The contribution of task-choice response selection to the switch cost in voluntary task switching.

Mental flexibility not only enables us to switch between tasks but also to select the tasks we want to perform. The latter scenario is central to voluntary task switching, in which participants are free to select on each trial which task to perform. The present study argues that voluntary task switching also includes and additional component, namely task-choice response selection. Task-choice response selection refers to the whole chain of processes involved in the overt report or indication of the task that was selected by emitting an arbitrary response. Task-choice response selection is not required to voluntarily switch between tasks, but serves the measurement of participants' covert task selection. The results of two experiments indicate that the contribution of task-choice response selection to switch performance in voluntary task switching is substantial. It is proposed that task-choice response selection delays the top-down retrieval of task rules in voluntary task switching.