P300 EVOKED BY SOMATOSENSORY STIMULUS AND S-R COMPATIBILITY / 体力科学

ABSTRACT

The purpose of this study was to examine how S-R compatibility affected P 300, the stimulusevaluation process and response process. The P 300 component is thought to reflect information processing of stimuli. Previous studies used visual stimuli. In this study, we measured S-R compatibility effects on EMG-RT and P 300 using electrical somatosensory stimuli. Subjects performed the oddball task (Task 1) and the four-choice stimuli response task (Task 2) . They were presented electrical stimuli through ring electrodes on the index and little fingers of both hands and instructed to respond quickly to stimuli. S-R compatibility was decided by position of the stimuli. EMG-RT and P 300 latency for compatible and incompatible conditions were analyzed.<BR>For ERP analysis, data of subjects who reacted faster to compatibility ware used. Neither P 300 latency nor amplitude differed significantly between compatibility and incompatibility in Tasks 1 and 2, but for Task 2, latency tended to be prolonged by incompatibility. Therefore, it is thought that S-R compatibility mainly has an effect on response processing. However, judging from the tendency of P 300 latency to be prolonged by incompatibility for Task 2, it was considered that there is the possibility that S-R compatibility influenced P 300 latency, even if using a somatosensory stimulus.