Musical instrument naming impairments: the crucial exception to the living/nonliving dichotomy in category-specific agnosia.

In category-specific agnosia (CSA) patients typically have more trouble naming animals, fruits, and vegetables than tools, furniture, and articles of clothing. A crucial exception to this living vs nonliving rule involves the category of musical instruments. Patients with problems naming living objects often repeatedly fail to name musical instruments. In CSA it is crucial to equate living and nonliving object lists on object name frequency, complexity, and familiarity. The present study shows, however, that even the most rigorously controlled object lists can lead to erroneous conclusions if nonliving stimuli contain an overrepresentation of musical instruments. Naming capabilities of a herpes encephalitis patient were assessed using matched lists of living and nonliving objects and showed no indication of category-specific deficits. When exemplars were separated into biological objects, musical instruments and man-made artifacts, strong category-specificity emerged: artifact naming was flawless whereas musical instrument and biological object naming were both severely impaired. It is concluded that CSA is a veridical phenomenon but that our understanding of CSA is limited by adhering to the spurious living/nonliving distinction.