Alcohol effects on visual attention, the impact of information processing

Abstract

This research examined the effect of a moderate dose of alcohol on covert orienting of visual attention to test the prediction that greater information processing requirements of the orienting cue would result in greater impairment of the reaction time (RT) to a target stimulus under alcohol. Thirty-six male social drinkers who were randomly assigned to either an alcohol (0.62 g/kg) or placebo group performed three tasks: 1) exogenous orienting, where a peripheral spatial cue reflexively draws attention to a predicted target location; 2) endogenous orienting, with a central numerical cue; 3) endogenous orienting, with the central cue requiring arithmetic to predict the target location. Valid, and invalid (i.e., incorrect) cues, and trials where no cue was presented occurred on a test of each task. The different information processing demands of the tasks were reflected by shorter RT on the exogenous task and longest RT on the endogenous arithmetic task. The groups performed the three tasks once before, and twice after placebo or alcohol. In accordance with the hypothesis, alcohol impaired (lengthened) RT on the two endogenous tasks, and did not affect the reflexive exogenous task (p>0.05). Results showed alcohol selectively impaired RT to valid trials on the endogenous tasks (p<0.001) and the intensity of impairment on the two tasks did not differ (p=0.917). The findings suggested that the amount of information processing involved in the tasks may be less important in determining the intensity of alcohol impairment than the mode of processing (reflexive vs controlled), or other functions, such as spatial working memory. Potential practical implications of the findings for accident prevention were discussed.