Micro Robot Control by Use of Electroencephalograms from Right Frontal Area

In order to develop a brain machine interface, the authors have investigated the brain activity during human recognition of characters and symbols representing directional meaning. They have recorded electroencephalograms (EEGs) from subjects viewing four types of Kanji (Chinese characters being used currently in the Japanese language) and arrows that were presented on a CRT. Each of the four characters or symbols denoted direction for upward, downward, leftward and rightward, respectively. Subjects were asked to read the characters or symbols, silently. EEGs were averaged for each stimulus type and direction, and event related potentials (ERPs) were obtained. The equivalent current dipole source localization (ECDL) method has been applied to these ERPs. In both cases, equivalent current dipoles (ECDs) were localized to areas related to the working memory for spatial perception, such as the right upper or the right middle frontal areas. Taking into account these facts, the authors have investigated a single trial EEGs of the subject precisely after the latency at 400 ms, and it was determined effective sampling latencies for the discriminant analysis to four types of arrow: ↑, ↓, ←, and →. EEG data have been sampled at latency from 400 ms to 900 ms at 25 ms interval by the three channels in the right upper and the right middle frontal gyri. Results of the discriminant analysis for four type objective variates, presented discriminant rates were above 80%. By four type code of infrared rays according to the discrimination results from a PC, the authors have controlled a micro robot, the e-puck, with four orders: forward, rotate clockwise, rotate counterclockwise and stop.