DIFFERENTIATION BETWEEN FINGER, TOE AND TONGUE MOVEMENT IN MAN BASED ON 40 HZ EEG

Movements of right and left index fingers, right toe and tongue were s tudied by EEG measurement in the alpha and gamma (30-40 Hz) bands. The EEG was recorded with a 56-electrode array over pre- and postcentral areas. For each movement the average power decrease, as a measurement of the event-related desynchronization or power increase in narrow fre quency bands, was calculated. Single-trial data from 8 electrodes, 3 f requency bands and 4 time points within a 1 sec window were subject to a classification task. It was found that, based on single EEG trials, the data from the 4 movements could be differentiated with an accurac y of 70% when alpha and gamma band activity were used but only with 58 % in the case of the alpha band activity alone. This shows that the ga mma band activity or 40 Pit EEG is strongly related to planning of a s pecific movement and therefore, improves the accuracy of classificatio n significantly.