Corticomuscular Coherence of the Extensor Carpi Radialis Muscle in a Dynamic, Manual Response Task

42 pagesCorticomuscular coherence (CMC) is hypothesized to be a measure by which the robustness of connectivity between the brain and muscles can be measured. This study utilized EEG and EMG over both extensor carpi radialis muscles. Electrical activity between 13 and 30Hz was recorded while 11 healthy participants conducted a dynamic motor control task with 10 different task conditions. The three key questions I sought to answer were: how does contralateral vs. ipsilateral coherence vary within healthy participants? How does contralateral coherence of an arm change depending on whether the other arm is held in contraction or relaxed during a block? How does coherence change for an arm depending on response type: whether it is always the responding arm during the task, maybe responding during the task, or not responding to the task? Results showed that contralateral coherence and phase coherence were significantly greater between tasks for both the right and left arms. Both contralateral coherence and phase coherence were greater when the opposite arm was held in contraction, rather than relaxed. No difference in measurements were found depending on the response type of either arm. Considering the variety of factors that affect CMC, I believe further research into a specific task is required to determine consistent patterns in heathy people. I hope that in the future a map of healthy coherence values will help to identify biomarkers for those living with motor system pathologies