Multiple sources underlie ERP indices of task-switching

Previous investigations of task-switching have reported that cue-related processes are indexed by a differential switch positivity (D-Pos) and that stimulus-related processes are indexed by a differential switch-negativity (D-Neg). The aim of the current study was to use low resolution electromagnetic tomography to localize the sources of D-Pos and D-Neg. Participants switched randomly between simple tasks and showed an increase in reaction time (RT) for switch relative to repeat trials, i.e., an RT switch cost. ERP waveforms showed a D-Pos in the cue-related interval and a D-Neg in the stimulus-related interval. D-Pos was localized to the superior parietal cortex, supporting arguments that D-Pos is associated with activating task rules during anticipatory reconfiguration. D-Neg was localized to the dorsolateral prefrontal cortex, implicating D-Neg in post-stimulus control