Distinguishing the neural mechanism of attentional control and working memory in feature-based attentive tracking.

Surface features are an important component in attentive tracking. However, the neural mechanisms underlying how features affect attentive tracking remain unknown. The present fMRI study addressed this issue by manipulating the intragroup feature complexity and intergroup feature similarity. In particular, this study distinguished the different neural mechanisms of intragroup feature complexity and intergroup feature similarity by investigating the roles of attentional control and working memory in dynamic feature-based attentive tracking. Behavioral and neuroimaging evidence showed that when targets are distinct from distractors, the intragroup feature complexity of the targets, rather than that of the distractors, mainly increases the visual working memory load and significantly activates the frontoparietal cortical circuit. Thus, the involvement of working memory in feature-based attentive tracking is modulated by goal-directed attention control. In addition, when targets are similar to distractors, the intergroup feature similarity (i.e., target-distractor similarity) mainly affects the allocation of attention. Specifically, target-distractor similarity affects the goal-directed attention toward the targets in a stimulus-driven way and induces an interaction between the ventral and dorsal attention networks.