A CATEGORY-SPECIFIC NAMING IMPAIRMENT AFTER TEMPORAL LOBECTOMY

Unilateral temporal lobectomy patients and normal control subjects wer e tested in a speeded naming task with pictures of living and nonlivin g things that were equated for name frequency, familiarity, and visual complexity. Although right temporal lobectomy patients and normal sub jects performed equally well with the living relative to nonliving thi ngs, left temporal lobectomy patients were disproportionately impaired at naming nonliving things. This result has several implications: Fir st, it supports the existence of category-specific naming impairments. In particular, it undermines the proposal that living-nonliving disso ciations are artifactual, resulting from the greater difficulty of liv ing things. Second, it demonstrates an asymmetry in the neural represe ntation of nonliving things, in favor of the left hemisphere. Third, i t casts doubt on the hypothesis that the anterior temporal cortices ar e convergence zones that are particularly necessary for the naming of living things.