Boosting Cortical Activity at Beta-Band Frequencies Slows Movement in Humans

Neurons have a striking tendency to engage in oscillatory activities. One important type of oscillatory activity prevalent in the motor system occurs in the beta frequency band, at about 20 Hz. It is manifest during the maintenance of tonic contractions and is suppressed prior to and during voluntary movement. This and other correlative evidence suggests that beta activity might promote tonic contraction, while impairing motor processing related to new movements. Hence, bursts of beta activity in the cortex are associated with a strengthening of the motor effects of sensory feedback during tonic contraction and with reductions in the velocity of voluntary movements. Moreover, beta activity is increased when…