Abstract
[Purpose] The aim of this study was to investigate the effect of divided attention on the first response of the somatosensory system using somatosensory evoked potentials (SEP). [Subjects and Methods] Twelve right-handed healthy subjects participated in this study. To evoke somatosensory responses, we used median nerve stimuli of the left or right side. The participants performed the mental arithmetic task of serial subtraction for the experimental condition, and did nothing for the control condition. The amplitudes and latencies of SEP components (N 20, P 25, N 33 and P 45) were measured. [Results] The latency of N 33 on left median nerve stimulation was significantly delayed by the mental arithmetic task, but not by right median nerve stimulation. [Conclusion] These findings suggest that a change in latency due to performance of mental arithmetic tasks inhibits activation of the right primary somatosensory area.
