A VERBAL-SEMANTIC CATEGORY-SPECIFIC RECOGNITION IMPAIRMENT

The paper reports a patient with a category-specific recognition deficit following herpes simplex encephalitis infection. The patient, SB, has greater difficulty identifying animals and foodstuffs than inanimate objects. We show that for the impaired categories, SB has intact structural knowledge when accessed visually. However, she was poor at retrieving this knowledge from other input modalities, and she had impaired verbal-semantic knowledge concerning the affected categories. She also showed item-specific consistency across time and modalities. SB's deficit is attributed to a loss of verbal-semantic knowledge. A contrast is drawn between SB and other patients in the literature, and it is suggested that category-specific problems can be linked to a number of different functional impairments. Problems emerge according to the similarity between items at a particular processing level, and to the use of cross-modality associations in differentiating within object classes.