The Development and Neural Basis of Rule-Guided Behavior: A fMRI Study of the Dimensional Change Card Sort Task

摘要

The ability to represent rules (i.e., rule representation) and flexibly switch among them based on task demands (i.e., rule switching) undergoes considerable development during childhood and adolescence. Furthermore, it has been suggested that rule representation and rule switching may be dissociable in terms of developmental trajectory and neural basis. Drawing from recent theoretical models of prefrontal cortex (PFC) organization, we investigated whether the maturation of rule representation parallels the hierarchical organization of lateral PFC, and it was predicted that higher-order rule representation would be associated with most activation in the anterior region of the PFC and that it would not attain maturity until adulthood. On the other hand, rule switching was predicted to be associated with more medial regions of the PFC and may show mature pattern by childhood. Participants in three age groups were tested: middle childhood (8--10 years), adolescence (14--16 years), and adulthood (20--22 years). While performing three versions of the Dimensional Change Card Sort (DCCS) task varying in rule representation demands, participants were scanned using fMRI to provide data on functional activities associated with rule representation and rule switching. Results indicated that the representation of complex higher-order rules to guide actions was associated with greater activation in the anterior regions of PFC (i.e., ventrolateral and rostrolateral PFC) when compared to the representation of a simpler set of rules, and this activation pattern did not show maturity until the adolescent period. On the other hand, rule switching regardless rule complexity appeared to involve a network of primarily occipitoparietal regions and cerebellum, and showed some maturity by childhood. Our findings provided partial support for the hierarchical organization of the PFC and its role in rule representation, and were consistent with past research demonstrating a developmental and neural dissociation between rule representation and rule switching.