At will or not at will: Electrophysiological correlates of preparation for voluntary and instructed task-switching paradigms.

The present study investigated whether the advanced reconfiguration processes of the voluntary switching (VTS) paradigm were different from those of the instructed task switching (ITS) paradigm by examining event-related potentials (ERPs) in a within-subjects design. Of importance, given that effector-to-task mapping might lead to differential preparatory strategies, two effector-to-task mapping groups were studied: the hand-to-task (HAND) and finger-to-task (FINGER) groups. Intriguingly, we found the increased posterior negativity for voluntary switch (and/or increased posterior positivity for voluntary repeat) was exclusive to the HAND group, whereas the increased switch-related late posterior positivity in the ITS paradigm was independent of the effector manipulation. Moreover, the lateralized readiness potentials (LRP) and the mu and beta motor-related amplitude asymmetries indicated that the differential switch-related modulations were not the byproduct of hand-specific preparation. The advanced preparatory strategies in the VTS and ITS paradigms are discussed.