Alzheimer's disease and memory-monitoring impairment: Alzheimer's patients show a monitoring deficit that is greater than their accuracy deficit

doi:10.1016/j.neuropsychologia.2011.05.008

Neuropsychologia

Volume 49, Issue 9, July 2011, Pages 2609-2618

https://doi.org/10.1016/j.neuropsychologia.2011.05.008 Get rights and content

Abstract

We assessed the ability of two groups of patients with mild Alzheimer's disease (AD) and two groups of older adults to monitor the likely accuracy of recognition judgments and source identification judgments about who spoke something earlier. Alzheimer's patients showed worse performance on both memory judgments and were less able to monitor with confidence ratings the likely accuracy of both kinds of memory judgments, as compared to a group of older adults who experienced the identical study and test conditions. Critically, however, when memory performance was made comparable between the AD patients and the older adults (e.g., by giving AD patients extra exposures to the study materials), AD patients were still greatly impaired at monitoring the likely accuracy of their recognition and source judgments. This result indicates that the monitoring impairment in AD patients is actually worse than their memory impairment, as otherwise there would have been no differences between the two groups in monitoring performance when there were no differences in accuracy. We discuss the brain correlates of this memory-monitoring deficit and also propose a Remembrance–Evaluation model of memory-monitoring.

Highlights

► We show that AD patients are strikingly unaware of the accuracy of their memories. ► AD group unable to distinguish between correct and incorrect responses. ► Memory monitoring deficit occurs even when AD and controls are matched on accuracy.

Section snippets

Participants

The participants consisted of twenty-four clinically diagnosed, mild AD patients (age range from 56 to 86) who were assigned to either the AD group or the AD-m group (i.e., 12 in each group). Twenty-four healthy older adults (age range from 62 to 90) were assigned to either the Older group or the Older-m group (i.e., 12 in each group). Each group consisted of 6 females and 6 males, except in the AD-m group where there were 5 females and 7 males. The AD group and the older group experienced the

Recognition performance and recognition monitoring

We examined recognition performance with hit rates (i.e., proportion of studied items judged “old”), corrected recognition rates (i.e., hit rates minus false alarm rates to novel items) and d′ scores (e.g., Snodgrass & Corwin, 1988). With respect to monitoring performance, there are two fundamentally different ways of measuring how individuals use confidence ratings to monitor and judge the accuracy of their responses (e.g., Koriat and Goldsmith, 1996, Pannu and Kaszniak, 2005, Yaniv et al.,

General discussion

This study examined the ability of AD patients and healthy older adults to monitor and judge the likely accuracy of recognition judgments and source judgments about who spoke something earlier. Participants listened to statements at encoding that were presented by a woman and a man, and at a subsequent test phase, participants provided confidence ratings about the likely accuracy of their recognition judgments (i.e., was this statement encountered during the encoding phase or not?) and source

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Self-unawareness concerning current symptoms remains a clinical challenge in Alzheimer's disease. Reduced self-awareness likely depends on complex biopsychosocial mechanisms that comprise multiple cognitive processes, regulated by personal goals and values. We specifically reviewed the cognitive processes impaired in unaware participants with AD by emphasizing the related impaired brain activity observed during task-based fMRI. Unawareness can be explained by a failure in functioning of or in connection between brain regions that intervene in access, retrieval and updating of (present or extended) self-information (posterior midline, medial temporal, inferior parietal cortices), or in its monitoring, evaluation, or control (medial and lateral prefrontal cortices). Although one must be cautious when relating function to brain regions, impaired processes were tentatively related to the Cognitive Awareness Model. Although brain function depends on neural networks, impaired brain activity during cognitive processes was discussed according to previous studies reporting correlations between brain regions and scores of anosognosia. The review provides a framework to help clinicians considering processes that can explain unawareness in dementia. In patients at early stages of AD, different levels of awareness of cognitive or social clinical changes might be described as impairment in the interaction between specific cognitive processes and contents.
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Patients with Alzheimer’s disease (AD) often exhibit an abnormally liberal response bias in recognition memory tests, responding “old” more frequently than “new.” Investigations have shown patients can to shift to a more conservative response bias when given instructions. We examined if patients with mild AD could alter their response patterns when the ratio of old items is manipulated without explicit instruction. Healthy older adults and AD patients studied lists of words and then were tested in three old/new ratio conditions (30%, 50%, or 70% old items). A subset of participants provided estimates of how many old and new items they saw in the memory test. We demonstrated that both groups were able to change their response patterns without the aid of explicit instructions. Importantly, AD patients were more likely to estimate seeing greater numbers of old than new items, whereas the reverse was observed for older adults. Elevated estimates of old items in AD patients suggest their liberal response bias may be attributed to their reliance on familiarity. We conclude that the liberal response bias observed in AD patients is attributable to their believing that more of the test items are old and not due to impaired meta-memorial monitoring abilities.
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Citation Excerpt :
Traditionally, metamemory theoretical framework (Nelson & Narens, 1990) distinguishes metacognitive judgments that are performed during retrieval attempt, with feeling-of-knowing (FOK), from metacognitive judgments that are performed directly after target retrieval, expressed as judgments of confidence (JOC). The few studies that have examined post-retrieval metacognitive judgments (JOC) in AD patients suggested that such metacognitive processes can be relatively preserved (Gallo, Cramer, Wong, & Bennett, 2012; Moulin, James, Perfect, & Jones, 2003), although it might depend on task-demands and the stage of dementia (Dodson et al., 2011). In contrast, predictive metacognitive judgments (FOK) have been found to be altered in AD-like pathology with AD patients and patients with mild cognitive impairment (MCI) tending to overestimate their abilities (Perrotin, Belleville, & Isingrini, 2007; Souchay, Isingrini, & Gil, 2002).
Patients with Alzheimer's disease (AD) show impairment of episodic memory and related metacognitive processes. The present study examined subjective metacognitive judgments preceding objective memory retrieval and investigated the neural correlates of pessimistic predictions for successfully retrieved memories in AD patients.
AD patients and healthy older (HO) participants provided predictive judgments on their recognition performance before retrieval of famous (semantic) and recently learned (episodic) names. Correlations between gray matter volume (GMV) in T1 images and behavioral scores were examined with multivariate (partial least square – PLS) and univariate (general linear model – GLM) analyses in AD patients.
AD patients showed a significant proportion of successful name recognition preceded by pessimistic prediction in episodic memory. PLS revealed that the behavioral pattern in AD patients was related with a mainly right lateralized pattern of GMV decrease including medial temporal lobe and posterior cingulate cortex (PCC), but also right ventrolateral prefrontal cortex (VLPFC). GLM further confirmed that pessimistic prediction negatively correlated with GMV in VLPFC.
Thus, impaired monitoring processes (possibly influenced by inaccurate beliefs) allowing inferences about one's own memory performance are primarily related to decrease GMV in VLPFC in AD patients.

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^☆: This research was supported by National Science Foundation grant 0925145 (CSD) and National Institute on Aging grants R01 AG025815 (AEB) and P30 AG13846 (AEB). This material is also the result of work supported with resources and the use of facilities at the Bedford VA Hospital in Bedford, MA.

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Alzheimer's disease and memory-monitoring impairment: Alzheimer's patients show a monitoring deficit that is greater than their accuracy deficit☆

Abstract

Highlights

Section snippets

Participants

Recognition performance and recognition monitoring

General discussion

Neuropsychologia

Neuropsychologia

Cortex

Neuropschologia

NeuroImage

Cortex

Neuropsychologia

Cortex

Experimental Neurology

Neuropsychologia

Neuropsychologia

Neuropsychologia

Cortex

Neuropsychologia

Neuroscience Letters

Brain & Cognition

Age equivalence in feeling-of-knowing experiences

Journal of Gerontology: Psychological Sciences

The confidence–accuracy relationship in eyewitness identification: Effects of lineup instructions, foil similarity and target-absent base rates

Journal of Experimental Psychology: Applied

When false recognition is unopposed by true recognition: Gist based memory distortion in Alzheimer's disease

Neuropsychology

Metacognition and false recognition in Alzheimer's disease: Further exploration of the distinctiveness heuristic

Neuropsychology

Memory and emotions for the September 11, 2001, terrorist attacks in patients with Alzheimer's disease, patients with mild cognitive impairment, and healthy older adults

Neuropsychology

Developmental aspects of the feeling of knowing

Developmental Psychology

Recognition memory and recollective experience in Alzheimer's disease

Memory

Confabulation, executive functions and source memory in Alzheimer's disease

Cognitive Neuropsychology

Aging, metamemory and high confidence errors: A misrecollection account

Psychology and Aging

Aging and a signal detection model of illusory recollection

Journal of Experimental Psychology: Learning, Memory, and Cognition

I misremember it well: Why older adults are unreliable eyewitnesses

Psychological Bulletin & Review