On the time-course and frequency selectivity of the EEG for different modes of response selection : evidence from speech production and keyboard pressing

Objective To compare brain activity in the alpha and beta bands in relation to different modes of response selection, and to assess the domain generality of the response selection mechanism using verbal and non-verbal tasks. Methods We examined alpha and beta event-related desynchronization (ERD) to analyze brain reactivity during the selection of verbal (word production) and non-verbal motor actions (keyboard pressing) under two different response modes: externally selected and self-selected. Results An alpha and beta ERD was observed for both the verbal and non-verbal tasks in both the externally and the self-selected modes. For both tasks, the beta ERD started earlier and was longer in the self-selected mode than in the externally selected mode. The overall pattern of results between the verbal and non-verbal motor behaviors was similar. Conclusions The pattern of alpha and beta ERD is affected by the mode of response selection suggesting that the activity in both frequency bands contributes to the process of selecting actions. We suggest that activity in the alpha band may reflect attentional processes while activity in the beta band may be more closely related to the execution and selection process. Significance These results suggest that a domain general process contributes to the planning of speech and other motor actions. This finding has potential clinical implications, for the use of diverse motor tasks to treat disorders of motor planning