Effects of alcohol on speed and accuracy in choice reaction time and visual search

Thirty-six subjects were each tested in three sessions on separate days, in which they were given 0, 0.33 or 1.0 ml alcohol per kg body weight (the order of administration being counterbalanced across subjects). Performance on two tasks requiring both speed and accuracy was studied in all three sessions. The first was a four-choice serial reaction time task in which the subject had to press one of four keys in response to four stimuli (A, B, C and D) presented in a random order. The second was a visual search task requiring the cancellation of two targets (the digits '0' and '1') from a random sequence of letters. Compared to no alcohol, the small dose did not affect speed but improved accuracy in both tasks, while the large dose impaired speed in the first task and accuracy in the second. The results therefore demonstrate that the effects of alcohol on performance are dependent upon both the quantity ingested and the particular task required. © 1987.