Acquisition of affective dispositions in dementia patients

In this study, we investigated the acquisition of affective dispositions towards neutral faces in patients with Alzheimer's disease and mixed dementia. Participants viewed four affectively neutral male faces from the International Affective Picture System. Biographical information about the depicted persons was presented, which described them in terms of positive or negative traits varying in intensity. Participants were asked to rate the pictures with respect to emotional valence, arousal, and preference prior to and after the presentation of the biographical information. Following a retention interval of 180 min, pictures were rated again and the biographical information was presented once more. Final ratings were obtained after another interval of 1300 min. As expected, healthy control participants identified the faces and recalled parts of the information in the delayed recall test. They showed pronounced changes in affective ratings. Patients did not recognize the faces in a recognition test after the retention intervals, but valence, arousal, and preference ratings were systematically altered by the affective content of biographies. The results suggest that acquisition and maintenance of implicit affective dispositions are preserved in dementia even when explicit memory is impaired.