The effects of different attentional demands in the identification of emotional facial expressions in Alzheimer's disease.

Alzheimer's disease (AD) is characterized by the progressive impairment of mental and emotional functions, including the processing of emotional facial expression (EFE). Deficits in decoding EFE are relevant in social contexts in which information from 2 or more sources may be processed simultaneously. To assess the role of contextual stimuli on EFE processing in AD, we analyzed the ability of patients with AD and healthy elderly adults to identify EFE when simultaneously performing another task. Each of the 6 basic EFEs was presented to 15 patients with AD and 35 controls in a dual task paradigm that is in parallel with a visuospatial or a semantic task. Results show that the decoding of EFEs was impaired in patients with AD when they were simultaneously processing additional visuospatial information, yet not when they were performed in conjunction with a semantic task. These findings suggest that the capacity to interpret emotional states is impaired in AD.