Reconfiguring mind and brain for an upcoming change of task
Preparing mind and brain for a change of cognitive task. To perform any cognitive task requires one to select and configure appropriate processing resources available in the mind/brain â€“ a "task-set". Voluntary "executive" control of task-set (doing the task one intends to do) interacts with stimulus-driven control of task-set (doing the task afforded by the environment). An increasingly popular way of studying this interaction is the task-switching paradigm, in which subjects respond to a series of stimuli, and the task to be performed changes from time to time. The main focus of interest is the "switch cost" â€” the long reaction times observed to the first stimulus following a task switch â€” and the reduction in (but not elimination of) the switch cost observed when time is available for preparation. This reduction has been interpreted as an index of a preparatory executive control process: "task-set reconfiguration". I will review recent challenges to this interpretation: some have gone so far as to claim that the switch cost does not reflect executive control at all, and others disagree about how the switch cost reflects executive control. I will describe some experiments that have led us to develop a more refined procedure that, we claim, does indeed index a preparatory task-set reconfiguration process. I will then present some electrophysiological data we have recently collected in this paradigm, and attempt to characterise the nature of the task-set reconfiguration process.