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.

When posterior cortical atrophy invests art: a case report.

A 63-year-old woman was referred for visuospatial difficulties. The clinical and neuropsychological examination in association with imaging and biomarkers led to a diagnosis of posterior cortical atrophy (PCA). The patient, an amateur watercolor artist, continued to paint throughout her disease and her paintings illustrate in an original way the progression of her disorders. At an advanced stage, the evolution of neurovisual disorders is difficult to evaluate in patients. While studies have shown changes in artistic style in neurodegenerative diseases, none of them concerned PCA. Artistic production enables a different approach to trying to understand the progression of disorders.

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.

Why do some Alzheimer's patients produce fewer false memories than healthy older participants in the Deese-Roediger-McDermott paradigm, which was especially designed for the study of false memories in a laboratory setting? Using a very simple methodology, this study examines a new explanatory factor inherent in the paradigm itself: the order of presentation of the words in the lists. A sample comprising 149 participants (36 younger, 40 middle-aged, 37 healthy older adults, and 36 Alzheimer's patients) performed a DRM task with either a classic descending forward associative strength (FAS) presentation order of the words or an ascending FAS presentation order. The results showed that this simple manipulation influenced the production of false memories in Alzheimer's patients only. Contrary to the other participants, Alzheimer's patients produced significantly more critical lures in the ascending FAS condition than in the descending FAS condition. These new data, interpreted in the light of serial position effects, invite a reconsideration of the relevance of the DRM paradigm for comparing the production of false memories in Alzheimer's patients and healthy older participants.

The Moderating Role of Education on the Relationship Between Perceived Stereotype Threat and False Memory in Aging.

Studies regularly show that an age-based stereotype threat impairs older adults' performance on memory tasks. Results regarding stereotype threat effects on false memories are less clear. Some studies suggest that education may moderate the relationship between an age-related stereotype threat and episodic memory performance in older adults. The present study aimed at examining the moderating role of education on the relationship between perceived stereotype threat (PST) and false memories in older adults. With this aim, 82 adults between 60 and 70 years of age performed a Deese-Roediger-McDermott (DRM) task followed by a free recall test and completed questionnaires assessing both their perception of an age-based stereotype threat and their education level. Regression analyses showed no effect of PST on the production of critical lures. However, as was expected, our results showed that in higher educated older adults, as the perception of stereotype increases, the production of critical lures increases. These results confirm the moderating role of education and highlight its key role in the relationship between the age-based stereotype threat and older adults' susceptibility to false memories.

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.

Intact Semantic Priming of Critical Lures in Alzheimer's Disease: Implications for False Memory.

OBJECTIVES: The present study examines the question of the activation of the critical lure (CL) in Alzheimer's patients with a Deese-Roediger-McDermott (DRM)-like task. More precisely, older adults and Alzheimer's patients performed a lexical decision task in which they were asked to categorize strings of letters as words or nonwords. Contrary to the DRM paradigm in which the activation of the CL is inferred from its production at recall, such a lexical decision task does not require the joint use of intentional recovery strategies and source-monitoring processes that are known to be particularly impaired in Alzheimer's patients. The performance at the lexical decision therefore reflects the activation of the CL without contamination from such strategic processes. METHOD: Twenty-nine older adults and 25 Alzheimer's patients performed a lexical decision task with DRM lists intermixed with neutral words and nonwords. RESULTS: Analysis indicated that older adults as well as Alzheimer's patients showed shorter lexical decision latencies for CLs than for other types of words. DISCUSSION: Contrary to the existing literature, our results suggest that the activation of the CL is preserved in Alzheimer's patients at mild to moderate stages of the disease.

Ugly aesthetic perception associated with emotional changes in experience of art by behavioural variant of frontotemporal dementia patients.

The aesthetic experience through art is a window into the study of emotions. Patients with behavioural variant of frontotemporal dementia (bvFTD) have early alteration of emotional processing. A new appreciation of art has been reported in some of these patients. We designed a computerized task using 32 abstract paintings that allowed us to investigate the integrity of patients' emotions when viewing the artwork. We evaluated both conscious and explicit appraisal of emotions [aesthetic judgment (beautiful/ugly), emotional relevance (affected or not by the painting), emotional valence (pleasant/unpleasant), emotional reaction (adjective choice) and arousal] and unconscious processing. Fifteen bvFTD patients and 15 healthy controls were included. BvFTD patients reported that they were "little touched" by the paintings. Aesthetic judgment was very different between the two groups: the paintings were considered ugly (negative aesthetic bias) and unpleasant (negative emotional bias) more often by the patients than by controls. Valence and aesthetic judgments correlated in both groups. In addition, there was a positive bias in the implicit task and for explicit emotional responses. Patients frequently chose the word "sad" and rarely expressed themselves with such adjectives as "happy". Our results suggest that bvFTD patients can give an aesthetic judgment, but present abstraction difficulties, as spectators, resulting from impairments in the cognitive processes involved. They also have difficulties in terms of emotional processes with the loss of the ability to feel the emotion per se (i.e., to feel an emotion faced with art) linked to behaviour assessment. This cognitive approach allows us to better understand which spectators are bvFTD patients and to show interactions between emotions and behavioural disorders.

A phenotype of atypical apraxia of speech in a family carrying SQSTM1 mutation.

SQSTM1 mutations, coding for the p62 protein, were identified as a monogenic cause of Paget disease of bone and of amyotrophic lateral sclerosis. More recently, SQSTM1 mutations were identified in few families with frontotemporal dementia. We report a new family carrying SQSTM1 mutation and presenting with a clinical phenotype of speech apraxia or atypical behavioral disorders, associated with early visuo-contructional deficits. This study further supports the implication of SQSTM1 in frontotemporal dementia, and enlarges the phenotypic spectrum associated with SQSTM1 mutations.

DAPHNE: A New Tool for the Assessment of the Behavioral Variant of Frontotemporal Dementia.

BACKGROUND: The diagnosis of behavioral variant of frontotemporal dementia (bvFTD) relies primarily on clinical features and remains challenging. The specificity of the recently revised criteria can be disappointing, justifying development of new clinical tools. OBJECTIVE: We produced a behavioral inventory named DAPHNE. This scale (adapted from Rascovsky's criteria) explores six domains: disinhibition, apathy, perseverations, hyperorality, personal neglect and loss of empathy. It is composed of ten items (five answer categories). The aim was (1) to assess the validity and reliability of DAPHNE and (2) to evaluate its contribution in differentiating patients. METHODS: Two scores were computed: DAPHNE-6 (screening) from the six domains and DAPHNE-40 (diagnosis) from the ten items. Reliability and reproducibility were assessed. External validity was studied with the Frontal Behavioral Inventory (FBI) and the Frontotemporal Behavioral Scale (FBS). Finally, the diagnostic performance of DAPHNE was compared to revised criteria, FBI and FBS. RESULTS: DAPHNE was administered to the caregivers of 89 patients, 36 with bvFTD, 22 with Alzheimer's disease, 15 with progressive supranuclear palsy and 16 with bipolar disorder. Reliability and reproducibility were excellent, as was external validity. DAPHNE-6 allowed bvFTD diagnosis (score ≥4) with a sensitivity of 92%, while DAPHNE-40 (score ≥15) had a specificity of 92%. CONCLUSION: We demonstrate excellent psychometric features for DAPHNE. This quick tool could help for both diagnosing and screening bvFTD.

Value of neuropsychological testing, imaging, and CSF biomarkers for the differential diagnosis and prognosis of clinically ambiguous dementia.

The objective of this study was to examine the diagnostic accuracy of imaging and CSF biomarkers in clinically ambiguous dementia (CAD). 69 patients were prospectively followed. The endpoint was clinical diagnosis at follow-up of 24 months based upon existing criteria. Medial temporal lobe atrophy score on MRI, distinctive patterns on 99 mTc-HMPAO-SPECT, and CSF levels of amyloid-ß peptide, total tau protein, and P-tau181P were used together with neuropsychological testing to assess Se (sensitivity) and Sp (specificity) of separate and combined markers. 60 patients reached the endpoint. A definite diagnosis was achieved in 48 patients. CSF biomarkers had a Sp of 71% and a Se of 100% for Alzheimer's disease (AD) diagnosis. Sp increased to 88% and 93% when MRI and MRI + SPECT were combined, at the expense of Se. CSF biomarkers levels also provided clues to frontotemporal (FTD) or vascular dementias (VaD) diagnosis when situated in an intermediate range between normal and pathological values. MRI and SPECT contributed mostly to the diagnosis of VaD (Se 88%, Sp 75%) and FTD (Se 73%, Sp 78%), respectively. Initial neuropsychological testing had a poor diagnostic accuracy, except for a neuropsychiatric inventory score >40 for the diagnosis of FTD (Se 73%, Sp 84%). Independent of the clinical diagnosis, medial temporal lobe atrophy and total-tau were best correlated with cognitive decline at 2 years. In conclusion, CSF biomarkers efficiently predict evolution toward an AD phenotype in CAD. Imaging biomarkers mostly contribute to the differential diagnosis between non-AD dementias. Initial neuropsychological testing was poorly contributive in CAD diagnosis.