Electrophysiological and Bispectral indeks applications in REM sleep

The goal of this study is to scrutinize the changes in electrophysiological responses to simple and complex auditory stimulations in REM sleep using Bispectral index (BIS) system besides Rechtschaffen and Kales (R&K) scoring system. Twelve healthy subjects participated in the study. Recordings have been performed with 40 channel NuAmps [Electroencephalography (EEG), Electrooculography (EOG) and chin Electromyography (EMG)] recording system, auditory stimulation unit, video and BIS system. During sleep recordings, simple auditory stimulations (1500 Hz, 80 dB, 500 ms) and /ba/, /da/, /ga/, /ka/, /ta/, /pa/ (80dB) syllables were applied. Auditory evoked potentials (AEP) are analyzed in Cz electrode in REM sleep and in BIS 70-80 index. It has been shown that, some of the AEP components for complex stimulations had longer latency than simple stimulations (p<0.05). This finding was obtained both by R&K and BIS system. As a result, it is considered that simple- complex discrimination can be possible and also that complex stimulations are processed longer in REM sleep.