Revised and extended norms for a picture naming test sensitive to category dissociations.

This study presents revised and extended norms for a picture naming test [Laiacona et al. (Arch Neurol Psicol Psichiatr 54:209-248, 1993)], based on 80 Snodgrass and Vanderwart (J Exp Psychol Human Learn Mem 6:174-215, 1980) pictures, devised to detect a categorical dissociation in the naming of items between biological and man-made categories. This survey is based on data from 215 healthy Italian participants. Since males are more frequently reported to have a disproportionate impairment of biological categories, norms have also been separately calculated for males and females and for the two categories of man-made objects and biological entities. Besides providing new normative values based on the Equivalent Scores approach, this study reappraises the interaction between categorical dissociations and sex in the normal population, and discusses some methodological aspects concerning the use of statistical norms.