Abstract
Rotten food, maggots, bodily waste-all elicit disgust in humans. Disgust promotes survival by encouraging avoidance of disease vectors1 but is also implicated in prejudice toward minority groups; avoidance of environmentally beneficial foods, such as insect protein; and maladaptive avoidance behavior in neuropsychiatric conditions.2-5 Unlike fear, pathological disgust is not improved substantially by exposure therapy clinically,6 nor in experimental work does behavioral avoidance of disgusting images habituate following prolonged exposure.7,8 Under normal physiological conditions, perception of disgusting stimuli disrupts myoelectrical rhythms in the stomach,9-13 inducing gastric dysrhythmias that correlate with neural signatures of disgust.11 However, the causal role of gastric rhythm in disgust avoidance is unknown. We manipulated gastric rhythm using domperidone, a peripheral dopamine D2/D3 antagonist and common anti-emetic, at a dose (10 mg) that acts to convert gastric dysrhythmias to normal rhythms.9 In a preregistered, randomized, double-blind, placebo-controlled crossover design in 25 healthy volunteers (aged 18-25), we measured the effects of domperidone on core disgust avoidance, using eye tracking to measure implicit (oculomotor) avoidance of disgusting images (feces) before and after an "exposure" intervention (monetary reinforcement for looking at disgusting images).7,8 We find that domperidone significantly reduces oculomotor disgust avoidance following incentivized exposure. This suggests that domperidone may weaken the "immunity" of disgust to habituation, putatively by reducing gastric dysrhythmias during incentivized engagement with disgusting stimuli. This indicates a causal role for disgust-related visceral changes in disgust avoidance, supporting the hypothesis that physiological homeostasis contributes to emotional experience.
| Original language | English |
|---|---|
| Pages (from-to) | 629-634.e3 |
| Journal | Current Biology |
| Volume | 31 |
| Issue number | 3 |
| Early online date | 24 Nov 2020 |
| DOIs | |
| Publication status | Published - 8 Feb 2021 |
Bibliographical note
Funding Information:The authors are grateful to Shivam Patel for randomization of order and to Victoria White for her support implementing the study. T.D., K.B., E.D., and C.L.N. are supported by the UK Medical Research Council (grant no. G101400 ). C.L.N. is supported by an AXA Research Fund Fellowship (grant no. G102329 ). T.D. and C.L.N. are supported by the National Institute for Health Research Cambridge Biomedical Research Centre .
Funding Information:
The authors are grateful to Shivam Patel for randomization of order and to Victoria White for her support implementing the study. T.D. K.B. E.D. and C.L.N. are supported by the UK Medical Research Council (grant no. G101400). C.L.N. is supported by an AXA Research Fund Fellowship (grant no. G102329). T.D. and C.L.N. are supported by the National Institute for Health Research Cambridge Biomedical Research Centre. Conceptualization, C.L.N.; Methodology, C.L.N. E.D. T.A. and T.D.; Investigation, C.L.N. E.D. and K.B.; Project Administration, C.L.N. and E.D.; Writing ? Original Draft, C.L.N. and E.D.; Software, E.D.; Formal Analysis, E.D.; Writing ? Review & Editing, T.A. K.B. and T.D.; Funding Acquisition, T.D.; Supervision, T.D. The authors declare no competing interests.
Publisher Copyright:
© 2020 The Author(s)