Event-related desynchronization related to the anticipation of a stimulus providing knowledge of results

In the present paper, event-related desynchronization (ERD) in the alpha an d beta frequency bands is quantified in order to investigate the processes related to the anticipation of a knowledge of results (KR) stimulus. In a t ime estimation task, 10 subjects were instructed to press a button 4 s afte r the presentation of an auditory stimulus. Two seconds after the response they received auditory or visual feedback on the timing of their response. Preceding the button press, a centrally maximal ERD is found. Preceding the visual KR stimulus, an ERD is present that has an occipital maximum. Contr ary to expectation, preceding the auditory KR stimulus there are no signs o f a modality-specific ERD. Results are related to a thalamo-cortical gating model which predicts a correspondence between negative slow potentials and ERD during motor preparation and stimulus anticipation. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.