Abstract
The skin potential level (SPL) and skin potential response (SPR) on the palmar surface of the finger and on the dorsal hand were studied on 15 male students during normal sleep.
The SPL on the finger, which was always negative during waking, was found to be closely correlated with the stages of sleep, the grade of decrease in negativity of the SPL reflecting the depth of sleep. This was not observed for the dorsal hand. Therefore the, finger SPL is a significant indicator of the depth of sleep as well as of the awake-sleep differentiation. The SPL regional differences were also recognized.
SPR rates for both sites were found to be significantly correlated with EEG phases during sleep, with maximal rate during slow wave sleep and a relative decrease during para-sleep. The SPR rate on dorsal hand was higher than that on the finger. For the dorsal hand positive SPR occurred, while negative SPR was seen exclusively on the finger. The amplitude of SPR seems to have no correlation with any of the sleep variables.
