Effects of parietal lesions on visual matching: Implications for reading errors

Three groups of subjects, left and right parietal patients and neurologically intact controls, performed a visual matching task. Two strings of letters that were either identical or differed by one letter were presented centrally; subjects were asked to make a same/different judgement. Response time and error data indicated that both left and right parietal patients had difficulty detecting mismatches at the end of the string contralateral to the lesion. The implications of these findings for other visual tasks are particularly important for the left parietal patients, who often display significant reading disorders. The reading performance of an individual left parietal patient is presented and the possible contribution of subtle spatial attention deficits to reading errors is discussed.