Living musical instruments and inanimate body parts?

In the literature about category effects in semantic memory, body parts and musical instruments are often considered atypical, because in cases with a disproportionate impairment of living categories body parts are relatively spared. while musical instruments are often severely defective. In this st udy the performance of 57 subjects affected by diseases generally associate d with lexical-semantic impairment, for the most part Alzheimer's disease a nd other forms of cortical degeneration, but also herpetic encephalitis and traumatic brain damage are analyzed. The subjects were given a picture nam ing task tapping eight categories: three living categories (animals, fruits and vegetables) and three non-living categories (tools, furniture and vehi cles), plus body parts and musical instruments. On a preliminary analysis a t the group level, body parts were the least impaired category and musical instruments the most severely impaired, the six living and non-living categ ories being intermediate. However, these differences disappeared after cova riance for lexical frequency, name agreement and age of acquisition. The re lationship between Living categories, non-living categories, musical instru ments and body parts was investigated by means of a Lisrel model of Confirm atory Factor Analysis. Two latent variables related to living and non-livin g categories respectively were defined, and it was found that both body par ts and musical instruments were significantly related only with non-living categories. The results showed that the definition of the latent variable e xpressing the substrate of non-living categories was less satisfactory than that expressing the living categories. On this basis, the conclusions of t his study appear statistically definite but their psychological interpretat ion is less straightforward. (C) 2001 Elsevier Science Ltd. All rights rese rved.