Scientists map how alcohol changes bodily sensations

A new study published in the Journal of Psychopharmacology offers insight into how alcohol changes our internal bodily experience — and why that might matter for understanding addiction. People who felt less bodily sensation tended to report greater stimulation and less sedation from alcohol — patterns associated with elevated risk for alcohol use disorder.

The study aimed to explore how alcohol affects interoception, the ability to sense internal bodily signals like heartbeats or feelings of warmth. Prior research has shown that alcohol alters heart rate and other physiological functions, and that people’s sensitivity to these changes may play a role in how alcohol feels and whether they continue drinking. However, most research has focused on cognitive effects or retrospective reports, not on the actual lived, bodily experience of intoxication as it unfolds in real time.

“We have known for a long time that people differ in the way they respond to alcohol effects, and that this differential responsiveness can be a risk marker for future addiction problems,” said study author Mateo Leganes-Fonteneau, an FNRS Chargé de Recherche at UCLouvain and Marie Curie Research Fellow at the University of Amsterdam.

“This has usually been studied by looking at subjective cognitive responses, using questionnaires, or observing basic physiological processes. However, we now know that our sensitivity to bodily states and the way we perceive our bodies plays a key role in shaping our behavior and motivation — but that part of the addiction puzzle is still understudied. With this research I wanted to show that we can measure the subjective bodily sensations associated with alcohol intoxication.”

To investigate this, the researchers recruited 37 adult social drinkers with no history of psychiatric disorders or substance use treatment. Participants completed two lab sessions in a double-blind, placebo-controlled design. On one occasion, they were given a moderate dose of alcohol (0.4 grams per kilogram of body weight, mixed with tonic water and bitters). On the other, they received a placebo beverage with identical taste and smell cues. The order of sessions was randomized.

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Throughout each session, participants were repeatedly asked to map where they felt bodily sensations using a digital tool called emBODY. This interactive tool allowed them to indicate, on a digital human figure, where they felt activation (such as tingling or warmth) and deactivation (such as numbness or heaviness). These maps were collected at several time points corresponding to the rising and falling phases of their blood alcohol levels.

In addition, participants filled out questionnaires assessing how sedated or stimulated they felt and completed a task designed to assess cardiac interoception. This task involved listening to their heartbeat and deciding whether a series of tones matched it in speed. Participants also rated their confidence in their decisions, which allowed researchers to assess both accuracy and metacognitive insight into their own interoceptive abilities.

The bodily maps revealed clear differences between the alcohol and placebo conditions. During the ascending phase of intoxication, when blood alcohol levels were rising, participants in the alcohol condition reported intense activation in the chest and head, as well as in the arms. As intoxication wore off during the descending phase, those sensations became more diffuse, with some deactivation (numbness) appearing in the limbs. These patterns were not observed in the placebo condition, which showed weaker and less widespread bodily sensations overall.

Importantly, the researchers found that the strength of bodily sensations was linked to actual physiological changes. During the ascending phase, increases in heart rate predicted greater reported bodily sensation in the alcohol condition, but not in the placebo group. During the descending phase, breath alcohol levels were similarly associated with stronger bodily sensations.

The way people felt their bodies during intoxication also predicted how they reported feeling mentally. Participants who experienced more bodily sensation tended to report greater sedation and less stimulation. This was especially true during the rising phase of intoxication, when alcohol typically produces its most energizing effects. People who reported fewer bodily sensations, on the other hand, reported feeling more stimulated and less sedated — suggesting a disconnect between their body’s response and their subjective awareness.

This pattern is noteworthy because earlier studies have shown that people who experience more stimulation and less sedation from alcohol tend to be at higher risk for problematic drinking. These individuals may find alcohol more rewarding and are more likely to seek out its stimulating effects, even as tolerance develops. The new findings suggest that reduced bodily sensation during intoxication may be another factor contributing to this risk, by making alcohol feel more pleasurable and less impairing.

The researchers also found that bodily sensations were related to how well participants could judge their heartbeats. During the descending limb of intoxication, those who reported more bodily sensation showed greater metacognitive sensitivity — meaning they had better insight into how accurate their heartbeat judgments were. This suggests that bodily sensations and interoceptive awareness are not separate systems but may be tightly linked during intoxication.

“People experience a range of bodily sensations when they are intoxicated, and there is inter-individual variability in the intensity of these sensations,” Leganes-Fonteneau told PsyPost. “Depending on how strong those sensations are, they will feel more or less intoxicated. We use our bodily sensations to build the conscious experience of intoxication. These bodily sensations partly reflect the effects of alcohol on physiological states, such as heart rate or breath alcohol content. Bodily sensations act as a window to the conscious perception of internal changes.”

Interestingly, the placebo condition also produced bodily sensations, especially during the early stages of the session. Participants reported some activation in the chest and head even when they had not consumed alcohol, and these sensations were associated with feelings of sedation. The researchers believe this reflects the power of expectancy and conditioning: repeated experiences of drinking alcohol may train the brain to anticipate bodily changes, even when the beverage contains no alcohol. These effects faded over time as the absence of real alcohol became more apparent.

“People experience bodily sensations when we give them a placebo, and these sensations are similar to those of alcohol,” Leganes-Fonteneau said. “This is important for understanding placebo effects, as they not only generate subjective mental states but also bodily sensations that have no underlying physiological change.”

By combining bodily mapping with physiological and psychological measures, the study provides a comprehensive picture of how alcohol affects the body from the inside out. It also supports the idea that bodily sensation is not just a passive side effect of intoxication but an active part of how people experience — and perhaps become vulnerable to — alcohol’s effects.

But as with all research, there are limitations to consider. First, it was based on a relatively small sample, which limited the ability to detect more nuanced effects, such as sex differences in bodily sensation. Another limitation is that the bodily mapping data were averaged across participants and time points, which may mask individual differences in how intoxication is felt. For example, some people may feel stimulation in their head while others feel sedation in their chest or limbs. A larger study could explore these differences more precisely and link them to personality traits, drinking history, or risk for addiction.

“We link these bodily sensations to subjective feelings of intoxication in a way that appears to map onto risk markers for alcohol misuse: those experiencing less bodily sensations would be at higher risk,” Leganes-Fonteneau said. “However, we still do not have cross-sectional (between groups) or longitudinal evidence that (in)sensitivity to bodily sensations of intoxication can predict alcohol misuse.”

“This is a study conducted in the laboratory, where participants sit by themselves and don’t have much to do, so they end up being able to reflect more directly on their bodily sensations. It is not clear how these bodily sensations would emerge in a real-world setting, where more exteroceptive and social information can distract them. At the same time, this insensitivity to bodily signals might be even more critical when there’s competing information, explaining why some people end up drinking too much without even realizing.”

Despite these caveats, the research marks an important step forward in understanding how bodily sensations contribute to the experience of alcohol intoxication. It suggests that people who are less tuned into their internal states may be more vulnerable to alcohol misuse — not because they lack self-control, but because they do not fully register the body’s warning signals. The researchers are currently working on follow-up studies exploring how bodily sensations relate to craving and hangovers, and how these signals can be tracked in everyday life using smartphone-based assessments.

“This work is more than anything a blueprint for how bodily sensations can be measured in applied addiction research and other mental disorders,” Leganes-Fonteneau explained. “We have produced additional work on the bodily sensations of alcohol craving and hangover and are working on integrating bodily sensations within ecological momentary assessment. This can in the future help us target bodily sensations in therapeutic settings.”

The study, “Mapping acute alcohol effects on bodily sensations: A cross-dimensional interoceptive approach,” was authored by Mateo Leganes-Fonteneau, Olivier Desmedt, Micah G. Allen, Reinout W. Wiers, and Pierre Maurage.