Auditory event-related potentials and psychological changes during sleep deprivation.

This study investigated the psychophysiological effects of sleep deprivation on auditory event-related potentials (AERPs) and their relationship with psychological parameters. Twenty-four subjects remained awake for 37 h under continuous surveillance. In the mornings and the evenings of 2 consecutive study days, AERPs were recorded and 4 self-rated scales (sleepiness, fatigue, anxiety, and mood) were quantified. The latencies of P300 and N200 were significantly prolonged (p < 0.001) and their amplitudes decreased (p < 0.05) as a consequence of sleep deprivation. However, the only significant change in N100 and P200 was an increase in the P200 amplitude (p < 0.05). The increase in the latencies of P300 and N200 were correlated with increased sleepiness (p < 0.05), and the increase in P200 amplitude was correlated with negative mood, anxiety, and fatigue (p < 0.05). Although the changes in P300 and N200 induced by sleep deprivation are due to sleepiness, which may slow cognitive processing and decrease the efficiency of mental processing, the increase in P200 may be related with increased anxiety, negative mood, and fatigue.