Summary: Why do people with alcohol use disorder often choose drinking over meaningful social connections? A new animal study pinpoints a specific brain region—the anterior insula—as a driver of that maladaptive choice.
Using rat models, researchers observed that activity in the anterior insula rises sharply just before a decision is made, biasing the brain toward alcohol instead of social reward. These findings clarify a neural mechanism that can distort decision-making in addiction and point toward more targeted interventions for people struggling with alcohol use disorder.
Key Facts
- Preference for alcohol: Rats trained to choose between alcohol and social interaction consistently preferred alcohol in the discrete-choice task.
- Anterior insula activation: The anterior insula—a brain area involved in internal state monitoring, planning, and decision-making—showed greater activity during alcohol-seeking than during social-seeking actions.
- Timing of the bias: The surge in anterior insula activity occurs during the cue period immediately before the animal commits to a choice, effectively nudging behavior toward alcohol.
- Relationship to decision speed: Mathematical modeling revealed that stronger anterior insula signals were associated with faster choices for alcohol once an alcohol preference was established.
- Clinical implication: The anterior insula appears to encode a decision bias favoring alcohol, making it a promising target for future therapies aimed at restoring healthier decision-making in people with alcohol use disorder.
Source: SfN
Background: Individuals with alcohol use disorder (AUD) commonly prioritize alcohol over healthier alternatives such as social interaction. The specific neural processes that drive this maladaptive preference are not fully understood.
In a study published in the Journal of Neuroscience, a team led by Nathan Marchant at Amsterdam UMC used male and female rats to examine how activity in the anterior insula contributes to choices between alcohol and social reward. Rats were trained to lever-press for either 20% ethanol or for a social reward in alternating sessions, and then placed in discrete-choice sessions where they selected one option or the other. Later, alcohol choices were punished to test flexibility of preference.
The animals developed a clear preference for alcohol over social reward during the unpunished choice sessions. Fiber photometry recordings targeted to the anterior insula showed that neural activity in this region increased during the cue period that preceded alcohol choices, and that this increase tracked the animals’ decision bias toward alcohol. When alcohol choices were punished and preference shifted away from alcohol, the relationship between anterior insula activity and decision bias was altered, indicating that the insula’s signal corresponds specifically to alcohol-seeking under the conditions where alcohol is preferred.
To dissect how this brain signal influences behavior, researchers applied Linear Ballistic Accumulator (LBA) modeling, which separates decision-making into component processes such as evidence accumulation and choice bias. The model outputs captured the observed behavior across training, choice, and punishment phases. Notably, the model-derived measure labeled “decision bias” matched variations in anterior insula activation: as the insula signal grew stronger for alcohol cues, the modeled bias toward alcohol increased and rats chose alcohol more quickly.
Taken together, the physiological recordings and computational analysis suggest that the anterior insula contributes to alcohol preference by encoding a bias in the evidence accumulation process—the internal weighing of options that leads to a choice. In other words, before a conscious decision is formed, the anterior insula can push the decision process toward alcohol, making alternative rewards less likely to be selected.
Lead author Nathan Marchant noted that this approach—combining neural recordings with formal decision models—allows researchers to break down decision-making into measurable variables. The same analytic framework could be adapted for human studies to determine whether similar anterior insula signals underlie maladaptive choices in people with AUD.
Key Questions Answered
Q: Does this mean some people’s brains are permanently “wired” to prefer alcohol over social connection?
A: Not necessarily permanently wired. The study shows that in states resembling addiction, the brain can develop a physical bias: anterior insula activity favors alcohol-related choices over social rewards. That bias can make healthier choices harder to select, but the experiments also showed that behavior can change when contingencies (like punishment) are introduced.
Q: Why is the anterior insula important?
A: The anterior insula integrates internal signals such as cravings and bodily states and helps prioritize actions. In the context of addiction, that integrative function appears to be commandeered to favor alcohol, effectively priming the decision process toward drinking before conscious deliberation occurs.
Q: Could this alcohol preference be reversed or “turned off”?
A: That is a central hope of this research. By pinpointing where and when the decision bias arises, scientists can explore targeted interventions—ranging from pharmacology to neuromodulation—that might dampen alcohol-related signals in the anterior insula and restore a healthier balance in decision-making.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The full journal paper was reviewed by the editorial team.
- Additional context was provided by staff writers.
About this addiction and neuroscience research news
Author: SfN Media
Source: SfN
Contact: SfN Media – SfN
Image: The image credit is to Neuroscience News.
Original Research: Closed access. “Anterior insula activity during alcohol and social reward self-administration and choice in male and female rats” by Yvar van Mourik, Dustin Schetters, Ilse Bassie, Mohamad El Samadi, Huibert D. Mansvelder, Taco J. De Vries and Nathan J. Marchant. Journal of Neuroscience. DOI: 10.1523/JNEUROSCI.1180-25.2026
Abstract
Anterior insula activity during alcohol and social reward self-administration and choice in male and female rats
Alcohol use disorder (AUD) involves a shift in behavior that elevates alcohol over healthier non-alcohol rewards, presenting major obstacles to treatment. Clarifying the neural mechanisms underlying this maladaptive preference is vital for developing effective interventions. Previous work showed that rats will choose alcohol over social reward in a discrete-choice paradigm.
In this study, researchers used fiber photometry to measure anterior insula cortex (aIC) activity during self-administration and choice, and applied Linear Ballistic Accumulator (LBA) modeling to parse decision processes. Male and female rats were transfected with the calcium indicator jGCaMP7f in aIC and trained to lever-press for social reward or 20% ethanol in alternating sessions, followed by choice sessions and a punishment phase for alcohol choices. Rats developed a preference for alcohol that reversed when alcohol choices were punished.
Model outputs described these behavioral changes, with a model-derived “decision bias” reflecting preference across phases. Photometry revealed that as alcohol preference emerged, increased aIC activity during the cue period preceding alcohol choices (relative to social choices) correlated significantly with decision bias toward alcohol. During punishment, the aIC activity bias no longer correlated with decision bias, despite behavioral shifts.
These results indicate that aIC activity is linked to alcohol reward and choice, and suggest that aIC contributes to alcohol preference by encoding a bias in the evidence accumulation process. This work highlights a specific role for anterior insula in the cognitive mechanisms of alcohol-seeking and identifies it as a potential target for therapeutic interventions.