A new virtual reality (VR) study has provided new insight into why some people may struggle with feeling connected to their own bodies, particularly in contexts involving depersonalisation or negative physical states.
In the experiment, researchers used a method called the full-body illusion (FBI), which involves making participants feel as though a virtual body is their own.
This illusion is usually triggered through external stimuli, such as seeing and feeling a virtual body being stroked while their real body is also stroked.
This is a “bottom-up” approach, where the brain responds to sensory inputs.
However, in this study, the researchers added a “top-down” factor by asking participants to identify with the virtual body while imagining it in a negative physical state—specifically, experiencing abdominal pain.
They then introduced a fear stimulus, a virtual knife stabbing into the virtual body.
Kazuki Yamamoto is author of the study.
The researcher said: “Using the full-body illusion in virtual reality—where people begin to feel a virtual body as their own— we investigated how interpreting the virtual body as one’s own body, while in a negative physical state, affects this illusion.
“This research can possibly relate to depersonalization, a condition where people struggle to feel their body as their own.”
The researchers measured participants’ skin conductance (a physical response to fear) to assess how strongly they felt the virtual body was their own.
The results showed that when participants imagined their virtual body experiencing pain, the FBI was weakened.
The higher the participants’ tendencies toward depersonalization, the less they felt the illusion of ownership over the virtual body.
This suggests that both the negative physical state and the individual’s psychological tendencies could inhibit the feeling of body ownership.
The study’s findings suggest that top-down factors—such as prior knowledge, expectations, and biases—can play a significant role in how we experience body ownership.
The researchers hypothesise that when people are asked to associate with a body in a negative state, like pain, it becomes harder for them to establish the feeling that the body belongs to them.
This research could improve understanding of conditions like depersonalization-derealization disorder, where individuals struggle to feel connected to their own bodies.
