Prior studies showed that problems in controlling inhibitions related to intrusive thoughts are tied to OCD. Brain imaging techniques were used to look at inhibitory control processes and the processing of fear and disgust, which are important in understanding contamination OCD. Specifically, the insula has been tied to disgust processing, and the amygdala has been tied to fear processing. However, the emotional factor behind controlling inhibitions and disgust in OCD needed more research.
This study by Dr. Gilbert and his team used functional magnetic resonance imaging (fMRI) to look for markers of emotional and inhibition processing in nine adults with contamination OCD and ten healthy controls. Participants completed a task used to measure response inhibition to disgust- and fear-evoking images while their brains were scanned using fMRI. The researchers found that the anterior insula was activated more in participants with OCD than controls when they had to inhibit responses to both disgusting and fear-evoking images, but the amygdala was not activated in either group. The results demonstrate the role of the insula in how contamination OCD works, which could serve to improve treatment.
*Berlin, H.A., Schulz, K.P., Zhang, S., Turetzky, R., Rosenthal, D., & Goodman, W. (2015). Neural correlates of emotional response inhibition in obsessive-compulsive disorder: A preliminary study. Psychiatry Research: Neuroimaging, 234, 259-264. doi:10.1016/j.pscychresns.2015.09.019