Electromyography Markers of Global Motor Inhibition While Stopping

Presenter: Isaiah Mills – Human Physiology

Faculty Mentor(s): Ian Greenhouse, Mitchell Fisher

Session: (In-Person) Poster Presentation

Stopping individual parts of complex movement plans is a critical part of controlling our bodies. While humans can coordinate movements effectively, our brains have limitations in selective stopping ability. Cancelling one action can affect other simultaneous actions, especially when these actions are bimanual. In one stopping task where participants had to cancel one finger movement while continuing a movement with the other hand, the executed lift was delayed from the target reaction time. This is thought to be caused by a neural pathway which nonselectively inhibits all actions before restarting continuing actions. Here, we record the activation of little finger muscles using electromyography during tonic muscle contraction. Subjects hold contraction as they perform a similar task involving timing bimanual index finger movements to a target time. During stop trials where one or both movements are inhibited we hypothesize that the amplitude of tonic EMG will decrease representing nonselective motor inhibition. Preliminary data analysis supports this hypothesis. This data will help us understand how healthy control of movement is facilitated by the brain, and during what period following a stop signal this network is actively suppressing movement. Patients who suffer from movement disorders like Parkinson’s struggle to control inhibitory processes, and we hope to learn more about the disease and how it affects these pathways by comparing healthy datasets to disease state.