Distinct β Band Oscillatory Networks Subserving Motor and Cognitive Control during Gait Adaptation

Everyday locomotion and obstacle avoidance requires effective gait adaptation in response to sensory cues. Many studies have shown that efficient motor actions are associated with mu rhythm (8-13 Hz) and beta band (13-35 Hz) local field desynchronizations in sensorimotor and parietal cortex, whereas a number of cognitive task studies have reported higher behavioral accuracy to be associated with increases in beta band power in prefrontal and sensory cortex. How these two distinct patterns of beta band oscillations interplay during gait adaptation, however, has not been established. Here we recorded 108 channel EEG activity from 18 participants (10 males, 22-35 years old) attempting to walk on a treadmill in synchrony with a series of pacing cue tones, and quickly adapting their step rate and length to sudden shifts in pacing cue tempo. Independent component analysis parsed each participant's EEG data into maximally independent component (IC) source processes, which were then grouped across participants into distinct spatial/spectral clusters. Following cue tempo shifts, mean beta band power was suppressed for IC sources in central midline and parietal regions, whereas mean beta band power increased in IC sources in or near medial prefrontal and dorsolateral prefrontal cortex. In the right dorsolateral prefrontal cortex IC cluster, the beta band power increase was stronger during (more effortful) step shortening than during step lengthening. These results thus show that two distinct patterns of beta band activity modulation accompany gait adaptations: one likely serving movement initiation and execution; and the other, motor control and inhibition.