Objective: As shown in previous research, alcohol suppresses negative priming, an effect that normally occurs when subjects are required to respond to information that had been previously ignored. The present research examined the generality of this effect by testing the effect of alcohol on responses to positively primed stimuli that did not require responding to previously ignored information.
Method: Twenty-eight male social drinkers performed a color-naming reaction time task that measured both negative and positive priming effects. After a baseline test on the task, they received either 0.56 g/kg of alcohol or a placebo, and then performed the task twice.
Results: The results showed a differential effect of alcohol on negative and positive priming. Alcohol suppressed negative priming, but had no effect on the magnitude of positive priming.
Conclusions: Evidence for a selective effect of alcohol on negative, but not positive, priming suggests that the drug does not reduce negative priming by impairing memory of priming stimulus information. Rather, the findings provide further support for a specific impairment of an inhibitory process that normally serves to prevent interference from distracting, to be ignored, stimuli. Impairment of this process by alcohol could represent a basic cognitive mechanism by which the drug disrupts performance of laboratory tasks that require visual attention, such as divided attention and vigilance tasks.