Do alcohol effects on interoception shape expectancies and subjective effects? A registered report using the heart rate discrimination task

Aims: Alcohol acutely impacts interoceptive processes, which in turn affect the perception of alcohol effects and the development of alcohol expectancies. However, previous research is limited by the tools used to measure cardiac interoception and subjective alcohol effects. This registered report proposes a re-examination of previous findings using a state-of-the-art measure of interoceptive capacity, the heart rate discrimination task, and measurements of subjective alcohol effects across both ascending and descending limbs. Methods: In a double-blind, placebo-controlled experiment, n=37 participants were given 0.4g/kg of ethanol, and a baseline measure of alcohol expectancies was obtained. Changes in interoceptive capacity after beverage administration, along with measures of light-headedness, mood, and biphasic alcohol effects, were assessed over two sessions.Hypotheses: As a registered in this secondary data analysis, alcohol is expected to acutely impact different indices of interoceptive capacity, and those changes are hypothesized to correlate with subjective alcohol effects and expectancies. Analyses will be conducted and results reported upon in-principle acceptance of this manuscript.