Neuroplasticity in the Adjustment to Blindness

Abstract

Loss of vision due to injury to the eyes results in deafferentation of very large areas of the human cortex and poses striking demands on other sensory systems to adjust to blindness in a society that heavily relies on vision. Blind subjects need to extract crucial spatial information from touch and hearing. To accomplish this, plastic trans-modal changes appear to take place by which a larger area of the sensorimotor cortex is devoted to the representation of the reading finger in Braille readers, and parts of the former visual cortex are recruited for the processing of tactile and auditory information. These findings provide evidence of trans-modal sensory plasticity in humans. Similar mechanisms might be involved in other forms of skill learning and recovery from lesions. Recent studies suggest the possibility that available neurophysiologic techniques might not only be used to reveal such plastic changes, but may also have a potential role in guiding the plastic changes, thus improving functional outcome.