Sensory Substitution and Augmentation Workshop Report

This report highlights and explores five questions that arose from the workshop on sensory substitution and augmentation at the British Academy, March 26 th through 28th, 2013. 1. Does sensory substitution generate perceptual or cognitive states? Sensory substitution devices (SSDs) deliver information about the environment normally perceived through stimulation in one sensory modality (the " substituted modality "), through the production of stimulation in another sensory modality (the " substituting modality "). Most SSDs aim to substitute for vision, and consist of a video camera that feeds information into a conversion unit which then converts that information into auditory or tactile stimuli. Such devices are often used by the blind to assist in their autonomous navigation of the world. For instance, tactile-vision sensory substitution (TVSS) devices are SSDs that convert patterns of luminance picked up by a camera into isomorphically-organized tactile stimuli which are delivered to the skin through a matrix of solenoids usually mounted on the back, or a matrix of electrodes held on the tongue. There is no doubt that sensory substitution devices can convey information to subjects using them. But is the information conveyed to subjects via SSDs perceptual information? Following Ophelia Deroy and Malika Auvray, we may call the assumption implicit in current discourse that the use of SSDs is akin to the appropriation of a sensory modality, the perceptual assumption. As Deroy and Auvray put the perceptual assumption: