Concrete word dyslexia.

An experimental investigation of a single patient, CAV, with an acquired dyslexia in which there was a significant impairment in his ability to read concrete words compared with abstract words is reported. CAV's ability to identify single letters and non-words was very impaired. His comprehension of words he could not read was poor and semantic primary effects were demonstrated. His concrete word dyslexia was characterized by a lack of consistency and by a high incidence of visual errors. Both quantitative and qualitative aspects of this hitherto undescribed syndrome are in some respects similar to those described in patients with the complementary syndrome of relative impairment of abstract word reading. It is argued that this concrete word reading deficit provides a further example of category specificity in the organization of the semantic systems subserving reading.