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Almeida VN. Somatostatin and the pathophysiology of Alzheimer's disease. Ageing Res Rev 2024; 96:102270. [PMID: 38484981 DOI: 10.1016/j.arr.2024.102270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 03/09/2024] [Accepted: 03/09/2024] [Indexed: 03/28/2024]
Abstract
Among the central features of Alzheimer's disease (AD) progression are altered levels of the neuropeptide somatostatin (SST), and the colocalisation of SST-positive interneurons (SST-INs) with amyloid-β plaques, leading to cell death. In this theoretical review, I propose a molecular model for the pathogenesis of AD based on SST-IN hypofunction and hyperactivity. Namely, hypofunctional and hyperactive SST-INs struggle to control hyperactivity in medial regions in early stages, leading to axonal Aβ production through excessive presynaptic GABAB inhibition, GABAB1a/APP complex downregulation and internalisation. Concomitantly, excessive SST-14 release accumulates near SST-INs in the form of amyloids, which bind to Aβ to form toxic mixed oligomers. This leads to differential SST-IN death through excitotoxicity, further disinhibition, SST deficits, and increased Aβ release, fibrillation and plaque formation. Aβ plaques, hyperactive networks and SST-IN distributions thereby tightly overlap in the brain. Conversely, chronic stimulation of postsynaptic SST2/4 on gulutamatergic neurons by hyperactive SST-INs promotes intense Mitogen-Activated Protein Kinase (MAPK) p38 activity, leading to somatodendritic p-tau staining and apoptosis/neurodegeneration - in agreement with a near complete overlap between p38 and neurofibrillary tangles. This model is suitable to explain some of the principal risk factors and markers of AD progression, including mitochondrial dysfunction, APOE4 genotype, sex-dependent vulnerability, overactive glial cells, dystrophic neurites, synaptic/spine losses, inter alia. Finally, the model can also shed light on qualitative aspects of AD neuropsychology, especially within the domains of spatial and declarative (episodic, semantic) memory, under an overlying pattern of contextual indiscrimination, ensemble instability, interference and generalisation.
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Affiliation(s)
- Victor N Almeida
- Institute of Psychiatry, Faculty of Medicine, University of São Paulo (USP), Brazil; Faculty of Languages, Federal University of Minas Gerais (UFMG), Brazil.
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2
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Keith CM, Haut MW, Wilhelmsen K, Mehta RI, Miller M, Navia RO, Ward M, Lindberg K, Coleman M, McCuddy WT, Deib G, Giolzetti A, D'Haese PF. Frontal and temporal lobe correlates of verbal learning and memory in aMCI and suspected Alzheimer's disease dementia. NEUROPSYCHOLOGY, DEVELOPMENT, AND COGNITION. SECTION B, AGING, NEUROPSYCHOLOGY AND COGNITION 2023; 30:923-939. [PMID: 36367308 DOI: 10.1080/13825585.2022.2144618] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022]
Abstract
Alzheimer's disease is primarily known for deficits in learning and retaining new information. This has long been associated with pathological changes in the mesial temporal lobes. The role of the frontal lobes in memory in Alzheimer's disease is less well understood. In this study, we examined the role of the frontal lobes in learning, recognition, and retention of new verbal information, as well as the presence of specific errors (i.e., intrusions and false-positive errors). Participants included one hundred sixty-seven patients clinically diagnosed with amnestic mild cognitive impairment or suspected Alzheimer's disease dementia who were administered the California Verbal Learning Test and completed high-resolution MRI. We confirmed the role of the mesial temporal lobes in learning and retention, including the volumes of the hippocampus, entorhinal cortex, and parahippocampal gyrus. In addition, false-positive errors were associated with all volumes of the mesial temporal lobes and widespread areas within the frontal lobes. Errors of intrusion were related to the supplementary motor cortex and hippocampus. Most importantly, the mesial temporal lobes interacted with the frontal lobes for learning, recognition, and memory errors. Lower volumes in both regions explained more performance variance than any single structure. This study supports the interaction of the frontal lobes with the temporal lobes in many aspects of memory in Alzheimer's disease.
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Affiliation(s)
- Cierra M Keith
- Department of Behavioral Medicine and Psychiatry, West Virginia University, Morgantown, West Virginia, United States
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
| | - Marc W Haut
- Department of Behavioral Medicine and Psychiatry, West Virginia University, Morgantown, West Virginia, United States
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
- Department of Neurology, West Virginia University, Morgantown, West Virginia, United States
| | - Kirk Wilhelmsen
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
- Department of Neurology, West Virginia University, Morgantown, West Virginia, United States
| | - Rashi I Mehta
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
- Department of Neuroradiology, West Virginia University, Morgantown, West Virginia, United States
| | - Mark Miller
- Department of Behavioral Medicine and Psychiatry, West Virginia University, Morgantown, West Virginia, United States
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
| | - R Osvaldo Navia
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
- Department of Medicine, West Virginia University, Morgantown, West Virginia, United States
| | - Melanie Ward
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
- Department of Neurology, West Virginia University, Morgantown, West Virginia, United States
| | - Katharine Lindberg
- Department of Behavioral Medicine and Psychiatry, West Virginia University, Morgantown, West Virginia, United States
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
| | - Michelle Coleman
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
| | - William T McCuddy
- Department of Neuropsychology, Barrow Neurological Institute, Phoenix, Arizona, United States
| | - Gerard Deib
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
- Department of Neuroradiology, West Virginia University, Morgantown, West Virginia, United States
| | - Angelo Giolzetti
- Department of Behavioral Medicine and Psychiatry, West Virginia University, Morgantown, West Virginia, United States
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
| | - Pierre-François D'Haese
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, United States
- Department of Neurology, West Virginia University, Morgantown, West Virginia, United States
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3
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Dalla Barba G, Nogier B, Rogan C, Kalafat M, Gagliardi G, Houot M, La Corte V. Episodic memory false recognition for familiar information in Alzheimer's disease. J Clin Exp Neuropsychol 2021; 43:579-598. [PMID: 34713758 DOI: 10.1080/13803395.2021.1975655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Patients with Alzheimer's disease (AD) suffer from various types of memory distortions. We showed that confabulations are plausible memories, mainly reflecting the recall of repeated personal events mistakenly considered by confabulating patients as specific and unique events. The aim of this study is to see whether the notion that over-learned information interferes in episodic memory recall, as it does in confabulation, can be extended to another type of memory distortion, namely false recognition (i.e., a claim to recognize something that was not encountered previously). If this is the case, it should be expected that in an episodic recognition memory task AD patients produce more false recognition for well known non-studied, non to-be-remembered material than for unknown non-studied, non to-be-remembered material. In order to verify this prediction, AD patients and normal controls (NC) were administered two experiments. In Experiment 1, we presented pictures, of which half were supposed to be well known and the other half unknown monuments. For each picture, participants were asked to say whether or not the monument was known or not to them. Immediately following this semantic encoding task, participants were administered an episodic recognition memory task in which, in the same way as in the previous phase, among the non-studied items, half were supposed to be well known and the other half unknown. In Experiment 2 the same procedure was used employing well known and unknown symbols. It was predicted that AD patients make more false recognitions for non-studied well-known items than for non-studied unknown items. The results show that this is actually the case, suggesting that confusion between "uniqueness," i.e., specific unique events, and "multiplicity," i.e., repeated events, is also involved in false recognition.
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Affiliation(s)
- Gianfranco Dalla Barba
- INSERM, Paris, France.,Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Paris, France.,Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Trieste, Italy
| | - Barbara Nogier
- Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, Inserm U975, Université Pierre et Marie Curie-Paris6, Paris, France
| | - Christina Rogan
- Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Paris, France
| | - Michel Kalafat
- Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Paris, France
| | - Geoffroy Gagliardi
- Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Paris, France
| | - Marion Houot
- Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Paris, France
| | - Valentina La Corte
- Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Sorbonne Universités, Université Pierre et Marie Curie-Paris6, Paris, France.,Institut de Psychologie, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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Gilet AL, Evrard C, Colombel F. DRM Paradigm: Evidence that Alzheimer's Patients Think of the Critical Lure as Often as Healthy Older Participants. Exp Aging Res 2021; 48:211-219. [PMID: 34570684 DOI: 10.1080/0361073x.2021.1980289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
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.
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Affiliation(s)
- Anne-Laure Gilet
- Laboratoire De Psychologie Des Pays De La Loire, LPPL, Université De Nantes, Nantes, France
| | - Christelle Evrard
- Laboratoire De Psychologie Des Pays De La Loire, LPPL, Université De Nantes, Nantes, France
| | - Fabienne Colombel
- Laboratoire De Psychologie Des Pays De La Loire, LPPL, Université De Nantes, Nantes, France
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5
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The Effectiveness of Item-Specific Encoding and Conservative Responding to Reduce False Memories in Patients with Mild Cognitive Impairment and Mild Alzheimer's Disease Dementia. J Int Neuropsychol Soc 2021; 27:227-238. [PMID: 32772946 PMCID: PMC7873137 DOI: 10.1017/s1355617720000715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Patients with mild Alzheimer's disease dementia are more susceptible to false memories than healthy older adults. Evidence that these patients can use cognitive strategies to reduce false memory is inconsistent. METHOD In the present study, we examined the effectiveness of conservative responding and item-specific deep encoding strategies, alone and in combination, to reduce false memory in a categorized word list paradigm among participants with mild Alzheimer's disease dementia (AD), amnestic single-domain mild cognitive impairment (MCI), and healthy age-matched older controls (OCs). A battery of clinical neuropsychological measures was also administered. RESULTS Although use of conservative responding alone tended to reduce performance in the MCI and OC groups, both deep encoding alone and deep encoding combined with conservative strategies led to improved discrimination for both gist memory and item-specific recollection for these two groups. In the AD group, only gist memory benefited from the use of strategies, boosted equally by deep encoding alone and deep encoding combined with conservative strategies; item-specific recollection was not improved. No correlation between the use of these strategies and performance on neuropsychological measures was found. CONCLUSIONS These results suggest that further evaluation of these strategies is warranted as they have the potential to reduce related and unrelated memory errors and increase both gist memory and item-specific recollection in healthy older adults and individuals with amnestic MCI. Patients with AD were less able to benefit from such strategies, yet were still able to use them to reduce unrelated memory errors and increase gist memory.
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6
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Effectiveness of tDCS at Improving Recognition and Reducing False Memories in Older Adults. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18031317. [PMID: 33535690 PMCID: PMC7908296 DOI: 10.3390/ijerph18031317] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 01/01/2023]
Abstract
BACKGROUND False memories tend to increase in healthy and pathological aging, and their reduction could be useful in improving cognitive functioning. The objective of this study was to use an active-placebo method to verify whether the application of transcranial direct current stimulation (tDCS) improved true recognition and reduced false memories in healthy older people. METHOD Participants were 29 healthy older adults (65-78 years old) that were assigned to either an active or a placebo group; the active group received anodal stimulation at 2 mA for 20 min over F7. An experimental task was used to estimate true and false recognition. The procedure took place in two sessions on two consecutive days. RESULTS True recognition showed a significant main effect of sessions (p < 0.01), indicating an increase from before treatment to after it. False recognition showed a significant main effect of sessions (p < 0.01), indicating a decrease from before treatment to after it and a significant session × group interaction (p < 0.0001). CONCLUSIONS Overall, our results show that tDCS was an effective tool for increasing true recognition and reducing false recognition in healthy older people, and suggest that stimulation improved recall by increasing the number of items a participant could recall and reducing the number of memory errors.
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Akhtar S, Howe ML, Hoepstine K. Can False Memories Prime Problem Solutions for Healthy Older Adults and Those With Alzheimer's Disease? J Gerontol B Psychol Sci Soc Sci 2020; 75:743-752. [PMID: 29873791 DOI: 10.1093/geronb/gby064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE Recent research has shown that false memories can have a positive consequence on human cognition in both children and young adults. The present experiment investigated whether false memories could have similar positive effects by priming solutions to insight-based problems in healthy older adults and people with Alzheimer's disease (AD). METHOD Participants were asked to solve compound remote associate task (CRAT) problems, half of which had been preceded by the presentation of Deese/Roediger-McDermott (DRM) lists whose critical lures (CL) were also the solutions to those problems. RESULTS The results showed that regardless of cognitive ability, when the CL was falsely recognized, CRAT problems were solved more often and reliably faster than problems that were not primed by a DRM list. When the CL was not falsely recognized, CRAT problem solution rates and times were no different from when there was no DRM priming. DISCUSSION These findings are consistent with predictions from theories of associative activation and demonstrate the importance of automatic spreading activation processes in memory across the life span.
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Affiliation(s)
- Shazia Akhtar
- Department of Psychology, City, University of London, UK
| | - Mark L Howe
- Department of Psychology, City, University of London, UK
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8
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McLachlan E, Rai S, Al-Shihabi A, Huntley J, Burgess N, Howard R, Reeves S. Neuroimaging correlates of false memory in 'Alzheimer's disease: A preliminary systematic review. Psychiatry Res Neuroimaging 2020; 296:111021. [PMID: 31887712 DOI: 10.1016/j.pscychresns.2019.111021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/28/2019] [Accepted: 12/06/2019] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is characterised by episodic memory impairment, but people also experience memory distortions, including false memories, which can impact on safety and reduce functioning. Understanding the neural networks that underpin false memories could help to predict the need for intervention and guide development of cognitive strategies to reduce memory errors. However, there is a relative absence of research into how the neuropathology of AD contributes to false memory generation. This paper systematically reviews the methodology and outcomes of studies investigating the neuroimaging correlates of false memory in AD. Four studies using structural imaging and three studies using functional imaging were identified. Studies were heterogenous in methodology and received mostly 'weak' quality assessment ratings. Combined, and consistent with neuroimaging findings in non-AD populations, results from identified studies provide preliminary support for the hypothesis that medial temporal lobe and prefrontal cortex dysfunction may lead to generation of false memories in AD. However, the small number of studies and significant heterogeneity within them means further study is necessary to assess replicability of results.
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Affiliation(s)
- Emma McLachlan
- Division of Psychiatry, University College London, Maple House, 149 Tottenham Court Rd, London, United Kingdom, W1T 7NF.
| | - Salina Rai
- Division of Psychiatry, University College London, Maple House, 149 Tottenham Court Rd, London, United Kingdom, W1T 7NF
| | - Ahmed Al-Shihabi
- Division of Psychiatry, University College London, Maple House, 149 Tottenham Court Rd, London, United Kingdom, W1T 7NF
| | - Jonathan Huntley
- Division of Psychiatry, University College London, Maple House, 149 Tottenham Court Rd, London, United Kingdom, W1T 7NF
| | - Neil Burgess
- Institute of Cognitive Neuroscience, University College London, Alexandra House, 17-19 Queen Square, Bloomsbury, London, United Kingdom, WC1N 3AZ
| | - Robert Howard
- Division of Psychiatry, University College London, Maple House, 149 Tottenham Court Rd, London, United Kingdom, W1T 7NF
| | - Suzanne Reeves
- Division of Psychiatry, University College London, Maple House, 149 Tottenham Court Rd, London, United Kingdom, W1T 7NF
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Abstract
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.
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10
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Malone C, Deason RG, Palumbo R, Heyworth N, Tat M, Budson AE. False memories in patients with mild cognitive impairment and mild Alzheimer's disease dementia: Can cognitive strategies help? J Clin Exp Neuropsychol 2019; 41:204-218. [PMID: 30179518 PMCID: PMC6399077 DOI: 10.1080/13803395.2018.1513453] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 08/05/2018] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that presents predominantly with impairments in learning and memory. Patients with AD are also susceptible to false memories, a clinically relevant memory distortion where a patient remembers an incorrect memory that they believe to be true. The use of cognitive strategies to improve memory performance among patients with AD by reducing false memories has taken on added importance given the lack of disease-modifying agents for AD. However, existing evidence suggests that cognitive strategies to reduce false memories in patients with AD are of limited effectiveness, although these strategies may be useful at earlier stages of the disease. The purpose of this review is to examine experimental findings of false memories and associated memory processes in patients with mild cognitive impairment due to AD and mild AD dementia. Cognitive strategies to reduce false memories in these patient populations are also reviewed. Approaches to clinically relevant future research are suggested and discussed.
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Affiliation(s)
- Christopher Malone
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, USA
| | - Rebecca G. Deason
- Department of Psychology, Texas State University, San Marcos, TX, USA
| | - Rocco Palumbo
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, USA
- Department of Neurology, Boston University Alzheimer’s Disease Center, Boston University School of Medicine, Boston, MA, USA
| | - Nadine Heyworth
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, USA
| | - Michelle Tat
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, USA
- Department of Neurology, Boston University Alzheimer’s Disease Center, Boston University School of Medicine, Boston, MA, USA
| | - Andrew E. Budson
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, USA
- Department of Neurology, Boston University Alzheimer’s Disease Center, Boston University School of Medicine, Boston, MA, USA
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11
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Zhang Y, Liu S. Analysis of structural brain MRI and multi-parameter classification for Alzheimer's disease. ACTA ACUST UNITED AC 2018. [PMID: 28622141 DOI: 10.1515/bmt-2016-0239] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Incorporating with machine learning technology, neuroimaging markers which extracted from structural Magnetic Resonance Images (sMRI), can help distinguish Alzheimer's Disease (AD) patients from Healthy Controls (HC). In the present study, we aim to investigate differences in atrophic regions between HC and AD and apply machine learning methods to classify these two groups. T1-weighted sMRI scans of 158 patients with AD and 145 age-matched HC were acquired from the ADNI database. Five kinds of parameters (i.e. cortical thickness, surface area, gray matter volume, curvature and sulcal depth) were obtained through the preprocessing steps. The recursive feature elimination (RFE) method for support vector machine (SVM) and leave-one-out cross validation (LOOCV) were applied to determine the optimal feature dimensions. Each kind of parameter was trained by SVM algorithm to acquire a classifier, which was used to classify HC and AD ultimately. Moreover, the ROC curves were depicted for testing the classifiers' performance and the SVM classifiers of two-dimensional spaces took the top two important features as classification features for separating HC and AD to the maximum extent. The results showed that the decreased cortical thickness and gray matter volume dramatically exhibited the trend of atrophy. The key differences between AD and HC existed in the cortical thickness and gray matter volume of the entorhinal cortex and medial orbitofrontal cortex. In terms of classification results, an optimal accuracy of 90.76% was obtained via multi-parameter combination (i.e. cortical thickness, gray matter volume and surface area). Meanwhile, the receiver operating characteristic (ROC) curves and area under the curve (AUC) were also verified multi-parameter combination could reach a better classification performance (AUC=0.94) after the SVM-RFE method. The results could be well prove that multi-parameter combination could provide more useful classified features from multivariate anatomical structure than single parameter. In addition, as cortical thickness and multi-parameter combination contained more important classified information with fewer feature dimensions after feature selection, it could be optimum to separate HC from AD to take the top two important features of them to construct SVM classifiers in two-dimensional space. The proposed work is a promising approach suggesting an important role for machine-learning based diagnostic image analysis for clinical practice.
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Affiliation(s)
- Yingteng Zhang
- School of Mathematics, South China University of Technology, Guangzhou 510640, China
| | - Shenquan Liu
- School of Mathematics, South China University of Technology, Guangzhou 510640, China
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12
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Sejunaite K, Lanza C, Riepe MW. Everyday Memory in Patients with Alzheimer's Disease: Fragmentary and Distorted. J Alzheimers Dis 2018; 60:1489-1498. [PMID: 29060940 DOI: 10.3233/jad-170493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Errors of omission are an established hallmark of memory impairment in Alzheimer's disease (AD). Much less is known about other memory errors in AD such as false memories. OBJECTIVE We investigated false memories in healthy elderly controls (HC; n = 23) and patients with AD (n = 20) using real-life tasks of watching news and commercials. METHODS Participants received a comprehensive neuropsychological assessment and were shown original news and commercials with a subsequent recognition task to assess veridical and false memories. RESULTS Subjective estimate of the number of errors were alike in HC and patients with AD. However, memory performance in both the news and the commercials task was significantly worse in patients with AD. Trail-Making Test and Symbol-Span Test were significant predictors of false memories on viewing news and commercials. In patients with AD, levels of Aβ1 - 42, but not levels of tau-protein were correlated with false memories in both tasks. CONCLUSIONS Everyday life in patients with AD is impeded not due to the incompleteness of memory but also due to its distortions. Furthermore, it is hindered by the lack of awareness towards these deficits. False memory content in patients with AD is associated with Aβ42 levels in the CSF as a surrogate of the overall extent to which the brain has been affected by AD pathology. Future studies will need to address the impact of this duality of memory failure on everyday life of patients with AD and their proxies in greater detail.
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Affiliation(s)
- Karolina Sejunaite
- Division of Mental Health and Old Age Psychiatry, Psychiatry II, Ulm University, Ulm, Germany
| | - Claudia Lanza
- Division of Mental Health and Old Age Psychiatry, Psychiatry II, Ulm University, Ulm, Germany
| | - Matthias W Riepe
- Division of Mental Health and Old Age Psychiatry, Psychiatry II, Ulm University, Ulm, Germany
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13
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Sejunaite K, Lanza C, Riepe MW. Everyday false memories in older persons with depressive disorder. Psychiatry Res 2018; 261:456-463. [PMID: 29407717 DOI: 10.1016/j.psychres.2018.01.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 01/12/2018] [Accepted: 01/14/2018] [Indexed: 11/26/2022]
Abstract
Generally we tend to think that memory in daily living is complete and accurate in healthy persons. However, current memory research has revealed inconspicuous memory faults. Rarely omissions and distortions of memory are researched with tasks resembling everyday life. We investigated healthy older control subjects (HC) and patients with depressive disorder (DD). Cognitive function was assessed with a comprehensive neuropsychological test battery and mood with the Montgomery-Asberg Depression Scale (MADRS). We assessed everyday veridical and distorted memories on showing participants original news and commercials. In most aspects of attention, executive functions, and memory, patients with DD performed worse than HC. Regarding memory content on viewing news or commercials the difference between patients with DD and HC was more pronounced for false memory content than for veridical memory content. Linear regression analysis showed the extent of false memory content being associated with mental flexibility as assessed with the Trail Making Test and mood as assessed with the MADRS for both information obtained on viewing news and commercials. Increase of false memories impedes overall accuracy of memory more than decrease of veridical memories in older persons with depressive disorder. Diminished executive functions and depressive mood partly explain these memory distortions.
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Affiliation(s)
- Karolina Sejunaite
- Department of Psychiatry and Psychotherapy II, Mental Health & Old Age Psychiatry, Ulm University, Ulm, Germany.
| | - Claudia Lanza
- Department of Psychiatry and Psychotherapy II, Mental Health & Old Age Psychiatry, Ulm University, Ulm, Germany.
| | - Matthias W Riepe
- Department of Psychiatry and Psychotherapy II, Mental Health & Old Age Psychiatry, Ulm University, Ulm, Germany.
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14
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Allen AP, Doyle C, Commins S, Roche RA. Autobiographical memory, the ageing brain and mechanisms of psychological interventions. Ageing Res Rev 2018; 42:100-111. [PMID: 29246541 DOI: 10.1016/j.arr.2017.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 10/18/2022]
Abstract
Elucidating the impact of healthy cognitive ageing and dementia on autobiographical memory (AM) may help deepen our theoretical understanding of memory and underlying neural changes. The distinction between episodic and semantic autobiographical memory is particularly informative in this regard. Psychological interventions, particularly those involving reminiscence or music, have led to differential effects on episodic and semantic autobiographical memory. We propose that executive function is a key mediator of psychological therapies on autobiographical memory. We also highlight that interventions that alleviate stress and improve mood, including in major depression, can enhance autobiographical memory. Future research employing more longitudinal approaches and examining moderating factors such as gender and education level will deepen our understanding of changes in AM in later life, enhance our theoretical understanding of the neuroscience of AM and ageing, and help to develop better targeted interventions for preserving AM in older adults.
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15
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Pitarque A, Satorres E, Sales A, Escudero J, Meléndez JC. Effects of Stimuli Repetition and Age in False Recognition. Psychol Rep 2017; 121:1106-1119. [PMID: 29298586 DOI: 10.1177/0033294117747284] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of the current study is to examine the effects of stimuli repetition and age in false recognition using the Deese-Roediger-McDermott experimental paradigm. Two matched samples of 32 young adults and 32 healthy older adults studied 10 lists of six words associated with three non-presented critical words. On half of the lists, the words were presented once, and on the other five lists, the words were presented three times, always following a same sequential order. After each study list, participants performed a self-paced recognition test containing 12 words: the 6 studied words and 6 other non-studied words (the 3 critical words and 3 distractors). The results show that false recognition increases with age and declines in both samples with repetitions (although more in the young adults than in the older people). Results are discussed in relation to the dual-process theories of (false) memory.
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Affiliation(s)
| | | | - Alicia Sales
- Faculty of Psychology, University of Valencia, Valencia, Spain
| | | | - Juan C Meléndez
- Faculty of Psychology, University of Valencia, Valencia, Spain
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16
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Deason RG, Tat MJ, Flannery S, Mithal PS, Hussey EP, Crehan ET, Ally BA, Budson AE. Response bias and response monitoring: Evidence from healthy older adults and patients with mild Alzheimer's disease. Brain Cogn 2017; 119:17-24. [PMID: 28926752 PMCID: PMC5798457 DOI: 10.1016/j.bandc.2017.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 08/25/2017] [Accepted: 09/05/2017] [Indexed: 11/23/2022]
Abstract
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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Affiliation(s)
- Rebecca G Deason
- Department of Psychology, Texas State University, San Marcos, TX, United States; Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, United States; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, United States.
| | - Michelle J Tat
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, United States; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, United States
| | - Sean Flannery
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, United States; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, United States
| | - Prabhakar S Mithal
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, United States; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, United States
| | - Erin P Hussey
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, United States; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, United States
| | - Eileen T Crehan
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, United States; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, United States
| | - Brandon A Ally
- Department of Neurological Surgery, University of Louisville, Louisville, KY, United States
| | - Andrew E Budson
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, United States; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA, United States
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17
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Gilet AL, Evrard C, Colombel F, Tropée E, Marie C, Corson Y. False Memories in Alzheimer's Disease: Intact Semantic Priming But Impaired Production of Critical Lures. J Gerontol B Psychol Sci Soc Sci 2017; 72:986-990. [PMID: 26976136 DOI: 10.1093/geronb/gbw032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/29/2016] [Indexed: 11/13/2022] Open
Abstract
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.
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Affiliation(s)
- Anne-Laure Gilet
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, France
| | - Christelle Evrard
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, France.,Centre Mémoire Ressources et Recherches, Centre Hospitalier Universitaire, Nantes, France
| | - Fabienne Colombel
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, France
| | - Elisa Tropée
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, France
| | - Célia Marie
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, France
| | - Yves Corson
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, France
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18
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Devitt AL, Tippett L, Schacter DL, Addis DR. Autobiographical memory conjunction errors in younger and older adults: Evidence for a role of inhibitory ability. Psychol Aging 2017; 31:927-942. [PMID: 27929343 DOI: 10.1037/pag0000129] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Because of its reconstructive nature, autobiographical memory (AM) is subject to a range of distortions. One distortion involves the erroneous incorporation of features from one episodic memory into another, forming what are known as memory conjunction errors. Healthy aging has been associated with an enhanced susceptibility to conjunction errors for laboratory stimuli, yet it is unclear whether these findings translate to the autobiographical domain. We investigated the impact of aging on vulnerability to AM conjunction errors, and explored potential cognitive processes underlying the formation of these errors. An imagination recombination paradigm was used to elicit AM conjunction errors in young and older adults. Participants also completed a battery of neuropsychological tests targeting relational memory and inhibition ability. Consistent with findings using laboratory stimuli, older adults were more susceptible to AM conjunction errors than younger adults. However, older adults were not differentially vulnerable to the inflating effects of imagination. Individual variation in AM conjunction error vulnerability was attributable to inhibitory capacity. An inability to suppress the cumulative familiarity of individual AM details appears to contribute to the heightened formation of AM conjunction errors with age. (PsycINFO Database Record
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19
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The processing of semantic relatedness in the brain: Evidence from associative and categorical false recognition effects following transcranial direct current stimulation of the left anterior temporal lobe. Cortex 2017. [DOI: 10.1016/j.cortex.2017.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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Toepper M. Dissociating Normal Aging from Alzheimer's Disease: A View from Cognitive Neuroscience. J Alzheimers Dis 2017; 57:331-352. [PMID: 28269778 PMCID: PMC5366251 DOI: 10.3233/jad-161099] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2017] [Indexed: 02/07/2023]
Abstract
Both normal aging and Alzheimer's disease (AD) are associated with changes in cognition, grey and white matter volume, white matter integrity, neural activation, functional connectivity, and neurotransmission. Obviously, all of these changes are more pronounced in AD and proceed faster providing the basis for an AD diagnosis. Since these differences are quantitative, however, it was hypothesized that AD might simply reflect an accelerated aging process. The present article highlights the different neurocognitive changes associated with normal aging and AD and shows that, next to quantitative differences, there are multiple qualitative differences as well. These differences comprise different neurocognitive dissociations as different cognitive deficit profiles, different weights of grey and white matter atrophy, and different gradients of structural decline. These qualitative differences clearly indicate that AD cannot be simply described as accelerated aging process but on the contrary represents a solid entity.
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Affiliation(s)
- Max Toepper
- Department of Psychiatry and Psychotherapy Bethel, Research Division, Evangelisches Krankenhaus Bielefeld (EvKB), Bielefeld, Germany
- Department of Psychiatry and Psychotherapy Bethel, Department of Geriatric Psychiatry, Evangelisches Krankenhaus Bielefeld (EvKB), Bielefeld, Germany
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21
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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. PSYCHOLOGICAL RESEARCH 2016; 82:429-438. [PMID: 27915365 DOI: 10.1007/s00426-016-0831-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 11/25/2016] [Indexed: 10/20/2022]
Abstract
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.
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22
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Pitarque A, Meléndez JC, Sales A, Mayordomo T, Satorres E, Escudero J, Algarabel S. The effects of healthy aging, amnestic mild cognitive impairment, and Alzheimer's disease on recollection, familiarity and false recognition, estimated by an associative process-dissociation recognition procedure. Neuropsychologia 2016; 91:29-35. [DOI: 10.1016/j.neuropsychologia.2016.07.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 07/06/2016] [Accepted: 07/10/2016] [Indexed: 11/28/2022]
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23
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Flanagan EC, Wong S, Dutt A, Tu S, Bertoux M, Irish M, Piguet O, Rao S, Hodges JR, Ghosh A, Hornberger M. False Recognition in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease-Disinhibition or Amnesia? Front Aging Neurosci 2016; 8:177. [PMID: 27489543 PMCID: PMC4951525 DOI: 10.3389/fnagi.2016.00177] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 07/04/2016] [Indexed: 11/13/2022] Open
Abstract
Episodic memory recall processes in Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) can be similarly impaired, whereas recognition performance is more variable. A potential reason for this variability could be false-positive errors made on recognition trials and whether these errors are due to amnesia per se or a general over-endorsement of recognition items regardless of memory. The current study addressed this issue by analysing recognition performance on the Rey Auditory Verbal Learning Test (RAVLT) in 39 bvFTD, 77 AD and 61 control participants from two centers (India, Australia), as well as disinhibition assessed using the Hayling test. Whereas both AD and bvFTD patients were comparably impaired on delayed recall, bvFTD patients showed intact recognition performance in terms of the number of correct hits. However, both patient groups endorsed significantly more false-positives than controls, and bvFTD and AD patients scored equally poorly on a sensitivity index (correct hits-false-positives). Furthermore, measures of disinhibition were significantly associated with false positives in both groups, with a stronger relationship with false-positives in bvFTD. Voxel-based morphometry analyses revealed similar neural correlates of false positive endorsement across bvFTD and AD, with both patient groups showing involvement of prefrontal and Papez circuitry regions, such as medial temporal and thalamic regions, and a DTI analysis detected an emerging but non-significant trend between false positives and decreased fornix integrity in bvFTD only. These findings suggest that false-positive errors on recognition tests relate to similar mechanisms in bvFTD and AD, reflecting deficits in episodic memory processes and disinhibition. These findings highlight that current memory tests are not sufficient to accurately distinguish between bvFTD and AD patients.
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Affiliation(s)
- Emma C. Flanagan
- Neuroscience Research AustraliaSydney, NSW, Australia
- Department of Clinical Neurosciences, University of CambridgeCambridge, UK
- Norwich Medical School, University of East AngliaNorwich, UK
| | - Stephanie Wong
- Neuroscience Research AustraliaSydney, NSW, Australia
- Australian Research Council Centre of Excellence in Cognition and its DisordersSydney, NSW, Australia
| | - Aparna Dutt
- Department of Neurology and Cognitive Neurology Unit, Apollo Gleneagles HospitalKolkata, India
| | - Sicong Tu
- Neuroscience Research AustraliaSydney, NSW, Australia
| | - Maxime Bertoux
- Department of Clinical Neurosciences, University of CambridgeCambridge, UK
- Norwich Medical School, University of East AngliaNorwich, UK
| | - Muireann Irish
- Neuroscience Research AustraliaSydney, NSW, Australia
- Australian Research Council Centre of Excellence in Cognition and its DisordersSydney, NSW, Australia
- School of Psychology, University of New South WalesSydney, NSW, Australia
| | - Olivier Piguet
- Neuroscience Research AustraliaSydney, NSW, Australia
- Australian Research Council Centre of Excellence in Cognition and its DisordersSydney, NSW, Australia
- School of Medical Sciences, University of New South WalesSydney, NSW, Australia
| | - Sulakshana Rao
- Department of Neurology and Cognitive Neurology Unit, Apollo Gleneagles HospitalKolkata, India
| | - John R. Hodges
- Neuroscience Research AustraliaSydney, NSW, Australia
- Australian Research Council Centre of Excellence in Cognition and its DisordersSydney, NSW, Australia
- School of Medical Sciences, University of New South WalesSydney, NSW, Australia
| | - Amitabha Ghosh
- Department of Neurology and Cognitive Neurology Unit, Apollo Gleneagles HospitalKolkata, India
| | - Michael Hornberger
- Norwich Medical School, University of East AngliaNorwich, UK
- Australian Research Council Centre of Excellence in Cognition and its DisordersSydney, NSW, Australia
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La Corte V, Serra M, George N, Pradat-Diehl P, Dalla Barba G. Different patterns of recollection impairment in confabulation reveal different disorders of consciousness: A multiple case study. Conscious Cogn 2016; 42:396-406. [PMID: 27173848 DOI: 10.1016/j.concog.2016.04.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 03/21/2016] [Accepted: 04/25/2016] [Indexed: 10/21/2022]
Abstract
Recollection is used to refer to the active process of setting up retrieval cues, evaluating the outcome, and systematically working toward a representation of a past experience that we find acceptable. In this study we report on three patients showing different patterns of confabulation affecting recollection and consciousness differentially. All patients confabulated in the episodic past domain. However, whereas in one patient confabulation affected only recollection of events concerning his personal past, present and future, in another patient confabulation also affected recollection of impersonal knowledge. The third patient showed an intermediate pattern of confabulation, which affected selectively the retrieval of past information, both personal and impersonal. We suggest that our results are in favor of a fractionation of processes involved in recollection underling different disorders of consciousness.
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Affiliation(s)
- Valentina La Corte
- Institute of Psychology, University Paris Descartes, Sorbonne Paris Cite, France; Inserm UMR 894, Center of Psychiatry and Neurosciences, Memory and Cognition Laboratory, Paris, France; Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; Departement de Neurologie, Institut de la Mémoire et de la Maladie d'Alzheimer, Hôpital de la Pitié-Salpêtrière, Paris, France.
| | - Mara Serra
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Italy
| | - Nathalie George
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Pascale Pradat-Diehl
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; AP-HP, Hôpital de La Pitié-La Salpêtrière, Service de médecine physique et de réadaptation, Paris, France
| | - Gianfranco Dalla Barba
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France; Departement de Neurologie, Institut de la Mémoire et de la Maladie d'Alzheimer, Hôpital de la Pitié-Salpêtrière, Paris, France; Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Italy; Inserm, Paris, France
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25
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Abstract
An important challenge for memory is the competition between appropriate and inappropriate information during retrieval. This competition is normally reduced thanks to controlled inhibitory processes that suppress irrelevant memories. In Alzheimer's disease (AD), compromise of suppression ability may result in strong competition between relevant and irrelevant memories during retrieval. The present review highlights this issue by examining studies using the directed forgetting method in AD. This method in which participants are typically instructed to forget no longer relevant information is argued to reflect suppression in memory. Studies using the directed forgetting method suggest that AD participants experience difficulties when they are asked to suppress no longer relevant information in working, autobiographical, source and destination memory. Difficulties in suppressing irrelevant information, as may be observed in AD, may hamper memory retrieval by activating irrelevant memories at the expense of relevant ones.
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Abstract
OBJECTIVE Memory formation is proposed to be a dual process that involves the simultaneous memorisation of both detailed information (item-specific memory) and gist information (gist memory). Memory deficits have been reported in patients with Parkinson's disease (PD); however, few studies have explicitly addressed the nature of these deficits. To obtain a detailed understanding of memory dysfunction in patients with PD, it is of crucial importance to establish whether item-specific memory and gist memory performance are impaired. The aim of this study is to explore whether gist memory and item-specific memory performance are still intact in patients with PD, as well as to determine which psychological mechanisms are responsible for memory formation. SETTING Two hospitals in northern Taiwan. PARTICIPANTS Thirty-nine patients with PD and 28 normal controls were recruited. Each participant received a gist-based recognition test following the Deese-Roediger-McDermott paradigm, as well as neuropsychological tests and measures of clinical characteristics. RESULTS Gist memory was impaired in patients with advanced-stage disease (Hoehn and Yahr (H&Y) stage: III) (F2,64=3.58, p=0.033), whereas item-specific memory was preserved throughout all disease stages. Correlation analysis showed that item-specific memory was related to executive functions in normal controls and early-stage patients with PD (H&Y stage: I-II); however, item-specific memory was related to episodic memory, rather than to executive functions, in advanced-stage patients with PD. Moreover, gist memory was related to episodic memory, but only in early-stage patients with PD. CONCLUSIONS We discovered that impaired gist memory is found in advanced-stage, but not in early-stage, patients with PD. Our findings suggest that the techniques used to take advantage of the relatively preserved gist memory in early-stage patients with PD, as well as the preserved item-specific memory in patients with PD of all stages, could be useful for memory rehabilitation programmes.
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Affiliation(s)
- Rwei-Ling Yu
- Institute of Behavioral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chun-Hsiang Tan
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Yih-Ru Wu
- Department of Neurology, Chang Gung Memorial Hospital-Linkou Branch, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Ruey-Meei Wu
- Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ming-Jang Chiu
- Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Mau-Sun Hua
- Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Psychology, National Taiwan University, Taipei, Taiwan
- Department of Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- Department of Psychiatry, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan
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27
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Guhra M, Thomas C, Boedeker S, Kreisel S, Driessen M, Beblo T, Ohrmann P, Toepper M. Linking CSF and cognition in Alzheimer's disease: Reanalysis of clinical data. Exp Gerontol 2015; 73:107-13. [PMID: 26585048 DOI: 10.1016/j.exger.2015.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 01/27/2023]
Abstract
OBJECTIVES Memory and executive deficits are important cognitive markers of Alzheimer's disease (AD). Moreover, in the past decade, cerebrospinal fluid (CSF) biomarkers have been increasingly utilized in clinical practice. Both cognitive and CSF markers can be used to differentiate between AD patients and healthy seniors with high diagnostic accuracy. However, the extent to which performance on specific mnemonic or executive tasks enables reliable estimations of the concentrations of different CSF markers and their ratios remains unclear. METHODS To address the above issues, we examined the association between neuropsychological data and CSF biomarkers in 51 AD patients using hierarchical multiple regression analyses. In the first step of these analyses, age, education and sex were entered as predictors to control for possible confounding effects. In the second step, data from a neuropsychological test battery assessing episodic memory, semantic memory and executive functioning were included to determine whether these variables significantly increased (compared to step 1) the explained variance in Aβ42 concentration, p-tau concentration, t-tau concentration, Aβ42/t-tau ratio, and Aβ42/Aβ40 ratio. RESULTS The different models explained 52% of the variance in Aβ42/t-tau ratio, 27% of the variance in Aβ42 concentration, and 28% of the variance in t-tau concentration. In particular, Aβ42/t-tau ratio was associated with verbal recognition and code shifting, with Aβ42 being related to verbal recognition and t-tau being related to code shifting. By contrast, the inclusion of neuropsychological data did not allow reliable estimations of Aβ42/Aβ40 ratio or p-tau concentration. CONCLUSION Our results showed that strong associations exist between the cognitive key symptoms of AD and the concentrations and ratios of specific CSF markers. In addition, we revealed a specific combination of neuropsychological tests that may facilitate reliable estimations of CSF concentrations, thereby providing important diagnostic information for non-invasive early AD detection.
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Affiliation(s)
- Michael Guhra
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany.
| | - Christine Thomas
- Clinical Centre Stuttgart, Clinic for Psychiatry and Psychotherapy for the Elderly, Prießnitzweg 24, D-70374 Stuttgart, Germany
| | - Sebastian Boedeker
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
| | - Stefan Kreisel
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
| | - Martin Driessen
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
| | - Thomas Beblo
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
| | - Patricia Ohrmann
- University of Muenster, Department of Psychiatry, Albert-Schweitzer-Campus 1, A9, D-48149 Muenster, Germany
| | - Max Toepper
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
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Algarabel S, Pitarque A, Sales A, Meléndez JC, Escudero J. False memories in Lewy-body disease. Scand J Psychol 2015; 56:599-606. [PMID: 26355527 DOI: 10.1111/sjop.12245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 06/19/2015] [Indexed: 11/28/2022]
Abstract
Recently, de Boysson, Belleville, Phillips et al. (2011) found that patients with Lewy-body disease (LBD) showed significantly lower rates of false memories than healthy controls, using the Deese-Roediger-McDermott (DRM) experimental procedure. Given that this result could be explained by the practically null rate of true recognition in the LBD group (0.09), we decided to replicate the study by de Boysson et al. (2011), but including a new condition that would maximize the true recognition rate (and analyze its effect on the rate of false memories). Specifically, in a DRM experiment, we manipulated (within subjects) two study and recognition conditions: in the "immediate" condition, both the LBD patients and the control group of healthy older people received a different recognition test after each study list (containing twelve words associated with a non-presented critical word), while in the "delayed" condition (similar to the one in de Boysson et al., 2011), the participants received the entire series of study lists and then took only one recognition test. The results showed that, in both samples, the "immediate" condition produced higher corrected rates of both true and false recognition than the "delayed" condition, although they were both lower in the LBD patients, which shows that these patients are capable of encoding and recognizing the general similitude underlying information (gist memory) in the right conditions.
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O'Connor MK, Deason RG, Reynolds E, Tat MJ, Flannery S, Solomon PR, Vassey EA, Budson AE. The imagination inflation effect in healthy older adults and patients with mild Alzheimer's disease. Neuropsychology 2015; 29:550-60. [PMID: 25893972 DOI: 10.1037/neu0000195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE The imagination inflation effect is a type of memory distortion defined as an increased tendency to falsely remember that an item has been seen, or an action has been performed, when it has only been imagined. For patients with very mild Alzheimer's disease (AD), susceptibility to the imagination inflation effect could have significant functional consequences in daily life. METHOD We assessed whether patients with very mild AD were more or less susceptible to the imagination inflation effect when compared with healthy older adults. In the first session, participants were read an action statement such as "fill the pillbox" and engaged in 1 of 3 activities: listened to the statement being read, performed the action, or imagined performing the action. During the second session, participants imagined action statements from the first session, as well as new action statements. During the recognition test, participants were asked to determine whether action statements were or were not performed during the first session. RESULTS We found that imagining performing actions increased the tendency of patients with very mild AD to falsely recall the action as having been performed to an extent similar to that of healthy older adults. CONCLUSION We concluded that, similar to healthy older adults, patients with very mild AD were susceptible to the imagination inflation effect, which we attributed to difficulties with source monitoring and reliance on familiarity.
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Affiliation(s)
| | | | - Erin Reynolds
- Department of Orthopaedic Surgery, University of Pittsburgh
| | - Michael J Tat
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System
| | - Sean Flannery
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System
| | | | - Elizabeth A Vassey
- Boston University Alzheimer's Disease Center, Department of Neurology, Boston University School of Medicine
| | - Andrew E Budson
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System
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State-based functional connectivity changes associate with cognitive decline in amnestic mild cognitive impairment subjects. Behav Brain Res 2015; 288:94-102. [PMID: 25907751 DOI: 10.1016/j.bbr.2015.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/04/2015] [Accepted: 04/09/2015] [Indexed: 11/21/2022]
Abstract
Episodic memory (EM) dysfunction is a central characteristic of amnestic mild cognitive impairment (aMCI) subjects, and has a high risk of converting to Alzheimer's disease (AD). However, it is unknown how the EM network is modulated when a situation is switched. Twenty-six aMCI and twenty-two cognitively normal (CN) subjects were enrolled in this study. All of the subjects completed multi-dimensional neuropsychological tests and underwent functional magnetic resonance imaging scans during a resting-state and an episodic memory retrieval task state. The EM network was constructed using a seed-based functional connectivity (FC) approach. AMCI subjects showed poorer cognitive performances in the episodic memory and executive function. We demonstrated that connectivity of the left posterior parahippocampal gyrus (LpPHG) connected to the left ventral medial prefrontal cortex and the right postcentral gyrus (RPCG) was significantly decreased in aMCI subjects compared to CN subjects. Meanwhile, there was increased connectivity of the LpPHG to the right dorsal medial prefrontal cortex (RDMPFC), RPCG, left inferior parietal cortex, and bilateral superior parietal lobe in all of the subjects that changed from a resting-state to a task-state. Interestingly, the changed LpPHG-RDMPFC connectivity strength was significantly correlated with EM scores and executive function in the aMCI subjects. As a result, general brain regions are functionally organized and integrated into the EM network, and this strongly suggests that more cognitive resources are mobilized to meet the challenge of cognitive demand in the task state. These findings extend our understanding of the underlying mechanisms of EM deficits in aMCI subjects.
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Evrard C, Colombel F, Gilet AL, Corson Y. Intact Semantic Priming of Critical Lures in Alzheimer's Disease: Implications for False Memory. J Gerontol B Psychol Sci Soc Sci 2015; 71:671-4. [PMID: 25693999 DOI: 10.1093/geronb/gbv006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 01/06/2015] [Indexed: 11/14/2022] Open
Abstract
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.
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Affiliation(s)
- Christelle Evrard
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, Nantes, France. Centre Mémoire Ressources et Recherches, Centre Hospitalier Universitaire, Nantes, France.
| | - Fabienne Colombel
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, Nantes, France
| | - Anne-Laure Gilet
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, Nantes, France
| | - Yves Corson
- Laboratoire de Psychologie des Pays de la Loire LPPL-EA 4638, Université de Nantes, Nantes, France
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Sunderaraman P, Sokolov E, Cines S, Sullo E, Orly A, Lerer B, Karlawish J, Huey E, Cosentino S. Untimed Design Fluency in Aging and Alzheimer's Disease: Psychometrics and Normative Data. APPLIED NEUROPSYCHOLOGY-ADULT 2015; 22:363-72. [PMID: 25679880 DOI: 10.1080/23279095.2014.940419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Design fluency tests, commonly used in both clinical and research contexts to evaluate nonverbal concept generation, have the potential to offer useful information in the differentiation of healthy versus pathological aging. Although normative data for older adults (OAs) are available for multiple timed versions of this test, similar data have been unavailable for a previously published untimed test, the Graphic Pattern Generation Test (GPG). Time constraints common to almost all of the available design fluency tests may cloud interpretation of higher-level executive abilities-for example, in individuals with slow processing speed. The current study examined the psychometric properties of the GPG and presents normative data in a sample of 167 healthy OAs and 110 individuals diagnosed with Alzheimer's disease (AD). Results suggest that a brief version of the GPG can be administered reliably and that this short form has high test-retest and interrater reliability. Number of perseverations was higher in individuals with AD as compared with OAs. A cutoff score of 4 or more perseverations showed a moderate degree of sensitivity (76%) and specificity (37%) in distinguishing individuals with AD and OAs. Finally, perseverations were associated with nonmemory indexes, thereby underscoring the nonverbal nature of this error in OAs and individuals with AD.
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Affiliation(s)
- Preeti Sunderaraman
- a Department of Psychology , Drexel University , Philadelphia , Pennsylvania
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Buratto LG, Zimmermann N, Ferré P, Joanette Y, Fonseca RP, Stein LM. False memories to emotional stimuli are not equally affected in right- and left-brain-damaged stroke patients. Brain Cogn 2014; 90:181-94. [PMID: 25129810 DOI: 10.1016/j.bandc.2014.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 06/14/2014] [Accepted: 07/09/2014] [Indexed: 11/18/2022]
Abstract
Previous research has attributed to the right hemisphere (RH) a key role in eliciting false memories to visual emotional stimuli. These results have been explained in terms of two right-hemisphere properties: (i) that emotional stimuli are preferentially processed in the RH and (ii) that visual stimuli are represented more coarsely in the RH. According to this account, false emotional memories are preferentially produced in the RH because emotional stimuli are both more strongly and more diffusely activated during encoding, leaving a memory trace that can be erroneously reactivated by similar but unstudied emotional items at test. If this right-hemisphere hypothesis is correct, then RH damage should result in a reduction in false memories to emotional stimuli relative to left-hemisphere lesions. To investigate this possibility, groups of right-brain-damaged (RBD, N=15), left-brain-damaged (LBD, N=15) and healthy (HC, N=30) participants took part in a recognition memory experiment with emotional (negative and positive) and non-emotional pictures. False memories were operationalized as incorrect responses to unstudied pictures that were similar to studied ones. Both RBD and LBD participants showed similar reductions in false memories for negative pictures relative to controls. For positive pictures, however, false memories were reduced only in RBD patients. The results provide only partial support for the right-hemisphere hypothesis and suggest that inter-hemispheric cooperation models may be necessary to fully account for false emotional memories.
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Affiliation(s)
| | - Nicolle Zimmermann
- Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
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Craik FIM, Barense MD, Rathbone CJ, Grusec JE, Stuss DT, Gao F, Scott CJM, Black SE. VL: a further case of erroneous recollection. Neuropsychologia 2014; 56:367-80. [PMID: 24560915 DOI: 10.1016/j.neuropsychologia.2014.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/06/2014] [Accepted: 02/08/2014] [Indexed: 11/19/2022]
Abstract
We report a single-case study of a female patient (VL) who exhibited frequent episodes of erroneous recollections triggered by everyday events. Based on neuropsychological testing, VL was classified as suffering from mild to moderate dementia (MMSE=18) and was given a diagnosis of probable Alzheimer׳s disease. Her memory functions were uniformly impaired but her verbal abilities were generally well preserved. A structural MRI scan showed extensive areas of gray matter atrophy particularly in frontal and medial-temporal (MTL) areas. Results of experimental recognition tests showed that VL had very high false alarm rates on tests using pictures, faces and auditory stimuli, but lower false alarm rates on verbal tests. We provide a speculative account of her erroneous recollections in terms of her MTL and frontal pathology. In outline, we suggest that owing to binding failures in MTL regions, VL׳s recognition processes were forced to rely on earlier than normal stages of analysis. Environmental features on a given recognition trial may have combined with fragments persisting from previous trials resulting in erroneous feelings of familiarity and of recollection that were not discounted or edited out, due to her impaired frontal processes.
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Affiliation(s)
- Fergus I M Craik
- Rotman Research Institute, Toronto, ON, Canada M6A 2E1; University of Toronto, ON, Canada.
| | - Morgan D Barense
- Rotman Research Institute, Toronto, ON, Canada M6A 2E1; University of Toronto, ON, Canada
| | - Clare J Rathbone
- Rotman Research Institute, Toronto, ON, Canada M6A 2E1; Oxford Brookes University, Oxford, UK
| | | | - Donald T Stuss
- Rotman Research Institute, Toronto, ON, Canada M6A 2E1; University of Toronto, ON, Canada
| | - Fuqiang Gao
- Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | | | - Sandra E Black
- Rotman Research Institute, Toronto, ON, Canada M6A 2E1; University of Toronto, ON, Canada; Sunnybrook Health Sciences Centre, Toronto, ON, Canada
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Bouzerda-Wahlen A, Nahum L, Ptak R, Schnider A. Mechanism of disorientation: Reality filtering versus content monitoring. Cortex 2013; 49:2628-36. [DOI: 10.1016/j.cortex.2013.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 05/13/2013] [Accepted: 07/30/2013] [Indexed: 10/26/2022]
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Hampson NE, Kemp S, Coughlan† AK, Moulin CJA, Bhakta BB. Effort Test Performance in Clinical Acute Brain Injury, Community Brain Injury, and Epilepsy Populations. APPLIED NEUROPSYCHOLOGY-ADULT 2013; 21:183-94. [DOI: 10.1080/09084282.2013.787425] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Natalie E. Hampson
- a Department of Neuropsychology , Salford Royal NHS Foundation Trust , Salford , United Kingdom
| | - Steven Kemp
- b Department of Neuropsychology , St. James's University Hospital , Leeds , United Kingdom
| | - Anthony K. Coughlan†
- b Department of Neuropsychology , St. James's University Hospital , Leeds , United Kingdom
| | | | - Bipin B. Bhakta
- d Academic Department of Rehabilitation Medicine, Faculty of Medicine and Health , University of Leeds , Leeds , United Kingdom
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Abstract
The autobiographical Implicit Association Test (aIAT; Sartori et al., 2008) is a variant of the Implicit Association Test (IAT; Greenwald et al., 1998) that is used to establish whether an autobiographical memory is encoded in the respondent's mind/brain. More specifically, with the aIAT, it is possible to evaluate which one of two autobiographical events is true. The method consists of a computerized categorization task. The aIAT includes stimuli belonging to four categories, two of them are logical categories and are represented by sentences that are always true (e.g., I am in front of a computer) or always false (e.g., I am climbing a mountain) for the respondent; two other categories are represented by alternative versions of an autobiographical event (e.g., I went to Paris for Christmas, or I went to New York for Christmas), only one of which is true. The true autobiographical event is identified because, in a combined block, it gives rise to faster reaction times when it shares the same motor response with true sentences. Here, we reviewed all the validation experiments and found more than 90% accuracy in detecting the true memory. We show that agreement in identifying the true autobiographical memory of the same aIAT repeated twice is, on average, more than 90%, and we report a technique for estimating accuracy associated with a single classification based on the D-IAT value, which may be used in single subject's investigations. We show that the aIAT might be used to identify also true intentions and reasons and conclude with a series of guidelines for building an effective aIAT.
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Affiliation(s)
- Sara Agosta
- Center for Neuroscience and Cognitive Systems, Italian Institute of Technology Rovereto, Italy
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Kivisaari SL, Monsch AU, Taylor KI. False positives to confusable objects predict medial temporal lobe atrophy. Hippocampus 2013; 23:832-41. [DOI: 10.1002/hipo.22137] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2013] [Indexed: 02/01/2023]
Affiliation(s)
- Sasa L. Kivisaari
- Memory ClinicDepartment of GeriatricsUniversity Hospital BaselBasel Switzerland
- Department of Behavioural SciencesUniversity of Helsinki Finland
| | - Andreas U. Monsch
- Memory ClinicDepartment of GeriatricsUniversity Hospital BaselBasel Switzerland
- University of BaselBasel Switzerland
| | - Kirsten I. Taylor
- Memory ClinicDepartment of GeriatricsUniversity Hospital BaselBasel Switzerland
- University Center for Medicine of Aging BaselBasel Switzerland
- Centre for SpeechLanguage and the BrainDepartment of Experimental PsychologyUniversity of CambridgeDowning StreetCambridge United Kingdom
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Sweeney-Reed CM, Riddell PM, Ellis JA, Freeman JE, Nasuto SJ. Neural correlates of true and false memory in mild cognitive impairment. PLoS One 2012; 7:e48357. [PMID: 23118992 PMCID: PMC3485202 DOI: 10.1371/journal.pone.0048357] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 09/24/2012] [Indexed: 12/04/2022] Open
Abstract
The goal of this research was to investigate the changes in neural processing in mild cognitive impairment. We measured phase synchrony, amplitudes, and event-related potentials in veridical and false memory to determine whether these differed in participants with mild cognitive impairment compared with typical, age-matched controls. Empirical mode decomposition phase locking analysis was used to assess synchrony, which is the first time this analysis technique has been applied in a complex cognitive task such as memory processing. The technique allowed assessment of changes in frontal and parietal cortex connectivity over time during a memory task, without a priori selection of frequency ranges, which has been shown previously to influence synchrony detection. Phase synchrony differed significantly in its timing and degree between participant groups in the theta and alpha frequency ranges. Timing differences suggested greater dependence on gist memory in the presence of mild cognitive impairment. The group with mild cognitive impairment had significantly more frontal theta phase locking than the controls in the absence of a significant behavioural difference in the task, providing new evidence for compensatory processing in the former group. Both groups showed greater frontal phase locking during false than true memory, suggesting increased searching when no actual memory trace was found. Significant inter-group differences in frontal alpha phase locking provided support for a role for lower and upper alpha oscillations in memory processing. Finally, fronto-parietal interaction was significantly reduced in the group with mild cognitive impairment, supporting the notion that mild cognitive impairment could represent an early stage in Alzheimer's disease, which has been described as a 'disconnection syndrome'.
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Affiliation(s)
- Catherine M Sweeney-Reed
- Memory and Consciousness Research Group, University Clinic for Neurology and Stereotactic Neurosurgery, Medical Faculty, Otto von Guericke University, Magdeburg, Germany.
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Abstract
Converging evidence from patient and neuroimaging studies suggests that memory is a collection of abilities that use different neuroanatomic systems. Neurologic injury may impair one or more of these memory systems. Episodic memory allows us to mentally travel back in time and relive an episode of our life. Episodic memory depends on the hippocampus, other medial temporal lobe structures, the limbic system, and the frontal lobes, as well as several other brain regions. Semantic memory provides our general knowledge about the world and is unconnected to any specific episode of our life. Although semantic memory likely involves much of the neocortex, the inferolateral temporal lobes (particularly the left) are most important. Procedural memory enables us to learn cognitive and behavioral skills and algorithms that operate at an automatic, unconscious level. Damage to the basal ganglia, cerebellum, and supplementary motor area often impair procedural memory.
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Marini M, Agosta S, Mazzoni G, Barba GD, Sartori G. True and False DRM Memories: Differences Detected with an Implicit Task. Front Psychol 2012; 3:310. [PMID: 22969740 PMCID: PMC3427911 DOI: 10.3389/fpsyg.2012.00310] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 08/06/2012] [Indexed: 11/13/2022] Open
Abstract
Memory is prone to illusions. When people are presented with lists of words associated with a non-presented critical lure, they produce a high level of false recognitions (false memories) for non-presented related stimuli indistinguishable, at the explicit level, from presented words (DRM paradigm). We assessed whether true and false DRM memories can be distinguished at the implicit level by using the autobiographical IAT (aIAT), a novel method based on indirect measures that permits to detect true autobiographical events encoded in the respondent's mind/brain. In our experiment, after a DRM task participants performed two aIATs: the first aimed at testing implicit memory for presented words (true-memories aIAT) and the second aimed at evaluating implicit memory for critical lures (false-memories aIAT). Specifically, the two aIATs assessed the association of presented words and critical lures with the logical dimension "true." Results showed that the aIAT detected a greater association of presented words than critical lures with the logical dimension "true." This result indicates that although true and false DRM memories are indistinguishable at the explicit level a different association of the true and false DRM memories with the logical dimension "true" can be detected at the implicit level, and suggests that the aIAT may be a sensitive instrument to detect differences between true and false DRM memories.
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Sauzéon H, Arvind Pala P, Larrue F, Wallet G, Déjos M, Zheng X, Guitton P, N'Kaoua B. The use of virtual reality for episodic memory assessment: effects of active navigation. Exp Psychol 2012; 59:99-108. [PMID: 22044787 DOI: 10.1027/1618-3169/a000131] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Episodic memory was assessed using Virtual Reality (VR). Forty-four (44) subjects visualized a target virtual apartment containing specific objects in each room. Then they visualized a second virtual apartment comprised of specific objects and objects shared by the two apartments. Subjects navigated in the virtual apartments in one of the following two conditions: active and passive. Four main episodic memory components were scored from the VR exposures: (1) learning effect; (2) active forgetting effect; (3) strategies at encoding and at retrieval; and (4) false recognitions (FRs). The effect of navigation mode (active vs. passive) on each memory component was examined. Active subjects had better learning and retrieval (recognition hits) performances compared to passive subjects. A beneficial effect of active navigation was also observed on the source-based FR rates. Active subjects made fewer source-based FRs compared to passive subjects. These overall results for the effect of active navigation are discussed in terms of the distinction between item-specific and relational processing.
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Affiliation(s)
- Hélène Sauzéon
- University of Bordeaux 2, Laboratoire EA 487 Cognition et Facteurs Humains, Bordeaux, Aquitaine, France.
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Deason RG, Hussey EP, Ally BA, Budson AE. Changes in response bias with different study-test delays: evidence from young adults, older adults, and patients with Alzheimer's disease. Neuropsychology 2012; 26:119-26. [PMID: 22409339 DOI: 10.1037/a0026330] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Along with impaired discrimination, patients with Alzheimer's disease (AD) often show an abnormally liberal response bias (greater tendency to respond "old"). Previously we matched discrimination by varying study-test list length and found that participants' usual bias is maintained, such that patients with AD were more liberal than healthy controls. However, this pattern could be a result of the way in which discrimination was matched. In this experiment, we examined whether matching discrimination with the use of a delay would lead to a liberal response bias in healthy younger and older adults as it might lead to the use of more similar memorial processing to the patients with AD. METHOD Younger adults, older adults, and patients with AD were run in 2 study-test sessions, with study and recognition test separated by either a 1-min or 1-day delay. RESULTS With the 1-min delay, both younger adults and healthy older adults showed a conservative response bias, while patients with AD showed a liberal response bias. When discrimination was matched between patients with AD and controls by the use of a delay, response bias was also matched, with all participants showing a more liberal response bias. CONCLUSIONS The current study suggests that how discrimination is matched between patients with AD and controls matters greatly. Potentially, this liberal bias is a result of healthy younger and older adults relying primarily on familiarity at the longer delay, thus using more similar memorial processes to patients with AD who are dependent on familiarity at any delay.
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Affiliation(s)
- Rebecca G Deason
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, 150 S. Huntington Ave, Boston, MA 02130, USA.
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MacDuffie KE, Atkins AS, Flegal KE, Clark CM, Reuter-Lorenz PA. Memory distortion in Alzheimer's disease: deficient monitoring of short- and long-term memory. Neuropsychology 2012; 26:509-16. [PMID: 22746309 PMCID: PMC3389800 DOI: 10.1037/a0028684] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE This study measured distortions of memory during short-term memory (STM) and long-term memory (LTM) versions of a semantically associated word list learning paradigm. Performance of patients with mild-to-moderate Alzheimer's disease (AD; MMSE ≥16) was compared with performance of age-matched, healthy older adult participants. METHOD In a STM version of the Deese-Roediger-McDermott (DRM) task, participants viewed four-word lists and were prompted for recall after a brief interval. The LTM task tested recall memory for 12-word lists. RESULTS Compared with the healthy group, the AD participants show greater impairment on the LTM task than on the STM task, although veridical recall is significantly reduced on both tasks. Furthermore, on both memory tasks, (1) participants with AD generate more nonsemantic intrusions than healthy older adult participants, and (2) semantic intrusion rate, when computed as a proportion of total recall, does not differ between groups. Notably, nonsemantic intrusions are consistently high for AD participants across both STM and LTM despite a marked difference in recall accuracy (65% and 23%, respectively). CONCLUSIONS STM impairment with some preserved semantic processing is evident in AD. The extent and variety of intrusions reported by AD participants indicates a breakdown in their ability to monitor and constrain their recall responses, even within seconds of initial learning.
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Affiliation(s)
- Katherine E MacDuffie
- Department of Psychology and Neuroscience, Duke University, 417 Chapel Drive, Box 90086, Durham, NC 27708, USA.
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Abstract
BACKGROUND Source monitoring (SM) refers to our ability to discriminate between memories from different sources. METHODS Twenty healthy high-cognitive functioning older adults, 20 healthy low-cognitive functioning older adults, and 20 older adults with dementia of Alzheimer's type (DAT) were asked to perform a series of SM tasks that varied in terms of the to-be-remembered source attribute (perceptual, spatial, temporal, semantic, social, and affective details). RESULTS Results indicated that older DAT adults had greater difficulty in SM compared to the healthy control groups, especially with spatial and semantic details. CONCLUSIONS Data are discussed in terms of the SM framework and suggest that poor memory for some types of source information may be considered as an important indicator of clinical memory function when assessing for the presence and severity of dementia.
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Deason RG, Hussey EP, Budson AE, Ally BA. Gist-based conceptual processing of pictures remains intact in patients with amnestic mild cognitive impairment. Neuropsychology 2012; 26:202-8. [PMID: 22229341 DOI: 10.1037/a0026958] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE The picture superiority effect, better memory for pictures compared to words, has been found in young adults, healthy older adults, and, most recently, in patients with Alzheimer's disease and mild cognitive impairment. Although the picture superiority effect is widely found, there is still debate over what drives this effect. One main question is whether it is enhanced perceptual or conceptual information that leads to the advantage for pictures over words. In this experiment, we examined the picture superiority effect in healthy older adults and patients with amnestic mild cognitive impairment (MCI) to better understand the role of gist-based conceptual processing. METHOD We had participants study three exemplars of categories as either words or pictures. In the test phase, participants were again shown pictures or words and were asked to determine whether the item was in the same category as something they had studied earlier or whether it was from a new category. RESULTS We found that all participants demonstrated a robust picture superiority effect, better performance for pictures than for words. CONCLUSIONS These results suggest that the gist-based conceptual processing of pictures is preserved in patients with MCI. While in healthy older adults preserved recollection for pictures could lead to the picture superiority effect, in patients with MCI it is most likely that the picture superiority effect is a result of spared conceptually based familiarity for pictures, perhaps combined with their intact ability to extract and use gist information.
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Affiliation(s)
- Rebecca G Deason
- Center for Translational Cognitive Neuroscience, VA Boston Healthcare System, Boston, MA, USA
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Saito M, Nishio Y, Kanno S, Uchiyama M, Hayashi A, Takagi M, Kikuchi H, Yamasaki H, Shimomura T, Iizuka O, Mori E. Cognitive profile of idiopathic normal pressure hydrocephalus. Dement Geriatr Cogn Dis Extra 2011; 1:202-11. [PMID: 22163245 PMCID: PMC3199897 DOI: 10.1159/000328924] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background/Aims Frontal lobe dysfunction is believed to be a primary cognitive symptom in idiopathic normal pressure hydrocephalus (iNPH); however, the neuropsychology of this disorder remains to be fully investigated. The objective of this study was to delineate a comprehensive profile of cognitive dysfunction in iNPH and evaluate the effects of cerebrospinal fluid (CSF) shunt surgery on cognitive dysfunction. Methods A total of 32 iNPH patients underwent neuropsychological testing of memory, attention, language, executive function, and visuoperceptual and visuospatial abilities. Of these 32 patients, 26 were reevaluated approximately 1 year following CSF shunt surgery. The same battery of tests was performed on 32 patients with Alzheimer's disease (AD) and 30 healthy elderly controls. Results The iNPH patients displayed baseline deficits in attention, executive function, memory, and visuoperceptual and visuospatial functions. Impairments of attention, executive function, and visuoperceptual and visuospatial abilities in iNPH patients were more severe than in those with AD, whereas the degree of memory impairment was comparable to that in AD patients. A significant improvement in executive function was observed following shunt surgery. Conclusion Patients with iNPH are impaired in various aspects of cognition involving both ‘frontal’ executive functions and ‘posterior cortical’ functions. Shunt treatment can ameliorate executive dysfunction.
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Affiliation(s)
- Makoto Saito
- Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Graduate School of Medicine, Sendai
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Episodic retrieval and the cortical binding of relational activity. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2011; 11:277-91. [DOI: 10.3758/s13415-011-0031-4] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Abe N, Fujii T, Nishio Y, Iizuka O, Kanno S, Kikuchi H, Takagi M, Hiraoka K, Yamasaki H, Choi H, Hirayama K, Shinohara M, Mori E. False item recognition in patients with Alzheimer's disease. Neuropsychologia 2011; 49:1897-902. [PMID: 21419789 DOI: 10.1016/j.neuropsychologia.2011.03.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 03/09/2011] [Accepted: 03/11/2011] [Indexed: 11/30/2022]
Abstract
Recent evidence suggests that patients with Alzheimer's disease (AD), as compared with normal individuals, exhibit increased false recognition by stimulus repetition in the Deese-Roediger-McDermott (DRM) task or associative recognition memory tasks, probably due to impaired recollection-based monitoring. However, because of possible alternative explanations for the findings of these previous studies, the evidence for impaired recollection-based monitoring in AD patients remains inconclusive. In this study, we employed stimulus repetition in old/new recognition judgments of single-item picture memory without a factor of association between the stimuli and examined whether AD patients showed increased false item recognition as compared with healthy controls. AD patients and healthy controls studied single-item pictures presented either once or three times. They were later asked to make an old/new recognition judgment in response to (a) Same pictures, pictures identical to those seen at encoding, (b) Similar lures, novel pictures similar to but not identical to those seen at encoding, and (c) Dissimilar lures, novel pictures not similar to those seen at encoding. For Same pictures, repeated presentation of stimuli increased the proportion of "old" responses in both groups. For Similar lures, repeated presentation of stimuli increased the rate of "old" responses in AD patients but not in control subjects. The results of the present study clearly demonstrated elevated false recognition by stimulus repetition in single-item recognition in AD patients. The present findings strongly support the view that AD patients are impaired in their ability to use item-specific recollection in order to avoid false recognition.
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Affiliation(s)
- Nobuhito Abe
- Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan
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de Boysson C, Belleville S, Phillips N, Johns E, Goupil D, Souchay C, Bouchard R, Chertkow H. False recognition in Lewy-body disease and frontotemporal dementia. Brain Cogn 2011; 75:111-8. [DOI: 10.1016/j.bandc.2010.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 10/01/2010] [Accepted: 10/27/2010] [Indexed: 11/25/2022]
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