Failed Stopping Transiently Suppresses the Electromyogram in Task-Irrelevant Muscles.

Area of Science:

• Motor control
• Neuroscience
• Human movement science

Background:

• Selective stopping of planned or ongoing movements is a crucial everyday motor skill.
• Action cancellation can lead to interference with simultaneous actions, potentially due to global motor inhibition.
• Previous research used brain stimulation and electromyography (EMG) to study corticomotor excitability during stopping.

Purpose of the Study:

• To investigate if global motor inhibition during selective stopping can be measured peripherally using only EMG.
• To assess the temporal resolution of EMG in detecting these inhibitory effects.
• To determine if EMG can serve as a physiological marker for stopping processes.

Main Methods:

• Eighteen participants performed a bimanual anticipatory response inhibition task.
• Participants maintained a tonic contraction of task-irrelevant abductor digiti minimi (ADM) muscles.
• Time series analysis of ADM EMG signals was used to detect inhibition patterns.

Main Results:

• Transient inhibition in ADM EMG signals was observed 150-203 ms after the stop signal during failed stopping trials.
• This inhibition pattern occurred in both hands across different selective stopping conditions (stop-all, stop-left, stop-right).
• Tonic muscle activity proved sensitive to global motor suppression effects, even with failed stopping.

Conclusions:

• EMG alone can detect peripheral physiological markers of global motor inhibition during selective stopping.
• This method offers high temporal resolution for studying the dynamics of stopping processes.
• EMG provides a valuable tool for probing the time course and extent of motor inhibition.