Thirty-three patients with probable Alzheimer's disease were examined on a standardized Color-to-Figure Matching Test (CFMT) for which patients select appropriate colors from a set of colored pencils to match outline pictures of common objects. Seven patients performing below the CFMT cut-off score were further assessed using other tests investigating the naming of these outline pictures of common objects as well as the naming and sorting of colors: One patient performed badly in all tests; three other patients could not be considered true cases of poor object-color retrieval because of their inability to name the objects; and in the remaining three patients with unimpaired object naming (although two of them had word-finding difficulties), their impaired object-color retrieval was found to dissociate from both color sorting and color naming. These findings support the notion of a separation of pure color processing from object-color knowledge. Thus for patients with Alzheimer's disease, there is evidence in a few instances for a dissociation between object-color retrieval and both color sorting and color naming.

Author notes

Following our usual practice, names of the authors are listed in alphabetical order; this does not imply a differential contribution to the paper.