ABSTRACT
Sensitivity to shared critical features among shapes that must be discriminated, as well as to the semantic relatedness of labels assigned to them, are not exclusive to ELM. Other instances of such effects have been observed. Possibly the most relevant case is that of patient IL, who showed CSVA due to brain damage produced by herpes simplex encephalitis (Arguin et al., 1996a). Following his recovery, IL complained of major memory problems-initially claiming no recollection of his past life, a problem that partially resolved afterwards-as well as prosopagnosia and visual object agnosia. On matched sets of line drawings of biological and man-made objects from the Snodgrass and Vanderwart (1980) set, he made 65% errors on biological items but only 20% with man-made items. Like most other CSVA cases, IL’s visual perceptual encoding was intact but he showed major difficulties in accessing stored structural descriptions of biological objects, both from vision (46% errors with animals and 48% errors with fruit and vegetables in the object decision task) and from verbal questions (45% errors on two-alternative forced-choice questions). His performance in these tasks was substantially better with man-made objects (28% errors on object decisions; 10% on verbal questions). His semantic memory appeared relatively spared and his performance on verbal questions probing non-sensory knowledge did not vary as a function of whether they concerned biological or non-biological objects (15% errors in both conditions).
