Limited evidence that alcohol affects emotional face processing via interoceptive pathways, a registered report

Background: Our brain uses interoceptive signals from the body to shape how we perceive emotions in others; however, whether interoceptive signals can be manipulated to alter emotional perceptions is unknown. This registered report examined whether alcohol administration triggers physiological changes that alter interoceptive signals and manipulate emotional face processing. 

Methods: Participants (n=36) were administered an alcohol or placebo beverage. Cardiovascular physiology (Heartrate variability, HRD) was recorded before and after administration. Participants completed a behavioral task in which emotional faces were presented in synchrony with different phases of the cardiac cycle (i.e., systole/diastole) to index of how interoceptive signals amplify them. 

Hypotheses: We hypothesized that alcohol administration would disrupt the cardiac amplification of emotional face processing. We further explored whether this disruption depended on the nature and magnitude of changes in cardiovascular physiology after alcohol administration. 

Results: We observed no main effects or interactions between alcohol administration and emotional face processing. We found that HRV at baseline negatively correlated with the cardiac amplification of emotional faces. The extent to which alcohol impacted HRV negatively correlated with the cardiac amplification of angry faces. 

Conclusions: This registered report failed to validate the primary hypotheses but offers some evidence that the effects of alcohol on emotional face processing, if any, could be mediated via changes in basic physiological signals that are integrated via interoceptive mechanisms. Results are interpreted within the context of interoceptive inference and could feed novel perspectives for the interplay between physiological sensitivity and interoception in the development of drug-related behaviors.