Schematic representation of the sensory substitution device (SSD) used in the behavioral part of the experiment, that is, the training sessions. A head-mounted video camera (attached to black covered goggles) allows online translation of visual patterns into sounds that are transmitted to the subject through headphones (demonstrations of the sounds produced by a pixel or a bar moving on the artificial retina of the SSD are currently available at the Perception Website (http://www.perceptionweb.com/perc0899/arno.html)).