Bursts and variability of beta oscillations mediate the effect of anxiety on motor exploration and motor learning

Abstract

Anxiety results in sub-optimal motor performance and learning through mechanisms still unknown. Here we addressed whether state anxiety impairs motor learning through changes in behavioral and neural variability. Participants completed a reward-based motor sequence learning paradigm, with separate phases for exploration (baseline) and learning. Anxiety was manipulated either during baseline or learning. We show that anxiety at baseline reduces motor variability, undermining subsequent reward-based learning. By contrast, unconstrained baseline exploration led to successful motor learning, even under the effect of anxiety. The behavioral changes were driven by changes in the variability of sensorimotor beta oscillations (13-30Hz, SBO). Moreover, bursts of SBO, a marker of physiological beta, lasted longer under the effect of anxiety, resembling recent findings of pathophysiological beta in movement disorders. Our findings suggest that changes in variability and burst duration in SBO represent a neural mechanism through which anxiety constrains movement variability, with detrimental consequences for motor learning.