Implicit Memory Performance of Patients With Alzheimer's Disease: A Brief Review

1995 ◽  
Vol 7 (3) ◽  
pp. 385-392 ◽  
Author(s):  
Marko Jelicic ◽  
Annette E. Bonebakker ◽  
Benno Bonke
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Implicit Memory ◽  
Learning Experience ◽  
Memory Performance ◽  
Future Research ◽  
Impaired Performance ◽  
Conscious Recollection ◽  
Previous Learning ◽  
Normal Performance

Memory can be assessed with either explicit or implicit tasks. Implicit memory tasks, in contrast with explicit tasks, do not refer to conscious recollection of a previous learning experience. Implicit memory is revealed by a change in task performance that can be attributed to previous learning. Amnesic patients perform poorly on explicit memory tasks, but exhibit normal performance on implicit tasks. Recently, researchers have studied the implicit memory performance of patients with Alzheimer's disease. This article aims to give an overview of the performance of Alzheimer patients on four tasks of implicit memory. Compared with normal elderly controls, patients with Alzheimer's disease seem to demonstrate impaired performance on conceptual, but not on perceptual, implicit memory tasks. This dissociation could yield important information about the neurologic systems subserving implicit memory processes. Some suggestions for future research into the implicit memory of Alzheimer patients are given.

scholarly journals 0421 Decreased Actigraphic Daytime Activity is Associated with Lower Memory Performance in Cognitively-Unimpaired Individuals with Autosomal Dominant Alzheimer’s Disease

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A161-A161
Author(s):  
E Pardilla-Delgado ◽  
L Ramirez Gomez ◽  
A Y Baena ◽  
M I Montes ◽  
Y Bocanegra ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Memory Performance ◽  
Word List ◽  
Brain Regions ◽  
Future Research ◽  
Daytime Activity ◽  
Mutation Carriers ◽  
Wrist Actigraphy ◽  
Circadian Dysfunction

Abstract Introduction Alzheimer’s disease (AD) impacts brain regions that control circadian regulation systems such as wakefulness and daytime physical activity. Recent evidence shows that AD pathology is damaging for wake-promoting neurons. Whether early changes in wakefulness and daytime activity occur during asymptomatic stages of familial AD (fAD) remains unknown. In this study, we aimed to investigate whether daytime activity differs between cognitively-unimpaired carriers of early-onset fAD and age-matched non-carrier family members. Further, we examined the associations between daytime activity and memory performance. Methods A total of 25 members of the large Colombian kindred with the Presenilin1 (PSEN1) E280A mutation were included in the study (9 mutation carriers and 16 non-carriers, mean age=38.2). PSEN1 mutation carriers develop dementia before the age of 50. All subjects underwent wrist actigraphy for 7-14 days to measure daytime activity (average activity per minute and per epoch), and completed the CERAD Word List Learning and the Free and Cued Selective Reminding Test (FCSRT). Results Compared to non-carriers, mutation carriers had less average daytime activity (Mann-Whitney U Test p=.04). Higher average daytime activity was associated with better memory recall in both the CERAD word list delayed recall (r=.47, p=.05) and the FCRST delayed total recall (r=.53, p=.02). No associations with age were observed. Conclusion Our results suggest that cognitively-unimpaired mutation carriers have reduced daytime activity, years before the onset of dementia. Reduced daytime activity in carriers is also associated with lower memory performance. Our preliminary findings add to the growing evidence that circadian dysfunction is present in early AD, and may play an important role in subsequent memory impairment. Future research with large samples is needed to further examine sleep and circadian dysfunction in asymptomatic individuals at genetic risk for AD. Support NIA 5R01AG054671-03 to YTQ

Preserved Implicit Memory for Lexical Information in Alzheimer's Disease

1992 ◽  
Vol 74 (3) ◽  
pp. 747-754 ◽  
Author(s):  
T. J. Perfect ◽  
J. J. Downes ◽  
P. De Mornay Davies ◽  
K. Wilson
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Implicit Memory ◽  
Early Stage ◽  
Memory Performance ◽  
Elderly Subjects ◽  
Anagram Solution ◽  
Lexical Information ◽  
Lexical Priming ◽  
Word Stem Completion

Recent studies have suggested that there is a specific impairment of implicit memory for lexical priming in Alzheimer's Disease. However, there are problems in accepting data from the word-stem completion paradigm as evidence of pure implicit-memory performance. To assess whether Alzheimer's Disease patients are relatively impaired on implicit memory for lexical information an anagram-solution task was adopted. A group of 16 early stage Alzheimer's Disease patients and a group of 16 normal elderly subjects were presented a list of 40 target words. Subsequent free recall was significantly poorer in the former group, but while both groups were significantly better at solving anagrams for words they had previously seen, there was no difference between the two groups in the amount of priming. The data are consistent with the view that previous reports of an implicit deficit in Alzheimer's Disease may not generalise to implicit tasks independent of explicit-memory performance.

Conceptual implicit memory performance in Alzheimer's disease.

2001 ◽  
Vol 15 (4) ◽  
pp. 483-491 ◽  
Author(s):  
Michele M. Lazzara ◽  
Andrew P. Yonelinas ◽  
Beth A. Ober
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Implicit Memory ◽  
Memory Performance

Implicit memory for words presented in short texts is preserved in Alzheimer's disease

2002 ◽  
Vol 33 (1) ◽  
pp. 169-174 ◽  
Author(s):  
J.-F. CAMUS ◽  
S. NICOLAS ◽  
E. WENISCH ◽  
I. MORRONE ◽  
F. BLANCHARD ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Implicit Memory ◽  
Explicit Memory ◽  
Priming Effect ◽  
Semantic Processing ◽  
Memory Performance ◽  
Read Aloud ◽  
Healthy Controls ◽  
Perceptual Aspect

Background. The level of efficiency of implicit memory in Alzheimer's disease remains unclear as previous studies using stem completion tasks have led to contradictory results.Method. The present study used target words embedded in significant short texts that subjects were required to read aloud (i.e. to enhance semantic processing). Texts were presented in two perceptual situations: ‘simple’ (blank spaces delimitating words) and ‘complex’ (spaces were filled by ‘8’s). In the completion phase, patients had to write the first word that came to mind in order to complete a three-letter stem. The recognition phase explored explicit memory performance. The performance of 24 Alzheimer patients was compared to a matched sample of healthy controls.Results. Reading times differed between groups and were shorter for healthy controls. Recognition was dramatically lower in patients, thus confirming the alteration of explicit memory in this pathology. However, a significant priming effect (e.g. the tendency to complete the stem with the aid of a previously explored word) was present in both groups and did not differ between patients and healthy controls.Conclusions. The absence of a correlation between priming and recognition scores suggests that this result cannot be explained by an explicit memory bias. Moreover, as the priming level was identical whatever the perceptual aspect of the text, we suggest that the priming effect is not only mediated by perceptual processes but also by lexical and conceptual processes, which to some extent are preserved during the light and moderate stages of this disease.

Priming performance in Alzheimer's disease: The role of task sensitivity

2001 ◽  
Vol 7 (3) ◽  
pp. 294-301 ◽  
Author(s):  
LAUREN E. NORTON ◽  
ARNE L. OSTERGAARD
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Memory Performance ◽  
Priming Effects ◽  
Test Task ◽  
Healthy Older Adults ◽  
Impaired Performance ◽  
Identification Test

Studies examining implicit memory performance in Alzheimer's disease (AD) have yielded inconsistent findings, with these patients demonstrating impaired performance within some priming studies and intact performance within others. The present study examined the role of task sensitivity in detecting impaired priming in memory-impaired patients. Twelve healthy older adults and 12 AD patients were administered a picture fragment identification test. Task sensitivity was increased by employing stimulus cues expected to produce larger and more variable priming effects than obtained in previous studies. A simple comparison of priming scores revealed that the AD patients demonstrated significantly impaired priming relative to normal control participants. However, further analysis of priming in relation to certain stimulus characteristics revealed that AD patients often demonstrated impaired priming when overall priming effects were large but relatively intact priming when priming effects were small. These findings suggest that the prevention of ceiling effects in control participants may aid in the detection of impaired priming in patient populations. (JINS, 2001, 7, 294–301.)

Impact of Comorbid Depression on Serial Position Effects in Alzheimer’s Disease

GeroPsych ◽  
2014 ◽  
Vol 27 (4) ◽  
pp. 161-169 ◽  
Author(s):  
Nienke A. Hofrichter ◽  
Sandra Dick ◽  
Thomas G. Riemer ◽  
Carsten Schleussner ◽  
Monique Goerke ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Serial Position ◽  
Episodic Memory ◽  
Memory Performance ◽  
Memory Function ◽  
Word List ◽  
Position Effects ◽  
Serial Position Effects ◽  
List Memory

Hippocampal dysfunction and deficits in episodic memory have been reported for both Alzheimer’s disease (AD) and major depressive disorder (MDD). Primacy performance has been associated with hippocampus-dependent episodic memory, while recency may reflect working memory performance. In this study, serial position profiles were examined in a total of 73 patients with MDD, AD, both AD and MDD, and healthy controls (HC) by means of CERAD-NP word list memory. Primacy performance was most impaired in AD with comorbid MDD, followed by AD, MDD, and HC. Recency performance, on the other hand, was comparable across groups. These findings indicate that primacy in AD is impaired in the presence of comorbid MDD, suggesting additive performance decrements in this specific episodic memory function.

Sources of priming in text rereading: Intact implicit memory for new associations in older adults and in patients with Alzheimer's disease.

1997 ◽  
Vol 12 (3) ◽  
pp. 536-547 ◽  
Author(s):  
Laura A. Monti ◽  
John D. E. Gabrieli ◽  
Robert S. Wilson ◽  
Laurel A. Beckett ◽  
Eliza Grinnell ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Implicit Memory ◽  
New Associations

scholarly journals Application of deep learning in detecting neurological disorders from magnetic resonance images: a survey on the detection of Alzheimer’s disease, Parkinson’s disease and schizophrenia

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Manan Binth Taj Noor ◽  
Nusrat Zerin Zenia ◽  
M Shamim Kaiser ◽  
Shamim Al Mamun ◽  
Mufti Mahmud
Keyword(s):  
Alzheimer’S Disease ◽  
Parkinson’S Disease ◽  
Alzheimer's Disease ◽  
Parkinson's Disease ◽  
Deep Learning ◽  
Magnetic Resonance ◽  
Neurological Disorders ◽  
Magnetic Resonance Images ◽  
Future Research ◽  
Comparative Performance

Abstract Neuroimaging, in particular magnetic resonance imaging (MRI), has been playing an important role in understanding brain functionalities and its disorders during the last couple of decades. These cutting-edge MRI scans, supported by high-performance computational tools and novel ML techniques, have opened up possibilities to unprecedentedly identify neurological disorders. However, similarities in disease phenotypes make it very difficult to detect such disorders accurately from the acquired neuroimaging data. This article critically examines and compares performances of the existing deep learning (DL)-based methods to detect neurological disorders—focusing on Alzheimer’s disease, Parkinson’s disease and schizophrenia—from MRI data acquired using different modalities including functional and structural MRI. The comparative performance analysis of various DL architectures across different disorders and imaging modalities suggests that the Convolutional Neural Network outperforms other methods in detecting neurological disorders. Towards the end, a number of current research challenges are indicated and some possible future research directions are provided.

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