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Sensitive Period (sensitive + period)

Distribution by Scientific Domains

Humanities and Social Sciences	34%
Life Sciences	31%
Medical Sciences	21%
Psychology	12%

Selected Abstracts

Commentary: An Early, Short, and Useful Sensitive Period in the Human Infant

BIRTH, Issue 2 2009
Marshall H. Klaus MD
No abstract is available for this article. [source]

Why All Counter-Evidence to the Critical Period Hypothesis in Second Language Acquisition Is not Equal or Problematic

LINGUISTICS & LANGUAGE COMPASS (ELECTRONIC), Issue 6 2008
Jason Rothman
That adult and child language acquisitions differ in route and outcome is observable. Notwithstanding, there is controversy as to what this observation means for the Critical Period Hypothesis' (CPH) application to adult second language acquisition (SLA). As most versions of the CPH applied to SLA claim that differences result from maturational effects on in-born linguistic mechanisms, the CPH has many implications that are amendable to empirical investigation. To date, there is no shortage of literature claiming that the CPH applies or does not apply to normal adult SLA. Herein, I provide an epistemological discussion on the conceptual usefulness of the CPH in SLA (cf. Singleton 2005) coupled with a review of Long's (2005) evaluation of much available relevant research. Crucially, I review studies that Long did not consider and conclude differently that there is no critical/sensitive period for L2 syntactic and semantic acquisition. [source]

Necessity to establish new risk assessment and risk communication for human fetal exposure to multiple endocrine disruptors in Japan

CONGENITAL ANOMALIES, Issue 2 2002
Emiko Todaka
ABSTRACT, Our recent study clearly shows that fetuses are exposed to multiple chemicals including endocrine disruptors in Japan. Although the embryo and fetus stages are the most sensitive period to chemicals in humans' life cycle, the health effects of the chemicals such as endocrine disruptors to them are largely unknown. The conventional risk assessment method cannot assess the risk to fetuses precisely. Now we need a new risk assessment, in which the target is fetuses and not the adults, in addition to the conventional risk assessment At the same time, we also need a new strategy to practically eliminate the risk for the future generations. To make the strategy effective, we suggest a new approach to reduce the risk and avoid the possible adverse health effects, using primary, secondary and tertiary preventions as they are used in public health. We also suggest a new concept of "pre-primary prevention" to reduce the risk for fetuses. Furthermore, to make this method even more practical, we suggest a new risk communication method. In this paper, we present a framework of risk avoidance of multiple chemical exposure to fetuses. [source]

Environmental complexity and central nervous system development and function

DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 2 2004
Mark H. Lewis
Abstract Environmental restriction or deprivation early in development can induce social, cognitive, affective, and motor abnormalities similar to those associated with autism. Conversely, rearing animals in larger, more complex environments results in enhanced brain structure and function, including increased brain weight, dendritic branching, neurogenesis, gene expression, and improved learning and memory. Moreover, in animal models of CNS insult (e.g., gene deletion), a more complex environment has attenuated or prevented the sequelae of the insult. Of relevance is the prevention of seizures and attenuation of their neuropathological sequelae as a consequence of exposure to a more complex environment. Relatively little attention, however, has been given to the issue of sensitive periods associated with such effects, the relative importance of social versus inanimate stimulation, or the unique contribution of exercise. Our studies have examined the effects of environmental complexity on the development of the restricted, repetitive behavior commonly observed in individuals with autism. In this model, a more complex environment substantially attenuates the development of the spontaneous and persistent stereotypies observed in deer mice reared in standard laboratory cages. Our findings support a sensitive period for such effects and suggest that early enrichment may have persistent neuroprotective effects after the animal is returned to a standard cage environment. Attenuation or prevention of repetitive behavior by environmental complexity was associated with increased neuronal metabolic activity, increased dendritic spine density, and elevated neurotrophin (BDNF) levels in brain regions that are part of cortical,basal ganglia circuitry. These effects were not observed in limbic areas such as the hippocampus. MRDD Research Reviews 2004;10:91,95. © 2004 Wiley-Liss, Inc. [source]

The development of stimulus-specific auditory responses requires song exposure in male but not female zebra finches

DEVELOPMENTAL NEUROBIOLOGY, Issue 1 2010
Kristen K. Maul
Abstract Juvenile male zebra finches develop their song by imitation. Females do not sing but are attracted to males' songs. With functional magnetic resonance imaging and event-related potentials we tested how early auditory experience shapes responses in the auditory forebrain of the adult bird. Adult male birds kept in isolation over the sensitive period for song learning showed no consistency in auditory responses to conspecific songs, calls, and syllables. Thirty seconds of song playback each day over development, which is sufficient to induce song imitation, was also sufficient to shape stimulus-specific responses. Strikingly, adult females kept in isolation over development showed responses similar to those of males that were exposed to songs. We suggest that early auditory experience with songs may be required to tune perception toward conspecific songs in males, whereas in females song selectivity develops even without prior exposure to song. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2010 [source]

Daily and developmental modulation of "premotor" activity in the birdsong system,

DEVELOPMENTAL NEUROBIOLOGY, Issue 12 2009
Nancy F. Day
Abstract Human speech and birdsong are shaped during a sensorimotor sensitive period in which auditory feedback guides vocal learning. To study brain activity as song learning occurred, we recorded longitudinally from developing zebra finches during the sensorimotor phase. Learned sequences of vocalizations (motifs) were examined along with contemporaneous neural population activity in the song nucleus HVC, which is necessary for the production of learned song (Nottebohm et al. 1976: J Comp Neurol 165:457,486; Simpson and Vicario 1990: J Neurosci 10:1541,1556). During singing, HVC activity levels increased as the day progressed and decreased after a night of sleep in juveniles and adults. In contrast, the pattern of HVC activity changed on a daily basis only in juveniles: activity bursts became more pronounced during the day. The HVC of adults was significantly burstier than that of juveniles. HVC bursting was relevant to song behavior because the degree of burstiness inversely correlated with the variance of song features in juveniles. The song of juveniles degrades overnight (Deregnaucourt et al. 2005: Nature 433:710,716). Consistent with a relationship between HVC activity and song plasticity (Day et al. 2008: J Neurophys 100:2956,2965), HVC burstiness degraded overnight in young juveniles and the amount of overnight degradation declined with developmental song learning. Nocturnal changes in HVC activity strongly and inversely correlated with the next day's change, suggesting that sleep-dependent degradation of HVC activity may facilitate or enable subsequent diurnal changes. Collectively, these data show that HVC activity levels exhibit daily cycles in adults and juveniles, whereas HVC burstiness and song stereotypy change daily in juveniles only. In addition, the data indicate that HVC burstiness increases with development and inversely correlates with song variability, which is necessary for trial and error vocal learning. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009 [source]

Developmental shifts in gene expression in the auditory forebrain during the sensitive period for song learning

DEVELOPMENTAL NEUROBIOLOGY, Issue 7 2009
Sarah E. London
Abstract A male zebra finch begins to learn to sing by memorizing a tutor's song during a sensitive period in juvenile development. Tutor song memorization requires molecular signaling within the auditory forebrain. Using microarray and in situ hybridizations, we tested whether the auditory forebrain at an age just before tutoring expresses a different set of genes compared with later life after song learning has ceased. Microarray analysis revealed differences in expression of thousands of genes in the male auditory forebrain at posthatch day 20 (P20) compared with adulthood. Furthermore, song playbacks had essentially no impact on gene expression in P20 auditory forebrain, but altered expression of hundreds of genes in adults. Most genes that were song-responsive in adults were expressed at constitutively high levels at P20. Using in situ hybridization with a representative sample of 44 probes, we confirmed these effects and found that birds at P20 and P45 were similar in their gene expression patterns. Additionally, eight of the probes showed male,female differences in expression. We conclude that the developing auditory forebrain is in a very different molecular state from the adult, despite its relatively mature gross morphology and electrophysiological responsiveness to song stimuli. Developmental gene expression changes may contribute to fine-tuning of cellular and molecular properties necessary for song learning. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2009 [source]

Critical and sensitive periods for reversing the effects of mechanosensory deprivation on behavior, nervous system, and development in Caenorhabditis elegans

DEVELOPMENTAL NEUROBIOLOGY, Issue 11 2007
Susan Rai
Abstract In these studies the nematode Caenorhabditis elegans was used as a model to investigate ways to reverse the effects of mechanosensory deprivation on behavior and development. Rose et al. (J Neurosci 2005; 25:7159,7168) showed that worms reared in isolation responded significantly less to a mechanical tap stimulus, were significantly smaller, and expressed significantly lower levels of a postsynaptic glutamate receptor subunit on the command interneurons of the tap response circuit and a presynaptic vesicle marker in the tap sensory neurons compared with worms raised in groups. Here, brief mechanical stimulation at any time throughout development reversed the effects of isolation on the response to tap and on postsynaptic glutamate receptor expression on the command interneurons, suggesting there is no critical period for these measures. In contrast to the high level of plasticity in glutamate receptor subunit expression on the interneurons, low levels of stimulation only rescued vesicle expression in the tap sensory neurons early in development and progressively higher levels of stimulation were required as the worm developed, suggesting a sensitive period immediately after hatching, followed by a period of decreasing plasticity. Stimulation during the first three stages of larval development, but not later, rescued the effects of isolation on worm length, suggesting there is a critical period for this measure that ends in the third larval stage. These results indicate that different effects of early isolation required different amounts and/or timing of stimulation to be reversed. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source]

Differential onset of infantile deprivation produces distinctive long-term effects in adult ex-laboratory chimpanzees (Pan troglodytes)

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 8 2008
Elfriede Kalcher
Abstract Maternal or social deprivation during early infancy inevitably produces social deficiencies in juvenile chimpanzees. Hypothesizing such deficiencies to persist into adulthood (a), and, as in humans, a sensitive period in early infancy for attachment formation (b), we predicted and found behavioral differences in resocialized adult ex-laboratory chimpanzees after about 20 years of solitary confinement depending on their age at onset of deprivation: early deprived (ED; mean: 1.2 years) chimpanzees engaged significantly less in social interactions, spent less time associated, and showed more nonsocial idiosyncrasies than did late deprived (LD; mean: 3.6 years) chimpanzees. In addition to these individual attributes relational qualities, specifically the combination of ED and LD chimpanzees within social groups, have an impact on social recovery. LDs can best exploit their social potential in the company of other LDs and EDs tend to stagnate in their recovery when socialized with other EDs. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 777,788, 2008 [source]

Multiple sensitive periods in human visual development: Evidence from visually deprived children

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2005
Terri L. Lewis
Abstract Psychophysical studies of children deprived of early visual experience by dense cataracts indicate that there are multiple sensitive periods during which experience can influence visual development. We note three sensitive periods within acuity, each with different developmental time courses: the period of visually-driven normal development, the sensitive period for damage, and the sensitive period for recovery. Moreover, there are different sensitive periods for different aspects of vision. Relative to the period of visually driven normal development, the sensitive period for damage is surprisingly long for acuity, peripheral vision, and asymmetry of optokinetic nystagmus, but surprisingly short for global motion. A comparison of results from unilaterally versus bilaterally deprived children provides insights into the complex nature of interactions between the eyes during normal visual development. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46: 163,183, 2005. [source]

Arousal, but not nursing, is necessary to elicit a decreased fear reaction toward humans in rabbit (Oryctolagus cuniculus) pups

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2003
Péter Pongrácz
Abstract Rabbits that are handled at the time of feeding during the first week postpartum show reduced fear of humans later in their lives as compared to unhandled controls. Effective handling has been shown to be confined to a sensitive period. Our study aimed to investigate if feeding itself (provided by a second doe, 6 hr after the standard nursing time) affects the levels of fear of humans later in life. Our results showed that (a) the prenursing state of excitement is only characteristic of the standard nursing and is not elicited by a second feeding 6 hr past the usual nursing time, repeated daily across the first week postpartum; and (b) handling linked to a second feeding 6 hr after the standard nursing does not reduce fear responses toward humans at weaning. We conclude that the aroused state, per se, is essential for the reduction of a rabbit's fear response toward humans provoked by early handling. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 192,199, 2003. [source]

Early pubertal maturation in the prediction of early adult substance use: a prospective study

ADDICTION, Issue 1 2009
Mohammad R. Hayatbakhsh
ABSTRACT Aims To examine whether self-reporting a later stage of pubertal development in early adolescence predicts young adults' use of illicit drugs. Design Population-based prospective birth cohort study. Setting Follow-up of a cohort of mothers and their children, recruited between 1981 and 1983. Participants Cohort of 2710 young adults who completed a self-report questionnaire about their use of cannabis and amphetamines at the 21-year follow-up. Measurements Young adults' use of cannabis and amphetamines were measured at the 21-year follow-up. Stage of pubertal development was assessed at the 14-year follow-up. Potential confounding and mediating variables were assessed between birth and when the child was 14 years. Findings Of 2710 young adults, 49.9% (47.3 females and 52.7% males) reported that they had used cannabis and 21.0% (18.9% females and 23.3% males) reported that they had used amphetamines and cannabis by 21 years. In multivariate analyses, adolescents with a later stage of puberty were more likely to use cannabis or amphetamines in young adulthood. This association was not confounded by mother's education or child's gender and age. Part of the relationship was explained by the higher frequency of child externalizing behaviour at 14 years. Conclusions The findings warrant further attention to puberty as a sensitive period in an individual's development. With regard to prevention, there is a need to understand more about the pathways between pubertal development, child behaviour problems and substance use. [source]

Heat shock in the developmentally sensitive period of butterfly eyespots fails to increase fluctuating asymmetry

EVOLUTION AND DEVELOPMENT, Issue 3 2003
Casper J. Breuker
SUMMARY Fluctuating asymmetry (FA) is considered to provide a means of evaluating developmental stability and to reflect an individual's quality or the stress experienced during development. Stress is predicted to increase the phenotypic variation of both FA and trait size. In this study we examined the effect of a particular heat shock on both FA and size of eyespots in the butterfly, Bicyclus anynana. We also examined whether those eyespots thought to be involved in partner choice and sexual selection were particularly sensitive to stress. We applied a heat shock of 39.5°C for 3 h before, during, and after a sensitive period in eyespot development. We examined the FA, variation in FA, size, and variation in size of five eyespots, two on the dorsal forewing (sexually selected traits), two on the ventral forewing, and one on the ventral hindwing (nonsexually selected traits). For each sex and treatment, the heat shock did not result in significant changes in mean trait size and FA nor in the variation of size and FA. There were no differences in the response to the heat shock between sexually and nonsexually selected traits. We discuss how the increased production of heat shock proteins, including HSP60, may have stabilized development and how this might explain the results. [source]

A 2-year-old child's memory of hospitalization during early infancy

INFANT AND CHILD DEVELOPMENT, Issue 6 2008
Aletha Solter
Abstract A child who had had surgery at 5 months of age, and who had been treated at the time for post-traumatic symptoms (reported in a previous paper by the author), was interviewed 2 years later and almost 3 years later to test for possible verbal recall of his hospitalization. He appeared to have some memories of the experience at 29 months of age, and he was able to superimpose verbal labels onto the preverbal memories. At 40 months of age, however, the memories were no longer verbally accessible. The results are discussed in the context of different theories of encoding, storage, retrieval, and loss of early memories. The findings from this study support other findings indicating that there appears to be some form of long-term memory in place early in life, at least for highly salient, traumatic events. There may be one memory system for traumatic memories, fully functional at birth, and a later developing, different system for neutral memories. It is further hypothesized that there may be a sensitive period around 2,3 years of age for the recall of early traumatic memories, and that verbal recall is more likely to be present in verbally precocious children during that period. Copyright © 2008 John Wiley & Sons, Ltd. [source]

The development and neural bases of face recognition

INFANT AND CHILD DEVELOPMENT, Issue 1-2 2001
Charles A. Nelson
Abstract Evidence from fields as diverse as cognitive, evolutionary, and developmental psychology, as well as cognitive neuroscience, has increasingly pointed to the ,special' nature of face recognition. A critical examination of the literature supports the view that faces begin to be seen as a separate class of objects within the first 6 months of life. Not surprisingly, the neural systems that underlie face recognition also come on line during this period of time. Less clear, however, are the mechanisms whereby these events occur. It seems likely that face recognition reflects an experience-expectant process, whereby exposure to faces during a sensitive period of development likely leads to perceptual and cortical specialization. However, it is unknown what the role of experience is in maintaining this ability, and how long this sensitive period lasts. After reviewing three related models that attempt to account for the way the ability to recognize faces develops, a number of suggestions are offered for testing the hypothesis that face recognition depends on experience for acquisition, and for evaluating the role of experience in maintaining this ability. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Relationships between nurse care-giving behaviours and preterm infant responses during bathing: a preliminary study

JOURNAL OF CLINICAL NURSING, Issue 1-2 2010
Jen-Jiuan Liaw
Aims., The purpose of this study was to explore the relationships between specific nurse care-giving behaviours and preterm infant behavioural responses during bathing and to identify nurse behaviours associated with infant ,stress'. Background., Although recent advances in medical technology have improved neonatal intensive care, the high mortality and morbidity rates in preterm infants have not decreased proportionally. As caregivers strive to reduce infant mortality and morbidity, a factor for consideration is which caregiver behaviours are associated with preterm infant well-being. Design., A descriptive correlational design. Method., Convenience samples of 24 preterm infants and 12 nurses were recruited. A total of 120 baths were videotaped. Infant and nurse behaviours were measured using the coding schemes developed by the researchers. Pearson coefficient correlation, non-parametric Kruskal,Wallis test, t -test and generalised linear models were methods for data analysis. Results., As nurses provided more support, stress was reduced in the infants, and their self-regulation during the bath was enhanced especially by the use of ,containment' and ,positional support'. Conversely, non-therapeutic caregiver behaviours including ,rapid and rough handling' of the baby, ,chatting with other people' and ,inappropriate handling' increased infant ,stress' during the bath. Conclusion., The findings provide new information about the link between care-giving and infant responses and how caregivers can better interact with preterm infants during a very sensitive period of brain development. Relevance to clinical practice., How nurses take care of the preterm infants influences their responses to care-giving stimuli. To interact better with the infant during care-giving procedures, nurses need to provide more supportive care-giving behaviours especially ,position support' and ,containment' based on the infant's needs, and avoid care-giving that may be too rough and occur too quickly without attending the baby's stressful signals, positioning the baby in hyperextension posture, or chatting with other people during procedures. [source]

,Poor children grow into poor adults': harmful mechanisms or over-deterministic theory?

JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 8 2002
Shahin Yaqub
Does childhood poverty lead to adult poverty? Evidence shows childhood is a sensitive period for developing cognition, physical vitality and personality. This is traceable to specific behavioural and biological mechanisms. However such science could easily drive over-deter ministic views about how childhood affects later life. The paper therefore discusses how damage from childhood poverty can,at least sometimes and partially,be resisted or reversed, both during childhood and in adulthood. As people reach biological maturity, alterations to their developmental trajectories rely increasingly on alterations in behavioural relationships. Opportunities remain vital throughout life for sustained socioeconomic attainment. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Ethanol-Mediated Fetal Dysmorphology and its Relationship to the Ontogeny of Maternal Liver Metallothionein

ALCOHOLISM, Issue 6 2009
Peter Coyle
Background:, Fetal zinc (Zn) deficiency arising from ethanol-induction of the Zn-binding protein metallothionein (MT) in the mother's liver has been proposed as a mechanism of teratogenicity. Here, we determine the ontogeny of MT and Zn homeostasis in rats and mice and then examine the effect of acute ethanol exposure in early embryonic development on this relationship. The protective effect of Zn against ethanol-mediated fetal dysmorphology is also examined. Methods:, Study 1: Maternal liver MT and Zn homeostasis was determined in Sprague,Dawley rats and C57BL/6J mice throughout gestation. Study 2: Rats were administered ethanol (25% in saline, intraperitoneal 0.015 ml/g) or vehicle alone on gestational day (GD) 9. Maternal liver MT and Zn, and plasma Zn was determined over the ensuing 24 hours. Study 3: Pregnant rats were treated with ethanol and Zn (s.c. 2.5 ,g Zn/g) on GD9 and fetal dysmorphology was assessed on GD 19. Results:, Study 1: Maternal liver MT began to rise around GD 9 peaking on GD 15 before falling to nonpregnant levels around term. The pregnancy-related increase in MT was associated with a fall in plasma Zn which was significantly lower on GD 15 thereafter returning to nonpregnant levels by parturition. Study 2: Ethanol administered to pregnant rats on GD 9 resulted in a 10-fold induction of MT in the maternal liver and was associated with a 33% rise in liver Zn and a 30% fall in plasma Zn, 16 hours after treatment. Study 3: Ethanol treatment on GD 9 resulted in a significant increase in craniofacial malformations which were prevented by concurrent Zn treatment. Conclusions:, The findings indicate that maternal liver MT levels are lowest in early gestation (before GD 10) making this a sensitive period where ethanol-induction of MT can affect fetal Zn homeostasis and cause fetal dysmorphology. The study further provides evidence of a protective role for Zn against ethanol-mediated teratogenicity. [source]

Searching for sex-reversals to explain population demography and the evolution of sex chromosomes

MOLECULAR ECOLOGY, Issue 9 2010
CLAUS WEDEKIND
Sex determination can be purely genetic (as in mammals and birds), purely environmental (as in many reptiles), or genetic but reversible by environmental factors during a sensitive period in life, as in many fish and amphibians (Wallace et al. 1999; Baroiller et al. 2009a; Stelkens & Wedekind 2010). Such environmental sex reversal (ESR) can be induced, for example, by temperature changes or by exposure to hormone-active substances. ESR has long been recognized as a means to produce more profitable single-sex cultures in fish farms (Cnaani & Levavi-Sivan 2009), but we know very little about its prevalence in the wild. Obviously, induced feminization or masculinization may immediately distort population sex ratios, and distorted sex ratios are indeed reported from some amphibian and fish populations (Olsen et al. 2006; Alho et al. 2008; Brykov et al. 2008). However, sex ratios can also be skewed by, for example, segregation distorters or sex-specific mortality. Demonstrating ESR in the wild therefore requires the identification of sex-linked genetic markers (in the absence of heteromorphic sex chromosomes) followed by comparison of genotypes and phenotypes, or experimental crosses with individuals who seem sex reversed, followed by sexing of offspring after rearing under non-ESR conditions and at low mortality. In this issue, Alho et al. (2010) investigate the role of ESR in the common frog (Rana temporaria) and a population that has a distorted adult sex ratio. They developed new sex-linked microsatellite markers and tested wild-caught male and female adults for potential mismatches between phenotype and genotype. They found a significant proportion of phenotypic males with a female genotype. This suggests environmental masculinization, here with a prevalence of 9%. The authors then tested whether XX males naturally reproduce with XX females. They collected egg clutches and found that some had indeed a primary sex ratio of 100% daughters. Other clutches seemed to result from multi-male fertilizations of which at least one male had the female genotype. These results suggest that sex-reversed individuals affect the sex ratio in the following generation. But how relevant is ESR if its prevalence is rather low, and what are the implications of successful reproduction of sex-reversed individuals in the wild? [source]

Genetic and attachment influences on adolescents' regulation of autonomy and aggressiveness

THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 11 2009
Peter Zimmermann
Background:, Adolescence is a time when intense emotions are elicited within the parent,adolescent relationship, often when autonomy subjectively is endangered. As emotion dysregulation is one of the risk processes for the development of psychopathology, adolescence may be perceived as a highly sensitive period for maladjustment. Inter-individual differences in emotionality and emotion regulation have been shown to be influenced or moderated by molecular genetic differences in the serotonin transporter gene (5-HTT) and by attachment patterns. We investigated whether both the 5-HTT and attachment are associated with emotionality and emotion regulation in an observed adolescent,mother interaction and the personality traits aggressiveness and anxiety in adolescence. Methods:, Ninety-one adolescents at age 12 were observed in interaction with their mothers during a standardized emotion-eliciting social task to assess emotionality and emotion regulation in relation to autonomy. Adolescents' aggressiveness and anxiety were assessed by mother report. Concurrent attachment quality was determined by an attachment interview. DNA samples were collected in order to assess the 5-HTTLPR, a repeat polymorphism in the promoter region of the serotonin transporter gene. Results:, While the short allele of the serotonin transporter gene was associated with a higher overall rate of autonomy behaviors, attachment security was related to more agreeable and less hostile autonomy. A significant interaction revealed a moderating effect of attachment security. Carriers of the short version of the 5-HTTLPR showed more agreeable autonomy when they had a secure attachment behavior strategy but showed more hostile autonomy when they were insecurely attached. Carriers of the short version of the 5-HTTLPR and insecurely attached adolescents were rated as more aggressive. Conclusions:, The study suggests a gene,attachment interaction in adolescents where the adolescent's attachment status moderates a genetically based higher negative reactivity in response to threats to autonomy in social interactions. [source]

Parenting and the development of conduct disorder and hyperactive symptoms in childhood: a prospective longitudinal study from 2 months to 8 years

THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 4 2003
Julian Morrell
Background:, This study investigated the early processes involved in the development of symptoms of conduct disorder and hyperactivity. Method:, The study employed a prospective design, over a period from 2 months to 8 years. Detailed observational data of early and later mother,child interactions were collected, infant prefrontal function (the A not B task) was assessed, and symptoms of child conduct disorder and hyperactivity were rated by maternal report at age 5 and 8 years. Results:, The principal findings of the study were that emotional dysregulation on the A not B task at 9 months predicted symptoms of conduct disorder at 5 and 8 years, and delayed object reaching times on the same task predicted hyperactive symptoms at 5 years. These two developmental trajectories were associated with distinct patterns of early parenting that were strongly influenced by infant gender. Thus, in boys early emotional dysregulation was predicted by rejecting and coercive parenting, and delayed reaching on the A not B task by coercive parenting, whereas in girls only continuity from earlier infant behaviour could be demonstrated. There was strong continuity between these early infant behaviours and later child disturbance that was partially mediated by parenting for conduct disorder symptoms (maternal hostile parenting in boys, and maternal coercive parenting in girls), but not for hyperactive symptoms. Conclusions:, These data would suggest that only in boys was there evidence for the existence of a sensitive period for the development of hyperactive symptoms, and to a lesser extent, conduct disorder symptoms. [source]

Early Contact versus Separation: Effects on Mother,Infant Interaction One Year Later

BIRTH, Issue 2 2009
Ksenia Bystrova MD
ABSTRACT: Background: A tradition of separation of the mother and baby after birth still persists in many parts of the world, including some parts of Russia, and often is combined with swaddling of the baby. The aim of this study was to evaluate and compare possible long-term effects on mother-infant interaction of practices used in the delivery and maternity wards, including practices relating to mother-infant closeness versus separation.Methods:A total of 176 mother-infant pairs were randomized into four experimental groups: Group I infants were placed skin-to-skin with their mothers after birth, and had rooming-in while in the maternity ward. Group II infants were dressed and placed in their mothers' arms after birth, and roomed-in with their mothers in the maternity ward. Group III infants were kept in the nursery both after birth and while their mothers were in the maternity ward. Group IV infants were kept in the nursery after birth, but roomed-in with their mothers in the maternity ward. Equal numbers of infants were either swaddled or dressed in baby clothes. Episodes of early suckling in the delivery ward were noted. The mother-infant interaction was videotaped according to the Parent-Child Early Relational Assessment (PCERA) 1 year after birth.Results:The practice of skin-to-skin contact, early suckling, or both during the first 2 hours after birth when compared with separation between the mothers and their infants positively affected the PCERA variables maternal sensitivity, infant's self-regulation, and dyadic mutuality and reciprocity at 1 year after birth. The negative effect of a 2-hour separation after birth was not compensated for by the practice of rooming-in. These findings support the presence of a period after birth (the early "sensitive period") during which close contact between mother and infant may induce long-term positive effect on mother-infant interaction. In addition, swaddling of the infant was found to decrease the mother's responsiveness to the infant, her ability for positive affective involvement with the infant, and the mutuality and reciprocity in the dyad.Conclusions:Skin-to-skin contact, for 25 to 120 minutes after birth, early suckling, or both positively influenced mother-infant interaction 1 year later when compared with routines involving separation of mother and infant. [source]

Environmental complexity and central nervous system development and function

Critical and sensitive periods for reversing the effects of mechanosensory deprivation on behavior, nervous system, and development in Caenorhabditis elegans

Multiple sensitive periods in human visual development: Evidence from visually deprived children

Maturation-Dependent Alcohol Resistance in the Developing Mouse: Cerebellar Neuronal Loss and Gene Expression During Alcohol-Vulnerable and -Resistant Periods

ALCOHOLISM, Issue 8 2008
Bahri Karaçay
Background:, Alcohol abuse during pregnancy injures the fetal brain. One of alcohol's most important neuroteratogenic effects is neuronal loss. Rat models have shown that the cerebellum becomes less vulnerable to alcohol-induced neuronal death as it matures. We determined if maturation-dependent alcohol resistance occurs in mice and compared patterns of gene expression during the alcohol resistant and sensitive periods. Methods:, Neonatal mice received alcohol daily over postnatal day (PD) 2 to 4 or PD8 to 10. Purkinje cells and granule cells were quantified on PD25. The temporal expression patterns of 4 neuro-developmental genes and 3 neuro-protective genes in the cerebellum were determined daily over PD0 to 15 to determine how gene expression changes as the cerebellum transitions from alcohol-vulnerable to alcohol-resistant. The effect of alcohol on expression of these genes was determined when the cerebellum is alcohol sensitive (PD4) and resistant (PD10). Results:, Purkinje and granule cells were vulnerable to alcohol-induced death at PD2 to 4, but not at PD8 to 10. Acquisition of maturation-dependent alcohol resistance coincided with changes in the expression of neurodevelopmental genes. The vulnerability of cerebellar neurons to alcohol toxicity declined in parallel with decreasing levels of Math1 and Cyclin D2, markers of immature granule cells. Likewise, the rising resistance to alcohol toxicity paralleled increasing levels of GABA ,-6 and Wnt-7a, markers of mature granule neurons. Expression of growth factors and genes with survival promoting function (IGF-1, BDNF, and cyclic AMP response element binding protein) did not rise as the cerebellum transitioned from alcohol-vulnerable to alcohol-resistant. All 3 were expressed at substantial levels during the vulnerable period and were not expressed at higher levels later. Acute alcohol exposure altered the expression of neurodevelopmental genes and growth factor genes when administered either during the alcohol vulnerable period or resistant period. However, the patterns in which gene expression changed varied among the genes and depended on timing of alcohol administration. Conclusions:, Mice have a temporal window of vulnerability in the first week of life, during which cerebellar neurons are more sensitive to alcohol toxicity than during the second week. Expression of genes governing neuronal maturation changes in synchrony with the acquisition of alcohol resistance. Growth factors do not rise as the cerebellum transitions from alcohol-vulnerable to alcohol-resistant. Thus, a process intrinsic to neuronal maturation, rather than rising levels of growth factors, likely underlies maturation-dependent alcohol resistance. [source]

The emotional foundations of high moral intelligence

NEW DIRECTIONS FOR CHILD & ADOLESCENT DEVELOPMENT, Issue 129 2010
Darcia Narvaez
Moral intelligence is grounded in emotion and reason. Neuroscientific and clinical research illustrate how early life co-regulation with caregivers influences emotion, cognition, and moral character. Triune ethics theory (Narvaez, 2008) integrates neuroscientific, evolutionary, and developmental findings to explain differences in moral functioning, identifying security, engagement, and imagination ethics that can be dispositionally fostered by experience during sensitive periods, but also situationally triggered. Mature moral functioning relies on the integration of emotion, intuition, and reasoning, which come together in adaptive ethical expertise. Moral expertise can be cultivated in organizations using the integrative ethical education model. © Wiley Periodicals, Inc. [source]

Life Course Health Development: An Integrated Framework for Developing Health, Policy, and Research

THE MILBANK QUARTERLY, Issue 3 2002
Neal Halfon
This article describes the Life Course Health Development (LCHD) framework, which was created to explain how health trajectories develop over an individual's lifetime and how this knowledge can guide new approaches to policy and research. Using recent research from the fields of public health, medicine, human development, and social sciences, the LCHD framework shows that ,Health is a consequence of multiple determinants operating in nested genetic, biological, behavioral, social, and economic contexts that change as a person develops. ,Health development is an adaptive process composed of multiple transactions between these contexts and the biobehavioral regulatory systems that define human functions. ,Different health trajectories are the product of cumulative risk and protective factors and other influences that are programmed into biobehavioral regulatory systems during critical and sensitive periods. ,The timing and sequence of biological, psychological, cultural, and historical events and experiences influence the health and development of both individuals and populations. The life course health development (LCHD) framework organizes research from several fields into a conceptual approach explaining how individual and population health develops and how developmental trajectories are determined by interactions between biological and environmental factors during the lifetime. This approach thus provides a construct for interpreting how people's experiences in the early years of life influence later health conditions and functional status. By focusing on the relationship between experiences and the biology of development, the LCHD framework offers a better understanding of how diseases occur. By suggesting new strategies for health measurement, service delivery, and research, as well as for improving health outcomes, this framework also supports health care-purchasing strategies to develop health throughout life and to build human health capital. [source]