| Abstract: | Skin potential level (SPL) on the palmar surface reduces its electro-negativity at the early stage of sleep and recovers it on waking up. This phenomenon suggests a close relationship between SPL and arousal change. The relationship and its applicability were studied by two experiments in which a vigilance task was imposed on subjects. In the first experiment the relation between changes in SPL and decrement of arousal level was examined. The results showed that electro-negativity in SPL reduced corresponding to the decrease of arousal level measured by task performance. On treatment of SPL, range correction was effective in reducing the individual difference. In the second experiment the above results were applied to designing a means to control the level of arousal and to finding the possibility of keeping a high level of arousal during the vigilance task. In the experiment a bell sound was released to arouse subjects when their SPL reached a pre-set threshold level. The decrement of arousal level which would cause behavioural errors was avoided by choosing the threshold level within a suitable range. This technique may be applicable to a doze alarm system for motor-vehicle drivers, aeroplane pilots, etc. |
