This seminar is open to all NACS students.
Speaker: Dustin Moraczewski
Title: Functional Specialization of the Right Temporo-Parietal Junction in Early Childhood
Abstract: Situated within the default mode network and at the boundary of other networks, the right temporo-parietal junction (rTPJ) is a nexus region that has been implicated in an array of processes such as attention reorienting, memory, language, social perception, and social cognition. In middle childhood, the rTPJ displays a specialization for mental state representation yet little is known about its functional organization in early childhood. However, early childhood is a key time to study change in rTPJ organization given the pronounced advances in social cognitive abilities during this age. The lack of studies in early childhood is likely due to the challenge of acquiring artifact-free MRI data in young children. Thus, the current study utilized a novel passive-viewing functional connectivity approach to examine regional rTPJ functional specialization in 4 (N = 31) and 6 (N= 36) year olds, and adults (N = 22), resulting in high success rates (4s: 70, 87%; 6s: 72, 78%). Participants watched screensaver-like abstract patterns and a clip of an engaging movie, both of which served to hold attention and decrease movement. A two-step principal component analysis was used to uncover local temporal and subsequent global spatial patterns that account for > 5% within-region time series variance on two resolutions of the rTPJ. Using these eigenimages to identify principal sub-regions, I will present an analysis of between-group differences in local organization using a measure inter-sub-regional homogeneity. In addition, since no region functions in isolation, I will show how local organization gives rise to between-group differences in whole-brain network connectivity. Also, given the role of the rTPJ in mental state representation, I will examine the relationship between local organization in the children and performance on a series of false belief behavioral tasks. Although the results show no between-group differences in local organization, interesting global differences emerged showing that adults exhibit greater within-network connectivity than the children.