Abstract
Skin potential level (SPL) on the palmar surface is known to reflect the level of arousal in some behavioral situations. In this paper, the relationship was ascertained in motorcar driving. SPL was measured for two subjects on ordinary roads under various experimental conditions. The results show that (1) in general, SPL was kept at high negative level, and (2) SPL reduced its electro-negativity when traffic conditions around the motorcar required less tension of the subject. In the case, the arousal level of the subject was thought to be low. From these results, it is concluded that SPL has sufficient sensitivity in detecting the decrease of the arousal level in motorcar driving. In the data processing of SPL, a range correction was effective in reducing the individual difference. The observed maximal reduction of electro-negativity was 80%, in which case the subject complained of serious drowsiness. SPL was kept at high negative level when the driver performed an additional light task or made conversation with an assistant driver.
