Walking to the beat: how to quantify neural entrainment
School/Affiliation:Université de Montréal
Co-Authors:Simone, Dalla Bella; Fabien, Dal Maso
Virtual or In-person:In-person
Walking along the beat of an auditory stimulus (e.g., the pulse of a metronome or music) can improve gait in clinical populations. These benefits may be modulated by the coupling of brain activity to the stimulus’ rhythm, a phenomenon called neural entrainment. While a better understanding of entrainment could optimize the design of rhythm-based therapies, it has never been studied during gait. Novel multivariate-analysis methods were used to extract an entrained component from electroencephalography (EEG) during finger tapping. Our objective was to adapt and validate these methods for a gait task and investigate which EEG-derived outcome measures were markers of entrainment. An open-access database of 20 participants equipped with 108 EEG electrodes and heel sensors was analyzed. Participants walked without and with a metronome matching preferred cadence, while synchronizing their footsteps to the beat. Step-to-beat synchronization was quantified from foot-strikes and beat onsets. The entrained component was successfully extracted as shown by power peaks at step frequency (i.e., beat frequency in cued condition) and medio-central topographies. From these components, we computed outcome measures that have been linked to entrainment. Surprisingly, linear mixed models revealed no difference in EEG power at step frequency between cued and uncued conditions. However, beta-power modulation across the gait-cycle was lower during cued gait. An increase in beta-power modulation was correlated to a decrease in step-to-beat synchronization. Thus, we recommend computing beta-power modulation to study neural entrainment during a gait task, as opposed to power at beat frequency. Our scripts are open access, making this study fully replicable.