THE NEUROSCIENCES AND MUSIC II I: DISORDERS AND PLASTICITY Beta and Gamma Rhythms in Human Auditory Cortex during Musical Beat Processing

We examined β- (∼20 Hz) and γ- (∼40 Hz) band activity in auditory cortices by means of magnetoencephalography (MEG) during passive listening to a regularmusical beat with occasional omission of single tones. The β activity decreased after each tone, followed by an increase, thus forming a periodic modulation synchronized with the stimulus. The β decrease was absent after omissions. In contrast, γ-band activity showed a peak after tone and omission, suggesting underlying endogenous anticipatory processes. We propose that auditory β and γ oscillations have different roles in musical beat encoding and auditory–motor interaction. Key words: neural oscillation; magnetoencephalography; event-related desynchroniza-tion (ERD); musical beat; auditory–motor interactio