Dynamic Perceptual Maps - A Psychophysical Approach to Spatiotemporal Interactions and Plasticity in Body Perception

Tactile illusions like sensory saltation provide a tool to assess the spatiotemporal dynamics of perceptual representations of our body. Brain imaging has been used to analyze the topographical properties of central body representations, but it is unclear how cerebral topography relates to the perceptual domain, and temporal dynamics were not evaluated. Here we show, that psychophysical methods based on spatiotemporal 2D-stimulus arrays can be used to quantify the transformation rules mapping the physical (anatomical) space of the body surface (dynamic tactile maps) via cerebral space (somatosensory maps in SI/SII) into perceptual space. Characteristic spatio-temporal functions are used to parametrize the dynamics of the representational cascade. Combining this technique with brain imaging can be used for dynamic causal modelling of the intermediate steps of the cascade as well as to construct realistic virtual environments based on one´s own body as reference space