Disgust Propensity, Not Disgust Sensitivity, Shapes the Reactivity of a Subjective Disgust Circuit in Humans

Area of Science:

• Neuroscience
• Psychology

Background:

• Disgust is an adaptive defense mechanism, but individual differences in disgust propensity and sensitivity are significant.
• Previous research suggests these traits may differentially affect neural responses to disgust, but their exact roles remain unclear.

Purpose of the Study:

• To systematically investigate how disgust propensity and disgust sensitivity modulate neural responses to disgust stimuli using fMRI.
• To clarify the distinct roles of disgust propensity and sensitivity in shaping subjective disgust experiences.

Main Methods:

• A large-scale fMRI study with 142 participants.
• Utilized carefully selected and validated visual stimuli eliciting disgust.
• Employed whole-brain voxel-wise regression, mediation, and network-level analyses.

Main Results:

• Disgust propensity, but not sensitivity, was associated with differential neural activity in the insula, caudate, putamen, thalamus, hippocampus, and parahippocampal gyrus.
• Mediation analyses indicated that disgust propensity influences disgust experience through insula-striatal-hippocampal pathways.
• Findings suggest a partly dissociable neural pattern for the two disgust traits.

Conclusions:

• Disgust propensity and sensitivity have distinct associations with neural responses to disgust.
• Trait disgust significantly shapes subjective disgust experiences via specific neural pathways.
• Disgust propensity and associated neural systems may be targets for managing disgust-related disorders.