Infant Placement and Language Exposure in Daily Life.

Children's daily contexts shape their experiences. In this study we assessed whether variations in infant placement (e.g., held, bouncy seat) are associated with infants' exposure to adult speech. Using repeated survey sampling of mothers and continuous audio recordings, we tested whether use of independence-supporting placements was associated with adult speech exposure in a Southeastern U.S. sample of 60 4- to 6- month- old infants (38% male, predominately White, not Hispanic/Latinx, from higher SES households). Within-subject analyses indicated that independence-supporting placements were associated with exposure to fewer adult words in the moment. Between-subjects analyses indicated that infants more frequently reported to be in independence-supporting placements that also provided posture support (i.e., exersaucer) were exposed to fewer adult words and less consistent adult speech across the day. These findings indicate that infants' opportunities for exposure to adult speech "in the wild" may vary based on immediate physical context.

Infants who experience more adult-initiated conversations have better expressive language in toddlerhood.

To understand how infants become engaged in conversations with their caregivers, we examined who tends to initiate conversations between adults and infants, differences between the features of infant- and adult-initiated conversations, and whether individual differences in how much infants engage in infant- or adult-initiated conversations uniquely predict later language development. We analyzed naturalistic adult-infant conversations captured via passive recording of the daily environment in two samples of 6-month-old infants. In Study 1, we found that at age 6 months, infants typically engage in more adult- than infant-initiated conversations and that adult-initiated conversations are, on average, longer and contain more adult words. In Study 2, we replicated these findings and, further, found that infants who engaged in more adult-initiated conversations in infancy had better expressive language at age 18 months. This association remained significant when accounting for the number of infant-initiated conversations at 6 months. Our findings indicate that early interactions with caregivers can have a lasting impact on children's language development, and that the extent to which parents initiate interactions with their infants may be particularly important.

Measuring naturalistic proximity as a window into caregiver-child interaction patterns.

The interactions most supportive of positive child development take place in moments of close contact with others. In the earliest years of life, a child's caregivers are the primary partners in these important interactions. Little is known about the patterns of real-life physical interactions between children and their caregivers, in part due to an inability to measure these interactions as they occur in real time. We have developed a wearable, infrastructure-free device (TotTag) used to dynamically and unobtrusively measure physical proximity between children and caregivers in real time. We present a case-study illustration of the TotTag with data collected over two (12-hour) days each from two families: a family of four (30-month-old son, 61-month-old daughter, 37-year-old father, 37-year-old mother), and a family of three (12-month-old daughter, 35-year-old-father, 33-year-old mother). We explored patterns of proximity within each parent-child dyad and whether close proximity would indicate periods in which increased opportunity for developmentally critical interactions occur. Each child also wore a widely used wearable audio recording device (LENA) to collect time-synced linguistic input. Descriptive analyses reveal wide variability in caregiver-child proximity both within and across dyads, and that the amount of time spent in close proximity with a caregiver is associated with the number of adult words and conversational turns to which a child was exposed. This suggests that variations in proximity are linked to-though, critically, not synonymous with-the quantity of a child's exposure to adult language. Potential implications for deepening the understanding of early caregiver-child interactions are discussed.

Neighborhood racial demographics predict infants' neural responses to people of different races.

Early in life, greater exposure to diverse people can change the tendency to prefer one's own social group. For instance, infants from racially diverse environments show less preference for their own-race (ingroup) over other-race (outgroup) faces than infants from racially homogeneous environments. Yet how social environment changes ingroup versus outgroup demarcation in infancy remains unclear. A commonly held assumption is that early emerging ingroup preference is based on an affective process: feeling more comfortable with familiar ingroup than unfamiliar outgroup members. However, other processes may also underlie ingroup preference: Infants may attend more to ingroup than outgroup members and/or mirror the actions of ingroup over outgroup individuals. By aggregating 7- to 12-month-old infants' electroencephalography (EEG) activity across three studies, we disambiguate these different processes in the EEG oscillations of preverbal infants according to social environment. White infants from more racially diverse neighborhoods exhibited greater frontal theta oscillation (an index of top-down attention) and more mu rhythm desynchronization (an index of motor system activation and potentially neural mirroring) to racial outgroup individuals than White infants from less racially diverse neighborhoods. Neighborhood racial demographics did not relate to White infants' frontal alpha asymmetry (a measure of approach-withdrawal motivation) toward racial outgroup individuals. Racial minority infants showed no effects of neighborhood racial demographics in their neural responses to racial outgroup individuals. These results indicate that neural mechanisms that may underlie social bias and prejudices are related to neighborhood racial demographics in the first year of life.

Advancing the RDoC initiative through the assessment of caregiver social processes.

The relationships infants and young children have with their caregivers are fundamental to their survival and well-being. Theorists and researchers across disciplines have attempted to describe and assess the variation in these relationships, leading to a general acceptance that caregiving is critical to understanding child functioning, including developmental psychopathology. At the same time, we lack consensus on how to assess these fundamental relationships. In the present paper, we first review research documenting the importance of the caregiver-child relationship in understanding environmental risk for psychopathology. Second, we propose that the National Institute of Mental Health's Research Domain Criteria (RDoC) initiative provides a useful framework for extending the study of children's risk for psychopathology by assessing their caregivers' social processes. Third, we describe the units of analysis for caregiver social processes, documenting how the specific subconstructs in the domain of social processes are relevant to the goal of enhancing knowledge of developmental psychopathology. Lastly, we highlight how past research can inform new directions in the study of caregiving and the parent-child relationship through this innovative extension of the RDoC initiative.

Mu rhythm desynchronization is specific to action execution and observation: Evidence from time-frequency and connectivity analysis.

Mu desynchronization is the attenuation of EEG power in the alpha frequency range recorded over central scalp locations thought to reflect motor cortex activation. Mu desynchronization during observation of an action is believed to reflect mirroring system activation in humans. However, this notion has recently been questioned because, among other reasons, the potential contamination of mu rhythm and occipital alpha activity induced by attention processes following presentation of visual stimuli in observation conditions. This study examined the validity of mu desynchronization as a measure of mirroring system activation in infants and further investigated the pattern of functional connectivity between the central and occipital regions during execution and observation of movement. EEG was recorded while 46 9-month-old infants executed grasping actions and observed an experimenter grasping. Current source density (CSD) was applied to EEG data and, time-frequency and connectivity analyses were performed in CSD transformed data. Mu desynchronization was evident over central regions during both execution and observation of movements. Independent alpha desynchronization over occipital region was also present in both conditions. The connectivity analyses revealed that central-occipital areas were functionally more connected compared to other areas of the brain during observation of movements. Collectively, the results demonstrate the validity of mu desynchronization as an index of infant mirroring system activity and support the proposal of a functional connection between distinct mirroring and attention processes during observation of action.

Development of inhibitory control during childhood and its relations to early temperament and later social anxiety: unique insights provided by latent growth modeling and signal detection theory.

BACKGROUND: Children with the temperament of behavioral inhibition (BI) face increased risk for social anxiety. However, not all children with BI develop anxiety symptoms. Inhibitory control (IC) has been suggested as a moderator of the pathway between BI and social anxiety. This study uses longitudinal data to characterize development of IC and tests the hypothesis that IC moderates associations between early BI and later social anxiety symptoms. METHODS: Children completed a Go/Nogo task at ages 5, 7, and 10 years as part of a longitudinal study of BI (measured at 2-3 years) and social anxiety symptoms (measured at 12 years). To assess IC development, response strategy (criterion) and inhibitory performance (d') were characterized using signal detection theory. Latent growth models were used to characterize the development of IC and examine relations among BI, IC parameters, and social anxiety symptoms. RESULTS: IC response strategy did not change between 5 and 10 years of age, whereas IC performance improved over time. BI scores in toddlerhood predicted neither initial levels (intercept) nor changes (slope) in IC response strategy or IC performance. However, between ages 5 and 10, rate of change in IC performance, but not response strategy, moderated relations between BI and later parent-reported social anxiety symptoms. Specifically, greater age-related improvements in IC performance predicted higher levels of social anxiety in high BI children. CONCLUSIONS: IC development in childhood occurs independent of BI levels. However, rapid increases in IC performance moderate risk for social anxiety symptoms in children with BI. Implications for theory and practice are discussed.

The role of the motor system in action understanding and communication: Evidence from human infants and non-human primates.

There is growing evidence that activation of the motor system during observation of actions, a phenomenon first observed in non-human primates, underlies action understanding and even communication. This review (a) examines the evidence on motor system activity as an underlying neural correlate of action understanding; (b) reviews the theoretical and empirical work linking action understanding and the development of communication, with a specific focus on the role that gestures play as an intermediary; and (c) discusses the research on and existing opportunities for understanding the link between the motor system and communication in both humans and non-human primates, through the lens of action perception. Bringing together findings and perspectives from developmental social cognition in both humans and non-human primates and applying recent neuroscientific perspectives will help to elucidate the processes underlying the ability to understand and communicate with others.

Low-income fathers' speech to toddlers during book reading versus toy play.

Fathers' child-directed speech across two contexts was examined. Father-child dyads from sixty-nine low-income families were videotaped interacting during book reading and toy play when children were 2;0. Fathers used more diverse vocabulary and asked more questions during book reading while their mean length of utterance was longer during toy play. Variation in these specific characteristics of fathers' speech that differed across contexts was also positively associated with child vocabulary skill measured on the MacArthur-Bates Communicative Development Inventory. Results are discussed in terms of how different contexts elicit specific qualities of child-directed speech that may promote language use and development.

Father input and child vocabulary development: the importance of Wh questions and clarification requests.

Individual differences in children's language skills have been shown to stem in part from variations in the quantity and quality of parent speech input. However, most research focuses on mothers' input whereas less is known about the effects of variability in father input. In this article, we review the relation between parent input and child language development with a focus on low-income families, and review general findings about similarities and differences in mother and father speech. Within this review, we highlight conversation-eliciting speech, such as wh questions and clarification requests, which occur, on average, more frequently in father input than mother input. Conversation-eliciting speech is challenging for 2-year-old children and has been shown in research with mothers to relate to child vocabulary development. We then report a study examining whether fathers' use of conversation-eliciting speech relates to children's developing vocabulary skills at 24 months of age within a sample of low-income African American families. Understanding that speech input varies among fathers, and specific strengths that fathers bring to interactions with their young children can help speech-language pathologists develop and implement more effective interventions.

Experience with pointing gestures facilitates infant vocabulary growth through enhancement of sensorimotor brain activity.

Exposure to communicative gestures, through their parents' use of gestures, is associated with infants' language development. However, the mechanisms supporting this link are not fully understood. In adults, sensorimotor brain activity occurs while processing communicative stimuli, including both spoken language and gestures. Using electroencephalogram (EEG) mu rhythm desynchronization (mu ERD), a marker of sensorimotor activity, we examined whether experimental manipulation of infants' exposure to gestures would affect language development, and specifically whether such an effect would be mediated by changes in sensorimotor brain activity. Mu ERD was measured in 10- to 12-month-old infants (N = 81; 42 male; 15% Hispanic, 62% White) recruited from counties surrounding a large mid-Atlantic university while they observed an experimenter gesturing toward or grasping an object. Half of the infants were randomized to receive increased gesture exposure through a parent-directed training. All 81 infants provided behavioral (infant and parent pointing and infant vocabulary) data prior to intervention and 72 provided behavioral data postintervention. Forty-two infants provided usable (post artifact removal) EEG data prior to intervention and 40 infants provided usable EEG data post-intervention. Twenty-nine infants provided usable EEG data at both sessions. Increased parent gesture due to the intervention was associated with increased infant right lateralized mu ERD at follow-up, but only while observing the experimenter gesturing not grasping. Increased mu ERD, again only while observing the experimenter gesture, was associated with increased infant receptive vocabulary. This is the first evidence suggesting that increasing exposure to gestures may impact infants' language development through an effect on sensorimotor brain activity. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Expectable Environments in Early Life.

Humans develop in the context of environmental information that can be considered either experience-expectant or experience-dependent. Though the exact timing of sensitive period closures and consequences of environmental experiences have not been well delineated, early life is a period of increased vulnerability. While some forms of care (e.g., institutional care for children; representing the absence of experience-expectant caregiving) are not present in the evolutionary history of humans, it is likely that what is considered significant hardship today may have been more typical experience-dependent environmental information in the evolutionary timescale. Thus, assumptions that threatening or neglectful experiences are unexpected for the human child may not fit well in the scope of the broader timescale of human history. We argue that it is important to consider early caregiving experiences from the context of what has been expected in our evolutionary past rather than what is expected in modern sociocultural terms.

Depressive symptoms in parents are associated with reduced empathy toward their young children.

BACKGROUND: While depression is typically associated with reduced levels of empathy, this association differs depending on how empathy is measured. Given the importance of empathy in the parent-child relationship, we sought to examine whether the associations between depression and dispositional empathy would also extend to empathy towards one's own child. METHODS: Within a non-clinical sample of 150 parents of young children, we examined the associations between self-reported depressive symptoms, dispositional empathic tendencies, and empathy specifically toward their own children, and how these associations might differ based on parent gender. RESULTS: Depressive symptoms were related to lower levels of cognitive and affective empathy, and higher levels of empathic distress. Over and above the association with dispositional empathy, depressive symptoms were associated with reduced levels of parents' affective empathy toward their own child. The associations between depressive symptoms and both dispositional and own-child specific empathy varied by parent gender. For fathers, depressive symptoms predicted own-child specific affective empathy, over and above dispositional affective empathy, while for mothers, depressive symptoms predicted own-child specific empathic distress, over and above dispositional empathic distress. CONCLUSIONS: The current findings provide further indication that caregivers with elevated depression may engage in patterns of thoughts and behaviors that have implications for their interactions with their children. Parents' experienced empathy toward their own child may be one mechanism by which depression impacts the early caregiving environment, and thus may be an important target for intervention in improving the early caregiving experiences for children at elevated risk due to parental depression. Differences in cognitive and affective empathy found among those with depression may be even more pronounced in the thoughts and feelings towards one's own child, making this an important clinical target.

Does intention matter? Relations between parent pointing, infant pointing, and developing language ability.

Infants' pointing is associated with concurrent and later language development. The communicative intention behind the point-i.e., imperative versus declarative-can affect both the nature and strength of these associations, and is therefore a critical factor to consider. Parents' pointing is associated with both infant pointing and infant language; however, less work has examined the intent behind parents' points. We explore relations between parents' and infants' pointing at the level of communicative intention, and examine how pointing relates to concurrent and longitudinal infant language skills. In a sample of 52 mother-infant dyads, we measured mother and infant pointing at infant age 12-months, and infant expressive and receptive language at 12-, 18-, and 24-months. We found that mothers produced points with a variety of intentions, however we did not find relations between mother and infant pointing within the different communicative intentions. Replicating previous research, infant declarative pointing was related both concurrently and longitudinally to their language ability. Mothers' declarative pointing was related to their infants' concurrent language, while their imperative pointing was not. Further, there was an interaction between parent and infant declarative pointing, such that the positive relation between parents' declarative pointing and their infants' concurrent receptive language was present only for those infants who were also producing declarative points themselves. Findings suggest that parents' declarative pointing may support both their infants' early word learning and, perhaps, provides a model for their infant to begin using points as well. This study constitutes an important initial exploration of these relations.

Exploring Infant Gesture and Joint Attention as Related Constructs and as Predictors of Later Language.

In infancy, use of gesture and the ability to engage in joint attention with others both predict later language development. Conceptually, gesture and joint attention abilities may reflect a similar underlying social communicative skill. However, these abilities are often studied separately. Despite the fact that gesture is often used in episodes of joint attention, little is known about the degree to which measures of gesture use and joint attention ability are associated with one another or how they similarly, or differentially, predict children's language abilities. Participants in the current study were 53 infants. At 12-months, multiple measures of infants' gesture use were gleaned from a free-play interaction with a parent. Infants' responding to and initiating joint attention were measured via the Early Social-Communicative Scales (ESCS, Mundy et al., 2003). Infants' expressive and receptive language was measured at 24-months with the Mullen Scales of Early Learning (Mullen, 1995). A factor analysis including gesture and joint attention measures indicated that at 12-months joint attention, particularly responding to joint attention, reflects a similar underlying construct with infant gesture use, yet they uniquely predict later language ability.