Cognitive control: Preparation of task switching components

Task performance often improves when tasks can be prepared in advance. However, the mechanisms that support advance preparation are highly debated. Proceeding under the hypothesis that switch-specific neural activation during advance preparation is the hallmark of controlled processing, this study investigates the behavioral and neural effects of component preparation during task-switching. Toward this end, fMRI was used to observe neural activity during preparation of response rules (RULE task) compared to preparation of stimulus set (PERCEPTUAL task). We predicted that switch-specific activation would be observed for RULE and PERCEPTUAL switching when component preparation was isolated from target-related activation. The results indicated that preparation for both tasks was supported by common regions of activation; however preparation for switches of response rule was supported by switch-specific activation of the anterior cingulate (ACC) and left lateral prefrontal cortex (LPFC). Shift-cost was also eradicated in this condition with enough preparation time, and was associated with an increase in ACC activation. Switches of stimulus set were not marked by specific neural activity during the preparation interval. While the amount of preparation time affected overall performance, PERCEPTUAL task switches did not benefit more from preparation time than task repeats. It was concluded that response rules can be reconfigured pre-target due to the support of ACC-LPFC activation, where preparation of stimulus sets is supported by a general type of configuration common to both components.