Emotion processing in the visual and auditory domains by patients with Alzheimer's disease

The ability to process emotional information was assessed in 42 individuals: 23 patients with Alzheimer's disease (AD) and 19 healthy elderly controls. Four tasks assessed the ability to recognize emotion in audiotaped voices, in drawings of emotional situations, and in videotaped vignettes displaying emotions in facial expression, gestures, and body movements. Hemispheric dominance for processing facial expressions of emotions was also examined. There were no consistent group differences in the ability to process emotion presented via the auditory domain (i.e., nonverbal sounds, such as crying or shrieking, and speech prosody). Controls were, however, significantly better than the AD patients in identifying emotions depicted in drawings of emotional situations and in videotaped scenes displaying faces, gestures, and body movements. These differences were maintained after statistically adjusting for the visuospatial abilities of the participants. After a statistical adjustment for abstraction ability, some of the tasks continued to differentiate the groups (e.g., the emotional drawings task, the videotaped displays of faces), but others did not. These results confirm and extend previous results indicating that AD patients do not have a primary deficit in the processing of emotion. They suggest that the difficulties of the AD patients in perceiving emotion are secondary to the cognitive impairments associated with AD.