Mapping acute alcohol effects on bodily sensations: a cross-dimensional approach to the interoceptive correlates of intoxication.

Background and aims:Interoceptive processes may underlie maladaptive patterns of alcohol use. Bodily sensations experienced during alcohol intoxication could therefore reveal distinct mechanistic components relevant for addiction theory and research. Here we apply a novel tools to examine how intoxication impacts somatic awareness using body maps and interoceptive psychophysics. Methods:In a double-blind, within-subjects, placebo-controlled study, participants (n=37) were administered 0.4g/kg of alcohol. We measured changes in bodily sensations during the ascending and descending limbs of the blood-alcohol curves using the emBODY tool. Additionally, we recorded biphasic measures of subjective alcohol effects, changes in heart rate, and assessed psychophysical measures of cardiac beliefs using the heart rate discrimination task.Results:Acute alcohol administration altered the topographical representation of bodily sensations, as reflected by strong feelings in the chest, limbs, and head. Such effects appeared as well in the placebo condition, albeit to a lesser extent. These subjective effects had physiological correlates, as indexed by modulation of heart rate and breath alcohol content. In the ascending limb, bodily sensations negatively correlated with subjective stimulation, and positively with sedation. Finally, intensity of bodily sensations correlated with the metacognitive sensitivity of cardiac beliefs, suggesting a cross-dimensional integration between bodily sensations and interoceptive awareness.Conclusions:These results support the utility of bodily mapping in the context of pharmacological studies, as the interoceptive components of alcohol intoxication could reveal a somatic basis for addictive behaviors. Future research should examine how individual differences in the impact of alcohol on bodily sensations could constitute a marker of vulnerability towards alcohol use disorder.