Time–frequency analysis of the EEG mu rhythm as a measure of sensorimotor integration in the later stages of swallowing

•Novel EEG techniques were used to map neural and muscular activity in swallowing.•Strongest mu activity occurred during the later pharyngeal and esophageal phases.•Cortical sensorimotor integration is critical to the later phases of swallowing. Electroencephalography (EEG) was used to map the temporal dynamics of sensorimotor integration relative to the strength and timing of muscular activity during swallowing. 64-channel EEG data and surface electromyographic (sEMG) data were recorded from 25 neurologically-healthy adults during swallowing and tongue-tapping. Events were demarcated so that sensorimotor activity primarily from the pharyngeal and esophageal phases of swallowing could be compared to activity resulting from tongue tapping. Independent component analysis identified bilateral clusters of sensorimotor mu components localized to the premotor and primary motor cortices as well as an infrahyoid myogenic cluster. Subsequent event-related spectral perturbations (ERSP) analyses showed event-related desynchronization (ERD) in the spectral power in the alpha (8–13Hz) and beta (15–25Hz) frequency bands of the mu clusters in both tasks. Mu ERD was stronger during swallowing when compared to tongue tapping (pFDR