Conveying perceptible virtual tactile maps with a minimalist sensory substitution device

Many sensory substitution interfaces for visually impaired subjects have been proposed, but very few are currently used, probably because of the lack of assessments from both sensory and cognitive standpoints. In this work we have assessed a minimalist sensory substitution device, as part of our DIGEYE system, able to elicit 3D cognitive maps from virtual tactile objects: first, we computed sensory thresholds allowing subjects to well discriminate height profiles with touch, then we assessed how two measures, one objective (Stimuli Rate) and one subjective (Perceived Levels of Difficulty), could be related to the complexity of different virtual objects. Trends indicate that our device is suitable within the psychophysical ranges, that both the rate at which tactile information is acquired and the perceived difficulty in processing this information seem to follow the complexity of explored virtual objects. This work is the base for further validations involving blind subjects.