The Association Between EEG and Sleep Perception During MSLT Naps on Subjects With Excessive Daytime Sleepiness

Discrepancy between objective and subjective sleep, referred to as sleep misperception, is common in normal sleepers but is most evident in insomniacs (1). Sleep and wake stages are typically defined by electroencephalographic (EEG) patterns. EEG is only one neurophysiological aspect of the sleep state and researchers have tried to correlate other factors with EEG sleep/wake patterns. These factors have included subjective reports of sleep onset, sleep quality and sleep depth (2-9); auditory arousal thresholds (AAT) (4,5,10-12); event related potentials (13-16); and button pressing paradigms to indicate behavioral wakefulness (17-20). Polysomnographic (PSG) variables such as sleep stage percentages (4,8), sleep onset latency (SOL) (12,21), total sleep time (TST) (2,3,9,11), and EEG frequency analysis (15,22) have also been studied in relation to sleep perception. No single factor or combination of factors has unequivocally been found to relate EEG, behavioral and subjective indexes of sleep. For example, AAT does not reliably correlate with self-reports of sleep depth/quality taken either at the end of the sleep period or following awakenings from particular sleep stages (4,5,10-12). Secondly, even though AAT is usually greatest in The Association Between EEG and Sleep Perception During MSLT Naps on Subjects With Excessive Daytime Sleepiness