COORDINATED NEUROMORPHOLOGY IN THE DEVELOPMENT OF SOCIAL INFORMATION PROCESSING

Abstract

Changes in social information processing that occur during adolescence are thought to rely on the functional and structural maturation of a network of interconnected brain regions referred to as “the social brain.” The morphology of these brain regions, individually, is thought to be associated with functional specialization and/or ability, but little is known about the relationship between the morphology of the network and its functional specialization. Studies suggest that repeatedly executed psychological processes are not only reflected in functional networks, but may also be related to coordinated morphological changes in the brain across multiple regions that are functionally and structurally connected. The present study sought to explore changes in neuromorphological covariation that occur in the social brain network between adolescence and adulthood (Aim 1), using magnetic resonance imaging and graph theory, and link the properties of this covariance to self-reported and behavioral aspects of social information processing, specifically resistance to peer influence (Aim 2.1), rejection sensitivity (Aim 2.2), and the control of automatic reactions to socially relevant stimuli (Aim 2.3). The specificity of these results to social stimuli was assessed by also analyzing covariance properties in relation to a non-social measure of cognitive functioning (Aim 2.4). Subjects were 217 healthy right-handed individuals between the ages of 13 and 25 – 77 adolescents (ages 13-17), 73 young adults (ages 18-21), and 67 adults (ages 22-25). Analyses involved extracting cortical thickness values for the social brain network for each subject, and conducting group-level graph theoretic analyses. Results suggest that older subjects, subjects who are less sensitive to social stimuli and those who perform better on a behavioral inhibition task, all share one characteristic: the density of covariance in the structural social brain network is low compared to individuals who are younger, more sensitive to social stimuli, and who perform worse on a behavioral inhibition task. Furthermore, this pattern was not observed in a non-social measure of cognitive functioning, suggesting a level of specificity to social information processing in the reported findings. By suggesting that selective structural covariance in the social brain may be characteristic of maturity but also more adaptive in social contexts, the findings from the present study contribute to the idea that adolescence is a time of great opportunity for shaping the brain's structural architecture.