A Causal Role for Gastric Rhythm in Human Disgust Avoidance

Area of Science:

• Neuroscience
• Gastroenterology
• Psychology

Background:

• Disgust elicits survival behaviors but can cause maladaptive avoidance in conditions like prejudice and neuropsychiatric disorders.
• Unlike fear, disgust-related avoidance is resistant to habituation through exposure therapy.
• Perception of disgust disrupts stomach rhythms, creating gastric dysrhythmias linked to neural disgust signals.

Purpose of the Study:

• To investigate the causal role of gastric rhythm in disgust avoidance.
• To determine if manipulating gastric rhythm with domperidone affects behavioral avoidance of disgusting stimuli.

Main Methods:

• A randomized, double-blind, placebo-controlled crossover study involving 25 healthy volunteers.
• Domperidone (10 mg) was used to normalize gastric rhythms, converting dysrhythmias to normal rhythms.
• Eye tracking measured oculomotor avoidance of disgusting images before and after an exposure intervention with monetary reinforcement.

Main Results:

• Domperidone significantly reduced oculomotor disgust avoidance after incentivized exposure.
• The drug appeared to weaken disgust's resistance to habituation.
• Gastric dysrhythmias were reduced during incentivized engagement with disgusting stimuli.

Conclusions:

• Visceral changes, specifically gastric rhythm, play a causal role in disgust avoidance.
• Physiological homeostasis may contribute to emotional experiences like disgust.
• Domperidone shows potential for weakening disgust habituation, offering insights into treating disgust-related disorders.