Hand cooling from illusion not linked to change in body ownership

An article in Acta Psychologica has a hot take on temperatures in hands that may, or may not, belong to you. The paper “No consistent cooling of the real hand in the rubber hand illusion” gives an example of the importance of distinguishing body ownership:

Consider a simple task such as walking towards another person –say, this huge big shot you noticed at a conference – and shaking hands… among this sea of moving limbs you will need to keep track of which ones are yours, so you can walk away again without making a complete fool out of yourself. To do so, your brain needs to know which parts of the world are “you” and which parts are not.

While it may seem clear to you that you own your own hand, psychologists can use the Rubber Hand Illusion (RHI)  to convince the brain that a rubber hand is your own hand. During the RHI, touches on the owned rubber hand can cause participants to feel the touch.

But what happens to the previously owned real hand? Older experiments suggested that when you disown your hand, the temperature of that hand drops slightly. Since many hands makes light work, this newer research was determined to replicate the experiments with as many owned, and not owned, hands as possible.

The researchers convinced 167 participants that the participants owned rubber hands. After extensive temperature measurements, they found that:

…although the presence of temperature changes of the hands in RHI experiments might be determined by various factors, an overall analysis of RHI  experiments in our lab in the last 5 years, covering five replications of the traditional RHI experiment and totaling 167 participants… suggests that hand temperature changes in the RHI are not causally related to changes in body ownership.