Virtual reality for body substitution

The UB researchers has conducted a range of experiments to demonstrate how virtual reality can be used to give the illusion that the whole body has changed.
The UB researchers has conducted a range of experiments to demonstrate how virtual reality can be used to give the illusion that the whole body has changed.
(18/02/2011)

A team from the University of Barcelona (Spain) led by Professor Mel Slater - a researcher for the Catalan Institution for Research and Advanced Studies (ICREA) based at the UBʼs Faculty of Psychology - has conducted a range of experiments to demonstrate how virtual reality can be used to give the illusion that the whole body has changed. The results will be presented during the 2011 Annual Meeting of the American Association for the Advancement of Science that takes place this weekend in Washington.

The UB researchers has conducted a range of experiments to demonstrate how virtual reality can be used to give the illusion that the whole body has changed.
The UB researchers has conducted a range of experiments to demonstrate how virtual reality can be used to give the illusion that the whole body has changed.
18/02/2011

A team from the University of Barcelona (Spain) led by Professor Mel Slater - a researcher for the Catalan Institution for Research and Advanced Studies (ICREA) based at the UBʼs Faculty of Psychology - has conducted a range of experiments to demonstrate how virtual reality can be used to give the illusion that the whole body has changed. The results will be presented during the 2011 Annual Meeting of the American Association for the Advancement of Science that takes place this weekend in Washington.

Researchers working at the Experimental Virtual Environments (EVENT) Lab for Neuroscience and Technology from the UB, which is directed by Professor Slater, have conducted an experiment to demonstrate how men can be tricked into thinking that their body has changed and been transformed into that of a woman. In another experiment the team has demonstrated how a similar technique can be used to induce the illusion of being fat. As Professor Slater explains, “Virtual reality has the power to transform our sensation not only of where we are but also of who we are”.

There are several applications of this research. One is scientific, since the results help scientists to understand how the brain maintains a representation of the body - how it distinguishes between what is and what is not part of ourselves. Another application is for rehabilitation, for example to help people overcome medical problems to do with body distortion illusions and associated pain. The technique can also be used for entertainment, enabling users to transform themselves as well as the scenario in which they are acting.
In the article “First Person Experience of Body Transfer in Virtual Reality” the UB scientists report how virtual reality was used to give men the illusion that their body had temporarily changed to that of a girl in a virtual environment. The 24 men who participated in the experiment put on a head-mounted display which placed them in a virtual room where they saw two virtual people - an older woman who was standing and stroking the arm of a seated young girl. After observing this scene for a few minutes the viewpoint of the men was transferred to that of the virtual girl. When they looked down at themselves they saw in virtual reality that their body had been substituted by the virtual body of the girl. If they looked in a virtual mirror they saw the reflection of themselves as the girlʼs body. When the woman stroked the shoulder of the girlʼs body they felt this on their own real body, establishing a synchrony between what they saw in the virtual reality and what they felt.
In a more recent study, 22 male participants entered into a virtual reality through a head-tracked head-mounted display. When they looked down they saw a different body - one that had a much larger stomach than their real one. They used a device to prod their own stomach; what they saw in the virtual reality was a stick tapping their fat stomach, but they felt their real stomach being prodded synchronously with what they saw. Participants therefore simultaneously saw the fat stomach being prodded while they felt their real stomach being prodded, giving them the illusion that their own stomach was fat. Evidence for the illusion was gathered through questionnaire responses and comparison of before and after self-estimates of stomach size.
Other contributors to the project include Maria V. Sanchez-Vives, an ICREA Research Professor at the August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Bernhard Spanlang, Senior Research Fellow at EVENT Lab; Jean-Marie Normand, Post-Doctoral Fellow at EVENT Lab; Elias Giannopoulos, Research Assistant at EVENT Lab; and Olaf Blanke, Director of the Laboratory of Cognitive Neuroscience (LNCO), Brain Mind Institute, Swiss Federal Institute of Technology.

Articles reference:

Slater M, Spanlang B, Sanchez-Vives MV, Blanke O (2010). First Person Experience of Body Transfer in Virtual Reality. PLoS ONE 5(5): e10564. doi:10.1371/journal.pone.0010564 

Normand J-M, Giannopoulos E, Spanlang B, Slater M (2011). Multisensory Stimulation Can Induce an Illusion of Larger Belly Size in Immersive Virtual Reality. PLoS ONE 6(1): e16128. doi:10.1371/journal.pone.0016128.