Oscillatory activity in sensorimotor function

Amplitude modulations in alpha/mu, beta, and gamma frequency bands are robustly linked to several aspects of sensorimotor function. Even a simple finger tap induces a prominent suppression of alpha/mu and beta power that already starts during the preparation phase, continues during execution, and ends in a rebound after movement termination. An increase in gamma power can often be observed around movement onset in contralateral motor cortex. Recordings from other parts of the motor system such as the basal ganglia and motoneurons in the spinal cord indicate that these modulations and frequency bands are a hallmark of the sensorimotor network. Beta oscillations in particular are considered crucial in mediating the facilitation and inhibition of motor output. This is exemplified by elevated beta amplitudes in local field potential recordings from the subthalamic nucleus in patients with Parkinson’s disease. This chapter outlines current ideas about the role of individual frequency bands in motor control, how coherence estimates between recordings from distant sites have revealed functional networks, and what we know about the involvement of oscillatory activity in movement disorders.