The virtual body schema project: How can body schema be objectively defined and measured?

The body schema can be loosely defined as the representation of the body in space, i.e., how you know you can reach the pint at the bar but not the bottle behind it; that you can fit through the door but not the cat-flap; that you must dive to kick a ball or duck to avoid a punch. Constructed from proprioceptive, somatosensory, visual, and auditory information, the body schema is like a bubble around the body, which includes bodily extensions such as clothes worn and tools wielded. When it goes awry, patients report a fascinating range of symptoms, for example amputees can experience pain originating in phantom hands. Given the importance of body schema to our everyday experience of the world, it is surprising just how little agreement there is between researchers (from philosophers, to neuroscientists, to roboticists) about the fundamentals: Namely, i) how can body schema be objectively defined, ii) how can body schema be objectively measured? The virtual body schema project aims to address these two challenges. Firstly, by constructing a psychological theory of body schema; through a series of experiments designed to explore the body schema as a representation in a space that is e.g., relative and/or absolute, topological and/or metric, innate and/or learnt? Secondly, by constructing a visualisation and virtual representation of a participant’s body schema, based on objective psychophysical measurements that may be rendered in realtime to a virtual avatar. An important aim will be to derive a set of principles for the design of body schema for better and safer artificial agents and robots. The project will involve developing novel virtual reality environments and motion capture technology.