Movement-related cortical potentials associated with saliva and water bolus swallowing

The purpose of this study was to document the movement-related cortical potentials associated with saliva and water bolus swallowing in seven right-handed healthy humans. As the subjects performed a saliva or water bolus swallowing task, electroencephalograms with electrodes at C3, Cz, and C4 and an electromyogram of the mylohyoid muscle complex were recorded. The early slope, referred to as the Bereitschafts potential, before saliva swallowing was significantly steeper than that before water bolus swallowing. Positive potential amplitude during water bolus swallowing was significantly larger than that during saliva swallowing. Negative slope and motor potential were not clearly present during performance of either swallowing task. Those findings imply that the features of movement-related cortical potential associated with pharyngeal swallowing are different from those associated with limb movement, and that both the cortical process associated with sensory information of pharyngeal swallowing and the cortical preparatory process of pharyngeal swallowing depend on the type of swallowing task.