Heart-to-heart: infant heart rate at 3 months is linked to infant-directed speech, mother-infant interaction, and later language outcomes

Introduction

Previous studies underscore the importance of speech input, particularly infant-directed speech (IDS) during one-on-one (1:1) parent-infant interaction, for child language development. We hypothesize that infants' attention to speech input, specifically IDS, supports language acquisition. In infants, attention and orienting responses are associated with heart rate deceleration. We examined whether individual differences in infants' heart rate measured during 1:1 mother-infant interaction is related to speech input and later language development scores in a longitudinal study.

Methods

Using a sample of 31 3-month-olds, we assessed infant heart rate during mother-infant face-to-face interaction in a laboratory setting. Multiple measures of speech input were gathered at 3 months of age during naturally occurring interactions at home using the Language ENvironment Analysis (LENA) system. Language outcome measures were assessed in the same children at 30 months of age using the MacArthur-Bates Communicative Development Inventory (CDI).

Results

Two novel findings emerged. First, we found that higher maternal IDS in a 1:1 context at home, as well as more mother-infant conversational turns at home, are associated with a lower heart rate measured during mother-infant social interaction in the laboratory. Second, we found significant associations between infant heart rate during mother-infant interaction in the laboratory at 3 months and prospective language development (CDI scores) at 30 months of age.

Discussion

Considering the current results in conjunction with other converging theoretical and neuroscientific data, we argue that high IDS input in the context of 1:1 social interaction increases infants' attention to speech and that infants' attention to speech in early development fosters their prospective language growth.

Infants' brain responses to social interaction predict future language growth

In face-to-face interactions with infants, human adults exhibit a species-specific communicative signal. Adults present a distinctive "social ensemble": they use infant-directed speech (parentese), respond contingently to infants' actions and vocalizations, and react positively through mutual eye-gaze and smiling. Studies suggest that this social ensemble is essential for initial language learning. Our hypothesis is that the social ensemble attracts attentional systems to speech and that sensorimotor systems prepare infants to respond vocally, both of which advance language learning. Using infant magnetoencephalography (MEG), we measure 5-month-old infants' neural responses during live verbal face-to-face (F2F) interaction with an adult (social condition) and during a control (nonsocial condition) in which the adult turns away from the infant to speak to another person. Using a longitudinal design, we tested whether infants' brain responses to these conditions at 5 months of age predicted their language growth at five future time points. Brain areas involved in attention (right hemisphere inferior frontal, right hemisphere superior temporal, and right hemisphere inferior parietal) show significantly higher theta activity in the social versus nonsocial condition. Critical to theory, we found that infants' neural activity in response to F2F interaction in attentional and sensorimotor regions significantly predicted future language development into the third year of life, more than 2 years after the initial measurements. We develop a view of early language acquisition that underscores the centrality of the social ensemble, and we offer new insight into the neurobiological components that link infants' language learning to their early brain functioning during social interaction.

Mother-infant social and language interactions at 3 months are associated with infants' productive language development in the third year of life

Previous studies underscore the importance of social interactions for child language development-particularly interactions characterized by maternal sensitivity, infant-directed speech (IDS), and conversational turn-taking (CT) in one-on-one contexts. Although infants engage in such interactions from the third month after birth, the prospective link between speech input and maternal sensitivity in the first half year of life and later language development has been understudied. We hypothesized that social interactions embodying maternal sensitivity, IDS and CTs in the first 3 months of life, are significantly associated with later language development and tested this using a longitudinal design. Using a sample of 40 3-month-old infants, we assessed maternal sensitivity during a structured mother-infant one-on-one (1:1) interaction based on a well-validated scoring system (the Coding Interactive Behavior system). Language input (IDS, CT) was assessed during naturally occurring interactions at home using the Language ENvironment Analysis (LENA) system. Language outcome measures were obtained from 18 to 30 months of age using the MacArthur-Bates Communicative Development Inventory. Three novel findings emerged. First, maternal sensitivity at 3 months was significantly associated with infants' productive language scores at 18, 21, 24, 27, and 30 months of age. Second, LENA-recorded IDS during mother-infant 1:1 interaction in the home environment at 3 months of age was positively correlated with productive language scores at 24, 27, and 30 months of age. Third, mother-infant CTs during 1:1 interaction was significantly associated with infants' productive language scores at 27 and 30 months of age. We propose that infants' social attention to speech during this early period-enhanced by sensitive maternal one-on-one interactions and IDS-are potent factors in advancing language development.

Exploring whether and how Black and White parents talk with their children about race: M(ai)cro race conversations about Black Lives Matter

Previous research on parent-led race conversations reports robust racial differences in the content of race conversations between Black and white parents. It was unknown, however, whether these racial differences shifted in the months immediately following the summer of 2020 when there was heightened public attention directed toward white parents, specifically, to talk with children about racism. In the present study, we investigated whether and how Black (n = 344) and white (n = 381) parents talked about Black Lives Matter (BLM) with their 8- to 11-year-old children. Overall, 80% of parents (n = 725) reported talking about BLM, but Black parents were significantly more likely to discuss BLM than white parents (p = .008). Further qualitative analysis of the content of parents' reports showed that Black parents were significantly more likely than white parents to provide responses about BLM that acknowledge racial inequality in society or explicitly affirm/support Black lives. White parents, in contrast, were significantly more likely to discuss BLM by focusing on equality but without acknowledging racial injustice or to provide responses that lacked clarity and/or substance. Using the m(ai)cro model of human development (Rogers, Niwa, et al., 2021), we discuss how parents' reported race conversations are shaped by the sociopolitical context and their role in disrupting (or perpetuating) systemic racism through socialization. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Social experiences and youth psychopathology during the COVID-19 pandemic: A longitudinal study

The early stages of the COVID-19 pandemic and associated stay-at-home orders resulted in a stark reduction in daily social interactions for children and adolescents. Given that peer relationships are especially important during this developmental stage, it is crucial to understand the impact of the COVID-19 pandemic on social behavior and risk for psychopathology in children and adolescents. In a longitudinal sample (N=224) of children (7-10y) and adolescents (13-15y) assessed at three strategic time points (before the pandemic, during the initial stay-at-home order period, and six months later after the initial stay-at-home order period was lifted), we examine whether certain social factors protect against increases in stress-related psychopathology during the pandemic, controlling for pre-pandemic symptoms. Youth who reported less in-person and digital socialization, greater social isolation, and less social support had worsened psychopathology during the pandemic. Greater social isolation and decreased digital socialization during the pandemic were associated with greater risk for psychopathology after experiencing pandemic-related stressors. In addition, children, but not adolescents, who maintained some in-person socialization were less likely to develop internalizing symptoms following exposure to pandemic-related stressors. We identify social factors that promote well-being and resilience in youth during this societal event.

Am I a good person? Academic correlates of explicit and implicit self-esteem during early childhood

Implicit and explicit self-esteem are not commonly measured in the same children. Using a cross-sectional design, data from 354 Croatian children (184 girls) in Grade 1 (Mage  = 7.55 years) and Grade 5 (Mage  = 11.58 years) were collected in Spring 2019. All children completed explicit and implicit self-esteem measures; math and language grades were obtained. For the explicit measure, older children showed lower self-esteem than younger children, and girls showed lower self-esteem than boys. For the implicit measure, there were no age effects, and girls showed higher self-esteem than boys. Although both types of self-esteem were positively associated with academic achievement, implicit self-esteem was associated more strongly with language than with math achievement. Discussion is provided about why self-esteem relates to academic achievement during childhood.

Differentiating Between Us & Them: Reduced In-Group Bias as a Novel Mechanism Linking Childhood Violence Exposure with Internalizing Psychopathology

Strong in-group bonds, facilitated by implicit favoritism for in-group members (i.e., in-group bias), promote mental health across development. Yet, we know little about how the development of in-group bias is shaped by early-life experiences. Childhood violence exposure is known to alter social information processing biases. Violence exposure may also influence social categorization processes, including in-group biases, in ways that influence risk for psychopathology. We examined associations of childhood violence exposure with psychopathology and behavioral and neural indices of implicit and explicit bias for novel groups in children followed longitudinally across three time points from age 5 to 10 years old (n = 101 at baseline; n = 58 at wave 3). To instantiate in-group and out-group affiliations, youths underwent a minimal group assignment induction procedure, in which they were randomly assigned to one of two groups. Youth were told that members of their assigned group shared common interests (in-group) and members of the other group did not (out-group). In pre-registered analyses, violence exposure was associated with lower implicit in-group bias, which in turn was associated prospectively with higher internalizing symptoms and mediated the longitudinal association between violence exposure and internalizing symptoms. During an fMRI task examining neural responses while classifying in-group and out-group members, violence-exposed children did not exhibit the negative functional coupling between vmPFC and amygdala to in-group vs. out-group members that was observed in children without violence exposure. Reduced implicit in-group bias may represent a novel mechanism linking violence exposure with the development of internalizing symptoms.

Prosociality and health: Identification with all humanity is a replicable predictor of prosocial motivation for health behaviors

The acute phase of the COVID-19 pandemic may have passed, but the pandemic remains a major worldwide health concern that demands continued vigilance. Are there individual differences that predict the motivation to continue to wear masks and to create physical distance in public? Previous research conducted early in the pandemic had suggested that a particular social identity-identification with all humanity-is one underlying factor that contributes to people's cooperation with health behavior guidelines. This highlights that the pandemic is not only an issue to be tackled with the tools of immunology and epidemiology. It also requires the tools from psychology-to measure the representations people have about themselves and others and how these representations drive values and decisions related to health. Here we report work on U.S. respondents that examined whether individuals' level of identification with all humanity predicts their prosocial health behaviors aimed at mitigating the spread of COVID-19. In 3 convergent studies (total N = 1,580), we find that identification with all humanity predicted the prosocial motivation to wear masks and to engage in physical distancing when in public without a mask. The results were obtained while controlling for a host of covariates, including demographics, educational attainment, and Big Five personality dimensions. We find that some people have a marked drive to care for the health of strangers, which is significantly linked to their concern for all humanity rather than being restricted to their care for their community or country. Discussion focuses on this social identification with humanity and its enduring, replicable role in predicting the motivation to engage in prosocial health behaviors. We note key implications for theories in social and developmental psychology as well as for research that may lead to practical applications for lessening the human toll of the current and future pandemics.

Early-childhood temperament moderates the prospective associations of coping with adolescent internalizing and externalizing symptoms

While appraisal and coping are known to impact adolescent psychopathology, more vulnerable or resilient responses to stress may depend on individual temperament. This study examined early life temperament as a moderator of the prospective relations of pre-adolescent appraisal and coping with adolescent psychopathology. The sample included 226 (62% female, 14–15 years) adolescents with assessments starting at 3 years of age. Adolescents were predominately White (12% Black 9% Asian, 11% Latinx, 4% Multiracial, and 65% White). Observed early-childhood temperament (fear, frustration, executive control, and delay ability) were tested as moderators of pre-adolescent coping (active and avoidant) and appraisal (threat, positive) on internalizing and externalizing symptoms during the pandemic. Interaction effects were tested using regression in R. Sex and family context of stress were covariates. Early-childhood temperament was correlated with pre-adolescent symptoms, however, pre-adolescent appraisal and coping but not temperament predicted adolescent psychopathology. Frustration moderated the relations of active and avoidant coping and positive appraisal to symptoms such that coping and appraisal related to lower symptoms only for those low in frustration. Executive control moderated the associations of avoidant coping with symptoms such that avoidance reduced the likelihood of symptoms for youth low in executive control. Findings underscore the role of emotionality and self-regulation in youth adjustment, with the impact of coping differing with temperament. These findings suggest that equipping youth with a flexible assortment of coping skills may serve to reduce negative mental health outcomes.

Dual-MEG interbrain synchronization during turn-taking verbal interactions between mothers and children

Verbal interaction and imitation are essential for language learning and development in young children. However, it is unclear how mother-child dyads synchronize oscillatory neural activity at the cortical level in turn-based speech interactions. Our study investigated interbrain synchrony in mother-child pairs during a turn-taking paradigm of verbal imitation. A dual-MEG (magnetoencephalography) setup was used to measure brain activity from interactive mother-child pairs simultaneously. Interpersonal neural synchronization was compared between socially interactive and noninteractive tasks (passive listening to pure tones). Interbrain networks showed increased synchronization during the socially interactive compared to noninteractive conditions in the theta and alpha bands. Enhanced interpersonal brain synchrony was observed in the right angular gyrus, right triangular, and left opercular parts of the inferior frontal gyrus. Moreover, these parietal and frontal regions appear to be the cortical hubs exhibiting a high number of interbrain connections. These cortical areas could serve as a neural marker for the interactive component in verbal social communication. The present study is the first to investigate mother-child interbrain neural synchronization during verbal social interactions using a dual-MEG setup. Our results advance our understanding of turn-taking during verbal interaction between mother-child dyads and suggest a role for social "gating" in language learning.

Infant brain imaging using magnetoencephalography: Challenges, solutions, and best practices

The excellent temporal resolution and advanced spatial resolution of magnetoencephalography (MEG) makes it an excellent tool to study the neural dynamics underlying cognitive processes in the developing brain. Nonetheless, a number of challenges exist when using MEG to image infant populations. There is a persistent belief that collecting MEG data with infants presents a number of limitations and challenges that are difficult to overcome. Due to this notion, many researchers either avoid conducting infant MEG research or believe that, in order to collect high-quality data, they must impose limiting restrictions on the infant or the experimental paradigm. In this article, we discuss the various challenges unique to imaging awake infants and young children with MEG, and share general best-practice guidelines and recommendations for data collection, acquisition, preprocessing, and analysis. The current article is focused on methodology that allows investigators to test the sensory, perceptual, and cognitive capacities of awake and moving infants. We believe that such methodology opens the pathway for using MEG to provide mechanistic explanations for the complex behavior observed in awake, sentient, and dynamically interacting infants, thus addressing core topics in developmental cognitive neuroscience.

Neural mechanisms underlying the income-achievement gap: The role of the ventral visual stream

Children from low-socioeconomic status (SES) households on average exhibit lower academic achievement than their higher-SES peers. We investigated a novel hypothesis that differences in early-developing sensory networks-specifically the ventral visual stream (VVS), which is involved in processing visual stimuli-contribute to SES-related disparities in executive functions (EF) and academic outcomes. We used fMRI to investigate SES-related differences in neural function in children (6-8 years, n = 62) during two attentional tasks involving attention to visual information: cued attention and memory-guided attention. Recruitment of VVS during both tasks was associated with EF and academic achievement, and SES-related differences in VVS activation during cued attention were marginally explained by differences in cognitive stimulation. VVS activation during cued attention mediated SES-related differences in academic achievement. Finally, the link between VVS activation during both tasks and academic achievement was mediated by differences in EF. We extend previous work by highlighting that: (i) early-developing visual processing regions play a role in supporting complex attentional processes, (ii) childhood SES is associated with VVS function, which is explained in part by SES-related differences in cognitive stimulation and (iii) provide preliminary evidence that individual differences in VVS function may play a role in the emergence of the income-achievement gap.

Linguistic and developmental influences on superordinate facial configuration categorization in infancy

Humans perceive emotions in terms of categories, such as "happiness," "sadness," and "anger." To learn these complex conceptual emotion categories, humans must first be able to perceive regularities in expressive behaviors (e.g., facial configurations) across individuals. Recent research suggests that infants spontaneously form "basic-level" categories of facial configurations (e.g., happy vs. fear), but not "superordinate" categories of facial configurations (e.g., positive vs. negative). The current studies further explore how infant age and language impact superordinate categorization of facial configurations associated with different negative emotions. Across all experiments, infants were habituated to one person displaying facial configurations associated with anger and disgust. While 10-month-olds formed a category of person identity (Experiment 1), 14-month-olds formed a category that included negative facial configurations displayed by the same person (Experiment 2). However, neither age formed the hypothesized superordinate category of negative valence. When a verbal label ("toma") was added to each of the habituation events (Experiment 3), 10-month-olds formed a category similar to 14-month-olds in Experiment 2. These findings intersect a larger conversation about the nature and development of children's emotion categories and highlight the importance of considering developmental processes, such as language learning and attentional/memory development, in the design and interpretation of infant categorization studies.

Exploring developmental changes in infant anticipation and perceptual processing: EEG responses to tactile stimulation

There is an increasing interest in alpha-range rhythms in the electroencephalogram (EEG) in relation to perceptual and attentional processes. The infant mu rhythm has been extensively studied in the context of linkages between action observation and action production in infancy, but less is known about the mu rhythm in relation to cross-modal processes involving somatosensation. We investigated differences in mu responses to cued vibrotactile stimulation of the hand in two age groups of infants: From 6 to 7 months and 13 to 14 months. We were also interested in anticipatory neural responses in the alpha frequency range prior to tactile stimulation. Tactile stimulation of infants' left or right hand was preceded by an audiovisual cue signaling which hand would be stimulated. In response to the tactile stimulus, infants demonstrated significant mu desynchronization over the central areas contralateral to the hand stimulated, with higher mu peak frequency and greater contralateral mu desynchronization for older infants. Prior to the tactile stimulus, both age groups showed significant bilateral alpha desynchronization over frontocentral sites, which may be indicative of generalized anticipation of an upcoming stimulus. The findings highlight the potential of examining the sensorimotor mu rhythm in the context of infant attentional development.

Contributions of Emotion Regulation and Brain Structure and Function to Adolescent Internalizing Problems and Stress Vulnerability During the COVID-19 Pandemic: A Longitudinal Study

BACKGROUND

Adolescence is a period of increased vulnerability for internalizing problems, particularly following stressful life events. We examined how emotion regulation and brain structure and function were associated with internalizing problems during the COVID-19 pandemic and moderated the association between pandemic-related stressors and internalizing problems.

METHODS

Data are from a longitudinal sample (N = 145, age range, 10-15 years) strategically assessed at 3 crucial time points: before the COVID-19 pandemic, early during the stay-at-home order period, and again 6 months later. We examined associations of amygdala and hippocampal volume and amygdala activation during an emotional processing task before the pandemic, examined use of emotion regulation strategies before and during the pandemic, and examined pandemic-related stressors with internalizing problems.

RESULTS

Greater exposure to pandemic-related stressors was associated with higher internalizing problems both early and later in the COVID-19 pandemic. Youths who reported more frequent use of rumination before the pandemic and higher use of expressive suppression and lower use of cognitive reappraisal early in the pandemic had higher internalizing problems early in the pandemic. Higher left amygdala activation to neutral relative to fearful faces before the pandemic was associated with greater internalizing problems and a stronger link between pandemic-related stressors and internalizing problems early in the pandemic.

CONCLUSIONS

Stressors related to the COVID-19 pandemic are strongly associated with adolescent internalizing problems, as are individual differences in emotional reactivity and regulation and their underlying neural mechanisms. Interventions that reduce pandemic-related stressors and foster adaptive emotion regulation skills may protect against adolescent psychopathology during this period of heightened exposure to stress.

Human infants can override possessive tendencies to share valued items with others

Possessiveness toward objects and sharing are competing tendencies that influence dyadic and group interactions within the primate lineage. A distinctive form of sharing in adult Homo sapiens involves active giving of high-valued possessions to others, without an immediate reciprocal benefit. In two Experiments with 19-month-old human infants (N = 96), we found that despite measurable possessive behavior toward their own personal objects (favorite toy, bottle), infants spontaneously gave these items to a begging stranger. Moreover, human infants exhibited this behavior across different types of objects that are relevant to theory (personal objects, sweet food, and common objects)-showing flexible generalizability not evidenced in non-human primates. We combined these data with a previous dataset, yielding a large sample of infants (N = 192), and identified sociocultural factors that may calibrate young infants' sharing of objects with others. The current findings show a proclivity that is rare or absent in our closest living relatives-the capacity to override possessive behavior toward personally valued objects by sharing those same desired objects with others.

Identifying with all humanity predicts cooperative health behaviors and helpful responding during COVID-19

In the ongoing COVID-19 pandemic, public health experts have produced guidelines to limit the spread of the coronavirus, but individuals do not always comply with experts' recommendations. Here, we tested whether a specific psychological belief-identification with all humanity-predicts cooperation with public health guidelines as well as helpful behavior during the COVID-19 pandemic. We hypothesized that peoples' endorsement of this belief-their relative perception of a connection and moral commitment to other humans-would predict their tendencies to adopt World Health Organization (WHO) guidelines and to help others. To assess this, we conducted a global online study (N = 2537 participants) of four WHO-recommended health behaviors and four pandemic-related moral dilemmas that we constructed to be relevant to helping others at a potential cost to oneself. We used generalized linear mixed models (GLMM) that included 10 predictor variables (demographic, contextual, and psychological) for each of five outcome measures (a WHO cooperative health behavior score, plus responses to each of our four moral, helping dilemmas). Identification with all humanity was the most consistent and consequential predictor of individuals' cooperative health behavior and helpful responding. Analyses showed that the identification with all humanity significantly predicted each of the five outcomes while controlling for the other variables (Prange < 10-22 to < 0.009). The mean effect size of the identification with all humanity predictor on these outcomes was more than twice as large as the effect sizes of other predictors. Identification with all humanity is a psychological construct that, through targeted interventions, may help scientists and policymakers to better understand and promote cooperative health behavior and help-oriented concern for others during the current pandemic as well as in future humanitarian crises.

Development of Math Attitudes and Math Self-Concepts: Gender Differences, Implicit-Explicit Dissociations, and Relations to Math Achievement

Three hundred and ninety-one children (195 girls; M_age  = 9.56 years) attending Grades 1 and 5 completed implicit and explicit measures of math attitudes and math self-concepts. Math grades were obtained. Multilevel analyses showed that first-grade girls held a strong negative implicit attitude about math, despite no gender differences in math grades or self-reported (explicit) positivity about math. The explicit measures significantly predicted math grades, and implicit attitudes accounted for additional variance in boys. The contrast between the implicit (negativity for girls) and explicit (positivity for girls and boys) effects suggest implicit-explicit dissociations in children, which have also been observed in adults. Early-emerging implicit attitudes may be a foundation for the later development of explicit attitudes and beliefs about math.

Mechanisms linking socioeconomic status and academic achievement in early childhood: Cognitive stimulation and language

There is a strong positive association between childhood socioeconomic status (SES) and academic achievement. This disparity may, in part, be explained by differences in early environmental experiences and language development. Cognitive stimulation-including language exposure, access to learning materials, caregiver involvement in children's learning, and variety of experiences-varies by SES and may link SES to language development. Childhood language development in turn is associated with academic achievement. In the current longitudinal study of 101 children (60-75 months), SES was positively associated with cognitive stimulation and performance on language measures. Cognitive stimulation mediated the association between SES and children's language. Furthermore, children's language mediated the association between SES and academic achievement 18 months later. In addition to addressing broader inequalities in access to resources that facilitate caregivers' abilities to provide cognitive stimulation, cognitive stimulation itself could be targeted in future interventions to mitigate SES-related disparities in language and academic achievement.

Math Is for Me: A Field Intervention to Strengthen Math Self-Concepts in Spanish-Speaking 3rd Grade Children

Children's math self-concepts-their beliefs about themselves and math-are important for teachers, parents, and students, because they are linked to academic motivation, choices, and outcomes. There have been several attempts at improving math achievement based on the training of math skills. Here we took a complementary approach and conducted an intervention study to boost children's math self-concepts. Our primary objective was to assess the feasibility of whether a novel multicomponent intervention-one that combines explicit and implicit approaches to help children form more positive beliefs linking themselves and math-can be administered in an authentic school setting. The intervention was conducted in Spain, a country in which math achievement is below the average of other OECD countries. We tested third grade students (N = 180; M _age = 8.79 years; 96 girls), using treatment and comparison groups and pre- and posttest assessments. A novelty of this study is that we used both implicit and explicit measures of children's math self-concepts. For a subsample of students, we also obtained an assessment of year-end math achievement. Math self-concepts in the treatment and comparison groups did not significantly differ at pretest. Students in the treatment group demonstrated a significant increase in math self-concepts from pretest to posttest; students in the comparison group did not. In the treatment group, implicit math self-concepts at posttest were associated with higher year-end math achievement, assessed approximately 3 months after the completion of the intervention. Taken together, the results suggest that math self-concepts are malleable and that social-cognitive interventions can boost children's beliefs about themselves and math. Based on the favorable results of this feasibility study, it is appropriate to formally test this novel multicomponent approach for improving math self-concepts using randomized controlled trial (RCT) design.

Enhancing same-gender imitation by highlighting gender norms in Chinese pre-school children

Children selectively imitate in-group over outgroup individuals under certain experimental conditions. We investigated whether this bias applies to gender in-groups in China. Three- and five-year-olds were shown how to operate novel objects by same-gender and opposite-gender models. Results indicate that the combination of verbally highlighting the gender identity of the model (e.g., 'I am a girl') and making gender norms explicit (e.g., 'girls play this way') significantly enhances high-fidelity imitation. This 'double social effect' was more robust in 5-year-olds than 3-year-olds. Our results underscore how language about gender and the norms for gender-based groups influence behavioural imitation. The pattern of findings enhances our knowledge about pre-schoolers' social learning and imitation as well as the powerful influence of language and group norms on children's voluntary actions and learning.

Early implicit-explicit discrepancies in self-esteem as correlates of childhood depressive symptoms

This longitudinal study examined early social-cognitive markers that might be associated with the emergence of childhood depression and anxiety. At 5 years of age, 137 children completed an implicit self-esteem measure. At 9 years of age, the same children completed measures of implicit self-esteem, explicit self-esteem, depression, and anxiety. Two novel findings emerged. First, higher implicit self-esteem at age 5 than explicit self-esteem at age 9 (implicit > explicit discrepancy) was associated with depressive symptoms at age 9, but not with symptoms of anxiety. Second, this cross-age implicit > explicit discrepancy was associated with depressive symptoms more strongly than was the same implicit > explicit discrepancy measured concurrently at age 9. The overall pattern suggests that the appearance of depressive symptoms in children is associated with discrepancies between implicit and explicit self-esteem and not just lower levels of implicit self-esteem or lower levels of explicit self-esteem taken alone. It is the direction and discrepancy across time that is particularly informative, such that discrepancies between early implicit representations and later explicit reports of self-worth reflect a developmental pathway associated with elevated risk for depressive symptoms. Taken altogether, this study illustrates the benefits of combining work in developmental, child-clinical, and social psychology to provide a more complete view of the developing child. We believe that combining implicit and explicit measures of self-esteem across developmental time points can be used to examine early markers of depression in children at younger ages than typically possible with explicit measures alone.

Body representation in infants: Categorical boundaries of body parts as assessed by somatosensory mismatch negativity

There is growing interest in developing and using novel measures to assess how the body is represented in human infancy. Various lines of evidence with adults and older children show that tactile perception is modulated by a high-level representation of the body. For instance, the distance between two points of tactile stimulation is perceived as being greater when these points cross a joint boundary than when they are within a body part, suggesting that the representation of the body is structured with joints acting as categorical boundaries between body parts. Investigating the developmental origins of this categorical effect has been constrained by infants’ inability to verbally report on the properties of tactile stimulation. Here we made novel use of an infant brain measure, the somatosensory mismatch negativity (sMMN), to explore categorical aspects of tactile body processing in infants aged 6–7 months. Amplitude of the sMMN elicited by tactile stimuli across the wrist boundary was significantly greater than for stimuli of equal distance that were within the boundary, suggesting a categorical effect in body processing in infants. We suggest that an early-appearing, structured representation of the body into ‘parts’ may play a role in mapping correspondences between self and other.

Body maps in the infant brain: implications for neurodevelopmental disabilities

This review and synthesis discusses recent work that has utilized brain imaging methods, such as the electroencephalogram (EEG) and magnetoencephalogram, to provide insights into the ways that the body is represented in the infant brain. One aspect of body representation concerns somatotopic maps of the body surface in somatosensory cortex. A good deal is known about the properties of these maps in adults, but there has been relatively little developmental work. Recent studies have provided new insights into the organization of infant neural body maps and have laid the foundations for examining their plasticity in relation to behavioral development. Other work has suggested that neural body maps may be involved in the registration of correspondences between self and other, with implications for early social development. Here, body representations are discussed in the context of preterm birth and autism spectrum disorder, providing novel perspectives relevant to developmental medicine and child neurology. WHAT THIS PAPER ADDS: ●Somatotopic body maps develop prenatally through intrinsic and activity-dependent mechanisms. ●There is increasing interest in understanding postnatal plasticity in body maps. ●Body representations may be involved in the registration of preverbal, interpersonal relationships.

Cognitive Stimulation as a Mechanism Linking Socioeconomic Status With Executive Function: A Longitudinal Investigation

Executive functions (EF), including working memory, inhibition, and cognitive flexibility, vary as a function of socioeconomic status (SES), with children from economically disadvantaged backgrounds having poorer performance than their higher SES peers. Using observational methods, we investigated cognitive stimulation in the home as a mechanism linking SES with EF. In a sample of 101 children aged 60-75 months, cognitive stimulation fully mediated SES-related differences in EF. Critically, cognitive stimulation was positively associated with the development of inhibition and cognitive flexibility across an 18-month follow-up period. Furthermore, EF at T1 explained SES-related differences in academic achievement at T2. Early cognitive stimulation-a modifiable factor-may be a desirable target for interventions designed to ameliorate SES-related differences in cognitive development and academic achievement.

Meta-Analytic Use of Balanced Identity Theory to Validate the Implicit Association Test

This meta-analysis evaluated theoretical predictions from balanced identity theory (BIT) and evaluated the validity of zero points of Implicit Association Test (IAT) and self-report measures used to test these predictions. Twenty-one researchers contributed individual subject data from 36 experiments (total N = 12,773) that used both explicit and implicit measures of the social-cognitive constructs. The meta-analysis confirmed predictions of BIT's balance-congruity principle and simultaneously validated interpretation of the IAT's zero point as indicating absence of preference between two attitude objects. Statistical power afforded by the sample size enabled the first confirmations of balance-congruity predictions with self-report measures. Beyond these empirical results, the meta-analysis introduced a within-study statistical test of the balance-congruity principle, finding that it had greater efficiency than the previous best method. The meta-analysis's full data set has been publicly archived to enable further studies of interrelations among attitudes, stereotypes, and identities.

Imitation in Chinese Preschool Children: Influence of Prior Self-Experience and Pedagogical Cues on the Imitation of Novel Acts in a Non-Western Culture

Both prior experience and pedagogical cues modulate Western children’s imitation. However, these factors have not been systematically explored together within a single study. This paper explored how these factors individually and together influence imitation using 4-year-old children born and reared in mainland China (N = 210)—a country that contains almost one-fifth of the world’s population, and in which childhood imitation is under-studied using experimental methodology. The behavior of children in this culture is of special interest to theory because traditional East Asian culture places high value on conformity and fitting in with the group. Thus, high-fidelity imitation is emphasized in the local culture. This value, practice, or norm may be recognized by children at a young age and influence their imitative performance. In this study, we crossed prior self-experience and pedagogical cues, yielding four demonstration groups in addition to a control group. This design allowed us to investigate the degree to which Chinese preschoolers’ imitation was modulated by the two experimental factors. High-fidelity imitation was significantly modulated by prior self-experience but not by pedagogical cues, as measured by the number of novel acts imitated and also the serial order of these acts. This study (i) expands our understanding of factors that modulate imitation of novel behaviors in preschoolers and (ii) contributes to efforts to broaden research beyond Western societies to enrich our theories, particularly regarding social learning and imitation. Imitation is a key mechanism in the acquisition of culturally appropriate behaviors, mannerisms, and norms but who, what, and when children imitate is malleable. This study points to both cross-cultural invariants and variations to provide a fuller picture of the scope and functions of childhood imitation.

Superordinate categorization of negative facial expressions in infancy: The influence of labels

Accurate perception of emotional (facial) expressions is an essential social skill. It is currently debated whether emotion categorization in infancy emerges in a "broad-to-narrow" pattern and the degree to which language influences this process. We used an habituation paradigm to explore (a) whether 14- and 18-month-old infants perceive different facial expressions (anger, sad, disgust) as belonging to a superordinate category of negative valence and (b) how verbal labels influence emotion category formation. Results indicated that infants did not spontaneously form a superordinate category of negative valence (Experiments 1 and 3). However, when a novel label ("toma") was added to each event during habituation trials (Experiments 2 and 4), infants formed this superordinate valance category when habituated to disgust and sad expressions (but not when habituated to anger and sadness). These labeling effects were obtained with two stimuli sets (Radboud Face Database and NimStim), even when controlling for the presence of teeth in the expressions. The results indicate that infants, at 14 and 18 months of age, show limited superordinate categorization based on the valence of different negative facial expressions. Specifically, infants only form this abstract emotion category when labels were provided, and the labeling effect depends on which emotions are presented during habituation. These findings have important implications for developmental theories of emotion. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

The Development of Negative Event-Emotion Matching in Infancy: Implications for Theories in Affective Science

Predicting another person's emotional response to a situation is an important component of emotion concept understanding. However, little is known about the developmental origins of this ability. The current studies examine whether 10-month-olds expect facial configurations/vocalizations associated with negative emotions (e.g., anger, disgust) to be displayed after specific eliciting events. In Experiment 1, 10-month-olds (N = 60) were familiarized to an Emoter interacting with objects in a positive event (Toy Given) and a negative event (Toy Taken). Infants expected the Emoter to display a facial configuration associated with anger after the negative event, but did not expect the Emoter to display a facial configuration associated with happiness after the positive event. In Experiment 2, 10- and 14-month-olds (N = 120) expected the Emoter to display a facial configuration associated with anger, rather than one associated with disgust, after an "anger-eliciting" event (Toy Taken). However, only the 14-month-olds provided some evidence of linking a facial configuration associated with disgust, rather than one associated with anger, to a "disgust-eliciting event" (New Food). Experiment 3 found that 10-month-olds (N = 60) did not expect an Emoter to display a facial configuration associated with anger after an "anger-eliciting" event involving an Unmet Goal. Together, these experiments suggest that infants start to refine broad concepts of affect into more precise emotion concepts over the first 2 years of life, before learning emotion language. These findings are a first step toward addressing a long-standing theoretical debate in affective science about the nature of early emotion concepts.

Altruistic food sharing behavior by human infants after a hunger manipulation

Altruistic behavior entails giving valuable benefits to others while incurring a personal cost. A distinctively human form of altruistic behavior involves handing nutritious food to needy strangers, even when one desires the food. Engaging in altruistic food transfer, instead of keeping the food, is costly, because it reduces the caloric intake of the benefactor vis-à-vis the beneficiary. Human adults engage in this form of altruistic behavior during times of war and famine, when giving food to others threatens one's own survival. Our closest living primate relatives, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), exhibit notable constraints on the proclivity to engage in such food transfer (particularly chimpanzees), although they share many social-cognitive commonalities with humans. Here we show that in a nonverbal test, 19-month-old human infants repeatedly and spontaneously transferred high-value, nutritious natural food to a stranger (Experiment 1) and more critically, did so after an experimental manipulation that imposed a feeding delay (Experiment 2), which increased their own motivation to eat the food. Social experience variables moderated the expression of this infant altruistic behavior, suggesting malleability.

Distinct aspects of the early environment contribute to associative memory, cued attention, and memory-guided attention: Implications for academic achievement

Childhood socioeconomic status (SES) is associated with numerous aspects of cognitive development and disparities in academic achievement. The specific environmental factors that contribute to these disparities remain poorly understood. We used observational methods to characterize three aspects of the early environment that may contribute to SES-related differences in cognitive development: violence exposure, cognitive stimulation, and quality of the physical environment. We evaluated the associations of these environmental characteristics with associative memory, cued attention, and memory-guided attention in a sample of 101 children aged 60-75 months. We further investigated whether these specific cognitive abilities mediated the association between SES and academic achievement 18 months later. Violence exposure was specifically associated with poor associative memory, but not cued attention or memory-guided attention. Cognitive stimulation and higher quality physical environment were positively associated with cued attention accuracy, but not after adjusting for all other environmental variables. The quality of the physical environment was associated with memory-guided attention accuracy. Of the cognitive abilities examined, only memory-guided attention contributed to SES-related differences in academic achievement. These findings suggest specificity in how particular aspects of early environmental experience scaffold different types of attention and memory subserved by distinct neural circuits and shed light on a novel cognitive-developmental mechanism underlying SES-related disparities in academic achievement.

Enhanced gaze-following behavior in Deaf infants of Deaf parents

Gaze following plays a role in parent-infant communication and is a key mechanism by which infants acquire information about the world from social input. Gaze following in Deaf infants has been understudied. Twelve Deaf infants of Deaf parents (DoD) who had native exposure to American Sign Language (ASL) were gender-matched and age-matched (±7 days) to 60 spoken-language hearing control infants. Results showed that the DoD infants had significantly higher gaze-following scores than the hearing infants. We hypothesize that in the absence of auditory input, and with support from ASL-fluent Deaf parents, infants become attuned to visual-communicative signals from other people, which engenders increased gaze following. These findings underscore the need to revise the 'deficit model' of deafness. Deaf infants immersed in natural sign language from birth are better at understanding the signals and identifying the referential meaning of adults' gaze behavior compared to hearing infants not exposed to sign language. Broader implications for theories of social-cognitive development are discussed. A video abstract of this article can be viewed at https://youtu.be/QXCDK_CUmAI.

Acquiring group bias: Observing other people's nonverbal signals can create social group biases

Evidence of group bias based on race, ethnicity, nationality, and language emerges early in the life span. Although understanding the initial acquisition of group bias has critical theoretical and practical implications, precisely how group biases are acquired has been understudied. In two preregistered experiments, we tested the hypothesis that generalized social group biases can be acquired through exposure to positive nonverbal signals directed toward a novel adult from one group and more negative nonverbal signals directed toward a novel adult from another group. We sought to determine whether children would acquire global nonverbal signal-consistent social group biases that extended beyond their explicit social preferences, by measuring children's preferences, imitation, and behavioral intentions. Supporting our preregistered hypotheses, preschool-age participants favored small and large groups whose member received positive nonverbal signals, relative to groups whose member received more negative nonverbal signals. We also replicated prior work indicating that children will acquire individual target biases from the observation of biased nonverbal signals. Here we make the case that generalized social group biases can be rapidly and unintentionally transmitted on the basis of observational learning from nonverbal signals. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Body representations as indexed by oscillatory EEG activities in the context of tactile novelty processing

Neural oscillatory activities in different frequency bands are known to reflect different cognitive functions. The current study investigates neural oscillations involved in tactile novelty processing, in particular how physically different digits of the hand may be categorized as being more or less similar to one another. Time-frequency analyses were conducted on EEG responses recorded from a somatosensory mismatch protocol involving stimulation of the 1st, 3rd, and 5th digits. The pattern of tactile stimulation leveraged a functional category boundary between the 1st digit (thumb) and the other fingers. This functional category has been hypothesized to derive, in part, from the way that the hand is used to grasp and haptically explore objects. EEG responses to standard stimuli (the 3rd digit, probability of 80%) and two deviant stimuli (1st digit as across-boundary deviant and 5th digit as within-boundary deviant, probability of 10% each) were examined. Analyses of EEG responses examined changes in power as well as phase information. Deviant tactile stimuli evoked significantly greater theta event-related synchronization and greater phase-locking values compared to the corresponding control stimuli. The increase in theta power evoked by the contrast of the 3rd digit and the 1st digit was significantly larger than for the contrast between the 3rd and 5th digits. Desynchronization in the alpha and beta bands was greater for deviant than control stimuli, which may reflect increased local cortical excitation to novel stimuli, modulated by top-down feedback processes as part of a hierarchical novelty detection mechanism. The results are discussed in the context of the growing literature on neural processes involved in the generation and maintenance of body representations.

Interpersonal Influences on Body Representations in the Infant Brain

Within cognitive neuroscience, there is burgeoning interest in how the body is represented in the adult brain. However, there are large gaps in the understanding of neural body representations from a developmental perspective. Of particular interest are the interconnections between somatosensation and vision, specifically infants’ abilities to register correspondences between their own bodies and the bodies of others. Such registration may play an important role in social learning and in engendering feelings of connectedness with others. In the current study, we further explored the interpersonal aspects of neural body representations by examining whether responses to tactile stimulation in 7-month-old infants are influenced by viewing another’s body. During EEG recording, infants (N= 60) observed a live presentation of an experimenter’s hand or foot being touched. During the presentation of touch to the adult’s hand or foot, the infant received a brief tactile touch to their right hand or right foot. This resulted in four conditions: (i) receive hand stimulation/observe hand stimulation, (ii) receive hand stimulation/observe foot stimulation, (iii) receive foot stimulation/observe hand stimulation, and (iv) receive foot stimulation/observe foot stimulation. Analyses compared responses overlying hand and foot regions when the observed limb matched the stimulated limb (congruent) and did not match (incongruent). In line with prior work, tactile stimulation elicited a somatotopic pattern of results in the somatosensory evoked potential (SEP) and the sensorimotor mu rhythm (6–9 Hz). Cross-modal influences were observed in the beta rhythm (11–13 Hz) response and in the late potential of the SEP response (400–600 ms). Beta desynchronization was greater for congruent compared to incongruent conditions. Additionally, tactile stimulation to the foot elicited larger mean amplitudes for congruent compared to incongruent conditions. The opposite was true for stimulation to the hand. This set of novel findings suggests the importance of considering cross-modal effects in the study of neural body representations in the infant brain. Continued work in this new area of infant neuroscience research can inform how interpersonal aspects of body representations may serve to undergird early social learning.

Chilean kindergarten children's beliefs about mathematics: Family matters

This study examines the relations among parental beliefs and practices about mathematics, children's beliefs about mathematics, participants' gender, and family socioeconomic status (SES). The study was conducted in Chile, a country with significant gender gaps in standardized test results in mathematics, with boys receiving significantly higher scores than girls. One hundred eighty Chilean kindergarteners (M_age = 5.6 years) of low and high SES completed both implicit and explicit measures of their beliefs about mathematics. Children's mothers and fathers also completed adult versions of these tests, as well as measures of home numeracy practices. This combination of child and parental assessments (both mother and father), including both implicit and explicit measures, provided a wider range of measures than in previous studies. On implicit measures of math-gender stereotypes, boys showed the math = boy stereotype significantly more strongly than girls did. Both fathers and mothers showed this stereotype on both implicit and explicit measures. Fathers also linked me = math (math self-concept) more strongly than mothers on both implicit and explicit measures. Kindergarten girls' implicit math self-concept was explained by a combination of parents' math self-concepts and SES. Taken together, these results show that by 5 years of age children are already developing beliefs about "who does math" in their culture, and that parental beliefs and practices are significantly linked to children's stereotypes and self-concepts about mathematics before they enter formal schooling. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The somatosensory mismatch negativity as a window into body representations in infancy

How the body is represented in the developing brain is a topic of growing interest. The current study takes a novel approach to investigating neural body representations in infants by recording somatosensory mismatch negativity (sMMN) responses elicited by tactile stimulation of different body locations. Recent research in adults has suggested that sMMN amplitude may be influenced by the relative distance between representations of the stimulated body parts in somatosensory cortex. The current study uses a similar paradigm to explore whether the sMMN can be elicited in infants, and to test whether the infant sMMN response is sensitive to the somatotopic organization of somatosensory cortex. Participants were healthy infants (n = 31) aged 6 and 7 months. The protocol leveraged a discontinuity in cortical somatotopic organization, whereby the representations of the neck and the face are separated by representations of the arms, the hands and the shoulder. In a double-deviant oddball protocol, stimulation of the hand (100 trials, 10% probability) and neck (100 trials, 10% probability) was interspersed among repeated stimulation of the face (800 trials, 80% probability). Waveforms showed evidence of an infant sMMN response that was significantly larger for the face/neck contrast than for the face/hand contrast. These results suggest that, for certain combinations of body parts, early pre-attentive tactile discrimination in infants may be influenced by distance between the corresponding cortical representations. The results provide the first evidence that the sMMN can be elicited in infants, and pave the way for further applications of the sMMN in studying body representations in preverbal infants.

Neural measures of anticipatory bodily attention in children: Relations with executive function

The ability to selectively direct attention to a certain location or modality is a key neurocognitive skill. One important facet of selective attention is anticipation, a foundational biological construct that bridges basic perceptual processes and higher-order cognition. The current study focuses on the neural correlates of bodily anticipation in 6- to 8-year-old children using a task involving tactile stimulation. Electroencephalographic (EEG) activity over sensorimotor cortex was measured after a visual cue directed children to monitor their right or left hand in anticipation of tactile stimulation. Prior to delivery of the tactile stimulus, a regionally-specific desynchronization of the alpha-range mu rhythm occurred over central electrode sites (C3/C4) contralateral to the cue direction. The magnitude of anticipatory mu rhythm desynchronization was associated with children's performance on two executive function tasks (Flanker and Card Sort). We suggest that anticipatory mu desynchronization has utility as a specific neural marker of attention focusing in young children, which in turn may be implicated in the development of executive function.

Infant brain responses to felt and observed touch of hands and feet: an MEG study

There is growing interest concerning the ways in which the human body, both one's own and that of others, is represented in the developing human brain. In two experiments with 7-month-old infants, we employed advances in infant magnetoencephalography (MEG) brain imaging to address novel questions concerning body representations in early development. Experiment 1 evaluated the spatiotemporal organization of infants' brain responses to being touched. A punctate touch to infants' hands and feet produced significant activation in the hand and foot areas of contralateral primary somatosensory cortex as well as in other parietal and frontal areas. Experiment 2 explored infant brain responses to visually perceiving another person's hand or foot being touched. Results showed significant activation in early visual regions and also in regions thought to be involved in multisensory body and self-other processing. Furthermore, observed touch of the hand and foot activated the infant's own primary somatosensory cortex, although less consistently than felt touch. These findings shed light on aspects of early social cognition, including action imitation, which may build, at least in part, on infant neural representations that map equivalences between the bodies of self and other.

Neuropsychology of Human Body Parts: Exploring Categorical Boundaries of Tactile Perception Using Somatosensory Mismatch Responses

The focus of the current study is on a particular aspect of tactile perception: categorical segmentation on the body surface into discrete body parts. The MMN has been shown to be sensitive to categorical boundaries and language experience in the auditory modality. Here we recorded the somatosensory MMN (sMMN) using two tactile oddball protocols and compared sMMN amplitudes elicited by within- and across-boundary oddball pairs. Both protocols employed the identity MMN method that controls for responsivity at each body location. In the first protocol, we investigated the categorical segmentation of tactile space at the wrist by presenting pairs of tactile oddball stimuli across equal spatial distances, either across the wrist or within the forearm. Amplitude of the sMMN elicited by stimuli presented across the wrist boundary was significantly greater than for stimuli presented within the forearm, suggesting a categorical effect at an early stage of somatosensory processing. The second protocol was designed to investigate the generality of this MMN effect, and involved three digits on one hand. Amplitude of the sMMN elicited by a contrast of the third digit and the thumb was significantly larger than a contrast between the third and fifth digits, suggesting a functional boundary effect that may derive from the way that objects are typically grasped. These findings demonstrate that the sMMN is a useful index of processing of somatosensory spatial discrimination that can be used to study body part categories.

Neural representations of the body in 60-day-old human infants

The organization of body representations in the adult brain has been well documented. Little is understood about this aspect of brain organization in human infancy. The current study employed electroencephalography (EEG) with 60-day-old infants to test the distribution of brain responses to tactile stimulation of three different body parts: hand, foot, and lip. Analyses focused on a prominent positive response occurring at 150-200 ms in the somatosensory evoked potential at central and parietal electrode sites. The results show differential electrophysiological signatures for touch of these three body parts. Stimulation of the left hand was associated with greater positive amplitude over the lateral central region contralateral to the side stimulated. Left foot stimulation was associated with greater positivity over the midline parietal site. Stimulation of the midline of the upper lip was associated with a strong bilateral response over the central region. These findings provide new insights into the neural representation of the body in infancy and shed light on research and theories about the involvement of somatosensory cortex in infant imitation and social perception.

Salience network response to changes in emotional expressions of others is heightened during early adolescence: relevance for social functioning

Adolescence is a unique developmental period when the salience of social and emotional information becomes particularly pronounced. Although this increased sensitivity to social and emotional information has frequently been considered with respect to risk behaviors and psychopathology, evidence suggests that increased adolescent sensitivity to social and emotional cues may confer advantages. For example, greater sensitivity to shifts in the emotions of others is likely to promote flexible and adaptive social behavior. In this study, a sample of 54 children and adolescents (age 8-19 years) performed a delayed match-to-sample task for emotional faces while undergoing fMRI scanning. Recruitment of the anterior cingulate and anterior insula when the emotion of the probe face did not match the emotion held in memory followed a quadratic developmental pattern that peaked during early adolescence. These findings indicate meaningful developmental variation in the neural mechanisms underlying sensitivity to changes in the emotional expressions. Across all participants, greater activation of this network for changes in emotional expression was associated with less social anxiety and fewer social problems. These results suggest that the heightened salience of social and emotional information during adolescence may confer important advantages for social behavior, providing sensitivity to others' emotions that facilitates flexible social responding.

Preschool physics: Using the invisible property of weight in causal reasoning tasks

Causal reasoning is an important aspect of scientific thinking. Even young human children can use causal reasoning to explain observations, make predictions, and design actions to bring about specific outcomes in the physical world. Weight is an interesting type of cause because it is an invisible property. Here, we tested preschool children with causal problem-solving tasks that assessed their understanding of weight. In an experimental setting, 2- to 5-year-old children completed three different tasks in which they had to use weight to produce physical effects-an object displacement task, a balance-scale task, and a tower-building task. The results showed that the children's understanding of how to use object weight to produce specific object-to-object causal outcomes improved as a function of age, with 4- and 5-year-olds showing above-chance performance on all three tasks. The younger children's performance was more variable. The pattern of results provides theoretical insights into which aspects of weight processing are particularly difficult for preschool children and why they find it difficult.

Socioeconomic disparities in academic achievement: A multi-modal investigation of neural mechanisms in children and adolescents

Growing evidence suggests that childhood socioeconomic status (SES) influences neural development, which may contribute to the well-documented SES-related disparities in academic achievement. However, the particular aspects of SES that impact neural structure and function are not well understood. Here, we investigate associations of childhood SES and a potential mechanism-degree of cognitive stimulation in the home environment-with cortical structure, white matter microstructure, and neural function during a working memory (WM) task across development. Analyses included 53 youths (age 6-19 years). Higher SES as reflected in the income-to-needs ratio was associated with higher parent-reported achievement, WM performance, and cognitive stimulation in the home environment. Although SES was not significantly associated with cortical thickness, children raised in more cognitively stimulating environments had thicker cortex in the frontoparietal network and cognitive stimulation mediated the assocation between SES and cortical thickness in the frontoparietal network. Higher family SES was associated with white matter microstructure and neural activation in the frontoparietal network during a WM task, including greater fractional anisotropy (FA) in the right and left superior longitudinal fasciculi (SLF), and greater BOLD activation in multiple regions of the prefrontal cortex during WM encoding and maintenance. Greater FA and activation in these regions was associated higher parent-reported achievement. Together, cognitive stimulation, WM performance, FA in the SLF, and prefrontal activation during WM encoding and maintenance significantly mediated the association between SES and parent-reported achievement. These findings highlight potential neural, cognitive, and environmental mechanisms linking SES with academic achievement and suggest that enhancing cognitive stimulation in the home environment might be one effective strategy for reducing SES-related disparities in academic outcomes.

Touching lips and hearing fingers: effector-specific congruency between tactile and auditory stimulation modulates N1 amplitude and alpha desynchronization

Understanding the interactions between audition and sensorimotor processes is of theoretical importance, particularly in relation to speech processing. Although one current focus in this area is on interactions between auditory perception and the motor system, there has been less research on connections between the auditory and somatosensory modalities. The current study takes a novel approach to this omission by examining specific auditory-tactile interactions in the context of speech and non-speech sound production. Electroencephalography was used to examine brain responses when participants were presented with speech syllables (a bilabial sound /pa/ and a non-labial sound /ka/) or finger-snapping sounds that were simultaneously paired with tactile stimulation of either the lower lip or the right middle finger. Analyses focused on the sensory-evoked N1 in the event-related potential and the extent of alpha band desynchronization elicited by the stimuli. N1 amplitude over fronto-central sites was significantly enhanced when the bilabial /pa/ sound was paired with tactile lip stimulation and when the finger-snapping sound was paired with tactile stimulation of the finger. Post-stimulus alpha desynchronization at central sites was also enhanced when the /pa/ sound was accompanied by tactile stimulation of the lip. These novel findings indicate that neural aspects of somatosensory-auditory interactions are influenced by the congruency between the location of the bodily touch and the bodily origin of a perceived sound.