Journal of the International Neuropsychological Society

Research Articles

Emotional valence and semantic relatedness differentially influence false recognition in mild cognitive impairment, Alzheimer’s disease, and healthy elderly

KATJA BRUECKNERa1 c1 and STEFFEN MORITZa2

a1 Epilepsy Center Hamburg, Protestant Hospital Alsterdorf, Hamburg, Germany

a2 Department of Psychiatry & Psychotherapy, University Hospital Hamburg Eppendorf, Hamburg, Germany

Abstract

This study examined whether patients with mild cognitive impairment (MCI) who are at higher risk for later Alzheimer disease (AD) display deficits comparable to patients with diagnosed dementia. We assessed 27 patients with MCI, 36 patients with AD, and 20 healthy older adults with an emotional variant of the Deese–Roediger–McDermott-paradigm. Participants studied four lists that were semantically related to a nonpresented critical theme word. These theme words were either depression-related (i.e., loneliness) or delusion-related (betrayal) or had a positive (holidays) or neutral (window) valence. Despite a normal overall emotional memory and a normal corrected overall false recognition, patients with MCI, as predicted, produced as many false memories as patients with AD. On closer examination, both patient groups showed enhanced false memories to unrelated stimuli and a significant bias to falsely remember stimuli with a positive valence. We conclude that although patients with MCI are not distinguishable from healthy older adults in terms of their overall emotional recognition, positively valenced memories and more specifically false positive memories may represent the signature of a breakdown of emotional memory along the continuum between normal aging and AD. (JINS, 2009, 15, 268–276.)

(Received March 17 2008)

(Reviewed December 19 2008)

(Accepted December 22 2008)

Correspondence:

c1 Correspondence and reprint requests to: Katja Brueckner, Epilepsy Center Hamburg, Protestant Hospital Alsterdorf, Bodelschwinghstr. 24, 22337 Hamburg, Germany. E-mail: k.brueckner@eka.alsterdorf.de