Early childhood is a time of significant change within multiple cognitive domains including social cognition, memory, executive function, and language; however, the corresponding neural changes remain poorly understood. This is likely due to the difficulty in acquiring artifact-free functional MRI data during complex task-based or unconstrained resting-state experiments in young children. In addition, task-based and resting state experiments may not capture dynamic real-world processing. Here we overcome both of these challenges through use of naturalistic viewing (i.e., passively watching a movie in the scanner) combined with inter-subject neural synchrony to examine functional specialization within 4- and 6-year old children. Using a novel and stringent crossed random effect statistical analysis, we find that children show more variable patterns of activation compared to adults, particularly within regions of the default mode network (DMN). In addition, we found partial evidence that child-to-adult synchrony increased as a function of age within a DMN region: the temporoparietal junction. Our results suggest age-related differences in functional brain organization within a cross-sectional sample during an ecologically valid context and demonstrate that neural synchrony during naturalistic viewing fMRI can be used to examine functional specialization during early childhood – a time when neural and cognitive systems are in flux.

No abstract

No abstract

Although children's social development is embedded in social interaction, most developmental neuroscience studies have examined responses to non-interactive social stimuli (e.g. photographs of faces). The neural mechanisms of real-world social behavior are of special interest during middle childhood (roughly ages 7-13), a time of increased social complexity and competence coinciding with structural and functional social brain development. Evidence from adult neuroscience studies suggests that social interaction may alter neural processing, but no neuroimaging studies in children have directly examined the effects of live social-interactive context on social cognition. In the current study of middle childhood, we compare the processing of two types of speech: speech that children believed was presented over a real-time audio-feed by a social partner and speech that they believed was recorded. Although in reality all speech was prerecorded, perceived live speech resulted in significantly greater neural activation in regions associated with social cognitive processing. These findings underscore the importance of using ecologically-valid and interactive methods to understand the developing social brain.