Infant Behavioral Development Research Articles

Negative impact of maternal depressive symptoms on infancy neurodevelopment: a moderated mediation effect of maternal inflammation.

Maternal depression promotes maternal inflammation and the risk of neurodevelopmental disorder in offspring, but the role of inflammation on the association between depression and neurodevelopment in offspring has not been extensively studied in humans. This study aims to examine the mediating role of maternal inflammation on the relationship between maternal depression and neurodevelopment in infants. 146 mother-child pairs were identified from Tianjin Maternal and Child Health Education and Service Cohort (Tianjin MCHESC). Maternal depression was investigated by the Center for Epidemiologic Studies Depression Scale and the Edinburgh Postnatal Depression Scale, and depressive trajectories were identified by latent class growth analysis. Inflammatory biomarkers in the three trimesters were assessed with enzyme-linked immunoassay. The Children Neuropsychological and Behavior Scale-Revision 2016 was used to measure neurodevelopment in infants. Principal component analysis was performed to identify inflammatory condition. Stepwise multiple linear regression analysis and mediation analysis were used to identify association among maternal depression, maternal inflammation and neurodevelopment in infants. Offspring in the low and moderate maternal depression groups exhibited higher adaptive behavior development quotient than those in the high maternal depression group. Higher maternal c-reactive protein level and higher inflammatory level in acute-phase of inflammation in the first trimester, and moderate maternal depression were associated with lower adaptive behavior quotients of infants. Inflammatory level in acute-phase of inflammation in the first trimester significantly mediated the association between maternal depression and adaptive behavior development of infants, with explaining 11.85% of the association. Maternal depression could impair adaptive behavior development in infants by inflammation.

Examining infantile facial features and their influence on caretaking behaviors in free-ranging Japanese macaques (Macaca fuscata).

Facial features of immature individuals play a pivotal role in eliciting caretaking behaviors in humans. It has been posited that non-human animals share particular infantile facial features with humans, which can elicit caregivers' attention and caretaking behaviors. Nevertheless, the empirical examination of this hypothesis is extremely limited. In this study, we investigated infantile facial features in Japanese macaques (Macaca fuscata), their developmental processes, and their correlation with caretaking and infant behaviors, based on 470 facial photographs from one free-ranging group. We measured the size of facial parts and evaluated these features using non-contact procedures with the animals. The results indicated that, although some partial species differences were observed, the infantile facial features in Japanese macaques were broadly consistent with those previously observed in humans and great apes. Furthermore, half of the infant subjects displayed non-linear developmental trajectories of infantile faces, similar to those suggested in humans. However, unlike previous studies in humans, infantile faces were not significantly associated with maternal or non-maternal caretaking behaviors, nor were their developmental changes correlated with infant behavioral development. These findings indicate that while many aspects of infantile facial features are shared among particular primates, humans may have evolved a uniquely elevated preference for selecting such features among the primate lineage.

A Developmental Social Neuroscience Perspective on Infant Autism Interventions

Research on early biomarkers and behavioral precursors of autism has led to interventions initiated during the infant period that could potentially change the course of infant brain and behavioral development in autism. This article integrates neuroscience and clinical perspectives to explore how knowledge of infant brain and behavioral development can inform the design of infant autism interventions. Focusing on infants ≤12 months, we review studies on behavioral precursors of autism and their neural correlates and clinical trials evaluating the efficacy of infant autism interventions. We then consider how contemporary developmental social neuroscience theories of autism can shed light on the therapeutic strategies used in infant autism interventions and offer a new perspective that emphasizes improving child outcome and well-being by enhancing infant–environment fit. Finally, we offer recommendations for future research that incorporates brain-based measures to inform individualized approaches to intervention and discuss ethical issues raised by infant autism interventions. Readers are referred to Supplemental Table 1 for a glossary of terms used in this article.

Skin-to-Skin Contact at Birth for Very Preterm Infants and Mother-Infant Interaction Quality at 4 Months

Good-quality parent-infant interactions have protective effects on infant socio-emotional and behavioral development. These interactions are especially critical for very preterm infants at risk of vulnerabilities related to immaturity. Skin-to-skin contact (SSC) has been found to improve mother-preterm infant interaction behaviors, but few studies exist regarding its benefits when initiated immediately after birth. To determine the effect of immediate SSC at birth for very preterm infants on mother-infant interaction quality at 4 months of corrected age. This secondary analysis used data from the Immediate Parent-Infant Skin-to-Skin Study (IPISTOSS), a randomized clinical trial conducted between April 1, 2018, and June 30, 2021, at 3 neonatal units in Sweden and Norway. Participants included very preterm infants (28-33 gestational weeks of age) and their parents. Four-month follow-up was concluded in December 2021. Data analyses were performed on March 16 and September 18, 2023. Infants were allocated to standard incubator care or SSC with either parent initiated at birth and continued throughout the first 6 hours after birth. The primary outcome was mother-infant interaction quality as measured with the Parent-Child Early Relational Assessment (PCERA), based on video recordings of a 5-minute free-play situation with mother-infant dyads at 4 months of corrected age. A multilevel regression analysis was performed. This analysis included 71 infants (31 twins [44%]) and 56 mothers. Infants had a mean (SD) gestational age of 31 weeks 3 (1.3) days, and more than half were male (42 [59%]); mothers had a mean (SD) age of 32 (4.9) years. There were 37 infants allocated to standard care and 34 to SSC with either parent after birth. During the first 6 hours after birth, fathers provided more SSC than mothers, with a median (IQR) of 3.25 (2.25-4.5) and 0.75 (0-2.5) hours, respectively. A statistically significant difference in 1 of 5 PCERA subscales (subscale 3: infant positive affect, communicative and social skills) was observed, with higher-quality mother-infant interaction in the SSC group at 4 months (Cohen d = 0.67 [95% CI, 0.17 to 1.17]; P = .01). This effect remained significant when adjusting for primiparity, child sex, and observation setting. In this study of the effect of immediate parent-infant SSC after very preterm birth, SSC was beneficial for the mother-infant relationship. These findings suggest that immediate SSC should be supported in the clinical setting. ClinicalTrials.gov Identifier: NCT03521310.

Maternal Perinatal Stress Trajectories and Negative Affect and Amygdala Development in Offspring.

Maternal psychological stress during pregnancy is a common risk factor for psychiatric disorders in offspring, but little is known about how heterogeneity of stress trajectories during pregnancy affect brain systems and behavioral phenotypes in infancy. This study was designed to address this gap in knowledge. Maternal anxiety, stress, and depression were assessed at multiple time points during pregnancy in two independent low-risk mother-infant cohorts (N=115 and N=2,156). Trajectories in maternal stress levels in relation to infant negative affect were examined in both cohorts. Neonatal amygdala resting-state functional connectivity MRI was examined in a subset of one cohort (N=60) to explore the potential relationship between maternal stress trajectories and brain systems in infants relevant to negative affect. Four distinct trajectory clusters, characterized by changing patterns of stress over time, and two magnitude clusters, characterized by severity of stress, were identified in the original mother-infant cohort (N=115). The magnitude clusters were not associated with infant outcomes. The trajectory characterized by increasing stress in late pregnancy was associated with blunted development of infant negative affect. This relationship was replicated in the second, larger cohort (N=2,156). In addition, the trajectories that included increasing or peak maternal stress in late pregnancy were related to stronger neonatal amygdala functional connectivity to the anterior insula and the ventromedial prefrontal cortex in the exploratory analysis. The trajectory of maternal stress appears to be important for offspring brain and behavioral development. Understanding heterogeneity in trajectories of maternal stress and their influence on infant brain and behavioral development is critical to developing targeted interventions.

Maternal perceived stress and infant behavior during the COVID-19 pandemic

BackgroundMaternal stress has negative consequences on infant behavioral development, and COVID-19 presented uniquely stressful situations to mothers of infants born during the pandemic. We hypothesized that mothers with higher levels of perceived stress during the pandemic would report higher levels of infant regulatory problems including crying and interrupted sleep patterns.MethodsAs part 6 sites of a longitudinal study, mothers of infants born during the pandemic completed the Perceived Stress Scale, the Brief Infant Sleep Questionnaire, and an Infant Crying survey at 6 (n = 433) and 12 (n = 344) months of infant age.ResultsMaternal perceived stress, which remained consistent at 6 and 12 months of infant age, was significantly positively correlated with time taken to settle infants. Although maternal perceived stress was not correlated with uninterrupted sleep length, time taken to put the infant to sleep was correlated. Perceived stress was also correlated with the amount of infant crying and fussiness reported at 6 months.ConclusionsMothers who reported higher levels of perceived stress during the pandemic reported higher levels of regulatory problems, specifically at 6 months. Examining how varying levels of maternal stress and infant behaviors relate to overall infant developmental status over time is an important next step.ImpactWomen giving birth during the COVID-19 pandemic who reported higher levels of stress on the Perceived Stress Scale also reported higher levels of infant fussiness and crying at 6 months old, and more disruptive sleep patterns in their infants at 6 months and 12 months old. Sleeping problems and excessive crying in infancy are two regulatory problems that are known risk factors for emotional and behavioral issues in later childhood. This paper is one of the first studies highlighting the associations between maternal stress and infant behaviors during the COVID-19 pandemic.

Calorie restriction and pravastatin administration during pregnancy in obese rhesus macaques modulates maternal and infant metabolism and infant brain and behavioral development.

Maternal obesity has been associated with a higher risk of pregnancy-related complications in mothers and offspring; however, effective interventions have not yet been developed. We tested two interventions, calorie restriction and pravastatin administration, during pregnancy in a rhesus macaque model with the hypothesis that these interventions would normalize metabolic dysregulation in pregnant mothers leading to an improvement in infant metabolic and cognitive/social development. A total of 19 obese mothers were assigned to either one of the two intervention groups (n = 5 for calorie restriction; n = 7 for pravastatin) or an obese control group (n = 7) with no intervention, and maternal gestational samples and postnatal infant samples were compared with lean control mothers (n = 6) using metabolomics methods. Gestational calorie restriction normalized one-carbon metabolism dysregulation in obese mothers, but altered energy metabolism in her offspring. Although administration of pravastatin during pregnancy tended to normalize blood cholesterol in the mothers, it potentially impacted the gut microbiome and kidney function of their offspring. In the offspring, both calorie restriction and pravastatin administration during pregnancy tended to normalize the activity of AMPK in the brain at 6 months, and while results of the Visual Paired-Comparison test, which measures infant recognition memory, was not significantly impacted by either of the interventions, gestational pravastatin administration, but not calorie restriction, tended to normalize anxiety assessed by the Human Intruder test. Although the two interventions tested in a non-human primate model led to some improvements in metabolism and/or infant brain development, negative impacts were also found in both mothers and infants. Our study emphasizes the importance of assessing gestational interventions for maternal obesity on both maternal and offspring long-term outcomes.

Impact of Maternal Obesity on the Gestational Metabolome and Infant Metabolome, Brain, and Behavioral Development in Rhesus Macaques.

Maternal gestational obesity is associated with elevated risks for neurodevelopmental disorder, including autism spectrum disorder. However, the mechanisms by which maternal adiposity influences fetal developmental programming remain to be elucidated. We aimed to understand the impact of maternal obesity on the metabolism of both pregnant mothers and their offspring, as well as on metabolic, brain, and behavioral development of offspring by utilizing metabolomics, protein, and behavioral assays in a non-human primate model. We found that maternal obesity was associated with elevated inflammation and significant alterations in metabolites of energy metabolism and one-carbon metabolism in maternal plasma and urine, as well as in the placenta. Infants that were born to obese mothers were significantly larger at birth compared to those that were born to lean mothers. Additionally, they exhibited significantly reduced novelty preference and significant alterations in their emotional response to stress situations. These changes coincided with differences in the phosphorylation of enzymes in the brain mTOR signaling pathway between infants that were born to obese and lean mothers and correlated with the concentration of maternal plasma betaine during pregnancy. In summary, gestational obesity significantly impacted the infant systemic and brain metabolome and adaptive behaviors.

Maternal stress effects on infant development in wild Verreaux's sifaka (Propithecus verreauxi)

Maternal effects mediated by nutrients or specific endocrine states of the mother can affect infant development. Specifically, pre- and postnatal maternal stress associated with elevated glucocorticoid (GC) output is known to influence the phenotype of the offspring, including their physical and behavioral development. These developmental processes, however, remain relatively poorly studied in wild vertebrates, including primates with their relatively slow life histories. Here, we investigated the effects of maternal stress, assessed by fecal glucocorticoid output, on infant development in wild Verreaux’s sifakas (Propithecus verreauxi), a group-living Malagasy primate. In a first step, we investigated factors predicting maternal fecal glucocorticoid metabolite (fGCM) concentrations, how they impact infants’ physical and behavioral development during the first 6 months of postnatal life as well as early survival during the first 1.5 years of postnatal life. We collected fecal samples of mothers for hormone assays and behavioral data of 12 infants from two birth cohorts, for which we also assessed growth rates. Maternal fGCM concentrations were higher during the late prenatal but lower during the postnatal period compared to the early/mid prenatal period and were higher during periods of low rainfall. Infants of mothers with higher prenatal fGCM concentrations exhibited faster growth rates and were more explorative in terms of independent foraging and play. Infants of mothers with high pre- and postnatal fGCM concentrations were carried less and spent more time in nipple contact. Time mothers spent carrying infants predicted infant survival: infants that were more carried had lower survival, suggesting that they were likely in poorer condition and had to be cared for longer. Thus, the physical and behavioral development of these young primates were impacted by variation in maternal fGCM concentrations during the first 6 months of their lives, presumably as an adaptive response to living in a highly seasonal, but unpredictable environment.Significance statementThe early development of infants can be impacted by variation in maternal condition. These maternal effects can be mediated by maternal stress (glucocorticoid hormones) and are known to have downstream consequences for behavior, physiology, survival, and reproductive success well into adulthood. However, the direction of the effects of maternal physiological GC output on offspring development is highly variable, even within the same species. We contribute comparative data on maternal stress effects on infant development in a Critically Endangered primate from Madagascar. We describe variation in maternal glucocorticoid output as a function of ecological and reproductive factors and show that patterns of infant growth, behavioral development, and early survival are predicted by maternal glucocorticoids. Our study demonstrates how mothers can influence offspring fitness in response to challenging environmental conditions.

Sleep behavior of infants with infantile hemangioma treated with propranolol\u2014a cohort study

Sleep problems are frequently reported in infants treated with propranolol for infantile hemangiomas, possibly serving as a marker for a negative impact on central nervous system function. In this cohort study, we objectively investigate the sleep behavior of infants with infantile hemangiomas on propranolol compared to a healthy, untreated control group. Sleep of propranolol-treated infants and controls was investigated using ankle actigraphy and a 24-h diary for 7–10 days at ages 3 and 6 months. The main outcome measures were the Number of Nighttime Awakenings and Sleep Efficiency. The main secondary outcome measures included 24-hour Total Sleep, daytime sleep behavior, and parent-rated infant sleep quality and behavioral development based on the Brief Infant Sleep Questionnaire (BISQ) and the age-appropriate Ages-and-Stages Questionnaire (ASQ), respectively. Fifty-four term-born infants were included in each cohort. No group difference in any investigated parameter was seen at age 3 months. At age 6 months, the propranolol group exhibited a decrease in Sleep Efficiency and a trend towards an increased Number of Nighttime Awakenings compared to the control group. Treated infants at 6 months also had shorter daytime waking periods. 24-hour Total Sleep was unaffected by propranolol. No negative impact of propranolol on subjective sleep quality and behavioral development was noted.Conclusion: Propranolol exerts a measurable yet mild impact on objectively assessed infants’ sleep measures. Behavioral developmental scores were unaffected. Our results support propranolol as first-line therapy for complicated infantile hemangiomas.What is Known:• Sleep disorders are frequently reported in infants with infantile hemangiomas treated with propranolol and often lead to treatment discontinuation.• Investigations of the sleep pattern in this patient group using objective measures are lacking.What is New:• The sleep pattern of propranolol-treated infants is assessed using actigraphy and a 24-h sleep diary and compared to healthy, untreated controls.• Propranolol leads to a decreased sleep efficiency at night and an increased demand of daytime sleep, yet effects are mild overall.

A birth cohort study of the association between prenatal serum bisphenol A concentration and infant neurobehavior development

Objective: To explore the association between maternal bisphenol A (BPA) exposure during pregnancy and neurobehavioral development in infant. Methods: Participants were from the Ma'anshan Birth Cohort, which was established from October 2008 to October 2010 based on four municipal medical and health institutions in Ma'anshan. High-performance liquid chromatography-tandem mass spectrometry was applied for the determination of serum BPA concentration in 1 783 pregnant women sampled at their first filing, and during 2.97 to 28.1 months age of the infants. Neurobehavioral development were assessed by 0-6-year-old pediatric examination table of neuropsychological development. Generalized linear model was used to analyze the association between serum BPA levels during pregnancy and infants' neurobehavioral development. Results: A total of 931 mother-child pairs had complete data on serum BPA detection during pregnancy and assessment of infants' neurobehavioral development status. The age of pregnant women at their first filing was (26.67±3.45) years old, and the M (P25,P75) of serum BPA concentration (ng/ml) was 0.23 (0.11, 0.52), with a detection rate of 84.1% (783/931). The age of infants was (13.18±5.46) months, and 53.5% (498) were boys. The developmental quotient scores of large motor, fine motor, adaptive ability, language ability and social behaviors of infants were (97.88±16.32), (97.16±15.35), (99.64±15.47), (95.3±16.04) and (98.95±14.76) points, respectively. Generalized linear model showed that after adjusting for factors such as delivery mode, feeding mode, family per capita monthly income, preterm delivery, gender, maternal age, residence, pre-pregnancy body mass index and residence time, serum BPA level in pregnancy was negatively associated with infant's development of social behavior [β (95%CI):-2.42 (-4.71, -0.12)]. The post-stratification analysis by infant age revealed that the serum BPA level in pregnancy was only negatively associated with the development of language and social behavior developmental quotient scores in infants between the ages of 12 and 18 months, with β (95%CI) about -6.66 (-13.06, -0.25) and -7.401 (-12.97, -1.83), respectively. Conclusion: BPA exposure during pregnancy affects language and social behavior development in infants, and the detection window is between 12 and 18 months old of the infant.

No Such Thing as a Baby: Responses to Infant Cry Paradigms Are Primarily Influenced by Parents’ Experiences and Behavior

SYNOPSISThis article builds on our previous work demonstrating that, when exposed to work–family conflict, parents with high levels of attachment anxiety exhibit greater work–family guilt and less tolerance of infant distress. We respond to commentaries suggesting that the theoretical model could be enhanced by better accounting for innate infant differences and parent psychopathology, arguing that it is possible that parents’ experiences of work–family conflict and attachment anxiety precede the development of psychopathology and may influence the development of infant temperament and behavior. We further explore clinical implications of our findings and identify key suggestions for future work, with an emphasis on the roles of parental experiences of childhood maltreatment and insensitive caregiving.

Resting gamma power during the postnatal critical period for GABAergic system development is modulated by infant diet and sex.

Gamma band activity (30-50 Hz) plays an essential role in brain development and function, but neither the early postnatal development nor subject and environmental factors influencing this development have been reported. We documented the development of resting gamma power using high density EEG recordings obtained each month from postnatal month 2 to 6 in 518 healthy infants who were breast-fed (170; 85 boys), fed milk formula (186; 97 boys), or fed soy formula (162; 90 boys). Gamma power was determined for 44 sites distributed over major brain regions and analyses were adjusted for background variables relevant to neurodevelopment. The results show gamma power follows a gradually increasing function across this time period that varies in topographic magnitude and is differentially influenced by subject and environmental variables-among which gestation, head circumference, and infant diet-sex interactions figure most prominently. Relationships between gamma power and standardized measures of infant behavioral development appear to be emerging but are in flux during this time. Since this postnatal period is considered critical in the development of the GABAergic system underlying the generation of gamma activity, the observed findings may reflect organizational changes that will influence the future development of gamma-related behavioral and neurocognitive functions.

Features and Associated Factors of the Behavioral Development of 24-month-old Children in Rural China: Follow-up Evaluation of a Randomized Controlled Trial

The aim of this study was to assess the risk factors associated with the behavioral development among 24-month-old children in rural northwestern China. A total of 657 children whose mothers had participated in a double-blinded, randomized, controlled trial of antenatal micronutrient supplementation in western China were followed until 24 months of age. Their mental, psychomotor, and behavioral development were assessed by the Bayley Scales of Infant Development. Multivariate logistic regression models were used to examine the factors associated with infant behavioral development. Six behavioral factors of infants were presented: activity, social adaptability, reactivity, endurance, concentration, and motor coordination. Further analysis demonstrated that maternal malnutrition, exposure to risk factors during pregnancy, and adverse birth outcomes negatively affected the behavioral development of children at 24 months, which is a common co-occurrence with cognitive and emotional problems. These results suggest that strategies to improve infant behavioral development should consider the maternal pregnancy status.

Prenatal neural origins of infant motor development: Associations between fetal brain and infant motor development.

Functional circuits of the human brain emerge and change dramatically over the second half of gestation. It is possible that variation in neural functional system connectivity in utero predicts individual differences in infant behavioral development, but this possibility has yet to be examined. The current study examines the association between fetal sensorimotor brain system functional connectivity and infant postnatal motor ability. Resting-state functional connectivity data was obtained in 96 healthy human fetuses during the second and third trimesters of pregnancy. Infant motor ability was measured 7 months after birth using the Bayley Scales of Infant Development. Increased connectivity between the emerging motor network and regions of the prefrontal cortex, temporal lobes, posterior cingulate, and supplementary motor regions was observed in infants that showed more mature motor functions. In addition, females demonstrated stronger fetal-brain to infant-behavior associations. These observations extend prior longitudinal research back into prenatal brain development and raise exciting new ideas about the advent of risk and the ontogeny of early sex differences.

Educator Argues for Integrating Infant MH in Child Psychiatry Training

Educator Argues for Integrating Infant MH in Child Psychiatry Training

Assessing infant cognitive development after prenatal iodine supplementation

Little information is available on infant behavioral development outcomes of prenatal iodine supplementation in regions of mild to moderate iodine deficiency. Studies performed to date, all of which relied on global developmental assessments, have yielded inconsistent findings with regard to psychomotor development, negative findings with regard to mental development, and no information as to the development of specific cognitive functions. Our review of these studies leads us to suspect that the use of global developmental assessments might partially explain the negative and inconsistent findings. To identify cognitive processes that might be sensitive to prenatal iodine supplementation, we examined the timing of thyroid hormone action on specific brain systems. The development of infant visual attention is sensitive to thyroid hormone during the early prenatal period, when the fetus is entirely dependent on maternal thyroid hormone. For this reason, infant visual attention has the potential to be a sensitive measure of infant outcomes in prenatal iodine supplementation studies. We suggest the assessment of infant visual attention, with follow-up examination of childhood executive functions, as a means of capturing the effects of maternal iodine deficiency and prenatal iodine supplementation on specific cognitive processes. In particular, we propose comparison of infant performance on global developmental tests and specialized tests of visual attention in pilot trials of prenatal iodine supplementation in regions of mild to moderate iodine deficiency. Only by comparing the 2 types of tests side by side will it be possible to establish whether the use of a sensitive measure of infant visual attention will increase the reliability of such supplementation studies. Recognizing that exposure misclassification may also provide a partial explanation for the inconsistent neurodevelopmental outcomes in previous studies, we suggest that urinary iodine concentration or creatinine-corrected iodine excretion be monitored regularly in such trials throughout the prenatal period.

Manual Activity and Onset of First Words in Babies Exposed and Not Exposed to Baby Signing

Support for baby signing (BS) with hearing infants tends to converge toward three camps or positions. Those who advocate BS to advance infant language, literacy, behavioral, and cognitive development rely heavily on anecdotal evidence and social media to support their claims. Those who advocate BS as an introduction to another language, such as American Sign Language (ASL), advocate early bilingual language learning. A third group warns against BS, emphasizing that it competes for attention with, and thereby potentially delays, spoken language acquisition in hearing infants. Empirical evidence to support any of these camps has been scarce. In this retrospective investigation we analyzed videotapes of sixteen infants from 9 through 18 months of age; eight had been exposed to BS, and eight had not been exposed to signing (NS). We compared their manual activity and found no differences in the quantity of manual activity accompanying vocal activity and no qualitative differences in the handshapes used during manual and vocal activity. More babies in the BS group reached the 4-, 10-, and 25-word milestones than babies in the NS group, but the differences were not statistically significant. In addition, monthly lexical growth from 12 to 18 months did not reveal signing to have a statistical impact on vocabulary acquisition. Discussion of these findings points to a tight relationship between manual and vocal activity in all sixteen babies, a relationship that aligns with previous theories and research on gestural and vocal development. Failure to find a statistical difference between the two groups’ development of words, however, calls for temperance in claiming that baby signing facilitates early word learning and cautions against claims that baby signing interferes with word learning.

Search asymmetry and eye movements in infants and adults.

Search asymmetry is characterized by the detection of a feature-present target amidst feature-absent distractors being efficient and unaffected by the number of distractors, whereas detection of a feature-absent target amidst feature-present distractors is typically inefficient and affected by the number of distractors. Although studies have attempted to investigate this phenomenon with infants (e.g., Adler, Inslicht, Rovee-Collier, & Gerhardstein in Infant Behavioral Development, 21, 253-272, 1998; Colombo, Mitchell, Coldren, & Atwater in Journal of Experimental Psychology: Learning, Memory and Cognition, 19, 98-109, 1990), due to methodological limitations, their findings have been unable to definitively establish the development of visual search mechanisms in infants. The present study assessed eye movements as a means to examine an asymmetry in responding to feature-present versus feature-absent targets in 3-month-olds, relative to adults. Saccade latencies to localize a target (or a distractor, as in the homogeneous conditions) were measured as infants and adults randomly viewed feature-present (R among Ps), feature-absent (P among Rs), and homogeneous (either all Rs or all Ps) arrays at set sizes of 1, 3, 5, and 8. Results indicated that neither infants' nor adults' saccade latencies to localize the target in the feature-present arrays were affected by increasing set sizes, suggesting that localization of the target was efficient. In contrast, saccade latencies to localize the target in the feature-absent arrays increased with increasing set sizes for both infants and adults, suggesting an inefficient localization. These findings indicate that infants exhibit an asymmetry consistent with that found with adults, providing support for functional bottom-up selective attention mechanisms in early infancy.

Translational Research Models and Methods for Mother-Infant Interactions and Developmental Studies

The disruption of mother-infant interactions can have life-long detrimental consequences for offspring and mothers. Recently, science has begun to emphasize translational research including preclinical and neurobiological research that may have direct implications for clinical populations and issues. This group of papers focuses broadly on translational studies highlighting factors that may affect or alter infant or child development and maternal response capability. Articles, both preclinical and clinical, highlight topics such as drug abuse, maternal neglect, altered reward systems, stress, biological and neural system development, child and infant behavioral development, genetics/epigenetics, intergenerational studies and logistical issues of comparative measurement. Articles include research methods papers, reviews, original research articles, techniques, and opinion articles that address these topics. New methods papers for comparative measures between clinical and preclinical populations are included. Our aims include introducing new translational models and methods for research through a group of outstanding papers focused on these topics.