Summary: Changes in the electrical rhythm of the stomach can prompt people to avert their gaze from images they find disgusting.
Source: University of Cambridge
Do wriggling maggots in spoiled food make you look away? Researchers at the University of Cambridge report that shifts in stomach rhythm help drive that instinctive response. The familiar expression “that makes my stomach turn” takes on a physiological meaning: when the stomach’s electrical pattern is disturbed, people are more likely to avoid looking at disgusting visual stimuli.
Disgust is an evolutionarily conserved emotion that steers us away from potential contaminants—rotten food, bodily waste and disease-carrying insects—protecting health and survival. However, for some people disgust becomes excessive or pathological, contributing to poor quality of life and resistance to standard treatments such as exposure therapy.
In a study published in Current Biology, scientists at the MRC Cognition and Brain Sciences Unit tested whether stabilizing gastric electrical rhythm changes how people view disgusting images. The drug used, domperidone, is a commonly prescribed anti-nausea medication that acts on peripheral dopamine receptors and can restore normal stomach myoelectric rhythms.
Domperidone stabilizes the coordinated electrical signals that guide stomach contractions and the movement of food through the digestive tract. Those signals can become irregular when someone is nauseous, hungry or full, and severe disruption is associated with nausea and vomiting. The team hypothesized that calming gastric dysrhythmias might reduce the tendency to avert gaze from disgusting images.
Twenty-five healthy volunteers aged 18–35 participated in a double-blind, randomized study. Participants received either a single 10 mg dose of domperidone or a placebo. Researchers recorded eye movements as volunteers viewed a set of images that mixed neutral items (for example, a scarf or buttons) and highly disgusting images such as feces.
Eye tracking took place before drug or placebo administration and again 30 minutes after taking the tablet. After this second viewing, the researchers introduced an incentive: participants received a small monetary reward (25 pence) for maintaining their gaze on a disgusting image for a sustained interval, accompanied by a brief auditory cue. Volunteers viewed the pictures again during this incentivized exposure and then completed a final non-incentivized viewing. At the start and end of the session participants also rated how disgusting they found each image.
Initially, domperidone did not produce a clear change in how long participants looked at disgusting images. As expected, both groups increased dwell time when offered payment to look. Crucially, during the final non-incentivized viewing—after the exposure with monetary reinforcement—participants who had received domperidone spent significantly more time looking at the disgusting images than those given placebo. On average, placebo participants looked at neutral images about 5.5 seconds longer than disgusting ones; that gap narrowed to roughly 2.5 seconds in the domperidone group.
Importantly, domperidone did not change subjective disgust ratings: participants still judged the images to be equally disgusting regardless of drug condition. The effect appeared specific to avoidance behavior measured via eye movements rather than to changes in reported disgust intensity.
“Previous work has shown that encountering a disgusting stimulus disrupts stomach electrical rhythms, which can make people feel sick and motivates avoidance,” said Dr Camilla Nord of the MRC Cognition and Brain Sciences Unit. “Our results indicate that stabilizing those rhythms reduces the tendency to avert gaze after exposure, supporting a causal role for gastric activity in disgust avoidance.”
Dr Edwin Dalmaijer, also at the MRC Unit, added: “We’ve found that looking at disgusting images does not readily habituate, which helps explain why exposure-based treatments for pathological disgust are often less effective than they are for fear. Our findings suggest domperidone may weaken that resistance when combined with engagement.”
Professor Tim Dalgleish noted that drug alone was not sufficient: “Calming stomach rhythms reduced avoidance, but overcoming disgust avoidance still required motivation or incentive. This combination could inform therapeutic approaches for pathological disgust, which occurs in various mental health conditions and can be disabling.”
Dr Nord highlighted why internal bodily signals matter: “When the brain constructs a representation of the world, it integrates external cues—like whether it’s light—with internal signals such as hunger or nausea. Our internal physiological state shapes perception, emotion and action. Just as heartbeat timing influences anxiety and learning, our study shows that stomach rhythm influences behavioral responses to disgust.”
Funding: This research was supported by the Medical Research Council, the AXA Research Fund and the National Institute for Health Research Cambridge Biomedical Research Centre.
About this neuroscience research news
Source: University of Cambridge
Contact: Craig Brierley – University of Cambridge
Image: Image is in the public domain
Original Research: Open access. “A Causal Role for Gastric Rhythm in Human Disgust Avoidance” by Camilla Nord et al., Current Biology
Abstract
A Causal Role for Gastric Rhythm in Human Disgust Avoidance
Highlights
- •Healthy volunteers received domperidone to normalize gastric rhythm or a placebo
- •The study measured how an exposure paradigm affected oculomotor disgust avoidance using eye tracking
- •Domperidone reduced gaze-based avoidance of disgusting images after incentivized exposure
- •Results support a causal role for gastric rhythm in driving disgust avoidance
Summary
Rotten food, maggots and bodily waste reliably trigger disgust in humans. Disgust encourages avoidance of disease vectors and can shape social attitudes and food choices; when excessive it contributes to maladaptive behavior in neuropsychiatric conditions. Unlike fear, pathological disgust often resists improvement through exposure, and behavioral avoidance of disgusting images typically does not habituate with prolonged viewing. In normal physiology, disgust-related perception disrupts stomach myoelectric rhythms, producing gastric dysrhythmias that correlate with neural markers of disgust. To test whether those visceral changes causally contribute to avoidance, the researchers used domperidone (10 mg) to convert gastric dysrhythmias toward normal rhythms in a preregistered, randomized, double-blind, placebo-controlled crossover study of healthy volunteers. Eye tracking captured implicit oculomotor avoidance of disgusting images (feces) before and after an exposure intervention that reinforced looking behavior with monetary rewards. Domperidone significantly reduced oculomotor disgust avoidance following incentivized exposure, suggesting that stabilizing gastric rhythm can weaken the resistance of disgust to habituation and supporting the idea that physiological homeostasis contributes to emotional experience.