Simple reaction time event-related potentials: effects of alcohol and sleep deprivation

The effects of two levels of alcohol intoxication and 30 hr of sleep deprivation on visual event-related potential (ERP) waveforms concomitant to simple reaction time (RT) were examined in 54 normal male subjects. In a previous study, we reported that alcohol and sleep deprivation each increased RT. At a 0.05 breath alcohol concentration (BAC), the combined treatments produced an additive increase in RT, whereas at a 0.08 BAC the combined treatments produced no increase beyond that seen with each alone. In this study we present the ERP findings. Sleep deprivation alone increased the latency of a 150 msec negative component (N1) of the ERP. Alcohol increased the latency of a 250 msec negative component (N2), but only in the absence of sleep deprivation. Furthermore, this increased latency of N2 was correlated with RT measures. These results suggested that sleep deprivation slowed initial stimulus detection, whereas alcohol slowed later processing and response activation.