Para-sleep and skin action potentials

Abstract

The skin potential level (SPL) and the skin potential response (SPR) during normal sleep were recorded on 14 male students. In order to investigate the patterns of SPL and SPR before, during, and after para-sleep, the recordings were taken from 20min before the onset of para-sleep to 20min after the offset of para-sleep.The findings in the present study were as follows:1. The SPLs were found to shift sharply toward a negatively lower level about 8min before the onset of para-sleep. The SPL gradients just before para-sleep showed significant difference from those of all night which were found to decrease in negativity gradually with the course of sleep (Fig. 2, Table 1).2. The SPR rates were found to decrease rapidly prior to the onset of para-sleep and they were positively correlated with SPLs. This diminution of SPRs could be clearly observed by visual inspection (Figs. 2 & 3, Table 2).3. These distinctive phenomena of SPL and SPR that preceded the para-sleep will be a useful indicator to tell the para-sleep in advance.4. The bursts of large amplitude SPRs were observed during para-sleep on more than half of the subjects. Of those SPR-bursts, there were two types of response pattern recognized, one like a mountain-chain and the other like a stairway (Fig. 3).5. It has been emphasized that changes of skin potential activities are synchronous with changes of sleep stage. Our data suggest that the synchronous changes are lost in the period of pre and post para-sleep.Finally, inhibitory mechanisms of skin potential activities were discussed based on the data.