I move, therefore I am? It depends!

The representation of our body in the brain is not fixed, but rather it is constantly being updated by the information received from our senses. As a result of this, it is possible to experimentally trick human participants to feel that a virtual hand belongs to them, by manipulating the sensory information they receive (for example, touch and vision). However, the way our actions contribute to this effect is still debated.

Brugada-Ramentol and colleagues tested how the control over the movements of a virtual limb can enhance the sense of ownership, the feeling that the hand felt like it was their own. In an immersive Virtual Reality system, human participants either observed a realistic static virtual hand or controlled it while performing a task and report how much they felt is to be as their own. The researchers hypothesized that the feeling that the virtual hand was theirs could be affected by the appearance of the virtual hand and the control over the actions of the virtual hand. The team manipulated the appearance of the virtual hand so that it appeared detached from the body (i.e. it was missing the forearm).

They found that when participants controlled the virtual hand, the sense of ownership increased, but only in conditions where the hand were the appearance of the virtual hand was manipulated. This was not the case when the participants saw the hand continuous to the body. Additionally, they found that the actions needed to match the movements performed by the participant for this to happen. Overall, these results show us that action plays an important role in the representation of our body in the brain, but it depends on the appearance.

Currently, the team is also assessing the importance of the consequence of the action on the sense of ownership.