Acute Alcohol Consumption Reduces Uncertainty Choices.

Background and aims: Drinking alcohol results in clear effects on decision-making in humans. Alcohol intake impairs information processing and executive function. However, the potential effects of alcohol on human uncertainty decision-making remain unknown.

Design: Here we examined the pattern of uncertain decision-making and working memory upon 3 alcohol intake paradigms (a dose of 1.5 g/L of body water, 1.0 g/L body water, and placebo beverage), with a 1-month wash-out between the 3 measurements. Twenty participants (15 males, 5 females) were randomly assigned to different groups and received alcohol drinking programs in different orders. The breath alcohol concentration was assessed to quantify alcohol intake effects, and the cortical silent period using the transcranial magnetic stimulation technique was assessed as an index for cortical inhibition level. The choice under risk and ambiguity task and N-Back task were assessed.

Results: The results showed that after intake of the alcoholic beverage with a concentration is 1.5 g/L, participants reduced tolerance for risk and ambiguity, resulting in an altered pattern of uncertain decision-making. What is more, under the same condition, acute alcohol consumption (1.5 g/L) efficiently reduced accuracy and d-prime of 2- and 3-back tasks, indicating the impairment of executive function. Such changes correlate to prolonged cortical silent period. However, no significant differences were observed in the acute alcohol consumption at a concentration of 1.0 g/L.

Conclusions: The study shows that alcohol intake reduces uncertain choices, along with enhanced cortical GABABR functions, suggesting alcohol-induced changes in decision-making. These findings provide insights into alcohol's mechanisms and potential targets for intervention, like transcranial magnetic stimulation on the frontal cortex or GABABR antagonist.