Social context shapes neural processing of others' actions in 9-month-old infants

Object exploration is facilitated by the physical and social environment in center-based child care

Object exploration is considered a driver of motor, cognitive, and social development. However, little is known about how early childhood education and care settings facilitate object exploration. This study examined if children's exploration of objects during free play was facilitated by the use of particular spatial components (floor, tables, and activity centers) and types of play (solitary, social, and parallel). Participants were 61 children (aged 11 to 48 months and 50.8% boys, socioeconomic levels representative of the Dutch population). Intraindividual variability in children's object exploration was predicted by the use of particular spatial components and the social setting, with small-to-medium effect sizes. Solitary and parallel play were positively associated with complex object exploration, especially when sitting or standing at child-height tables. During social play, object exploration was mostly absent.

A Corpus Study on the Difference of Turn-Taking in Online Audio, Online Video, and Face-to-Face Conversation

Daily conversation is usually face-to-face and characterized by rapid and fluent exchange of turns between interlocutors. With the need to communicate across long distances, advances in communication media, online audio communication, and online video communication have become convenient alternatives for an increasing number of people. However, the fluency of turn-taking may be influenced when people communicate using these different modes. In this study, we conducted a corpus analysis of face-to-face, online audio, and online video conversations collected from the internet. The fluency of turn-taking in face-to-face conversations differed from that of online audio and video conversations. Namely, the timing of turn-taking was shorter and with more overlaps in face-to-face conversations compared with online audio and video conversations. This can be explained by the limited ability of online communication modes to transmit non-verbal cues and network latency. In addition, our study could not completely exclude the effect of formality of conversation. The present findings have implications for the rules of turn-taking in human online conversations, in that the traditional rule of no-gap-no-overlap may not be fully applicable to online conversations.

Down and up! Does the mu rhythm index a gating mechanism in the developing motor system?

Developmental research on action processing in the motor cortex relies on a key neural marker - a decrease in 6-12 Hz activity (coined mu suppression). However, recent evidence points towards an increase in mu power, specific for the observation of others' actions. Complementing the findings on mu suppression, this raises the critical question for the functional role of the mu rhythm in the developing motor system. We here discuss a potential solution to this seeming controversy by suggesting a gating function of the mu rhythm: A decrease in mu power may index the facilitation, while an increase may index the inhibition of motor processes, which are critical during action observation. This account may advance our conception of action understanding in early brain development and points towards critical directions for future research.

Supplementation With Iron Syrup or Iron-Containing Multiple Micronutrient Powders Alters Resting Brain Activity in Bangladeshi Children

BACKGROUND

Anemia and iron deficiency have been associated with poor child cognitive development. A key rationale for the prevention of anemia using supplementation with iron has been the benefits to neurodevelopment. However, little causal evidence exists for these gains.

OBJECTIVES

We aimed to examine effects of supplementation with iron or multiple micronutrient powders (MNPs) on brain activity measures using resting electroencephalography (EEG).

METHODS

Children included in this neurocognitive substudy were randomly selected from the Benefits and Risks of Iron Supplementation in Children study, a double-blind, double-dummy, individually randomized, parallel-group trial in Bangladesh, in which children, starting at 8 mo of age, received 3 mo of daily iron syrup, MNPs, or placebo. Resting brain activity was recorded using EEG immediately after intervention (month 3) and after a further 9-month follow-up (month 12). We derived EEG band power measures for delta, theta, alpha, and beta frequency bands. Linear regression models were used to compare the effect of each intervention with that of placebo on the outcomes.

RESULTS

Data from 412 children at month 3 and 374 at month 12 were analyzed. At baseline, 43.9% were anemic and 26.7% were iron deficient. Immediately after intervention, iron syrup, but not MNPs, increased the mu alpha-band power, a measure that is associated with maturity and the production of motor actions (iron vs. placebo: mean difference = 0.30; 95% CI: 0.11, 0.50 μV²; P = 0.003; false discovery rate adjusted P = 0.015). Despite effects on hemoglobin and iron status, effects were not observed on the posterior alpha, beta, delta, and theta bands, nor were effects sustained at the 9-month follow-up.

CONCLUSIONS

The effect size for immediate effects on the mu alpha-band power is comparable in magnitude with psychosocial stimulation interventions and poverty reduction strategies. However, overall, we did not find evidence for long-lasting changes in resting EEG power spectra from iron interventions in young Bangladeshi children. This trial was registered at www.anzctr.org.au as ACTRN12617000660381.

Challenges and new perspectives of developmental cognitive EEG studies

Despite shared procedures with adults, electroencephalography (EEG) in early development presents many specificities that need to be considered for good quality data collection. In this paper, we provide an overview of the most representative early cognitive developmental EEG studies focusing on the specificities of this neuroimaging technique in young participants, such as attrition and artifacts. We also summarize the most representative results in developmental EEG research obtained in the time and time-frequency domains and use more advanced signal processing methods. Finally, we briefly introduce three recent standardized pipelines that will help promote replicability and comparability across experiments and ages. While this paper does not claim to be exhaustive, it aims to give a sufficiently large overview of the challenges and solutions available to conduct robust cognitive developmental EEG studies.

The Early Motor Questionnaire revisited: Starting points, standardized scores, and stability

Motor skills are an important aspect of development during infancy and have been found to predict development in other domains. Therefore, fast and reliable assessments of infant motor skills are needed. The current study revisited a time and cost-effective parent-report measure of infants' motor skills-the Early Motor Questionnaire (EMQ)-and aimed to improve the utility of the EMQ as a tool to examine variability, stability, and individual differences in early motor development. A sample of 446 parents of infants provided a total of 775 EMQ responses for analyses. Using this large sample, regression was used to create age-independent scores for global, gross motor, fine motor, and perception-action scores on the EMQ. Age-adjusted scores were then converted to t-scores to facilitate score interpretation for past and future studies using the EMQ. Finally, starting flags for different age groups were created to decrease the time it takes parents to complete the EMQ. Together, these changes to the EMQ will improve the utility and interpretability of the measure. The EMQ is free to use and available in the supplemental materials or via www.onlinebabylab.com/emq.

Neural correlates of familiar and unfamiliar action in infancy

Behavioral evidence shows that experience with an action shapes action perception. Neural mirroring has been suggested as a mechanism underlying this behavioral phenomenon. Suppression of electroencephalogram (EEG) power in the mu frequency band, an index of motor activation, typically reflects neural mirroring. However, contradictory findings exist regarding the association between mu suppression and motor familiarity in infant EEG studies. In this study, we investigated the neural underpinnings reflecting the role of familiarity in action perception. We measured neural processing of familiar (grasp) and novel (tool-use) actions in 9- and 12-month-old infants. Specifically, we measured infants' distinct motor/visual activity and explored functional connectivity associated with these processes. Mu suppression was stronger for grasping than for tool use, whereas significant mu and occipital alpha (indexing visual activity) suppression were evident for both actions. Interestingly, selective motor-visual functional connectivity was found during observation of familiar action, a pattern not observed for novel action. Thus, the neural correlates of perception of familiar actions may be best understood in terms of a functional neural network rather than isolated regional activity. Our findings provide novel insights on analytic approaches for identifying motor-specific neural activity while also considering neural networks involved in observing motorically familiar versus unfamiliar actions.

Dialogic Book-Sharing as a Privileged Intersubjective Space

Parental reading to young children is well-established as being positively associated with child cognitive development, particularly their language development. Research indicates that a particular, "intersubjective," form of using books with children, "Dialogic Book-sharing" (DBS), is especially beneficial to infants and pre-school aged children, particularly when using picture books. The work on DBS to date has paid little attention to the theoretical and empirical underpinnings of the approach. Here, we address the question of what processes taking place during DBS confer benefits to child development, and why these processes are beneficial. In a novel integration of evidence, ranging from non-human primate communication through iconic gestures and pointing, archaeological data on Pre-hominid and early human art, to experimental and naturalistic studies of infant attention, cognitive processing, and language, we argue that DBS entails core characteristics that make it a privileged intersubjective space for the promotion of child cognitive and language development. This analysis, together with the findings of DBS intervention studies, provides a powerful intellectual basis for the wide-scale promotion of DBS, especially in disadvantaged populations.

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.