New Delhi: In 1998, researchers Matthew Botvinick and Jonathan Cohen of the University of Pittsburgh, PA, detailed an experiment that people would later refer to as the “rubber hand illusion” (RHI).
In the experiment, 10 people sat down, resting their left arm on a table. A screen hid each participant’s arm from view, and instead, they could see a life-sized rubber hand model.
The researchers placed the hand right in front of the person so that they could see it from the same angle as they would their own hand.
After asking each participant to fix their gaze on the rubber hand, the experimenters used two small paintbrushes to stroke the rubber hand and the participant’s actual hand at the same time.
After 10 minutes, the participants reported feeling the rubber hand as though it were their own.
Now, new research has used the RHI to help people with contamination-related OCD overcome their fears.
Exposure therapy encourages people with OCD to start touching potentially contaminating surfaces without washing their hands afterward.
However, says Jalal, “exposure therapy can be very stressful and so is not always effective or even feasible for many patients.”
This limitation is what made him and his colleagues want to explore other options, such as contaminating a fake hand instead.
The new research builds on previous RHI experiments that Jalal carried out together with fellow neuroscientist Vilayanur S. Ramachandran, who is a co-author of the new study.
In these previous studies, Jalal and Ramachandran contaminated the fake hand with fake feces, and the participants reported feeling disgusted in the same way that they would if they had used their own hand.