Task-switching paradigms are widely used to study cognitive control. Typically, switch costs (SC) emerge, reflecting performance costs in switch compared to repetition trials. Previous research reported asymmetrical SC (ASC), with larger SC for affective compared to neutral task-sets. This asymmetry likely reflects the dominance of the affective task-set, requiring inhibition to perform the neutral task-set, thus increasing SC for the affective task-set. While transient control processes have been studied, the neural correlates of ASC remain unclear. Additionally, it is unknown how neutral-affective task-set pairings influence sustained control processes, as reflected by the mixing costs (MC), the performance differences between repetition- and single-task trials, and their neural correlates.
To address these gaps, participants completed a cued task-switching paradigm during electroencephalographic recording, judging either the gender (neutral-task) or emotional expression (affective-task) of faces.
Behaviorally, ASC were obtained, with larger SC for the affective compared to neutral task-set, consistent with increased affective dominance. In contrast, MC were unaffected by task-set pairing. Neurally, during the cue-stimulus interval, the parietal switch positivity (SP) was reduced for affective compared to neutral task-sets, coinciding with increased SC which suggests an impaired task-set reconfiguration. However, the mixing positivity (MP) remained unchanged by the task-set pairing.
These findings indicate that neutral-affective task-set pairings selectively modulate transient neural correlates of cognitive control, as reflected by the reduced SP for the affective task-set, while sustained processes, as reflected by MP, remained unaffected. This study provides novel insights into how neutral-affective task-set pairings modulate transient but not sustained control processes.