Showing papers in "Developmental Psychobiology in 2011"
TL;DR: This work argues that based on evolutionary theory, neurophysiological knowledge, and recent findings, personality is probably less stable than often thought and developmental changes in the regulation of DNA expression are probably more relevant than individual differences in DNA sequence.
Abstract: We 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 environment correlations and interactions and argue that developmental changes in the regulation of DNA expression are probably more relevant than individual differences in DNA sequence. We end by suggesting perspectives for future research. (C) 2011 Wiley Periodicals, Inc. Dev Psychobiol 53: 641-655, 2011.
145 citations
TL;DR: Full-term infants exposed to prenatal betamethasone displayed a larger cortisol response to the heel-stick procedure, despite no differences in baseline levels, which adds to accumulating evidence that prenatal exposure to elevated GCs programs the development of the HPA axis.
Abstract: 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), infants exposed to betamethasone earlier in gestation displayed the largest cortisol response to the heel-stick. These data add to accumulating evidence that prenatal exposure to elevated GCs programs the development of the HPA axis.
131 citations
TL;DR: This work elaborate the meta-theoretical ideas underlying common theoretical concepts and integrate them into an overarching meta- theoretical and methodological framework and shows that assumptions of analogy to concepts of human personality are not always warranted and that some theoretical developments may be based on methodological artifacts.
Abstract: Animal 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 overarching meta-theoretical and methodological framework. This unravels commonalities and differences, and shows that assumptions of analogy to concepts of human personality are not always warranted and that some theoretical developments may be based on methodological artifacts. Yet, my results also highlight possible directions for new theoretical developments in animal behavior research.
114 citations
TL;DR: It is concluded that, by the age of 3, children exhibit rudimentary episodic memory skills, and that strict reliance on verbal recall may underestimate their episodi memory ability.
Abstract: There 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 performed equivalently to 4-year-olds on the where components of the test, however, their performance on the when component remained inferior to that of 4-year-olds. We conclude that, by the age of 3, children exhibit rudimentary episodic memory skills, and that strict reliance on verbal recall may underestimate their episodic memory ability.
112 citations
TL;DR: It is shown that individuals of clonal pea aphids exhibit consistent behavioral differences in their escape responses to a predator attack (dropping vs. nondropping off a plant).
Abstract: Individuals 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 (dropper, nondropper, and inconsistent). Manipulations of early environmental conditions had little qualitative impact on such patterns. We discuss the importance of our findings for future studies of the evolutionary and ecological consequences of personality variation.
104 citations
TL;DR: This study provides the first evidence that naturally occurring variation in endogenous glucocorticoid concentrations in milk are associated with infant temperament.
Abstract: One pathway by which infant mammals gain information about their environment is through ingestion of milk. We assessed the relationship between stress-induced cortisol concentrations in milk, maternal and offspring plasma, and offspring temperament in rhesus monkeys. Milk was collected from mothers after a brief separation from their infants at 3–4 months postpartum, and blood was drawn at this time for both mothers and infants. Offspring temperament was measured at the end of a 25-hr assessment. Cortisol concentrations in milk were in a range comparable to those found in saliva, and were positively correlated with maternal plasma levels. Mothers of males had higher cortisol concentrations in milk than did mothers of females, and cortisol concentrations in maternal milk were related to a Confident temperament factor in sons, but not daughters. This study provides the first evidence that naturally occurring variation in endogenous glucocorticoid concentrations in milk are associated with infant temperament. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 53: 96–104, 2011.
90 citations
TL;DR: Investigation of the development of respiratory sinus arrhythmia (RSA), an established index of parasympathetic nervous system (PNS), and preejection period (PEP) in children aged 8-10 years found that initial levels of RSA and PEP and the slope of RSA over time were predicted by several demographic factors including the child's sex and race.
Abstract: Autonomic nervous system (ANS) activity has been linked repeatedly to children's socioemotional and behavioral adaptive functioning and development, yet the literature on how various indexes of ANS activity develop in childhood is sparse. We utilized latent growth modeling to investigate the development of respiratory sinus arrhythmia (RSA), an established index of parasympathetic nervous system (PNS), and preejection period (PEP), a marker of sympathetic nervous system (SNS) influence on the heart, in children aged 8-10 years. At age 8, 251 children (128 girls, 123 boys; 162 European American, 89 African American) participated. Longitudinal data were collected during two additional waves when children were 9 and 10 years of age, with a 1-year lag between each wave. Children's RSA and PEP exhibited significant stability over time. Marginally significant variability was found among children in how RSA changed over time (slope), but there was no significant interindividual variability in PEP changes over development. A conditional growth curve model (i.e., one with predictor variables) showed that initial levels of RSA and PEP and the slope of RSA over time were predicted by several demographic factors including the child's sex and race; RSA of European American children showed significant increases over time while African American children had higher initial RSA but no significant change over time. Findings extend basic knowledge in developmental biopsychology and have implications for research focusing on ANS measures as important predictors, moderators, and mediators of childhood adaptation.
89 citations
TL;DR: Test hypotheses relating to how prairie vole families function under undisturbed, standard laboratory conditions suggest that the study in prairie voles may help improve the understanding of family systems and how perturbations to these systems can affect adults and offspring.
Abstract: Family relationships help shape species-typical social and emotional development, but our understanding of how this shaping occurs is still relatively limited. Prairie voles are a socially monogamous and biparental species that is well situated to complement traditional animal models, such as rats and mice, in investigating the effects of family experience. In this series of studies, we aimed to test hypotheses relating to how prairie vole families function under undisturbed, standard laboratory conditions. In the first study, we compared the parental behavior of primiparous biparental (BP) and single-mother (SM) prairie vole family units for 12 postnatal days and then tested for sex differences, behavioral coordination, and family structure effects. Under BP conditions, nest attendance was coordinated and shared equally by both sexes, while pup-directed and partner-directed licking and grooming (LG) were coordinated in a sex and social-context-dependent manner. Contrary to our expectations, SMs showed no evidence of strong parental compensation in response to the lack of the father, indicating a minimal effect of family structure on maternal behavior but a large effect on pup care. In the second study, we examined the effects of these BP and SM rearing conditions on family dynamics in the next generation and found that SM-reared adult parents exhibited lower rates of pup-directed LG in comparison to BP-reared counterparts. Situated in the context of human family dynamics and psychology, these results suggest that the study in prairie voles may help improve our understanding of family systems and how perturbations to these systems can affect adults and offspring.
84 citations
TL;DR: It is concluded that in mammals, individual differences in early growth, physiology and behavior potentially important for the development of animal personality, are shaped to an appreciable extent by early sibling relations and that this little-researched field deserves closer attention.
Abstract: Although 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 birth and weaning, as well as marked within-litter differences in prenatal body mass and placental efficiency. We then report individual differences in preweaning behaviors associated with these morphological variables such as position occupied in the litter huddle and development of motor ability, as well as physiological differences in thermoregulation, immune parameters, and endocrine indicators of stress. Finally, we report first evidence from wild rabbits that early relations among littermates may have long-term consequences for individual differences in behavioral style. We conclude that in mammals, individual differences in early growth, physiology and behavior potentially important for the development of animal personality, are shaped to an appreciable extent by early sibling relations and that this little-researched field deserves closer attention.
83 citations
TL;DR: Altered programming of the hypothalamic-pituitary-adrenal (HPA) axis in preterm children, as well as their greater sensitivity to environmental context such as maternal interactive behavior, are suggested.
Abstract: Cortisol levels were compared in children born preterm at extremely low gestational age (ELGA; 24–28 weeks), very low gestational age (VLGA; 29–32 weeks), and full-term in response to cognitive assessment at 18 months corrected age (CA). Further, we investigated the relationship between maternal interactive behaviors and child internalizing behaviors (rated by the mother) in relation to child cortisol levels. ELGA children had higher “pretest” cortisol levels and a different pattern of cortisol response to cognitive assessment compared to VLGA and full-terms. Higher cortisol levels in ELGA, but not full-term, children were associated with less optimal mother interactive behavior. Moreover, the pattern of cortisol change was related to internalizing behaviors among ELGA, and to a lesser degree VLGA children. In conclusion, our findings suggest altered programming of the hypothalamic-pituitary-adrenal (HPA) axis in preterm children, as well as their greater sensitivity to environmental context such as maternal interactive behavior.
77 citations
TL;DR: It is argued here, that nonrandom behavioral correlations across contexts and time might underlie the variability commonly found in biomedical mouse studies.
Abstract: The 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 conducted in our laboratory with inbred mice. Interestingly, behavioral patterns of individual animals seem to be correlated across context and time. In evolutionary biology, “animal personalities” have been discussed recently to comprise such stable patterns. We argue here, that nonrandom behavioral correlations across contexts and time might underlie the variability commonly found in biomedical mouse studies. Dev Psychobiol © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:624–630, 2011.
TL;DR: The finding that maternal depression/anxiety affects gene expression of placental SLC6A4 suggests a possible mechanism for the effect(s) of maternal mood on fetal neurodevelopmental programming.
Abstract: We 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-HSD2 expression levels were positively correlated. The finding that maternal depression/anxiety affects gene expression of placental SLC6A4 suggests a possible mechanism for the effect(s) of maternal mood on fetal neurodevelopmental programming. SSRI treatment does not further alter the elevated SLC6A4 expression levels observed with exposure to maternal depression or anxiety. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:711–723, 2011.
TL;DR: The Emergence of Personality in Animals (EMPA) as discussed by the authors is a special issue of the journal Dev Psychobiol focusing on the evolution of personality in animals and their origins.
Abstract: Interest 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 often rapid ontogenetic change. Debate continues, however, about the right methodologies to characterize the phenomenon and attempt to do so in a comparable manner across taxa that differ as widely in the expression of “personality” as insects and mammals. This makes it necessary to discuss this field in an interdisciplinary context among psychologists and biologists, and was the rational for a meeting on “The Emergence of Personality in Animals” held in May 2010 at the Center for Interdisciplinary Research (Zentrum fur Interdisziplinare Forschung; ZiF), Bielefeld, Germany. The diversity of topics, viewpoints and organisms covered and the excitement created by the ensuing discussions is reflected in the resulting collection of papers forming this special issue. Dev Psychobiol © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:505–509, 2011.
TL;DR: William Greenough used stereological tools, electron microscopy, and the Golgi stain to demonstrate that enrichment led to dendritic growth and synapse addition, and these forms of plasticity accounted for cortical expansion and a reduction in cell density.
Abstract: Fifty 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 research in humans is limited to regional effects, the analysis of the cellular and synaptic effects of enrichment, and their contribution to volumetric increases can inform us of the potential cellular and subcellular plasticity the leads to volume change in humans
TL;DR: It is concluded that age-related increases in basic retention are a fundamental aspect of mammalian memory development and, in humans, these increases may play a vital role in the offset of childhood amnesia.
Abstract: Age-related changes in long-term memory during infancy and early childhood were examined using the Visual Recognition Memory (VRM) procedure. Independent groups of 1-, 2-, 3-, and 4-year-olds were familiarized with a visual stimulus and were tested either immediately or after a delay that ranged from 24 hr to 6 months. Although all age groups exhibited a significant novelty preference when tested immediately after familiarization, clear age-related differences emerged over longer retention intervals. We conclude that age-related increases in basic retention are a fundamental aspect of mammalian memory development and, in humans, these increases may play a vital role in the offset of childhood amnesia.
TL;DR: This paper examined how temperamental inhibition and maternal punishment contributed to preschoolers' adrenocortical activity while interacting with adult strangers, and whether HPA functioning moderated relations between dispositional and familial factors and children's internalizing and externalizing problems.
Abstract: Previous 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 protocols. Mothers reported on temperamental inhibition, maternal punishment and children's problems. Maternal punishment predicted higher cortisol levels 20 and 65 min after meeting adult strangers. Prolonged cortisol elevation was associated with having fewer externalizing problems. Boys who experienced more maternal punishment and had higher cortisol 20 min after meeting strangers manifested more externalizing problems. Girls who were more inhibited and had prolonged cortisol elevations had more internalizing problems. In accord with biopsychosocial models of psychopathology, HPA functioning in preschoolers was sensitive to variations in socialization experiences, and moderated children's risk for emotional and behavioral problems. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:694–710, 2011.
TL;DR: It is found that attentional set shifting becomes adult-like at an earlier age than reversal learning, and it is hypothesize that prefrontal cortical subregions show slightly different developmental trajectories.
Abstract: As 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 also more susceptible to distraction than adult rats when an irrelevant stimulus dimension is introduced as part of a complex stimulus. Moreover, we find that attentional set shifting becomes adult-like at an earlier age than reversal learning. As these functions are mediated by distinct prefrontal subregions, that is, the prelimbic and orbitofrontal cortices, respectively, we hypothesize that prefrontal cortical subregions show slightly different developmental trajectories. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:391–401, 2011.
TL;DR: The results strongly suggest that the early development alters the ontogeny of personality types, with heavier individuals being bolder and more explorative, and body mass and litter size influenced the changes in the behavioral responses in successive tests, further supporting the importance of the litter size-dependent body mass for the ontogeney of personalities.
Abstract: Features 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 behavioral responses within and across contexts. Based on these responses, we calculated three new variables by PCA, which we interpreted to mainly reflect boldness, exploration, and anxiety. Overall, our results strongly suggest that the early development alters the ontogeny of personality types, with heavier individuals being bolder and more explorative. Furthermore, body mass and litter size influenced the changes in the behavioral responses in successive tests, further supporting the importance of the litter size-dependent body mass for the ontogeny of personalities. Anxiety also depended on litter size, however, in a nonlinear way. Animals born to litters of small or large sizes had higher scores, whereas individuals from medium-sized litters were less anxious. This optimum curve indicates that opposing effects of litter size are involved in shaping personalities in young rats.
TL;DR: Reciprocal sympathetic activation, or increases in sympathetic activity accompanied by decreases in parasympathetic activity, was associated with better regulation of emotion for all levels of temperamental surgency supporting previous work that reciprocal activation is an adaptive form of autonomic control.
Abstract: The 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 behavioral maladjustment. Reciprocal sympathetic activation, or increases in sympathetic activity accompanied by decreases in parasympathetic activity, was associated with better regulation of emotion for all levels of temperamental surgency supporting previous work that reciprocal activation is an adaptive form of autonomic control.
TL;DR: The results demonstrate that early social conditions can affect physiological stress responses in nestlings and that behavioral personality traits measured after fledging can be affected by the social experience in the nest.
Abstract: Environmental 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 from male-biased broods. The results demonstrate that early social conditions can affect physiological stress responses in nestlings and that behavioral personality traits measured after fledging can be affected by the social experience in the nest.
TL;DR: Findings indicate that variation in fetal HR reactivity-an index of emerging regulatory capacities-is likely influenced by multiple acute and chronic factors associated with women's psychobiology.
Abstract: The tremendous plasticity, and activity-dependency of the developing nervous system during fetal life, make this period a prime target for investigations of influences on the course of psychobiological development. Recent research across diverse disciplines has focused on identifying early life origins of adult disease (Godfrey & Barker, 2001), and has demonstrated that factors in pregnant women’s health, such as elevations in life stress, may explain some of the individual differences in children’s future risk for physical as well as psychological disorders (Barker, 2000; Davis et al., 2004; O’Connor, Heron, Golding, Beveridge, & Glover, 2002; Van den Bergh & Marcoen, 2004; Van den Bergh et al., 2005; O’Connor et al., 2005; Pawlby, Hay, Sharp, Waters, & O’Keane, 2009).
In our ongoing work, we have reasoned that if the psychological functioning of pregnant women affects offsprings’ long–term development, we should be able to identify markers of that influence when it occurs, that is, during the prenatal period. In prior reports, we showed that prenatal maternal depression, as well as high trait anxiety, predict an increase in fetal heart rate (HR) during women’s laboratory–based, acute stress experience (Stroop test) compared to fetuses of euthymic women who show no significant change in HR (Monk et al., 2000; Monk et al., 2004). Others found that maternal depression during pregnancy is associated with greater fetal movement and slower return to baseline HR following vibroaccoustic stimulation applied to the women’s abdomen (Allister, Lester, Carr, & Liu, 2001; Dieter, Emory, Johnson, & Raynor, 2008). Because increases in fetal HR are often coincident with fetal movements (DiPietro et al., 2004), these findings are consistent in suggesting that greater fetal reactivity to external stimuli maybe a characteristic of fetal neurodevelopment when women experience significant prenatal mood dysregulation.
Several studies have attempted to identify characteristics of pregnant women’s physiology that are potentially mood–based, and related to alterations in fetal neurobehavior, which would support the concept of women’s psychosocial functioning being ‘transduced to the fetus’ and shaping fetal development. The maternal HPA–axis has been a focus of this research {Wadhwa, 2005 #2514;Weinstock, 2005 #2656, as it is a major effector of psychosocial stress, and anxiety and depression are associated with elevations in resting cortisol CITES, even during pregnancy (EVANS). Using a laboratory stressor paradigm similar to ours, Fink et al. found that fetuses of women who had a cortisol increase following an arithmetic task, versus those who did not, had higher resting HR and less short–term HR variability 20 minutes after the stressor task ended. There was a trend finding for participants who had a cortisol increase to report higher levels of life stress {Fink, 2010 #4937}. In other work, higher resting maternal cortisol during the 3rd trimester of pregnancy was associated with greater amplitude and amount (time spent) of fetal movement during a 50 minute observation period (DiPietro, Kivlighan, Costigan, & Laudenslager, 2009). Sandman et al., found that higher levels of placenta–derived corticotropin releasing hormone (pCRH) (which, in contrast to CRH in the hypothalamus, shows increased synthesis in response to glucocorticoid exposure), is linked to increased fetal HR reactivity (‘arousal’) studied in a vibroaccoustic habituation paradigm (Sandman, Wadhwa, Chicz-DeMet, Porto, & Garite, 1999). Taken together, these studies raise the following question: are differences in fetal HR associated with maternal psychiatric status also related to differences in maternal cortisol levels?
So far, we have found minimal indication that women’s psychobiological experience was being ‘transduced’ to the fetus and determining the fetal HR response to women’s exposure to a laboratory stressor. Our results showed no psychiatric diagnostic group differences in women’s cardiorespiratory activity that paralleled the group differences observed in fetal HR reactivity (Monk et al., 2000; Monk et al., 2004), and, across all subjects, only a small inverse association between changes in women’s systolic blood pressure and fetal HR (Monk et al., 2004). Instead, based on our results, we have posited that women’s significant cardiorespiratory reactivity during the stressor task functions as a stimulus that triggers a HR increase in fetuses of depressed or anxious women who already have been shaped over the course of gestation to be more reactive (Monk et al., 2004). To support this interpretation, we sought in this study to manipulate an acute change in maternal cardiorespiratory activity, and investigate it as a stimulus that could differentiate reactive from non–reactive fetuses, while simultaneously considering whether maternal cortisol level is associated with fetal HR. That is, a correlation between maternal cortisol and fetal HR in the laboratory likely reflects maternal–fetal experiences outside the laboratory, and thus finding an association would support the hypothesis that women’s psychosocial functioning shapes fetal development via maternal HPA–axis functioning.
Specifically, the purpose of the present study was to replicate our prior results showing a greater fetal HR increase during maternal laboratory stress associated with women’s diagnosis of clinical depression (Monk et al., 2004), and to determine whether higher levels of women’s cortisol is associated with higher fetal HR. We also used a paced breathing task, in which participants increase and decrease their respiration rate according to a standardized protocol (Wilhelm, Grossman, & Coyle, 2004), to manipulate a specific aspect of women’s physiological activity (rapid changes in breathing) to determine its effects on fetal HR, and as a stimulus that reveals differences in fetal HR reactivity.
TL;DR: The authors reviewed 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 and highlighted the importance of adopting more ecologically valid methods and for integrating the various approaches in deriving new models for social deficits in autism.
Abstract: Autism 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 in deriving new models for social deficits in autism will be highlighted. Future research should build on the emerging synergy of different aspects of social neuroscience.
TL;DR: It was found that individuals used their nonpreferred-hand more often in contralateral space than at the midline position, and using an object resulted in significantly more preferred-hand reaches than picking up an object.
Abstract: The effects of task complexity, object location, and object type on reaching behavior were examined. Two hundred ninety-two right-handed and 38 left-handed participants (grouped into five age groups) were asked to pick up or pick up and use objects in different regions of peripersonal space. It was found that individuals used their nonpreferred-hand more often in contralateral space than at the midline position. Using an object resulted in significantly more preferred-hand reaches than picking up an object. Furthermore, task complexity, object location, and object type interacted with each other depending upon age group and hand preference.
TL;DR: The results suggest that psychosocial stressors have a greater impact on neural and endocrine function than physical stressors do and emphasize the impact of prenatal stress on fetal growth, and neural andendocrine function.
Abstract: Stress during gestation can result in early and long-term developmental aberrations. 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 endocrine function. The results also suggest that psychosocial stressors have a greater impact on neural and endocrine function than physical stressors do.
TL;DR: The results suggest that, like adults, auditory-visual integration for young infants begins early during sensory processing rather than later during higher-level cognitive processing, however, unlike adults, infants' brain responses may be biased towards synchrony.
Abstract: Infants' 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 condition. These results suggest that, like adults, auditory-visual integration for young infants begins early during sensory processing rather than later during higher-level cognitive processing. However, unlike adults, infants' brain responses may be biased towards synchrony. Furthermore, effects of attentional and memory processing confirm interpretations of behavioral looking patterns suggesting infants find synchrony more familiar.
TL;DR: Results indicate that at least some fetuses can be predicted to develop in conditions allowing for ample visual experience before birth, which could have intriguing implications for the ontogeny of early visuo-motor abilities in newborns and infants.
Abstract: It is commonly assumed that, whereas auditory and olfactory learning take place already during fetal development, visual experience and learning are not possible before birth. This paper explores the conditions for visual experience in the last two months of human gestation, when the fetal visual system is mature enough to permit directed vision if a sufficient amount of light is available. Light transmission from the external environment to the uterine cavity is modeled, based on the measured transmission coefficients of biological tissues. Results indicate that illumination in the uterine cavity is highly variable, depending on factors such as external illumination and the mother's abdominal thickness. At least some fetuses can be predicted to develop in conditions allowing for ample visual experience before birth. This finding could have intriguing implications for the ontogeny of early visuo-motor abilities in newborns and infants.
TL;DR: Controlling for iron status, Ghanaian infants displayed precocity in gross motor development and most fine-motor reach-and-grasp tasks and iron status showed linear trends for gross motor milestones and fine motor skills with small objects.
Abstract: Motor development, which allows infants to explore their environment, promoting cognitive, social, and perceptual development, can be influenced by cultural practices and nutritional factors, such as iron deficiency. This study compared fine and gross motor development in 209 9-month-old infants from urban areas of China, Ghana, and USA (African-Americans) and considered effects of iron status. Iron deficiency anemia was most common in the Ghana sample (55%) followed by USA and China samples. Controlling for iron status, Ghanaian infants displayed precocity in gross motor development and most fine-motor reach-and-grasp tasks. US African-Americans performed the poorest in all tasks except bimanual coordination and the large ball. Controlling for cultural site, iron status showed linear trends for gross motor milestones and fine motor skills with small objects. Our findings add to the sparse literature on infant fine motor development across cultures. The results also indicate the need to consider nutritional factors when examining cultural differences in infant development.
TL;DR: The results indicate that prenatal sensory stimulation can significantly bias postnatal responsiveness to social stimuli, thereby altering the course of early learning and memory.
Abstract: Many 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, on the one hand, and generate novel behavioral phenotypes, on the other. In the current study, we show that briefly exposing bobwhite quail embryos to a heterospecific Japanese quail (JQ) maternal call significantly enhanced their acquisition of a preference for that call when chicks were provided with subsequent postnatal exposure to the same call. This was true whether postnatal exposure involved playback of the maternal call contingent upon chick contact vocalizations or yoked, non-contingent exposure to the call. Chicks that received both passive prenatal and contingent postnatal exposure to the JQ maternal call redirected their species-typical auditory preference, showing a significant preference for JQ call over the call of their own species. In contrast, chicks receiving only prenatal or only postnatal exposure to the JQ call did not show this redirection of their auditory preference. Our results indicate that prenatal sensory stimulation can significantly bias postnatal responsiveness to social stimuli, thereby altering the course of early learning and memory.
TL;DR: Data suggest the utility of comparing neural and behavioral indicators of cognitive performance in children and uniquely highlight the importance of considering intraindividual variability in task performance in studies that explore error processing.
Abstract: Childhood 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 related to ERN amplitude. These data suggest the utility of comparing neural and behavioral indicators of cognitive performance in children and uniquely highlight the importance of considering intraindividual variability in task performance in studies that explore error processing.
TL;DR: Assessing the relationship between impulsivity and maternal behavior in AR and MR rats found that impulsivity was inversely related to pup licking-impulsive rats were less maternal and more action impulsive than MR rats.
Abstract: Early life environment and maternal care can have long-lasting effects on behavior and physiology. Previously, we found that compared to mother-reared (MR) female rats, rats reared without mothers, siblings, and nest, through artificially rearing (AR), show reduced levels of maternal behavior when they grow up. These effects can be reversed if AR pups are provided with extra “licking-like” tactile stimulation during the preweaning period [Gonzalez et al. [2001] Developmental Psychobiology, 38(1), 11–42]. We also found that AR rats are more action impulsive and have reduced attentional capacities in comparison to their MR siblings [Lovic, Fletcher, & Fleming, in preparation; Lovic & Fleming [2004] Behavioural Brain Research 148: 209–219]. However, it is unknown whether increased impulsivity contributes to reduced levels of maternal behaviors. The purpose of this study was to assess the relationship between impulsivity and maternal behavior in AR and MR rats. Female rats were reared with (MR) or without mothers (AR) and half of the AR rats received additional stroking stimulation. As adults, AR and MR rats were mated and maternal behavior towards their own pups was assessed. In addition, rats were assessed on impulsive action (differential reinforcement of low-rate schedule; DRL-20s). Consistent with previous findings, AR rats were both less maternal and more action impulsive than MR rats. Partial correlations revealed that impulsivity was inversely related to pup licking-impulsive rats were less maternal. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 53: 13–22, 2011.