Understanding the Role of Sensorimotor Beta Oscillations

Abstract

Beta oscillations have been predominantly observed in sensorimotor cortices and basal ganglia structures and they are thought to be involved in somatosensory processing and motor control. Although beta activity is a distinct feature of healthy and pathological sensorimotor processing, the role of this rhythm is still under debate. Here we review recent findings about the role of beta oscillations during experimental manipulations (i.e., drugs and brain stimulation) and their alteration in aging and pathology. We show how beta changes when learning new motor skills and its potential to integrate sensory input with prior contextual knowledge. We conclude by discussing a novel methodological approach analyzing beta oscillations as a series of transient bursting events.

Keywords: beta bursts; beta desynchronization; beta rebound; brain oscillations; functional role; sensorimotor processing.

FIGURE 1

MRBD and PMBR. (A) Schematic representation of sensorimotor beta activity. During a motor task beta activity drops below baseline (MRBD—light blue shaded area) just prior to and during movement execution. After movement ends, beta activity increases rapidly (PMBR—light orange shaded area) before slowly returning to baseline level. (B) Schematic representation of MRBD and PMBR spatial distribution. MRBD (light blue dot) is commonly localized to the postcentral gyrus whereas PMBR (light orange dot) is often localized to the precentral gyrus. (C) Time-frequency plots showing MRBD and PMBR in M1 (left—reproduced and adapted with permission from Little et al., 2019) and STN (right—reproduced and adapted with permission from Alegre et al., 2005). Both plots show oscillatory activity changes specific to the beta band (13–30 Hz) in the period prior to movement and following movement termination. The color scale indicates relative energy changes with respect to baseline level (blue colors indicate a decrease; red colors indicate an increase). The movement begins at time 0 (magenta dashed line). MRBD: movement related beta decrease; PMBR, post-movement beta rebound; M1: primary motor cortex; STN, subthalamic nucleus.