Task structure boundaries affect response preparation

Rethinking attentional reset: Task sets determine the boundaries of adaptive control

Adaptive control processes that minimise distraction often operate in a context-specific manner. For example, they may minimise distraction from irrelevant conversations during a lecture but not in the hallway afterwards. It remains unclear, however, whether (a) salient perceptual features or (b) task sets based on such features serve as contextual boundaries for adaptive control in standard distractor-interference tasks. To distinguish between these possibilities, we manipulated whether the structure of a standard, visual distractor-interference task allowed (Experiment 1) or did not allow (Experiment 2) participants to associate salient visual features (i.e., colour patches and colour words) with different task sets. We found that changing salient visual features across consecutive trials reduced a popular measure of adaptive control in distractor-interference tasks-the congruency sequence effect (CSE)-only when the task structure allowed participants to associate these visual features with different task sets. These findings extend prior support for the task set hypothesis from somewhat atypical cross-modal tasks to a standard unimodal task. In contrast, they pose a challenge to an alternative "attentional reset" hypothesis, and related views, wherein changing salient perceptual features always results in a contextual boundary for the CSE.

Dissociating the Neural Correlates of Planning and Executing Tasks with Nested Task Sets

Task processing (e.g., the preparation and execution of responses) and task representation (e.g., the activation and maintenance of stimulus-response and context information) are two facets of cognitive control supported by lateral frontal cortex (LFC). However, the mechanistic overlap (or distinction) between these two facets is unknown. We explored this by combining a complex task mapping with a precueing procedure. Participants made match/nonmatch judgments on pairs of stimuli during fMRI recording. Precues on each trial gave variable amounts of information to the participant in anticipation of the stimulus. Our results demonstrated that regions throughout LFC were more active at the stimulus (when responses could be executed) than at the cue (when they could only be prepared), indicating that they supported execution of the task agnostic to the specific task representation. A subset of regions in the left caudal LFC showed increased activity with more cue information at the cue and the reverse at the stimulus, suggesting their involvement in reducing uncertainty within the task representation. These results suggest that one component of task processing is preparing and executing the task according to the relevant representation, confined to left caudal LFC, whereas nonrepresentational functions that occur primarily during execution are supported by different regions throughout the rest of LFC. We further conducted an exploratory investigation of connectivity between the two groups of regions in this study and their potential relationship to the frontoparietal and cingulo-opercular networks. Regions with both patterns of activity appear to be part of the frontoparietal network.

Task representation affects the boundaries of behavioral slowing following an error

Researchers have recognized the role that task representation plays in our behavior for many years. However, the specific influence that the structure of one's task representation has on executive functioning has only recently been investigated. Prior research suggests that adjustments of cognitive control are affected by subtle manipulations of aspects of the stimulus-response pairs within and across task sets. This work has focused on examples of cognitive control such as response preparation, dual-task performance, and the congruency sequence effect. The current study investigates the effect of task representation on another example of control, post-error slowing. To determine if factors that influence how people represent a task affect how behavior is adjusted after an error, an adaptive attention-shifting task was developed with multiple task delimiting features. Participants were randomly assigned to a separate task set (two task sets) or an integrated task set (one task set) group. For the separate set group, the task sets switched after each trial. Results showed that only the integrated set group exhibited post-error slowing. This suggests that task representation influences the boundaries of cognitive control adjustments and has implications for our understanding of how control is organized when adjusting to errors in performance.