Now you make false memories; now you do not: the order of presentation of words in DRM lists influences the production of the critical lure in Alzheimer's disease

DRM Paradigm: Evidence that Alzheimer's Patients Think of the Critical Lure as Often as Healthy Older Participants

BACKGROUND

Up to now, in the Deese-Roediger-McDermott (DRM) paradigm, the lower production of false memories in Alzheimer's disease has been explained in terms of non-activation of the critical lure.

OBJECTIVES

The aim of this study was to examine the critical lure activation process from items of DRM lists in Alzheimer's patients, using a free association task.

METHOD

Twenty-six young adults, 25 older adults, and 17 Alzheimer's patients performed a free association task with DRM words.

RESULTS

Analyses indicated that Alzheimer's patients produced as many critical lures in the free association task as healthy older participants, but significantly fewer than younger participants.

CONCLUSION

Our results suggest that the low production of critical lures in DRM tasks usually reported in Alzheimer's patients might not be due to a semantic deficit that prevents the activation of the critical lure.

Personality and social memory: High source and destination memory in extroverts

We evaluated relationship between personality and memory for social interactions. More specifically, we investigated the relationship between extraversion and the ability to remember who told us some information (i.e., source memory) and the ability to remember to whom we told that information (i.e., destination memory). On a source memory task, participants received information from pictures of celebrities; a subsequent recognition test required them to identify the celebrities from whom they had received that information. On a destination memory task, participants were invited to tell information to celebrities; a later recognition task instructed them to identify the celebrity to whom they had previously told that information. Besides the assessment of source and destination memory, participants answered a questionnaire regarding extraversion. Results demonstrated significant positive correlation between extraversion and source memory, as well as significant positive correlation between extraversion and destination memory. In other words, the more participants described themselves as extraverts, the higher their source and destination memory. During social communications (e.g., in a conversation), extraverts may demonstrate high source and destination memory as these individuals typically value social communication, public sharing, and processing of social information.

False Memory in Alzheimer's Disease

Patients with Alzheimer's Disease (AD) not only are suffering from amnesia but also are prone to memory distortions, such as experiencing detailed and vivid recollections of episodic events that have never been encountered (i.e., false memories). To describe and explain these distortions, we offer a review to synthesize current knowledge on false memory in AD into a framework allowing for better understanding of the taxonomy and phenomenology of false memories and of the cognitive mechanisms that may underlie false memory formation in AD. According to this review, certain phenomenological characteristics of memories (e.g., high emotional load, high vividness, or high familiarity) result in misattributions in AD. More specifically, this review proposes that generalized decline in cognitive control and inhibition in AD may result in difficulties in suppressing irrelevant information during memory monitoring, especially when irrelevant (i.e., false) information is characterized by high emotion, vividness, or familiarity. This review also proposes that binding deficits in AD decrease the ability to retrieve relevant contextual details, leading to source monitoring errors and false memories. In short, this review depicts how phenomenological characteristics of memories and failures of monitoring during retrieval contribute to the occurrence of false memory in AD.

False Memories in Alzheimer's Disease: Intact Semantic Priming But Impaired Production of Critical Lures

Objectives

This study explores the activation of the critical lure (CL) and its production in Deese-Roediger-McDermott (DRM) tasks in Alzheimer's disease and aging. In a previous lexical decision task including DRM lists, we showed that the activation of the CL occurs normally in Alzheimer's patients. Here, we reproduce this study and add a production (DRM) task in order to compare both processes in the same groups of participants.

Method

Eighteen older adults and 20 Alzheimer's patients performed a conventional DRM task, followed by a lexical decision task with DRM lists intermixed with neutral words and nonwords.

Results

Analyses indicated that Alzheimer's patients produced significantly fewer CLs than older participants in the DRM task, but that they showed, like older adults, shorter lexical decision latencies for CLs than for other types of words.

Discussion

This study provides evidence that the low production of CLs regularly documented in Alzheimer's patients in the DRM paradigm is not necessarily explained by their nonactivation. The results are discussed in the light of the hypothesis of a rapid disappearance of the episodic mnemonic trace of the CLs in Alzheimer's patients.