title: Tactile-'visual' acuity of the tongue in early blind individuals.
abstract: This study compares the 'tactile-visual' acuity of the tongue for 15 early blind participants with that of 24 age-matched and sex-matched sighted controls. Snellen's tumbling E test was used to assess 'visual' acuity using the tongue display unit. The tongue display unit is a sensory substitution device that converts a visual stimulus grabbed by a camera into electro-tactile pulses delivered to the tongue via a grid made out of electrodes. No overall significant difference was found in thresholds between early blind (1/206) and sighted control (1/237) participants. We found, however, a larger proportion of early blind in the two highest visual acuity categories (1/150 and 1/90). These results extend earlier findings that it is possible to measure visual acuity in the blind individuals using the tongue. Moreover, our data demonstrate that a subgroup of early blind participants is more efficient than controls in conveying visual information through the tongue.
authors.affiliation: Chaire de Recherche Harland Sanders, Ecole d'Optométrie, Université de Montréal, Quebec, Canada.
authors.forename: Daniel-Robert
authors.initials: DR
authors.lastname: Chebat
authors.forename: Constant
authors.initials: C
authors.lastname: Rainville
authors.forename: Ron
authors.initials: R
authors.lastname: Kupers
authors.forename: Maurice
authors.initials: M
authors.lastname: Ptito
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D001766:Blindness / Q000503:physiopathology*; D004193:Discrimination Learning / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D006941:Hyperesthesia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity / Q000502:physiology; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D012682:Sensory Aids; D012683:Sensory Deprivation / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology; D014059:Tongue / Q000294:innervation / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*