Can Motivation Increase Compensatory Effects of Alcohol Placebos on Cognitive Performance?

Recent research on alcohol-placebo manipulations has challenged the traditional notion that consumption of placebo beverages reliably results in decreased performance on a variety of tasks due to assumption of an intoxicated role. Instead, it appears that under certain circumstances participants may engage in compensatory behaviors in an adaptation to overcome the anticipated deleterious effects of alcohol intoxication and that this compensation can sometimes improve performance of those who receive placebos relative to simple no-alcohol control drinks. The current study sought to determine what effect motivation might have on the compensatory behavior of alcohol-placebo participants on a variety of cognitive tasks that have been shown to be negatively affected by alcohol intoxication. Seventy-two undergraduates (36 female) were administered an alcohol-placebo beverage or a non-alcoholic beverage whose content was accurately portrayed. Participants were randomly assigned to a no-motivation condition in which they were told that the cognitive tasks were exploratory in nature or a high-motivation condition in which they were given financial incentives for good performance, as well as informed that the tasks measure "intelligence" and "cognitive flexibility". After drinking, participants completed a variety of cognitive tasks including measures of processing speed, ability to inhibit prepotent responses, working memory, and divided attention. Results indicated that whereas increasing motivation only resulted in improved performance on one out of the five tasks included in this study, providing participants with placebo beverages led to increases in cognitive task performance on the three most cognitively demanding tasks. This pattern of results indicated that compensatory effects in placebo conditions are widespread and robust. One explanation for these compensatory effects is that they are driven by well-learned adaptations acquired through repeated experiences attempting to overcome deleterious effects of intoxication in critical cognitive domains. Further, it appears that the compensatory effects are to some extent automatic because if they were attributable to volitional effort moderated by obvious incentives, one would have expected improved performance in the High Motivation condition, but this was evident on only one task.