Facial Expression Recognition Patterns in Mild and Moderate Alzheimer's Disease.

Facial expression recognition is one of the essential abilities for social cognition. We aimed to compare facial expression recognition among people with mild and moderate Alzheimer's disease (AD) and to identify which factors were associated with impairment according to disease severity. We included 52 participants with either mild or moderate AD. FACES includes four subtasks requiring matching expressions with picture stimuli (tasks 1 and 2), labelling emotions (task 3), and recognizing situations with evident emotional content (task 4). There were significant differences between groups in FACES global scores, task 2 and task 4. In the mild AD group, FACES global score was influenced by educational background and cognitive performance, task 1 was associated with comprehension and constructive praxis, task 2 was associated with cognitive flexibility, and task 3 was associated with word finding. In subtask 4, no significant associations were found after adjusting for level of cognitive decline. In the moderate AD group, the awareness of emotional state domain was associated with FACES global score, task 1 was associated with constructive praxis, task 3 was associated with neuropsychiatric symptoms, and task 4 was associated with the ability to recognize emotions through situations. No significant associations were found on task 2, after adjusting for level of cognitive decline. Our findings suggest emotional processing difficulties across AD stages. However, when participants needed to recognize the most preponderant emotion in a situation with evident emotional content, our results suggest that in both groups there was no influence of cognitive impairment.