Effect of alcohol on the speed of shifting endogenous and exogenous attention

The study aimed to investigate to what extent acute moderate doses of alcohol affect the speed of endogenous versus exogenous attentional shift times. Subjects viewed an array of 10 moving clocks and reported the time a clock indicated when cued. Target clocks were indicated by peripheral or central cues, including conditions of pre-cuing. This allowed assessing shift times when attention was pre-allocated, when peripheral cues triggered exogenous attention shifts, and when central cues triggered endogenous attention shifts. Each subject participated in 2 sessions (alcohol/placebo), whereby the order of drug intake was counterbalanced across subjects, and subjects were blinded to conditions. Confirming previous results, we show that pre-cuing resulted in the fastest shift times, followed by exogenous cuing, with endogenous attentional shifts being slowest. Alcohol increased attentional shift times across all 3 conditions compared to placebo. Thus, the detrimental effects of alcohol on attentional shift times did not depend on the type of attention probed.