Alcohol and Speed-Accuracy Tradeoff

Abstract

Performance on two auditory choice reaction time (RT) tasks was studied in a group of 12 subjects under the influence of graded doses of ethyl alcohol ranging from placebo to 1 g/kg body weight. Deadline procedures were employed in a side discrimination and a pitch discrimination task to permit the calculation of speed-accuracy tradeoff functions (accuracy versus RT). Accuracy declined as a function of dose, but alcohol did not significantly influence RT. Conversely, accuracy was not affected by task; but the pitch discrimination task required an average of 88 ms more time than the side task. Alcohol dose and task produced independent effects on the speed-accuracy tradeoff function. As dose increased, the slope of the tradeoff function declined; but slopes were equivalent for the two tasks. On the other hand, the x-intercept (where accuracy equals chance levels) was 90 ms greater for the pitch task than for the side task.