Certainty About Movement Prediction Influences Beta and Gamma Oscillations

Abstract

Different contexts change the degree of certainty people have in order to predict upcoming observable movements. The aim of the present study was to reveal how certainty affects oscillatory brain activities in the beta (13-35Hz) and gamma (40-100Hz) frequency range. In a magnetoencephalographic (MEG) experiment, participants were asked to indicate whether presented action verbs (e.g. ‘to wave’) matched the subsequent display of a movement occurring in a video. The predictability of upcoming observable movements was manipulated by changing the chance of a match between action verb and displayed movement. Posterior beta and visual gamma power were shown to be relatively stronger for highly predictable conditions, as compared to conditions with lower predictability, during and shortly before display of the movement. These findings provide a window upon top-down inference processes, as indexed by beta power modulations and onto visual areas in order to minimize prediction error, as reflected by gamma band activity. Overall, we concluded that a context which influences the certainty about upcoming, observable movements of other people, triggers an active interplay of oscillatory activity in the beta and gamma frequency band.