Engineers and computer experts continue to strive for new innovations to improve the quality of life for the blind. But a new research study suggests that Braille, the first great innovation for the blind may offer more in stimulating the visual cortex that any technology incorporating only audio signals.
Previous studies have previously established a physiological correlation among blind people using Braille. This relationship was verified using functional magnetic resonance imaging (fMRI), positron emission tomography (PET) and transcranial magnetic stimulation (TMS). These studies established that visual cortex, key to processing visual signals, plays a functional role enabling the blind perform Braille reading.
Controversy persists, however, concerning differences in the engagement of primary visual cortex between persons who become blind early in life versus those who acquire blindness later (e.g., before age three vs. after age 12). The differing results with early versus late onset blindness raise questions regarding the period of susceptibility for cross-modal reorganization. A previous fMRI study of verb generation for Braille nouns revealed anatomically distinct activation foci corresponding to V1, V2, V3, VP, and LO in both early blind and late blind subjects. This result, if compared to vision in sighted subjects, suggests a distributed network of specialized functional areas. However, assignment of specific functionality remains unclear.