The Excitability of the Motor Cortex for Planning Dexterous Manipulation
My senior research project has quite the title and I didn't understand what it meant at first. It basically is studying the movement of the hand. In my senior project, I will be researching whether the excitability of the hand muscles change depending on if the human subject positions the digits versus positions and applies a force. I will be in a lab at ASU three times a week. In ASU, we will be using a Trans-cranial Magnetic Stimulation (TMS) machine to stimulate the hand muscles in the subjects. The TMS was used originally to treat mood disorders, but when put near the head around the area where the brain controls the hand, the TMS sends a current through magnetic coils into the brain (shown in the figure below) that can stimulate an action potential that would result with a twitch. The strength of the twitch can be controlled by the strength of the current sent by the TMS. The data which I will be analyzing will consist of the muscle (electromyographic) activity, measuring the excitability of the hand muscles. My theory is that, by adding an additional task of applying a force on an object along with positioning the digits, there will be greater excitability of the motor cortex. It could be hypothesized that there is no difference in the excitability because the process of the actions of the muscles involves all the same muscles in applying the force as in positioning the fingers. But more excitability is required to stimulate more strength to the muscles when applying the force.
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| Above the brain is the TMS. Within the circle at the end of the rod are magnetic coils. The magnetic coils induce a current into the green circle on the brain. (I do not own this picture) |
I chose this project because I would learn more about the motor abilities of my hands, which would be helpful to know for my desired career path--working and improving prosthetic limbs, especially for amputee veterans. Ever since sophomore year, I’ve wanted to specialize with prosthetic limbs to help amputee war veterans. Men and women commit their lives for their nation, and some return after sacrificing a limb. The relationship between a person participating in military service and its nation is personal in a way that’s subjective to this person, yet impersonal because this person fights for all the individuals of that nation. Inspired, I committed myself to creating the same relationship with these men and women. I looked up what major prosthetics would be under and I came across biomedical engineering. I was so intrigued at what I found that I committed myself to becoming a biomedical engineer, hopefully specializing in prosthetics. This project will teach me the relationship between the brain and the fingers.
