Self-recognition in senile dementia

Eighteen women with senile dementia of the Alzheimer type were observed in two situations of mirror-image stimulation, which were repeated after a 3-week interval. Six out of six subjects scoring 5 on the Global Deterioration Scale of Reisberg et al. reacted appropriately to an unfamiliar mark on their forehead when they observed it in the mirror, thus showing clear self-recognition. Fifty percent of the subjects at GDS 6 showed such evidence of self-recognition, and no subject at GDS 7 did so. In contrast, whereas 50% of GDS 5 subjects responded to a directly visible mark on the back of the hand, all GDS 6 subjects reacted to this mark. These results suggest that the capacity for self-recognition may start to be compromised by GDS stage 6, and that the eventual failure to show self-recognition in severe senile dementia cannot be dismissed in terms of a simple lack of motivation.