Sensory substitution devices (SSDs) aim to compensate for the loss of a sensory modality, typically vision, by converting information from the lost modality into stimuli in a remaining modality. “The vOICe” is a visual-to-auditory SSD which encodes images taken by a camera worn by the user into “soundscapes” such that experienced users can extract information about their surroundings. Here we investigated how much detail was resolvable during the early induction stages by testing the acuity of blindfolded sighted, naïve vOICe users. (...) Initial performance was well above chance. Participants who took the test twice as a form of minimal training showed a marked improvement on the second test. Acuity was slightly but not significantly impaired when participants wore a camera and judged letter orientations “live”. A positive correlation was found between participants' musical training and their acuity. The relationship between auditory expertise via musical training and the lack of a relationship with visual imagery, suggests that early use of a SSD draws primarily on the mechanisms of the sensory modality being used rather than the one being substituted. If vision is lost, audition represents the sensory channel of highest bandwidth of those remaining. The level of acuity found here, and the fact it was achieved with very little experience in sensory substitution by naïve users is promising. (shrink)

Visual information can be provided to blind users through sensory substitution devices that convert images into sound. Through extensive use to develop expertise, some blind users have reported visual experiences when using such a device. These blind expert users have also reported visual phenomenology to other sounds even when not using the device. The blind users acquired synthetic synaesthesia, with visual experience evoked by sounds only after gaining such expertise. Sensorimotor learning may facilitate and perhaps even be required to develop (...) expertise in the use of multimodal information. Furthermore, other areas where expertise is acquired in dividing attention amongst cross-modal information or integrating such information might also give rise to synthetic synaesthesia. (shrink)

Jeffery et al. suggest that three-dimensional environments are not represented according to their volumetric properties, but in a quasi-planar fashion. Here we take into consideration the role of visual experience and the use of technology for spatial learning to better understand the nature of the preference of horizontal over vertical spatial representation.