sex ratio of the litter, at postnatal day (pnd) 3, in wild‐type rats, on personality traits in adulthood. We measured the treatment effects on aggression, defensive burying, and open field behavior at pnd 90 and 120, as well as on their contextual generality, and stability over time (differential and structural consistency). Main effects of litter composition were found on open field behavior at pnd 120 but not on the other behaviors. Since correlations between behaviors changed ov... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5032591 Wed, 13 Jul 2011 23:00:00 +0100 5032591 http://www.medworm.com/index.php?rid=5032590&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20585 AbstractIn mammals, the development of individual behavioral profiles can be influenced considerably by social factors during early phases of life. In guinea pigs, for instance, sons whose mothers experienced social instability during pregnancy and lactation show an infantilized behavioral profile. Here, we examined whether the same phenomenon exists also in wild cavies, the ancestor of the domestic guinea pig. Using a comparable experimental approach, our results revealed a similar behavioral infantilization as well as a delayed gonadal development of sons when their mothers had lived under unstable social conditions. These data show clearly that the behavioral and hormonal profile of male wild cavies can be shaped significantly by the social environment in which their mothers lived durin... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5032590 Wed, 13 Jul 2011 23:00:00 +0100 5032590 http://www.medworm.com/index.php?rid=5032589&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20584 AbstractOne hundred six infants participated in a longitudinal study of cognition–emotion integration exploring the effects of attentional control on regulation of negative affect across infancy. At both 5 and 10 months, attentional control was measured behaviorally (looking time to neutral stimulus), physiologically (cardiac reactivity), and with temperament‐based parental ratings of orienting/regulation. Looking and cardiac measures were examined both before and after a mild stressor. At 5 months, post‐distress negative affect was related only to distress‐related increases in heart rate. At 10 months, however, behavioral, cardiac, and parent‐report aspects of attentional control explained unique variance in post‐distress negative affect. Attentional control measures at 5 mont... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5032589 Wed, 13 Jul 2011 23:00:00 +0100 5032589 http://www.medworm.com/index.php?rid=5032588&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20583 AbstractWhen adults view very realistic humanoid robots or computer avatars they often exhibit an aversion to them. This phenomenon, known as the “uncanny valley,” is assumed to be evolutionary in origin, perhaps tapping into modules for disgust or attractiveness that detect violations of our normal expectations regarding social signals. Here, we test an alternative hypothesis that the uncanny valley is developmental in origin and, thus, that specific early experience with real human faces leads to its eventual emergence. To test this idea, we measured visual preferences in response to all possible pairs of a human face, realistic avatar face, and an unrealistic avatar face in groups of 6‐, 8‐, 10‐, and 12‐month‐old infants. Consistent with the developmental hypothesis, we fo... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5032588 Wed, 13 Jul 2011 23:00:00 +0100 5032588 http://www.medworm.com/index.php?rid=5032587&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20581 AbstractSiblings share similar genetics and environments, however, their behavior can be quite different. To determine if within‐litter variance in neonatal–maternal interactions predict adult sibling behavioral variance, we observed mother–pup interactions during postnatal days 1–8 in four Sprague–Dawley rat litters and measured adult offspring behavioral responses to social and physical novelty. Our results indicate that pup and maternal behavior varied by at least twofold within each litter, and that specific pup behaviors within each litter (perioral contact) were associated with increased maternal licking. Furthermore, siblings that received more licks and made more perioral contact during postnatal days 1–8 had longer latencies to approach novel objects in adulthood than ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5032587 Wed, 13 Jul 2011 23:00:00 +0100 5032587 http://www.medworm.com/index.php?rid=5032586&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20580 AbstractSalivary cortisol has been useful for evaluating children's physiological responses to stress and for identifying factors that predict their magnitude and duration. However, results have been somewhat equivocal across studies, and this has motivated researchers to identify sources of variance and error. Here, we examined the prevalence of preschoolers' noncompliance during saliva collection and aimed to learn about noncompliant children in terms of their hypothalamus–pituitary–adrenal function, behavior in other situations, and symptoms of behavioral problems. Results were based on measures of cortisol, children's behavior during saliva collection and a mother–child teaching interaction, and ratings of problem behavior by teachers and parents. Results show that 12% (21/174) o... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5032586 Wed, 13 Jul 2011 23:00:00 +0100 5032586 http://www.medworm.com/index.php?rid=5090527&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20590 AbstractThe current study examined behavioral measures and response‐locked event‐related brain potentials (ERPs) derived from a Go/No‐Go task in a large (N = 328) sample of 5‐ to 7‐year‐olds in order to better understand the early development of response monitoring and the impact of child age and sex. In particular, the error‐related negativity (ERN, defined on both error trials alone and the difference between error and correct trials, or ΔERN), correct response negativity (CRN), and error positivity (Pe) were examined. Overall, the ERN, CRN, and the Pe were spatially and temporally similar to those measured in adults and older children. Even within our narrow age range, older children were faster and more accurate; a more negative ΔERN and a more positive Pe were asso... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5090527 Thu, 30 Jun 2011 23:00:00 +0100 5090527 http://www.medworm.com/index.php?rid=5043673&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20588 AbstractThe current study investigated a set of abilities collectively referred to as executive function (EF). Substantial improvement in EF ability occurs between 3 and 6 years of age (e.g., Carlson [2005] Developmental Neuropsychology, 28(2):595–616). This improvement is thought to reflect changes in brain development, especially in areas of prefrontal cortex and frontal cortex, which occur during this time period (e.g., Luu & Posner [2003] Brain 126:2119–2120). Little work has examined preschoolers' cortical activity during EF tasks, despite the frequent use of performance on such tasks as indirect measures of (pre)frontal functioning. The current study measured continuous EEG activity in 104 preschool aged children as they completed a battery of EF tasks. Changes from baseline ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5043673 Thu, 30 Jun 2011 23:00:00 +0100 5043673 http://www.medworm.com/index.php?rid=5032585&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20577 AbstractIn maternal potentiation, the rate of vocalization by a young organism during isolation is greatly enhanced if that isolation has been immediately preceded by an interaction with the mother (or other adult female in the case of rats). The enhancement in isolation‐induced vocalization rate does not occur if the young animal had an interaction with other social companions like littermates or with familiar inanimate stimuli like home cage shavings. The present study demonstrates that pups whose vagus nerve is cut below the diaphragm do not potentiate vocalization after an interaction with their dam. The vocalization rates of denervated pups in a first isolation, in the presence of the dam, and during cold exposure do not differ from control pups. Their non‐vocal behaviors also app... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=5032585 Thu, 30 Jun 2011 23:00:00 +0100 5032585 http://www.medworm.com/index.php?rid=4941119&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20554 AbstractThe quest to understand how the brain is able to store information for later retrieval has been pursued by many scientists through the years. Although many have made very significant contributions to the field and our current understanding of the process, few have played as pivotal a role in advancing our understanding as William T. Greenough. The current report will utilize associative learning, a training paradigm that has greatly assisted in our understanding of memory consolidation, to demonstrate how findings emerging from the Greenough laboratory helped to not only shape our current understanding of learning induced anatomical plasticity, but to also launch future analyses into the molecular players involved in this process, especially the Fragile X Mental Retardation Protein... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941119 Sun, 19 Jun 2011 00:31:12 +0100 4941119 http://www.medworm.com/index.php?rid=4941118&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20558 AbstractThis invited address is offered in celebration of the career of Dr. William T. Greenough, especially the mentorship aspect of this illustrious career. It details how glutamate has been a thread throughout my professional career, including in my training with Bill. Our investigations of the role of metabotropic glutamate receptors in synaptic plasticity, specifically in relation to the fragile‐X mental retardation protein, are described. I then discuss how glutamate has played a role in my current professional life as a psychiatrist working in palliative care. Finally, I end with some words about how the training I received from Bill has had, and continues to have, an impact on my professional development. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:482–488, 2011. (Source:... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941118 Sun, 19 Jun 2011 00:31:12 +0100 4941118 http://www.medworm.com/index.php?rid=4941117&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20564 AbstractInvestigation of protein translation at the synapse, using functioning synaptic particles termed synaptoneurosomes, has led to identification of Fragile X protein as a key synaptic component. In its absence, some key mRNAs are translated more diffusely in the cell, and more slowly. Recent studies have implicated ERK (extracellular receptor regulated kinase) as a central factor in regulating the kinetics of translation at the synapse. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:476–481, 2011. (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941117 Sun, 19 Jun 2011 00:31:11 +0100 4941117 http://www.medworm.com/index.php?rid=4941116&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20557 AbstractBehavioral experience has long been known to influence functional outcome after brain injury, but only recently has its pervasive role in the reorganization of the adult brain after damage become appreciated. We briefly review findings from animal models on the role of experience in shaping neuronal events after stroke‐like injury. Experience‐dependent neural plasticity can be enhanced or impaired by brain damage, depending upon injury parameters and timing. The neuronal growth response to some experiences is heightened due to interactions with denervation‐induced plasticity. This includes compensatory behavioral strategies developed in response to functional impairments. Early behavioral experiences can constrain later experience‐dependent plasticity, leading to suboptimal... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941116 Sun, 19 Jun 2011 00:31:09 +0100 4941116 http://www.medworm.com/index.php?rid=4941115&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20563 AbstractFifty years ago, Mark Rosenzweig and coworkers described environmental effects on brain chemistry and gross brain weight. William Greenough then used stereological tools, electron microscopy, and the Golgi stain to demonstrate that enrichment led to dendritic growth and synapse addition. Together these forms of plasticity accounted for cortical expansion and a reduction in cell density. In parallel with other investigators, Greenough demonstrated that these effects were not limited to the rodent, the cortex, or development, but instead generalize to many species, brain regions, and life stages. Studies of the anatomical effects of enrichment foreshadowed the recent empirical evidence for cortical volumetric increases after environmental experience and training in humans. Since rese... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941115 Sun, 19 Jun 2011 00:31:08 +0100 4941115 http://www.medworm.com/index.php?rid=4941114&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20560 AbstractBill Greenough's work provides a framework for thinking about synaptogenesis not only as a key step in the initial wiring of neural systems according to a species typical plan (i.e., experience‐expectant development), but also as a mechanism for storing information based an individual's unique experience over its lifetime (i.e., experience‐dependent plasticity). Analysis of synaptic development in vitro brings a new opportunity to test the limits of expectant‐expectant development at the level of the individual neuron. We analyzed dendritic growth, synapse formation, and the development of specialized cytoplasmic microdomains during development in cultured hippocampal neurons, to determine if the timing of each of these events is correlated. Taken together, the findings repor... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941114 Sun, 19 Jun 2011 00:31:06 +0100 4941114 http://www.medworm.com/index.php?rid=4941113&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20559 AbstractBill Greenough's work on the cell biology of information storage suggests that we cannot understand the mechanism of long‐term memory without understanding the series of cellular transactions that drive coordinated structural changes in neurons, glia, and blood vessels. Here, we show that after 4 days of differential housing, neuropil of EC cortex has expanded significantly, but the vasculature has not, resulting in a dilution of the blood supply. Significant growth of neurons and astrocytes has been reported within this time period, suggesting expression of synaptic plasticity might involve temporally coordinated genomic responses by both neurons and glia. Given that astrocytes appear to couple neuronal and vascular growth during development, we hypothesize that they may also me... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941113 Sun, 19 Jun 2011 00:31:03 +0100 4941113 http://www.medworm.com/index.php?rid=4941112&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20556 AbstractAutism is an early onset neurodevelopmental disorder characterized by disruption of early social interaction. Although the social disability of autism remains the central defining feature of the condition, mechanisms that might account for this disability remain poorly understood. This paper briefly reviews some aspects of the social deficit in autism focusing on new approaches to characterizing social information processing problems, potential brain mechanisms, and theoretical models of the disorder. It will touch on aspects of specific social processes that appear to develop in unusual ways in autism including facial perception, joint attention, and social information processing. The importance of adopting more ecologically valid methods and for integrating the various approaches... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941112 Sun, 19 Jun 2011 00:31:01 +0100 4941112 http://www.medworm.com/index.php?rid=4941111&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20562 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941111 Sun, 19 Jun 2011 00:30:59 +0100 4941111 http://www.medworm.com/index.php?rid=4941109&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20582 AbstractMany transformations that occur in adolescence are related to emotion and emotion regulation, yet very little is known about the autonomic underpinnings of these changes. The aim of the study was to document age‐related differences in autonomic responses to social stress and relations to emotion regulation. Ninety‐nine female adolescents engaged in a paced breathing and a spontaneous speech task while electrocardiography measurements were taken. Spectral decomposition of the heart period data was used to create measures of sympathetic and parasympathetic activity. Results revealed a positive correlation between age and sympathetic activity and a negative correlation between age and parasympathetic activity. These findings contribute to a better understanding of the age‐relate... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941109 Sun, 19 Jun 2011 00:30:45 +0100 4941109 http://www.medworm.com/index.php?rid=4941110&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20579 AbstractSpatial normalization and segmentation of pediatric brain magnetic resonance images (MRI) data with adult templates may impose biases and limitations in pediatric neuroimaging work. To remedy this issue, we created a single database made up of a series of pediatric, age‐specific MRI average brain templates. These average, age‐specific templates were constructed from brain scans of individual children obtained from two sources: (1) the NIH MRI Study of Normal Brain Development and (2) MRIs from University of South Carolina's McCausland Brain Imaging Center. Participants included young children enrolled at ages ranging from 8 days through 4.3 years of age. A total of 13 age group cohorts spanning the developmental progression from birth through 4.3 years of age were used to const... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4941110 Thu, 16 Jun 2011 23:00:00 +0100 4941110 http://www.medworm.com/index.php?rid=4907201&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20576 AbstractThe development of hand preferences for object‐directed actions and pointing gestures was investigated in toddlers sampled bimonthly between 15 and 25 months of age. Language level was also assessed, in an attempt to examine the relationship between handedness and language development. Results did not reveal any changes over the study period in the mean Handedness Index of the whole sample, both for bimanual manipulative activities and pointing gestures. However, the categorization of participants as left‐handers, right‐handers, or non‐lateralized revealed that most of children presented nonlinear individual trajectories in the development of hand preference. Moreover, the only significant correlations observed between hand preferences for manipulation and pointing were neg... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4907201 Tue, 07 Jun 2011 23:00:00 +0100 4907201 http://www.medworm.com/index.php?rid=4907200&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20572 AbstractIt is still unclear whether infants become right‐handed because of their left‐hemisphere specialization for language (through gestural communication for instance), whether they speak predominantly with their left hemisphere because of this hemisphere's superiority in controlling sequential actions which first results in right‐handedness, or whether the two lateralization processes develop independently. To tackle this question, we followed 26 human infants from 8 to 20 months to evaluate the temporal relationship between the emergence of hand preference for grasping objects and for declarative pointing (communicative gesture). Our results show that when grasping and pointing are compared in similar conditions, with objects presented in several spatial positions, the tendency ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4907200 Tue, 07 Jun 2011 23:00:00 +0100 4907200 http://www.medworm.com/index.php?rid=4907199&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20570 AbstractPrenatal stress disrupts normal sexual differentiation and behavior with concomitant alterations in brain development; however, its effects on the cytoarchitecture of neurons in the sexually dimorphic medial preoptic area (mPOA) of the hypothalamus is not known. Morphometric analysis of the mPOA of adult rats showed sex differences as neurons from control females had significantly greater numbers of basal dendritic branches and cumulative basal dendritic length as compared to control male neurons. Prenatal stress significantly altered these sexual dimorphisms, as prenatally stressed (P‐S) males had increased measures of cell body area, perimeter, cumulative basal dendritic length, and branch point numbers as compared to control males. Prenatal stress also altered the cytoarchitec... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4907199 Tue, 07 Jun 2011 23:00:00 +0100 4907199 http://www.medworm.com/index.php?rid=4907198&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20571 AbstractThe zebrafish has been one of the preferred vertebrate model organisms of developmental biology, and is becoming an important research tool for behavioral neuroscience and behavior genetics. A prominent feature of zebrafish is their strong shoaling tendency. Most recently, the first study investigating the development of shoaling in zebrafish demonstrated that a few days after hatching zebrafish do not shoal, but that shoaling tendency gradually increases during development. The current study investigates this phenomenon using the nearest neighbor distance, a measure most frequently employed for the quantification of shoal cohesion in fish. We demonstrate that shoal cohesion increases with age, while thigmotaxis, “wall hugging,” does not show a consistent age‐dependent change... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4907198 Tue, 07 Jun 2011 23:00:00 +0100 4907198 http://www.medworm.com/index.php?rid=4835510&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20569 AbstractIn an infant's developing cortex, the explanation for the mechanisms underlying the activations and deactivations in response to visual stimuli remains controversial. While previous near‐infrared spectroscopy (NIRS) studies in awake infants have demonstrated cortical activations in response to meaningful/attractive visual stimuli, functional magnetic resonance imaging (fMRI) studies performed on sleeping infants showed negative blood oxygenation level‐dependent (BOLD) responses to high‐luminance unpatterned stimulations, such as a photic stimulation. To examine the effect of the characteristics of visual stimuli on cortical processing in awake infants, we measured cortical hemodynamic responses in 6‐month‐old infants during the presentation of a high‐luminance unpattern... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4835510 Tue, 17 May 2011 23:00:00 +0100 4835510 http://www.medworm.com/index.php?rid=4835509&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20567 AbstractA recent study found appetitive reinforcement in infant rats given 1.0 but not 2.0 g/kg ethanol and only when ethanol was delivered intragastrically (i.g., but not if intraperitoneally, i.p.; Nizhnikov, Pautassi, Truxell, & Spear [2009] Alcohol 43, 347–358). Corticosterone release could modulate ethanol's motivational effects. The goal of this study was to replicate the differential capability of i.g. vs. i.p. ethanol to induce conditioning and to find hormonal correlates underlying this phenomenon. Experiment 1 confirmed that 1.0 g/kg ethanol induced conditioned preference in infant rats when given i.g. but not i.p. In Experiment 2 corticosterone was assessed at 20, 40, 60, or 120 min after ethanol (0.0, 0.5, 1.0, and 2.0 g/kg, i.g. or i.p.). Route of administration ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4835509 Tue, 17 May 2011 23:00:00 +0100 4835509 http://www.medworm.com/index.php?rid=4835508&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20566 AbstractOxytocin (OT) has an organizational effect within the central nervous system and can have long‐lasting effects on the expression of social behavior. OT has recently been implicated in modulating the release of serotonin through activation of receptors in the raphe nuclei. Here we test the hypothesis that OT can have an organizational effect on the serotonergic system. Male prairie voles received an intraperitoneal injection on postnatal day 1 with 3.0 or .3 µg OT, an OT antagonist, or a saline control. Brains were collected on day 21 and immunostained for serotonin. Serotonin axons were quantified in the anterior hypothalamus, cortical amygdala, medial amygdala, paraventricular nucleus of the hypothalamus, and ventromedial hypothalamus. Males treated with 3.0 µg OT displaye... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4835508 Tue, 17 May 2011 23:00:00 +0100 4835508 http://www.medworm.com/index.php?rid=4785030&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20555 This study aimed to assess the impact of prenatal restraint or predator stress on pilocarpine‐induced epileptic behavior. Pregnant rats were exposed to stressors on gestational days 15, 16, and 17. Restraint stress consisted of daily restraint of the dam. During predator stress, caged rats were exposed to a cat in a cage. On postnatal day 25, male pups were injected with pilocarpine and the behavior of each rat was observed. Prenatal stress led to low birth weight and increased blood corticosterone levels. Both stressors significantly potentiated pilocarpine‐induced seizures. Predator‐stressed pups exhibited significantly severe tonic–clonic seizures compared with restraint‐stressed animals. These data emphasize the impact of prenatal stress on fetal growth, and neural and endocr... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4785030 Wed, 04 May 2011 23:00:00 +0100 4785030 http://www.medworm.com/index.php?rid=4785029&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20551 AbstractAutonomic reactivity was studied in individuals with fragile X syndrome (FXS), a genetic disorder partially characterized by abnormal social behavior. Relative to age‐matched controls, the FXS group had faster baseline heart rate and lower amplitude respiratory sinus arrhythmia (RSA). In contrast to the typically developing controls, there was a decrease in RSA with age within the FXS group. Moreover, within the FXS group heart rate did not slow with age. The FXS group also responded with an atypical increase in RSA to the social challenge, while the control group reduced RSA. In a subset of the FXS group, the autonomic profile did not change following 2 months and 1 year of lithium treatment. The observed indices of atypical autonomic regulation, consistent with the Polyvagal Th... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4785029 Wed, 04 May 2011 23:00:00 +0100 4785029 http://www.medworm.com/index.php?rid=4907197&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20575 AbstractDevelopment of the hypothalamic‐pituitary‐adrenal (HPA) axis is influenced by external factors during early life in mammals, which optimizes adult function for predicted conditions. We have hypothesized that adolescence represents a sensitive period for the development of some aspects of adult stress response regulation. This was based on prior work showing that repeated exposure of rats to a stressor across an adolescent period increases fearfulness in a novel environment in adulthood and results in lower levels of dopamine receptor subtype‐2 protein in prefrontal cortex. Here, we further our investigation of both acute and long‐term effects of repeated adolescent stressor exposure on physiological (i.e., corticosterone) and behavioral (i.e., defensive behavior) measures o... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4907197 Sat, 30 Apr 2011 23:00:00 +0100 4907197 http://www.medworm.com/index.php?rid=4879955&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20568 In this study we investigated the effects of lipopolysaccharide administration on physiological parameters in pregnant dams and their male offspring aged 9 weeks. In gestational Day 10, pregnant mice were injected intrapritoneally with Salmonella enterica lipopolysaccharide to model prenatal exposure to infection. The following results were obtained for offspring from dams stressed during pregnancy: (a) reduced anxiety‐related behavior in the elevated plus maze; (b) reduced food and water intake; (c) reduced body weight from birth up to postnatal Day 40. The observed data provide experimental evidence showing that prenatal stress can have complex and long‐lasting physiological/behavioral consequences in offspring. © 2011 Wiley Periodicals, Inc. Dev Psychobiol (Source: Developmental Ps... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4879955 Sat, 30 Apr 2011 23:00:00 +0100 4879955 http://www.medworm.com/index.php?rid=4835507&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20565 AbstractDuring a single, 2‐hr session with a scented foster dam, preweanling rat pups form an affiliative attraction to an odor associated with the maternal caregiver, manifest as a huddling preference. To identify maternal stimuli that induce this filial preference, we quantitatively examined behavioral interactions during odor conditioning. Bout duration of skin‐to‐skin (STS) contact was positively associated with the preference. In contrast, simple physical contact and anogenital licking were not significantly related to the preference. The frequency of nonanogenital licking was negatively associated with the preference as well as with bout duration of STS contact. When odor conditioning was conducted with a warm cylinder, ambient warmth, or stroking as the unconditioned stimulus,... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4835507 Sat, 30 Apr 2011 23:00:00 +0100 4835507 http://www.medworm.com/index.php?rid=4808537&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20552 This study seeks to examine early emerging executive functioning skills in monkeys (Macaca fascicularis) by using an error analysis approach where traditional measures of the tasks, as well as identification of major error patterns are related. Results show that during the infancy and early juvenile period, two processes that help support set‐maintenance could be differentiated: modulation of responses to novelty and persistence despite negative feedback. The results suggest that these two aspects of set‐maintenance were largely independent. Modulation of responses to novelty was most prominent in the infancy and early juvenile period. The ability to persist with a response set despite negative feedback emerged in the early juvenile period and was related to task performance until the ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4808537 Sat, 30 Apr 2011 23:00:00 +0100 4808537 http://www.medworm.com/index.php?rid=4785028&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20549 AbstractWe sought to determine if maternal depression, anxiety, and/or treatment with selective serotonin reuptake inhibitors (SSRIs) affect placental human serotonin transporter (SLC6A4), norepinephrine transporter (SLC6A2), and 11β‐hydroxysteroid dehydrogenase type 2 (11β‐HSD2) gene expression. Relative mRNA expression was compared among placental samples (n = 164) from healthy women, women with untreated depression and/or anxiety symptoms during pregnancy, and women who used SSRIs. SLC6A4 expression was significantly increased in placentas from women with untreated mood disorders and from women treated with SSRIs, compared to controls. SLC6A2 and 11β‐HSD2 expression was increased in noncontrol groups, though the differences were not significant. SLC6A4, SLC6A2, and 11β‐H... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4785028 Sat, 30 Apr 2011 23:00:00 +0100 4785028 http://www.medworm.com/index.php?rid=4660832&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20542 In this study, male and female Lister‐hooded rats were tested at early adolescence (postnatal day, pnd, 28), mid‐adolescence (pnd 40), or early adulthood (pnd 80) in a novel object recognition task (n = 12 males/females per age group). Males displayed a higher preference for the novel object than females at mid‐adolescence, with no sex difference at early adolescence. Adult females interacted with the novel object more than adult males, but not when side biases were removed. Sex differences at mid‐adolescence were not found in other measures, suggesting that the difference at this age was specific to situations involving choice of novelty. The results are considered in the context of age‐ and sex‐dependent interactions between gonadal hormones and the dopamine system. © 20... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4660832 Thu, 31 Mar 2011 23:00:00 +0100 4660832 http://www.medworm.com/index.php?rid=4618546&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20540 AbstractResponsiveness of adult rodent caretakers to infant rodents is necessary for their survival and proper development. Both olfactory and auditory cues are known to influence adult behavior toward the young. In the present study, we found that adults respond differentially to a recording of potentiated vs. non‐potentiated ultrasound vocalizations of a 12‐day‐old rat pup, either in the presence or absence of olfactory cues. The combination of olfactory and potentiated ultrasonic vocalization produced the greatest effect. Adult behavior was also affected by the adults' sex and parental experience in an interaction. Parental experience of females made them more responsive to the type of ultrasonic vocalization; males were little affected. Female experience, of course, includes the ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4618546 Tue, 22 Mar 2011 21:47:10 +0100 4618546 http://www.medworm.com/index.php?rid=4618552&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20548 AbstractFive‐year‐old Japanese monkeys were tested on long‐term visual recognition memory. The objects used were those that they had encountered daily during their first 2 years of life as to‐be‐remembered stimuli: persons, peers, and places. After a 3‐year delay, we conducted a recognition test using the preferential looking paradigm where the monkeys were presented with pictures of these familiar stimuli in combination with those of novel stimuli. The monkeys looked relatively longer at pictures of familiar stimuli than at those of novel stimuli, while participants in the control group, who had never seen the stimuli in question, showed no discriminative preference. The monkeys thus recognized the familiar stimuli through the pictures, suggesting retention of visual informati... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4618552 Tue, 22 Mar 2011 00:00:00 +0100 4618552 http://www.medworm.com/index.php?rid=4618551&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20544 AbstractAnimal researchers are increasingly interested in individual differences in behavior. Their interpretation as meaningful differences in behavioral strategies stable over time and across contexts, adaptive, heritable, and acted upon by natural selection has triggered new theoretical developments. However, the analytical approaches used to explore behavioral data still address population‐level phenomena, and statistical methods suitable to analyze individual behavior are rarely applied. I discuss fundamental investigative principles and analytical approaches to explore whether, in what ways, and under which conditions individual behavioral differences are actually meaningful. I elaborate the meta‐theoretical ideas underlying common theoretical concepts and integrate them into an ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4618551 Tue, 22 Mar 2011 00:00:00 +0100 4618551 http://www.medworm.com/index.php?rid=4618550&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20543 AbstractThe prefrontal cortex continues to develop throughout adolescence in several species, and our laboratory has demonstrated that during adolescence there is a decrease in neurons in the rat medial prefrontal cortex (mPFC). A PFC‐dependent task, the delayed alternation task, was used in the present study to examine the function of the mPFC while it is still maturing in rats of both sexes. A deficit was found in adolescents when compared to adults during 15‐ and 60‐s delays but not at other delays (5, 10, 30, and 90 s). Furthermore, adolescents committed more perseverative errors. No significant sex differences occurred at any delay for either age group; however, in the no delay training sessions, adolescent males reached criterion faster than females. These results indicate th... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4618550 Tue, 22 Mar 2011 00:00:00 +0100 4618550 http://www.medworm.com/index.php?rid=4618549&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20546 AbstractThe sensory processing of odorants is a dynamic process that requires plasticity at multiple levels. In the olfactory bulb (OB), inhibitory interneurons undergo lifelong replacement through a process known as adult neurogenesis. These newly born cells are incorporated in a learning‐dependent fashion, a process which has led some to suggest this as a primary mechanism through which the OB retains a high degree of plasticity throughout life. A continued focus of researchers in this field has been to understand the molecular mechanisms controlling adult subventricular zone (SVZ) neurogenesis and the innate functional role of these cells. Brain‐derived neurotrophic factor (BDNF) has been identified as a strong candidate molecule regulating adult OB neurogenesis. We review what is k... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4618549 Tue, 22 Mar 2011 00:00:00 +0100 4618549 http://www.medworm.com/index.php?rid=4618548&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20541 The objective of this longitudinal study was to quantitatively describe the changes in the object‐oriented arm movements that precede the transition to goal‐directed reaching movements in infancy. Arm kinematics in 10 full‐term infants were recorded biweekly from the age of 10 to 28 weeks while objects were presented for prehension. The kinematics were analyzed across three progressive phases of object‐oriented arm movements (early, before, and after onset of reaching movements). As infant age increased through the stage of object‐oriented movements, the distinguishing feature was that there was a decrease in movement jerk (when normalized to a dimensionless quantity), which reflects the increasing ability to adaptively modulate arm movements. This change in the dynamic character... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4618548 Tue, 22 Mar 2011 00:00:00 +0100 4618548 http://www.medworm.com/index.php?rid=4618547&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20545 AbstractPrevious research has provided inconsistent evidence for the relations between young children's hypothalamic–pituitary–adrenal (HPA) functioning and their temperament, parenting, and adjustment. Building biopsychosocial models of adjustment, we examined how temperamental inhibition and maternal punishment contributed to preschoolers' adrenocortical activity while interacting with adult strangers. We also examined whether HPA functioning moderated relations between dispositional and familial factors and children's internalizing and externalizing problems. A total of 402 preschool‐aged children from three independent samples with parallel and overlapping measures were studied. Salivary cortisol levels were measured twice while interacting with adult strangers during testing pro... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4618547 Tue, 22 Mar 2011 00:00:00 +0100 4618547 http://www.medworm.com/index.php?rid=4534231&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20538 AbstractIndividuals are often consistent in their behavior but vary from each other in the level of behavior shown. Despite burgeoning interest in such animal personality variation, studies on invertebrates are scarce, and studies on clonal invertebrates nonexistent. This is surprising given the obvious advantages of using invertebrates/clones to tackle the crucial question why such consistent behavioral differences exist. Here we show that individuals of clonal pea aphids exhibit consistent behavioral differences in their escape responses to a predator attack (dropping vs. nondropping off a plant). However, behavior was not repeatable at the clonal level. Genetically identical clones expressed various phenotypes but different clones produced different proportions of each phenotype (droppe... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4534231 Tue, 01 Mar 2011 00:00:00 +0100 4534231 http://www.medworm.com/index.php?rid=4534230&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20537 AbstractAs neuropsychiatric disorders such as schizophrenia, attention deficit disorder, and mood disorders all impact executive function and are likely to be diagnosed prior to adulthood, it is important to understand the normal ontogeny of executive function. Previous behavioral research has shown that adolescents' executive function is different than that of adults. In the present study, we use a previously validated cognitive test, the intradimensional/extradimensional (ID/ED) set‐shifting task, to assess attentional set shifting and reversal learning in adolescent and adult, male, Long‐Evans rats. These data suggest that adolescent rats are more cognitively rigid than adult rats and have impairments in the shifting, but not formation, of an attentional set. Adolescent rats are als... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4534230 Tue, 01 Mar 2011 00:00:00 +0100 4534230 http://www.medworm.com/index.php?rid=4534229&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20533 AbstractEnvironmental conditions during early development play a crucial role in shaping an organism's phenotype. To test how social group size affects stress response and behavioral characteristics, we used great tits (Parus major) from selection lines for exploratory behavior, a proxy for an avian personality trait, and birds from the wild in a brood size manipulation experiment. Nestlings were tested for stress response using an established stress test and after independence subjects were tested for exploratory behavior. Nestlings from small broods showed a stronger stress response than nestlings from normal‐sized broods. Exploratory behavior was not affected by brood size but associated with sex ratio in the nest. Birds from female‐biased broods became faster explorers than those f... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4534229 Tue, 01 Mar 2011 00:00:00 +0100 4534229 http://www.medworm.com/index.php?rid=4534228&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20524 This study had two goals: to determine the developmental trajectory of the maturation of this phenotype and to address its parental lineage. Interestingly, individuals most aggressive as adults were less likely to attack in early puberty. However, looking at the transition of agonistic behavior from play fighting to adult aggression, impulsive‐aggressive individuals were less likely to engage in play fighting attacks and more likely to engage in more mature agonistic behavior. Additionally, parental lineages were compared for the aggressive responses expressed by their adult offspring. Most impulsive‐aggressive individuals were offspring of few select males, which were more likely to produce this phenotype, without an association with females or specific litters. These findings identif... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4534228 Tue, 01 Mar 2011 00:00:00 +0100 4534228 http://www.medworm.com/index.php?rid=4534227&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20539 AbstractOctodon degus is a social caviomorph species that exhibits strong social bonds and robust distress responses to maternal separation. To understand the impact of early social isolation on social motivation, we investigated how social isolation during infancy, associated with repeated restricted interactions with mother and siblings, altered social motivation in young degus. In Experiment 1, three treatments were compared: complete isolation (ISOLATED group), nearly complete isolation, with daily half hour partition‐restricted reunions with the mother and siblings (RESTRICTED group), and social‐housing with the mother and siblings (FAMILY group). After 10 days of treatment, all subjects underwent a 5‐day choice test between mothers and unfamiliar females. During the treatment p... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4534227 Tue, 01 Mar 2011 00:00:00 +0100 4534227 http://www.medworm.com/index.php?rid=4486116&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20532 AbstractEarly experiences contribute powerfully to the development of neural systems that underlie various perceptual and cognitive abilities in humans. In one of the first studies to systematically control infants' exposure to a familiar object, we examined the effects of controlled experience on the neural correlates of visual recognition in two groups of infants. One group received 1 month of in‐home familiarization to a 3D model of a female face. Another group received 1.5 min of in‐lab familiarization to the 3D model of a female face, creating two conditions that differed in the amount and, importantly, the context of exposure to a familiar stimulus. Following familiarization, event‐related potentials (ERPs) were recorded at 3 months of age while infants viewed pictures of the... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4486116 Thu, 17 Feb 2011 21:12:11 +0100 4486116 http://www.medworm.com/index.php?rid=4486118&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20536 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4486118 Wed, 16 Feb 2011 00:00:00 +0100 4486118 http://www.medworm.com/index.php?rid=4486117&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20534 In conclusion, this study shows that hemp seed supplementation does not improve the reproductive and neurobehavioral performances of rats. Pregnant women and nursing mothers should be cautious about the using of Cannabis sativa L. byproducts in their diets. © 2011 Wiley Periodicals, Inc. (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4486117 Wed, 16 Feb 2011 00:00:00 +0100 4486117 http://www.medworm.com/index.php?rid=4447600&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20529 AbstractThis paper reviews the arguments against the instinct concept and the nature–nurture dichotomy put forward by Zing‐Yang Kuo (1898–1970) during the 1920s. Kuo insisted that nativism represented a kind of finished psychology, and that the labels of nature and nurture reflected and promoted one's ignorance of the development of a trait. Also discussed are his lesser known lines of research on the origins of the so‐called rat‐killing instinct in cats and his analysis on the determinants of animal fighting. His research illustrated the shortcomings of a nature–nurture framework and highlighted the necessity of his developmentally grounded alternative to studying behavior. Reasons for why Kuo's work has been marginalized in modern histories of psychology are also discussed. �... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4447600 Tue, 08 Feb 2011 20:27:38 +0100 4447600 http://www.medworm.com/index.php?rid=4447603&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20528 AbstractThe present study investigated whether three methodologies currently used in animal as well as human adult startle research could be adapted for measuring the startle response in 5‐month‐old infants. The three methods performed: an automated and computerized recording of the infants' whole‐body motor reactions (Automated Infant Motor Movement Startle Seat, AIMMSS); a coding of the infants' facial muscular contractions involved in the startle response (FACS, Baby FACS); an analysis of the infants' eyeblink intensity in response to the startle probes (Eye‐Blink Strength scale). The results showed that these methods accurately registered the latency and intensity parameters of the reactions to acoustic startle stimuli. A correlational analysis showed, also, that the three meth... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4447603 Tue, 08 Feb 2011 00:00:00 +0100 4447603 http://www.medworm.com/index.php?rid=4447602&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20527 AbstractThere is considerable debate about the phylogenic and ontogenic origins of episodic memory. In the present experiment, we examined episodic memory in 3‐ and 4‐year‐old children. To do this, we developed a hide‐and‐seek task that allowed us to assess children's recall of the what‐where‐when (www) of the hiding event. In this task, the experimenter and the child hid three plush toys in three separate locations around the house. After a brief retention interval, children were asked to verbally recall, in order (i.e., when), what toy was hiding where. Following this verbal test, children were given the opportunity to find the toys. On the verbal recall test, 4‐year‐olds reported more information than 3‐year‐olds. On the behavioral recall test, 3‐year‐olds perf... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4447602 Tue, 08 Feb 2011 00:00:00 +0100 4447602 http://www.medworm.com/index.php?rid=4447601&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20530 AbstractThe present study examined the effects of exercising (voluntary wheel running) during adolescence on attentional function in male and female spontaneously hypertensive rats (SHRs), a commonly used animal model of attention‐deficit/hyperactivity disorder (ADHD). Once rats reached adulthood, they received one session in which a light was presented 12 times but not reinforced, followed by training sessions in which the light was paired with a food reward. Male and female SHRs that had access to running wheels exhibited levels of unconditioned orienting behavior that were similar to Wistar–Kyoto rats (normo‐active control) while SHRs that did not have access to running wheels exhibited higher levels of unconditioned orienting behavior. When the light was later paired with food th... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4447601 Tue, 08 Feb 2011 00:00:00 +0100 4447601 http://www.medworm.com/index.php?rid=4402465&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20523 AbstractThe effects of short‐term bilateral naris occlusion (inducing olfactory deprivation) on mother–pup interactions, suckling behavior and hormonal status during post‐natal development in Wistar rats were studied. Bilateral naris occlusion was performed on 8‐day‐old rat pups and its effects were evaluated at Day 9 and at Day 15. The narins opened spontaneously between Day 12 and 14. Olfactory‐deprived pups exhibited a greater level of corticosterone at both ages versus untreated or sham animals. Olfactory deprivation via naris occlusion, in young rats, alters mother–pup interactions with a decrease in the duration of mother–pup retrieving and an increase in pup licking. Olfactory‐deprived pups showed also a lower mean duration of nursing and a decrease in nipple attac... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4402465 Wed, 26 Jan 2011 00:00:00 +0100 4402465 http://www.medworm.com/index.php?rid=4402464&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20526 AbstractAdult, virgin rats do not spontaneously display maternal behavior when exposed to foster pups. However, continuous daily exposure of the female to foster pups for about 5–7 days can induce a set of maternal behaviors similar to those shown by postpartum dams. Induction latencies depend upon a number of factors, including the stress and anxiety levels of the female. The goal of this study was to attempt to mitigate the likely stressfulness of being singly housed during testing by enriching the rat's home cage environment and to determine if the concomitant environmental change would alter the latency to express maternal behavior. In addition, the effect of varying the number of test pups used for testing was examined. Two groups of virgin Sprague–Dawley rats were first tested on... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4402464 Wed, 26 Jan 2011 00:00:00 +0100 4402464 http://www.medworm.com/index.php?rid=4402463&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20525 AbstractInfants' unitary perception of their multisensory world, including learning from people (faces and speech), hinges on temporal synchrony. Despite its importance, relatively little work has investigated the brain processes involved in infants' perception of temporal synchrony. In two experiments, we examined event‐related brain potentials (ERPs) to asynchronous and synchronous audio‐visual speech in infants. Both experiments showed the early auditory P2 was greater for the synchronously presented pairings and later attentional processing (Nc) was greater for asynchronous pairings. In addition, dynamic stimuli used in Experiment 2 produced a greater early visual response (N1) to the asynchronous condition and an enhanced memory‐related slow wave (PSW) later for the synchronous ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4402463 Sat, 01 Jan 2011 00:00:00 +0100 4402463 http://www.medworm.com/index.php?rid=4279429&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20520 AbstractWe investigated whether positive daily peer‐interactions counteract the effects of isolation in Octodon degus. Twenty‐five‐day‐old degus were either isolated (ISO), socially housed (SOCIAL), or isolated and allowed 1‐hr daily peer interaction (PARTIAL‐ISO). The animals were observed over 4 weeks. Just prior to isolation and after 2 weeks of individual housing, the subjects were assessed for response to pleasant stimuli via a sucrose preference test and to fearful situations in open field and startle tests. Two weeks after the previous tests, the subjects were retested as above and observed in novelty and sociability tests. Only the ISO group showed significant alterations in sensitivity to reward and increased risk‐taking behavior in fearful situations. The ISO group ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4279429 Wed, 22 Dec 2010 21:59:06 +0100 4279429 http://www.medworm.com/index.php?rid=4279430&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20521 AbstractMany precocial birds show a robust preference for the maternal call of their own species before and after hatching. This differential responsiveness to species‐specific auditory stimuli by embryos and neonates has been the subject of study for more than four decades, but much remains unknown about the dynamics of this ability. Gottlieb [Gottlieb [1971]. Development of species identification in birds: An enquiry into the prenatal determinants of perception. Chicago/London: University of Chicago Press.] demonstrated that prenatal exposure to embryonic vocalizations serves to canalize the formation of species‐specific preferences in ducklings. Apart from this, little is known about the features of the developmental system that serve to canalize such species‐typical preferences, ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4279430 Wed, 22 Dec 2010 00:00:00 +0100 4279430 http://www.medworm.com/index.php?rid=4243658&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20519 AbstractThe aim of the present study was to examine the moderating role of parasympathetic and sympathetic nervous system functioning on the relationship between child temperament and emotion regulation. Sixty‐two 4.5‐year olds (31 females) were rated by their parents on temperamental surgency. Respiratory sinus arrhythmia (RSA) and pre‐ejection period (PEP) were measured at baseline and in reaction to an interaction with an unfamiliar person and a cognitive test. The preschoolers' ability to self‐regulate emotion was assessed in response to a disappointment. Results revealed little or no PEP reactivity to the unfamiliar person to be related to poorer emotion regulation for children high in surgency, indicating that the lack of sympathetic activation may be a risk factor for behavi... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4243658 Tue, 07 Dec 2010 00:00:00 +0100 4243658 http://www.medworm.com/index.php?rid=4243657&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20514 AbstractThere are striking similarities between the visual defect of amblyopia and the motor deficit of the extremities produced by such types of damage to the central nervous system (CNS) as stroke and traumatic brain injury, both after and before maturity. Part of the motor deficit of the extremities following CNS injury can be attributed to a learning phenomenon termed “learned nonuse” or if present from birth, “developmental disregard.” The same mechanism is hypothesized to be involved in the development of amblyopia. Treatments that are efficacious in the remediation of these defects, Constraint‐Induced Movement therapy and amblyopia training, also share a number of strong similarities. In addition, plastic brain changes are produced by CI therapy and are hypothesized to occ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4243657 Wed, 01 Dec 2010 00:00:00 +0100 4243657 http://www.medworm.com/index.php?rid=4198738&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20515 AbstractThe fundamental concept in the emerging field of rehabilitation and brain plasticity is that although there is much constancy in brain function and organization across our lifetime, there is remarkable variability as well. This variability reflects the brain's capacity to alter its structure and function in reaction to environmental diversity as well as to perturbations including injury throughout the lifespan. Although the term brain plasticity is now widely used, it is not easily defined and is used to refer to changes at many levels in the nervous system ranging from molecular events, such as changes in gene expression, to behavior (e.g., Shaw & McEachern (Eds.) [2001]. Toward a Theory of Neuroplasticity. Philadelphia, USA: Psychology Press). The focus of our work has been t... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4198738 Wed, 24 Nov 2010 00:00:00 +0100 4198738 http://www.medworm.com/index.php?rid=4194293&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20517 AbstractIn human and chimpanzee infants, neonatal rightward supine head orientation bias predicts later right hand use preference. In an evolutionarily older primate species such as the rhesus monkey, a left hand preference has been reported, but there are no data on head orientation biases. Supine head orientation bias was measured experimentally in 16 rhesus monkey neonates and compared with prone head orientation bias as well as with various measures of hand use preference. A group‐level leftward supine head bias was found that corresponded to greater activity in the left hand while supine; however, supine head orientation did not predict later hand preference as measured by reaching or manipulation on a coordinated bimanual task. These data suggest that a trajectory for handedness in... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4194293 Tue, 23 Nov 2010 00:00:00 +0100 4194293 http://www.medworm.com/index.php?rid=4177197&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20518 AbstractChildhood is associated with improvements in task accuracy, response time, and reductions in intraindividual trial‐to‐trial variability in reaction times. The aims of this study were to investigate neural indicators of error monitoring to better understand the mechanisms underlying these cognitive developments in primary school aged children. Specifically, this study explored the development of error processing in 36 children aged 7 years and 41 children aged 9 years, as indexed by two electrophysiological indices of error processing, the error‐related negativity (ERN) and the error positivity (Pe). Notably, the amplitude and latency of the ERN and Pe did not differ significantly between the age groups. However, intraindividual variability in response time (RT) was strongly r... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4177197 Wed, 17 Nov 2010 00:00:00 +0100 4177197 http://www.medworm.com/index.php?rid=4177196&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20516 This study examined ethanol intake in P and alcohol‐nonpreferring (NP) rats 3 hr after birth (Experiment 1, surrogate nipple test), at postnatal days (PD) 8, 12, and 18 (Experiment 2, consumption from the floor procedure) and at adolescence (Experiment 3, two‐bottle choice test at PD32). The high‐preference genotype was readily expressed 3 hr after birth. P neonates drank twice as much ethanol as their NP counterparts. This heightened ethanol preference transiently reversed at P8, reemerged as weaning approached (P18) and was fully expressed during adolescence. These results help to clarify the ontogeny of genetic predisposition for ethanol. Genetic predisposition for higher ethanol intake in P than in NP rats seems to be present immediately following birth. © 2010 Wiley Periodi... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4177196 Wed, 17 Nov 2010 00:00:00 +0100 4177196 http://www.medworm.com/index.php?rid=4177195&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20513 AbstractWomen's experiences during pregnancy are predictive of variation in neurobehavioral profiles in their children. Few studies have assessed these relationships during the prenatal period. In 113 women in the 36th –38th gestational week (mean age 26.3 ± 5.4 years), electrocardiogram, blood pressure, respiration, salivary cortisol, and fetal heart rate (HR) were measured during baseline, a psychological challenge (Stroop color–word matching task), and a standardized paced breathing protocol. Subjects underwent the Structured Clinical Interview for DSM‐IV prior to testing and were grouped as: depressed, co–morbid for depression and anxiety, anxiety disorder only, and control. There was a significant main effect of maternal diagnostic group on fetal HR only during the Stroop... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4177195 Wed, 17 Nov 2010 00:00:00 +0100 4177195 http://www.medworm.com/index.php?rid=4177194&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20507 AbstractModern theories of brain function emphasize the importance of distributed functional networks and synchronized activity within and between networks in mediating cognitive functions. This view highlights the importance of considering brain‐behavior relationships after focsal lesions not only as the result of local structural damage but also as a more widespread alteration of the physiological state of networks connected to the lesion. Recent findings demonstrate coherent activity in large‐scale brain networks not only during task performance, but also, surprisingly, at rest in the absence of stimuli, tasks, or overt responses. Moreover, breakdown of coherent activity at rest, even in regions that are structurally intact, correlates with behavioral deficits and with their recover... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4177194 Wed, 17 Nov 2010 00:00:00 +0100 4177194 http://www.medworm.com/index.php?rid=4198737&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20504 We present the results of some preliminary studies to test this concept, and a discussion of network models as a measure of neurobiological change. © 2010 Wiley Periodicals, Inc. Dev Psychobiol (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4198737 Mon, 01 Nov 2010 00:00:00 +0100 4198737 http://www.medworm.com/index.php?rid=4194292&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20510 The objective of this study was to determine the consequences for HPA axis functioning among healthy full‐term newborns of prenatal treatment with the synthetic glucocorticoid (GC), betamethasone, which is the routine treatment for threatened preterm delivery. Ninety full‐term infants were recruited into two study groups (30 betamethasone treated; 60 comparison group matched for GA at birth and sex). The cortisol and behavioral response to the painful stress of a heel‐stick blood draw was assessed 24 hr after birth. Full‐term infants exposed to prenatal betamethasone displayed a larger cortisol response to the heel‐stick procedure, despite no differences in baseline levels. Further, within the recommended window of betamethasone administration (24–34 gestational weeks), infan... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4194292 Mon, 01 Nov 2010 00:00:00 +0100 4194292 http://www.medworm.com/index.php?rid=4177193&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20508 AbstractThe human brain possesses a remarkable ability to adapt in response to changing anatomical (e.g., aging) or environmental modifications. This form of neuroplasticity is important at all stages of life but is critical in neurological disorders such as amblyopia and stroke. This review focuses upon our new understanding of possible mechanisms underlying functional deficits evidenced after adult‐onset stroke. We review the functional interactions between different brain regions that may contribute to motor disability after stroke and, based on this information, possible interventional approaches to motor stroke disability. New information now points to the involvement of non‐primary motor areas and their interaction with the primary motor cortex as areas of interest. The emergence... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4177193 Mon, 01 Nov 2010 00:00:00 +0100 4177193 http://www.medworm.com/index.php?rid=4147358&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20509 AbstractNoninvasive brain stimulation is a technique for inducing changes in the excitability of discrete neural populations in the human brain. A current model of the underlying pathological processes contributing to the loss of motor function after stroke has motivated a number of research groups to investigate the potential therapeutic application of brain stimulation to stroke rehabilitation. The loss of motor function is modeled as resulting from a combination of reduced excitability in the lesioned motor cortex and an increased inhibitory drive from the nonlesioned hemisphere over the lesioned hemisphere. This combination of impaired neural function and pathological suppression resonates with current views on the cause of the visual impairment in amblyopia. Here, we discuss how the r... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4147358 Mon, 01 Nov 2010 00:00:00 +0100 4147358 http://www.medworm.com/index.php?rid=4113560&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20505 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4113560 Fri, 29 Oct 2010 21:37:32 +0100 4113560 http://www.medworm.com/index.php?rid=4080070&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20491 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4080070 Tue, 19 Oct 2010 16:45:37 +0100 4080070 http://www.medworm.com/index.php?rid=4080069&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20500 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4080069 Tue, 19 Oct 2010 16:45:35 +0100 4080069 http://www.medworm.com/index.php?rid=4063457&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20493 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4063457 Tue, 31 Aug 2010 23:00:00 +0100 4063457 http://www.medworm.com/index.php?rid=4016153&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20497 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4016153 Tue, 31 Aug 2010 23:00:00 +0100 4016153 http://www.medworm.com/index.php?rid=4008543&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20489 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=4008543 Tue, 31 Aug 2010 23:00:00 +0100 4008543 http://www.medworm.com/index.php?rid=3990700&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20488 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3990700 Tue, 31 Aug 2010 23:00:00 +0100 3990700 http://www.medworm.com/index.php?rid=3923315&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20486 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3923315 Tue, 31 Aug 2010 23:00:00 +0100 3923315 http://www.medworm.com/index.php?rid=3918462&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20484 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3918462 Tue, 31 Aug 2010 23:00:00 +0100 3918462 http://www.medworm.com/index.php?rid=3905808&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20481 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3905808 Fri, 27 Aug 2010 07:35:25 +0100 3905808 http://www.medworm.com/index.php?rid=3825709&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20480 Previous studies on the ontogeny of spatial learning report that rats younger than 19-21 days of age are incapable of learning the location of a platform relative to distal cues in the Morris water task. Here, we manipulated the spatial relationship of a cued platform to the pool and the distal visual room cues to investigate whether distal cues can control navigation among 16- to 24-day-old rats. Rats were trained to navigate to a cued platform in a rich distal cue environment. During critical test trials, the pool was shifted to a different, overlapping position and the cued platform was placed either in the same absolute location in the room or the same relative location in the pool as during training. Rats aged 17 days and older exhibited a disruption in performance when the cued platf... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3825709 Thu, 05 Aug 2010 23:00:00 +0100 3825709 http://www.medworm.com/index.php?rid=3728417&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20475 The present study used a cross-fostering procedure to investigate the effects of early traumatic experience on vocal expressions of emotions in rhesus macaques (Macaca mulatta). The subjects of the study were 12 juvenile females: six were born to abusive mothers and reared by nonabusive controls, and six were born to controls and reared by abusive mothers. The cross-fostering took place within 24-48 hr after birth. Vocalizations were recorded from the subjects in their social groups during their first 2 years of life. Abusive mothers maltreated their adopted daughters in the first 2-3 months after birth with patterns similar to those previously shown with their biological offspring. Abused females produced proportionally more noisy screams compared to controls. While controls used noisy sc... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3728417 Tue, 06 Jul 2010 23:00:00 +0100 3728417 http://www.medworm.com/index.php?rid=3728419&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20478 Naïve female prairie voles show significant variability in their behavioral response to newborns. We investigated whether that behavioral response (a) was related to the quality of postpartum maternal behavior; (b) was affected by postpartum maternal experience; and (c) could be selectively bred. The behavior of females was recorded in three conditions: as naïve in a nonreproductive context, as single lactating (no male present), and as experienced mother in a nonreproductive context. Finally, females and males with similar behavioral response to newborns were selectively bred for three generation. Males were removed before the offspring was born. Our results revealed that (a) naïve females that attacked pups, spent more time distant from them after parturition than those that were mate... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3728419 Mon, 05 Jul 2010 23:00:00 +0100 3728419 http://www.medworm.com/index.php?rid=3728418&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20477 Despite repetitive behaviors being a common feature of a number of clinical disorders and ubiquitous in normative development, little attention has been given to their ontogeny or temporal dynamics. We characterized these features in a mouse model of repetitive behavior to identify discrete trajectories of development and developmental changes in temporal dynamics. Three qualitatively distinct trajectory groups were identified which allowed for an examination of the interaction between temporal organization and developmental trajectory. Significant differences in temporal dynamics were found across development and among trajectory groups. Significant interactions of trajectory group and developmental period on temporal organization were also found. The combination of group-based trajectory... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3728418 Mon, 05 Jul 2010 23:00:00 +0100 3728418 http://www.medworm.com/index.php?rid=3887481&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20482 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3887481 Wed, 30 Jun 2010 23:00:00 +0100 3887481 http://www.medworm.com/index.php?rid=3852365&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20450 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3852365 Wed, 30 Jun 2010 23:00:00 +0100 3852365 http://www.medworm.com/index.php?rid=3852364&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20449 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3852364 Wed, 30 Jun 2010 23:00:00 +0100 3852364 http://www.medworm.com/index.php?rid=3852363&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20446 Abstract (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3852363 Wed, 30 Jun 2010 23:00:00 +0100 3852363 http://www.medworm.com/index.php?rid=3852362&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20479 (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3852362 Wed, 30 Jun 2010 23:00:00 +0100 3852362 http://www.medworm.com/index.php?rid=3708909&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20472 This study examined the time window construct for session spacing with 6- to 18-month-old human infants. Infants of all ages exhibited the retention benefit of two (integrated) sessions only when the second session occurred within the time window, but only 6-month-olds remembered longer when it occurred late in the time window. Combined with 3-month-olds' data, these findings document the generality and predictive validity of the time window construct throughout the infancy period with one modification: Integration late in the time window only benefits infants younger than 9 months. © 2010 Wiley Periodicals, Inc. Dev Psychobiol (Source: Developmental Psychobiology) Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3708909 Tue, 29 Jun 2010 23:00:00 +0100 3708909 http://www.medworm.com/index.php?rid=3708910&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20476 Domestic chicks walk within 3-4 hr after hatching following 21 days of incubation. However, differences in light exposure can vary incubation duration. Based on pilot studies, we predicted that there would be a positive relationship between incubation duration and locomotor competence at hatching. Embryos were incubated in one of three conditions that varied light duration and intensity, and overground locomotor performance was tested on the day of hatching. Chicks incubated in continuous bright light hatched 1-2 days earlier than chicks incubated in less or no light. Kinematic findings indicated that locomotor skill was similar across incubation conditions and led us to reject our hypothesis. We propose that light may accelerate locomotor development without adversely affecting skill. Our... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3708910 Mon, 28 Jun 2010 23:00:00 +0100 3708910 http://www.medworm.com/index.php?rid=3669366&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20471 In this pilot study the severity of autism spectrum disorders (ASD) was associated with alterations in white matter development. Children with ASD and without ASD were assessed by magnetic resonance imaging (MRI) for their myelination development on a regional basis. Measures were obtained in medial frontal cortex, temporal poles, and temporo-parietal junction in both left and right hemispheres. Children with ASD showed myelination that was greater than expected for their age in both left and right medial frontal cortex and showed myelination that was less than expected in left temporo-parietal junction. The severity of ASD symptoms, as assessed by the Autism Diagnostic Observation Schedule - Generic, was associated more with left hemisphere alterations than right hemisphere. © 2010 Wiley... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3669366 Thu, 17 Jun 2010 23:00:00 +0100 3669366 http://www.medworm.com/index.php?rid=3669368&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20474 We examined grasp characteristics and their development in 35 children with trisomy 21, aged 4-18 years, who performed simple manual tasks (two manual tasks of the Movement Assessment Battery for Children, and grasping of five wooden blocks whose size was determined by their hand size). The age-matched comparison group included 35 typically developing children. Children with trisomy 21 were found to use fewer fingers than children in the comparison group in each task. They also used specific grasps and tended to extend fingers that were not involved in the grip. While some specific grasp characteristics of children with trisomy 21 decreased with age, other did not, and remained present throughout development. The perceptual-motor development of children with trisomy 21 should be analyzed i... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3669368 Tue, 15 Jun 2010 23:00:00 +0100 3669368 http://www.medworm.com/index.php?rid=3669367&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20473 Early visual deprivation caused by bilateral congenital cataracts produces deficits in discriminating faces that differ in the spacing of features, but not in feature shape (Le Grand et al. [2001] Nature 410: 810). We investigated whether these deficits are specific to human faces by testing patients' ability to discriminate between stimuli differing only in feature spacing in human and monkey faces (Experiment 1) and in houses (Experiment 2). Patients, as a group, showed deficits on only one task: they had lower accuracy than normal in discriminating feature spacing in human faces. In contrast, they were normal in discriminating feature spacing in monkey faces and in houses. The results suggest that early visual experience is necessary to set up (or preserve) the neural architecture used ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3669367 Tue, 15 Jun 2010 23:00:00 +0100 3669367 http://www.medworm.com/index.php?rid=3620007&cid=s_33722_36_f&fid=33722&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fdev.20469 The present study investigated if oral exposure to milk or amniotic fluid (AF) alters responsiveness to sensory stimulation in the neonatal rat, and whether these effects are mediated by the opioid system. Facial wiping evoked by intraoral lemon infusion was used as a measure of sensory responsiveness. Pups were tested in a supine posture, because they showed more paw-face strokes during facial wiping than pups tested prone (Experiment 1). Moreover, pups orally exposed to milk (Experiment 2) or AF (Experiment 3) showed a diminished wiping response to lemon compared to controls exposed to water. Blockade of opioid receptors with the nonselective antagonist naltrexone (Experiment 4) or the kappa antagonist nor-binaltorphimine (Experiment 5) reinstated higher levels of facial wiping after AF ... Developmental Psychobiology journals http://www.medworm.com/rss/comments.php?id=3620007 Tue, 01 Jun 2010 23:00:00 +0100 3620007