Structural and functional connectivity uniquely contribute to explained variance in episodic memory performance in cognitively normal older adults

Abstract Objectives The current study examined recognition memory dysfunction and its neuroanatomical substrates in cognitively normal older adults and those diagnosed with mild cognitive impairment (MCI). Methods Participants completed the Mnemonic Similarity Task, which provides simultaneous measures of recognition memory and mnemonic discrimination. They also underwent structural neuroimaging to assess volume of medial temporal cortex and hippocampal subfields. Results As expected, individuals diagnosed with MCI had significantly worse recognition memory performance and reduced volume across medial temporal cortex and hippocampal subfields relative to cognitively normal older adults. After controlling for diagnostic group differences, however, recognition memory was significantly related to whole hippocampus volume, and to volume of the dentate gyrus/CA3 subfield in particular. Recognition memory was also related to mnemonic discrimination, a fundamental component of episodic memory that has previously been linked to dentate gyrus/CA3 structure and function. Discussion Results reveal that hippocampal subfield volume is sensitive to individual differences in recognition memory in older adults independent of clinical diagnosis. This supports the notion that episodic memory declines along a continuum within this age group, not just between diagnostic groups.

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P2-343: Correlations between functional connectivity, structural brain volume, and episodic memory in cognitively normal older adults

Alzheimer s & Dementia ◽

10.1016/j.jalz.2011.05.1220 ◽

2011 ◽

Vol 7 ◽

pp. S420-S421

Author(s):

Jing He ◽

Owen Carmichael ◽

Evan Fletcher ◽

Baljeet Singh ◽

Ana-Maria Iosif ◽

...

Keyword(s):

Older Adults ◽

Functional Connectivity ◽

Episodic Memory ◽

Brain Volume ◽

Cognitively Normal ◽

Structural Brain

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A systematic review and meta-analysis of individual differences in naturalistic sleep quality and episodic memory performance in young and older adults

Neuroscience & Biobehavioral Reviews ◽

10.1016/j.neubiorev.2021.05.010 ◽

2021 ◽

Author(s):

Emily Hokett ◽

Aditi Arunmozhi ◽

Jessica Campbell ◽

Paul Verhaeghen ◽

Audrey Duarte

Keyword(s):

Systematic Review ◽

Older Adults ◽

Individual Differences ◽

Episodic Memory ◽

Sleep Quality ◽

Memory Performance ◽

Meta Analysis

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Wisdom and fluid intelligence are dissociable in healthy older adults

International Psychogeriatrics ◽

10.1017/s1041610221000521 ◽

2021 ◽

pp. 1-11

Author(s):

Cutter A. Lindbergh ◽

Heather Romero-Kornblum ◽

Sophia Weiner-Light ◽

J. Clayton Young ◽

Corrina Fonseca ◽

...

Keyword(s):

Older Adults ◽

Episodic Memory ◽

San Francisco ◽

Fluid Intelligence ◽

Memory Performance ◽

Positive Association ◽

Cross Sectional Study ◽

Self Report ◽

Cross Sectional ◽

Healthy Older Adults

ABSTRACT Objectives: The relationship between wisdom and fluid intelligence (Gf) is poorly understood, particularly in older adults. We empirically tested the magnitude of the correlation between wisdom and Gf to help determine the extent of overlap between these two constructs. Design: Cross-sectional study with preregistered hypotheses and well-powered analytic plan (https://osf.io/h3pjx). Setting: Memory and Aging Center at the University of California San Francisco, located in the USA. Participants: 141 healthy older adults (mean age = 76 years; 56% female). Measurements: Wisdom was quantified using a well-validated self-report-based scale (San Diego Wisdom Scale or SD-WISE). Gf was assessed via composite measures of processing speed (Gf-PS) and executive functioning (Gf-EF). The relationships of SD-WISE scores to Gf-PS and Gf-EF were tested in bivariate correlational analyses and multiple regression models adjusted for demographics (age, sex, and education). Exploratory analyses evaluated the relationships between SD-WISE and age, episodic memory performance, and dorsolateral and ventromedial prefrontal cortical volumes on magnetic resonance imaging. Results: Wisdom showed a small, positive association with Gf-EF (r = 0.181 [95% CI 0.016, 0.336], p = .031), which was reduced to nonsignificance upon controlling for demographics, and no association with Gf-PS (r = 0.019 [95% CI −0.179, 0.216], p = .854). Wisdom demonstrated a small, negative correlation with age (r = −0.197 [95% CI −0.351, −0.033], p = .019), but was not significantly related to episodic memory or prefrontal volumes. Conclusions: Our findings indicate that most of the variance in wisdom (>95%) is unaccounted for by Gf. The independence of wisdom from cognitive functions that reliably show age-associated declines suggests that it may hold unique potential to bolster decision-making, interpersonal functioning, and other everyday activities in older adults.

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Effects of amnesia on processing in the hippocampus and default mode network during a naturalistic memory task: a case study

10.31234/osf.io/e9n8c ◽

2018 ◽

Author(s):

Christiane Oedekoven ◽

James L. Keidel ◽

Stuart Anderson ◽

Angus Nisbet ◽

Chris Bird

Keyword(s):

Functional Connectivity ◽

Episodic Memory ◽

Memory Performance ◽

Memory Task ◽

Structural Mri ◽

Brain Regions ◽

Left Hippocampus ◽

Cortical Regions ◽

The Right ◽

Encoding And Retrieval

Despite their severely impaired episodic memory, individuals with amnesia are able to comprehend ongoing events. Online representations of a current event are thought to be supported by a network of regions centred on the posterior midline cortex (PMC). By contrast, episodic memory is widely believed to be supported by interactions between the hippocampus and these cortical regions. In this MRI study, we investigated the encoding and retrieval of lifelike events (video clips) in a patient with severe amnesia likely resulting from a stroke to the right thalamus, and a group of 20 age-matched controls. Structural MRI revealed grey matter reductions in left hippocampus and left thalamus in comparison to controls. We first characterised the regions activated in the controls while they watched and retrieved the videos. There were no differences in activation between the patient and controls in any of the regions. We then identified a widespread network of brain regions, including the hippocampus, that were functionally connected with the PMC in controls. However, in the patient there was a specific reduction in functional connectivity between the PMC and a region of left hippocampus when both watching and attempting to retrieve the videos. A follow up analysis revealed that in controls the functional connectivity between these regions when watching the videos was correlated with memory performance. Taken together, these findings support the view that the interactions between the PMC and the hippocampus enable the encoding and retrieval of multimodal representations of the contents of an event.

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P1-670: BRIDGING POSITIONS IN A SOCIAL NETWORK MODERATES THE RELATIONSHIP BETWEEN DEPRESSIVE SYMPTOMS AND EPISODIC MEMORY PERFORMANCE AMONG OLDER ADULTS

Alzheimer s & Dementia ◽

10.1016/j.jalz.2018.06.682 ◽

2006 ◽

Vol 14 (7S_Part_11) ◽

pp. P600-P600

Author(s):

Hairin Kim ◽

Seyul Kwak ◽

Jeanyung Chey ◽

Yoosik Youm ◽

Junsol Kim

Keyword(s):

Older Adults ◽

Social Network ◽

Depressive Symptoms ◽

Episodic Memory ◽

Memory Performance ◽

The Relationship

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The effect of amyloid deposition on longitudinal resting-state functional connectivity in cognitively normal older adults

Alzheimer s Research & Therapy ◽

10.1186/s13195-019-0573-1 ◽

2020 ◽

Vol 12 (1) ◽

Cited By ~ 2

Author(s):

Chemin Lin ◽

Maria Ly ◽

Helmet T. Karim ◽

Wenjing Wei ◽

Beth E. Snitz ◽

...

Keyword(s):

Neural Networks ◽

Older Adults ◽

Cognitive Function ◽

Functional Connectivity ◽

Resting State ◽

Clinical Symptoms ◽

Rate Of Change ◽

Resting State Functional Connectivity ◽

Cognitive Changes ◽

Cognitively Normal

Abstract Background Pathological processes contributing to Alzheimer’s disease begin decades prior to the onset of clinical symptoms. There is significant variation in cognitive changes in the presence of pathology, functional connectivity may be a marker of compensation to amyloid; however, this is not well understood. Methods We recruited 64 cognitively normal older adults who underwent neuropsychological testing and biannual magnetic resonance imaging (MRI), amyloid imaging with Pittsburgh compound B (PiB)-PET, and glucose metabolism (FDG)-PET imaging for up to 6 years. Resting-state MRI was used to estimate connectivity of seven canonical neural networks using template-based rotation. Using voxel-wise paired t-tests, we identified neural networks that displayed significant changes in connectivity across time. We investigated associations among amyloid and longitudinal changes in connectivity and cognitive function by domains. Results Left middle frontal gyrus connectivity within the memory encoding network increased over time, but the rate of change was lower with greater amyloid. This was no longer significant in an analysis where we limited the sample to only those with two time points. We found limited decline in cognitive domains overall. Greater functional connectivity was associated with better attention/processing speed and executive function (independent of time) in those with lower amyloid but was associated with worse function with greater amyloid. Conclusions Increased functional connectivity serves to preserve cognitive function in normal aging and may fail in the presence of pathology consistent with compensatory models.

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