Effect of moderate doses of alcohol on simple auditory reaction time in a vigilance setting.

An experiment was performed with 11 voluntary male subjects to test the effects of moderate doses of alcohol on simple auditory RT in a vigilance setting. Subjects were tested during a 30-min. session, during which signals were presented with an average intersignal interval of 3.75 sec. Subjects responded by pressing a microswitch held in the preferred hand. Analysis indicated that absolute means increased as a function of alcohol dose. With time-on-task alcohol produced a faster increase in RT and especially affected the longest RTs. Number of extreme long reactions (blockings) and mean duration of these reactions increased under alcohol and were directly related to time on task; alcohol produced a much faster increase in number of blockings with time on task. Results were discussed in terms of attentional processes and habituation theory. Some practical implications of the results were pointed out.