“I feel your disgust and relief”: can the action understanding system (mirror neuron system) be recruited to induce disgust and relief from contamination vicariously, in individuals with obsessive–compulsive disorder symptoms?

ABSTRACT

Research has shown that brain regions mediating disgust (e.g., the insula) become activated when viewing others’ disgust, a response mediated, perhaps by the mirror neuron system or the Theory of Mind module. In a novel behavioral experiment, we explore vicarious disgust and relief, in individuals with obsessive–compulsive disorder (OCD) symptoms. Participants (N = 10) provided disgust ratings to self-contamination or watching the contamination of an experimenter; and to the experimenter washing his own hands after the subjects had been contaminated. To our surprise, we found that subjects experienced disgust from merely watching the experimenter contaminating himself. More intriguingly, after subjects had contaminated themselves, they obtained relief from merely watching the experimenter washing his own hands; even while recognizing the logical absurdity of this. The result is counterintuitive since neither the subjects nor anyone else would have predicted this. These preliminary findings – if confirmed in placebo-controlled studies – might pave the way toward novel therapeutic approaches for OCD.

KEYWORDS:

• Contamination aversion
• obsessive–compulsive disorder
• mirror neuron system
• vicarious disgust
• vicarious relief

Acknowledgments

We thank Divya Krishnakumar, research assistant at the Center for Brain and Cognition at UC San Diego, for her superb assistance with experimental design and data collection for this study. We also thank Herb Lurie, for ongoing stimulating discussions on mirror neurons and insights on the clinical utility and applications of the current findings.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Lately there has been a lively debate regarding the degree of autonomy and modular organization of the MNS, and the largely semantic issue has been raised as to whether it is the same as what psychologists have long called the perception-action understanding system. The significance of our experiments, however, would not depend in any way on which terminology one uses.

2. While a participant did not complete condition 3, his remaining data were not excluded from analyses.

3. Although participants reported statistically similar levels of disgust during “vicarious disgust” and “non-vicarious” disgust exposure (M = 8.8 vs. M = 9.1), it is likely that the low statistical power of the current study, was not able to detect any differences. The central finding, however, is that disgust was experienced vicariously.

Additional information

Funding

This work was supported by the Center for Brain and Cognition at UC San Diego.