Hamilton et al. (2000)
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'''Introduction''''' | '''Introduction''''' | ||
| + | Recent findings using functional imaging and neurophysiologic studies in early blind subjects have suggested that activation of the occipital cortex is associated with the reading of Braille. The study involves a woman who was blind from birth who sustained bilateral occipital damage following an ischemic stroke. Prior to the stroke, the women was an exceptional Braille reader and worked for the national radio station for blind people in Spain. After the stroke occurred, she was no longer able to read Braille but her somatosensory perception appeared to be otherwise functioning normally. This case study adds credence to the growing amounts of evidence for the recruitment of striate and prestriate cortex for Braille reading in early blind subjects. Studies have shown that an increase in regional cerebral blood flow in the striate and prestriate cortex in congenitally and early blind subjects during tactile (touch) tasks, whereas normally sighted individuals showed decreased levels of regional cerebral blood flow. Studies have also shown that when repetitive transcranial magnetic stimulation is used to transiently disrupt the function of the occipital cortex, interference occurs with tactile reading of Braille in early blind subjects but not in sighted control subjects. | ||
Revision as of 10:01, 28 April 2008
Alexia for Braille following bilateral occipital stroke in an early blind woman (Hamilton et al. 2000) Tom Makin
Introduction Recent findings using functional imaging and neurophysiologic studies in early blind subjects have suggested that activation of the occipital cortex is associated with the reading of Braille. The study involves a woman who was blind from birth who sustained bilateral occipital damage following an ischemic stroke. Prior to the stroke, the women was an exceptional Braille reader and worked for the national radio station for blind people in Spain. After the stroke occurred, she was no longer able to read Braille but her somatosensory perception appeared to be otherwise functioning normally. This case study adds credence to the growing amounts of evidence for the recruitment of striate and prestriate cortex for Braille reading in early blind subjects. Studies have shown that an increase in regional cerebral blood flow in the striate and prestriate cortex in congenitally and early blind subjects during tactile (touch) tasks, whereas normally sighted individuals showed decreased levels of regional cerebral blood flow. Studies have also shown that when repetitive transcranial magnetic stimulation is used to transiently disrupt the function of the occipital cortex, interference occurs with tactile reading of Braille in early blind subjects but not in sighted control subjects.
