On the mechanism underlying facial-affective agnosia in senile demented patients.

Two experiments were conducted in which senile demented patients were shown pictures of happy, sad, and angry faces, and tested for their ability to recognize these emotional expressions. Their affect recognition was obviously impaired, as they tended to respond to the line or feature characteristics of the faces, instead of the affective meaning that was suggested by the facial expressions. This impairment was somewhat overcome either by adding verbal cues which created an affective set, or by making feature detection irrelevant to the recognition process. It was shown that if the tendency to detect features is defeated, senile people can extract emotional meaning from facial stimuli. The data suggested that the mechanism underlying facial-affect agnosia is an impairment in the associative connections between the visual impression of facial expression and affective meaning.