ELECTROENCEPHALOGRAPHY (EEG) AND ITS USE IN MOTOR LEARNING AND CONTROL

Electroencephalography (EEG) is a non-invasive technique of measuring electric currents generated from active brain regions and is a useful tool for researchers interested in motor control. The study of motor learning and control seeks to understand the way the brain understands , plans and executes movement both physical and imagined. Thus , the purpose of this study was to better understand the ways in which electroencephalography can be used to measure regions of the brain involved with motor control and learning. For this purpose , two independent studies were completed using EEG to monitor brain activity during both executed and imagined actions. The first study sought to understand the cognitive demand of altering a running gait and provides EEG evidence of motor learning. 13 young healthy runners participated in a 6-week in-field gait-retraining program that altered running gait by increasing step rate (steps per minute) by 5-10%. EEG was collected while participants ran on a treadmill with their original gait as a baseline measurement. After the baseline collection , participants ran for one minute at the same speed with a 5-10% step rate increase while EEG was collected. Participants then participated in a 6-week in-field gait-retraining program in which they received bandwith feedback while running in order to learn the new gait. After completing the 6-week training protocol , participants returned to the lab for post training EEG collection while running with the new step rate. Power spectral density plots were generated to measure frequency band power in all gait-retraining phases. Results in the right prefrontal cortex showed a significant increase in beta (13-30 Hz) while initially running with the new gait compared to the baseline step rate. Previous work suggests the right prefrontal cortex is involved with the inhibition of a previously learned behavior and thus , our results suggest an increase in cognitive load to inhibit the previous full stride motion. After training , this increase in beta over the right prefrontal cortex decreased , suggesting motor adaptations had occurred as a result of motor learning. These results give promising evidence for a new method of ensuring permanent changes in performance that will benefit rehabilitation and athletic performance training programs. The second study in this project sought to understand differences in right and left-handers as they mentally simulate movement. 24 right and left-handed individuals (12 right-handers , 12 left-handers) were shown pictures of individual hands on a screen while EEG was collected. Previous research has shown than while solving this task , participants mentally rotate a mental representation of their own hand to determine the handedness of the image. Event-related potential results showed that right-handers had an earlier and greater activation in the parietal regions than left-handers , whereas left-handers had a later and greater activation in the motor related brain regions compared to right-handers. These results suggest differing strategies while mentally solving motor related tasks between right and left-handers. We speculate this is a result of left-handers' need to adapt to a majorly right-hand dominant environment. Both these studies show the benefits of using EEG to understand the motor system in physically executed and imagined actions