This paper presents some results of a Japanese experiment to investigate variations in the reaction time and the P300 component of the event-related brain potential (ERP), that are evident under the influence of alcohol. Four female and five male university students, aged from 21 to 27, participated in the experiment. Red, yellow and green lights were emitted as random stimuli, using light emission diodes (LEDs) controlled by a microcomputer. Reaction times under the influence of alcohol were measured, and the hypothesis was considered that any variability in reaction time was linked to the P300 component of ERPs, as measured by a polygraph. It was found that choice reaction time became unstable after the consumption of alcohol; the mean and standard deviation of the reaction time increased 30 minutes after drinking alcohol. The P300 of averaged ERPs suggested that stimulus evaluation time and response selection time both became unstable under the influence of alcohol. The instability of reaction times after consuming alcohol seems to be one reason why drunk drivers cause more accidents than drivers who have not been drinking.
Abstract