Implicit reading in Chinese pure alexia.

A number of recent studies have shown that some patients with pure alexia display evidence of implicit access to lexical and semantic information about words that they cannot read explicitly. This phenomenon has not been investigated systematically in Chinese patients. We report here a case study of a Chinese patient who met the criteria for pure alexia and had lesions in the left occipitotemporal region and the splenium of the corpus callosum. His explicit and implicit reading was evaluated with various stimuli in a number of tasks. We found that despite his severe impairment in overt reading and the definition of any characters, his performance was well above chance in various implicit tasks. His accuracy with respect to lexical decisions was so high that his performance was almost normal. These findings provide unequivocal evidence for the existence of implicit reading in Chinese patients with pure alexia and further support the involvement of the right hemisphere.