Habituation of Somatosensory Event-Related Potentials in Subthreshold Rhythmic (1 Hz) Electrocutaneous Stimulation of the Arm during the Slow-Wave Stage of Daytime Sleep

Abstract

Previous studies have shown that low-frequency subthreshold electrocutaneous stimulation of the arm during deep slow-wave sleep in humans improves sleep quality. The main cognitive processes are known to operate during sleep, and use of event-related potentials is the main method for analysis of these processes. The aims of the present work were to study the characteristics of somatosensory event-related potentials (sERP) on rhythmic (1 Hz) subthreshold electrocutaneous volley stimulation of the arm during the slow-wave stage of daytime sleep and to evaluate the potential for habituation of sERP to rhythmic stimulation during sleep. Subthreshold stimulation during sleep produced somatosensory event-related potentials (ERP) (group mean, n = 16) in which three long-latency components could be identifi ed, which were more marked in the frontal lead of the contralateral hemisphere. Comparison of sERP averaged from the beginning and end of the volley of stimuli (30 stimuli) demonstrated signifi cant decreases in the amplitudes of all sERP components by the end of the volley. It is suggested that the decrease in sERP amplitude in slow-wave sleep is due to the simplest form of stimulus-dependent nonassociative learning - habituation.