An FMRI Study On The Language Function Of The Blind’s Visual Cortex Under The Task Of Sentence Production

The functional change of visual cortex after visual deprivation is a hot issue in linguistic research, it is doubted that whether language processing is covered by visual cortex. The researches on neuroscience confirm that the blinds’ visual cortex is activated when process non-visual information, including Braille reading, verb generation and language comprehension task. There are researches convincing visual cortex processing from the perspective of language comprehension, but few proved from the aspect of overt language production.This essay studies the activation of the blind of the congenitally blinds who become blind in their later life, and the normal people via f MRI, with the focus on the disparity in language area, auditory area and visual cortex of each group during language production. It is discovered that the occipital lobe’s motivation of congenitally blinds is more intensive, and no differences are detected between acquired blinds and normal people, which means that the visual cortex of congenitally blinds have ability to process language information, and acquired blinds who have different visual deprivation time cause no activation in visual cortex.Meanwhile, the intensive motivation of the left part of occipital lobe indicates that different parts of occipital lobe have different cognitive functions in congenitally blinds. The activation of auditory cortex in congenital blinds is weaker than acquired blinds and normal people; the reason is that auditory cortex has plasticity after visual deprivation. According to the motivation of language areas in frontal lobe of all subjects, we argue that the frontal lobe is less affected because of the visual deprivation.The visual cortex which serviced for visual information should have been changed into process language information after being congenitally blind. Traditional language evolution argues that there has a specific brain region responsible for language processing. But this study found that the primary processing functional area still have the ability to process language information, and the congenitally blinds’ visual cortex may develop into another language processing center.