scholarly journals Pre-stimulus oscillatory activity predicts successful episodic encoding for both young and older adults

2018 ◽  
Author(s):  
Jon Strunk ◽  
Audrey Duarte

AbstractHealthy aging is associated with declines in episodic memory performance that are due in part to deficits in encoding. Emerging results from young adult studies suggest that the neural activity during the time-period preceding stimulus presentation is sensitive to episodic memory performance. It is unknown whether age-related declines in episodic memory are due solely to changes in the recruitment of processes elicited by stimuli during encoding or also in processes recruited in anticipation of these stimuli. Here, we recorded oscillatory EEG while young and old participants encoded visual and auditory words that were preceded by cues indicating the stimulus modality. Alpha oscillatory activity preceding and following stimulus onset was predictive of subsequent memory accuracy similarly across age. Frontal beta oscillations linked to semantic elaboration during encoding were reduced by age. Post-stimulus theta power was positively predictive of episodic memory accuracy for old but not young adults, potentially reflecting older adults’ tendency to self-generate associations during encoding. Collectively, these results suggest that the preparatory mobilization of neural processes prior to encoding that benefits episodic memory performance is not affected by age.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sidni A. Justus ◽  
Patrick S. Powell ◽  
Audrey Duarte

AbstractResearch on memory in autism spectrum disorder (ASD) finds increased difficulty encoding contextual associations in episodic memory and suggests executive dysfunction (e.g., selective attention, cognitive flexibility) and deficient metacognitive monitoring as potential contributing factors. Findings from our lab suggest that age-related impairments in selective attention contribute to those in context memory accuracy and older adults tended to show dependence in context memory accuracy between relevant and irrelevant context details (i.e., hyper-binding). Using an aging framework, we tested the effects of selective attention on context memory in a sample of 23 adults with ASD and 23 typically developed adults. Participants studied grayscale objects flanked by two types of contexts (color, scene) on opposing sides and were told to attend to only one object-context relationship, ignoring the other context. At test, participants made object and context recognition decisions and judgment of confidence decisions allowing for an evaluation of context memory performance, hyper-binding, and metacognitive performance for context judgments in a single task. Results showed that adults with ASD performed similarly to typically developed adults on all measures. These findings suggest that context memory performance is not always disrupted in adults with ASD, even when demands on selective attention are high. We discuss the need for continued research to evaluate episodic memory in a wider variety of adults with ASD.


2016 ◽  
Author(s):  
Tam T. Tran ◽  
Nicole C. Hoffner ◽  
Sara C. LaHue ◽  
Lisa Tseng ◽  
Bradley Voytek

AbstractAlpha oscillations are modulated in response to visual temporal and spatial cues, However, the neural response to alerting cues is less explored, as is how this response is affected by healthy aging. Using scalp EEG, we examined how visual cortical alpha activity relates to working memory performance. Younger (20-30 years) and older (60-70 years) participants were presented with a visual alerting cue uninformative of the position or size of a lateralized working memory array. Older adults showed longer response times overall, and reduced accuracy when memory load was high. Older adults had less consistent cue-evoked phase resetting than younger adults, which predicted worse performance. Alpha phase prior to memory array presentation predicted response time, but the relationship between phase and response time was weaker in older adults. These results suggest that changes in alpha phase dynamics, especially prior to presentation of task-relevant stimuli, potentially contribute to age-related cognitive decline.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 704-705
Author(s):  
Atsuko Hayashi

Abstract In older adults, it is important to maintain awareness of memory as well as memory performance. However, it is not clear whether the awareness of episodic and lexical memory changes with age and is related to self-evaluation of memory and executive function. Here age-related changes and the relationship between metamemory, executive function, and metamemory scale were investigated. Healthy old (n=40) and young (n=34) groups participated in this study. In the episodic memory task, participants were asked to memorize ten Kanji words and to estimate the number of words they could recall after ten minutes. In the lexical memory task, they rated the likelihood that they could write a target Kanji word written in hiragana and then wrote them down. They were also asked to complete the metamemory in adulthood(MIA) and the position stroop task. In the episodic and lexical memory and the position stroop task and MIA subscales, the performances of the younger group were significantly better than those of the older group. In the episodic memory task, there were correlations between the metamemory and MIA subscales in both groups, but in the lexical memory task, only in the old group. No correlation was found between the results of both memory tasks and the stroop test. These results suggest that older people overestimate memory performances in the episodic and lexical memory tasks and metamemory performances may be associated with self-evaluation of memory. In addition, metamemory might not be related to frontal lobe function as shown in executive function tasks.


2018 ◽  
Vol 1 (1) ◽  
pp. 94-105 ◽  
Author(s):  
Kristen C. McGatlin ◽  
Kimberly M. Newberry ◽  
Heather R. Bailey

AbstractDeclines in episodic memory accompany both healthy aging and age-related diseases, such as dementia. Given that memory complaints are common in the aging population, a wealth of research has evaluated the underlying mechanisms of these declines and explored strategy interventions that could offset them. In the current paper, we describe a newer approach to improving memory: event segmentation training. Event segmentation is an encoding strategy in which individuals parse continuous activity into meaningful chunks. The ability to segment activity is associated with later memory for the events, but unfortunately, this segmentation ability declines with age. Importantly, interventions designed to improve event segmentation have resulted in memory improvements for both young and older adults. We will review these past experiments as well as some new event segmentation training work that uses older adults’ semantic knowledge to improve their segmentation and episodic memory. We believe that future research on event segmentation is a promising avenue for improving older adults’ ability to remember everyday activities.


2021 ◽  
Author(s):  
Jamie Murray ◽  
David Donaldson

Healthy aging leads to a significant decline in episodic memory, producing a reduction in thelikelihood of successful recollection, such that older adults remember less than younger adults.Emerging evidence from behavioral and neuroimaging studies demonstrate that recollectedinformation can also be more or less precise, highlighting a source of variability in memoryperformance not typically considered in studies of aging. Consequently, it is unknown whetherolder adults, compared to younger adults, only show a significant reduction in recollection rate or also exhibit a decline in recollection precision. Here, we provide new insight into age-relatedmemory decline by employing a novel source task that allows us to examine both the quantity(rate) and quality (precision) of episodic memory retrieval. First, we validated our task,demonstrating that it can effectively capture variability in both the rate and precision in olderadults. Second, we directly compared younger and older adults’ performance as a function ofstudy-test delay, showing significant reductions in both the rate and precision of recollectionwith age. Finally, we asked whether age-related changes in recollection can be accounted for bya reduction in attention, revealing that the division of attention in young adults results in areduction in rate but shows little evidence for a change in precision. Our results raise questionsabout the nature of age-related memory decline, highlighting the importance of measuring boththe quality and quantity of memory, and suggest new routes to achieve the early detection anddiagnosis of abnormal aging deficits.


2020 ◽  
Author(s):  
Patrick Pruitt ◽  
Lingfei Tang ◽  
Jessica Hayes ◽  
Noa Ofen ◽  
Jessica S. Damoiseaux

Negative subsequent memory effects in functional MRI studies of memory formation, have been linked to individual differences in memory performance, yet the effect of age on this association is currently unclear. To provide insight into the brain systems related to memory across the lifespan, we examined functional neuroimaging data acquired during episodic memory formation and behavioral performance from a memory recognition task in a sample of 109 participants, including three developmental age groups (8-12, 13-17, 18-25 year-olds) and one additional group of older adults (55-85 year-olds). Young adults showed the highest memory performance and strongest negative subsequent memory effects, while older adults showed reduced negative subsequent memory effects relative to young adults. Across the sample, negative subsequent memory effects were associated with better memory performance, and there was a significant interaction between negative subsequent memory effects and memory performance by age groups. Posthoc analyses revealed that this effect was driven by a strong association between negative subsequent memory effects and memory performance in adolescents and young adults, but not in children and older adults. These findings suggest that negative subsequent memory effects may differentially support memory performance across a lifespan trajectory characterized by developmental maturation and age-related deterioration.


2019 ◽  
Vol 3 (1) ◽  
pp. 173-194 ◽  
Author(s):  
Simon W. Davis ◽  
Amanda Szymanski ◽  
Homa Boms ◽  
Thomas Fink ◽  
Roberto Cabeza

Understanding the precise relation between functional connectivity and structural (white matter) connectivity and how these relationships account for cognitive changes in older adults are major challenges for neuroscience. We investigate these issues using an approach in which structural equation modeling (SEM) is employed to integrate functional and structural connectivity data from younger and older adults ( n = 62), analyzed with a common framework based on regions connected by canonical tract groups (CTGs). CTGs (e.g., uncinate fasciculus) serve as a common currency between functional and structural connectivity matrices, and ensure equivalent sparsity in connectome information. We used this approach to investigate the neural mechanisms supporting memory for items and memory for associations, and how they are affected by healthy aging. We found that different structural and functional CTGs made independent contributions to source and item memory performance, suggesting that both forms of connectivity underlie age-related differences in specific forms of memory. Furthermore, the relationship between functional and structural connectivity was best explained by a general relationship between latent constructs—a relationship absent in any specific CTG group. These results provide insights into the relationship between structural and functional connectivity patterns, and elucidate their relative contribution to age-related differences in source memory performance.


2018 ◽  
Author(s):  
A. Swierkot ◽  
M. N. Rajah

AbstractHealthy aging is associated with declines in episodic memory and with widespread cortical thinning. These parallel declines suggest that age-related changes in cortical thickness may contribute to episodic memory decline with age. The current study uses a cross-sectional study design to examine whether regional cortical thickness mediates the relationship between age and episodic memory, as measured by a context memory task for faces. Mediation and conditional mediation models were tested using bootstrapping in order to determine how age-associated changes in regional cortical thickness mediated age-associated changes in performance on the context memory task. We observed that right superior frontal cortical thickness conditionally mediated spatial context memory only in middle-aged and older adults; and right caudal middle frontal cortical thickness conditionally mediated context memory only in older adults. Left lingual cortical thickness mediated spatial context memory across the adult lifespan, but this effect was most evident at midlife. Right parahippocampal cortical thickness mediated context memory, independent of age. We conclude that our cortical thickness results were generally consistent with the posterior-to-anterior shift in aging hypothesis (Davis et al., 2008) for episodic memory.


2014 ◽  
Vol 28 (3) ◽  
pp. 148-161 ◽  
Author(s):  
David Friedman ◽  
Ray Johnson

A cardinal feature of aging is a decline in episodic memory (EM). Nevertheless, there is evidence that some older adults may be able to “compensate” for failures in recollection-based processing by recruiting brain regions and cognitive processes not normally recruited by the young. We review the evidence suggesting that age-related declines in EM performance and recollection-related brain activity (left-parietal EM effect; LPEM) are due to altered processing at encoding. We describe results from our laboratory on differences in encoding- and retrieval-related activity between young and older adults. We then show that, relative to the young, in older adults brain activity at encoding is reduced over a brain region believed to be crucial for successful semantic elaboration in a 400–1,400-ms interval (left inferior prefrontal cortex, LIPFC; Johnson, Nessler, & Friedman, 2013 ; Nessler, Friedman, Johnson, & Bersick, 2007 ; Nessler, Johnson, Bersick, & Friedman, 2006 ). This reduced brain activity is associated with diminished subsequent recognition-memory performance and the LPEM at retrieval. We provide evidence for this premise by demonstrating that disrupting encoding-related processes during this 400–1,400-ms interval in young adults affords causal support for the hypothesis that the reduction over LIPFC during encoding produces the hallmarks of an age-related EM deficit: normal semantic retrieval at encoding, reduced subsequent episodic recognition accuracy, free recall, and the LPEM. Finally, we show that the reduced LPEM in young adults is associated with “additional” brain activity over similar brain areas as those activated when older adults show deficient retrieval. Hence, rather than supporting the compensation hypothesis, these data are more consistent with the scaffolding hypothesis, in which the recruitment of additional cognitive processes is an adaptive response across the life span in the face of momentary increases in task demand due to poorly-encoded episodic memories.


2021 ◽  
pp. 1-13
Author(s):  
Alexandra L. Clark ◽  
Alexandra J. Weigand ◽  
Kelsey R. Thomas ◽  
Seraphina K. Solders ◽  
Lisa Delano-Wood ◽  
...  

Background: Age-related cerebrovascular and neuroinflammatory processes have been independently identified as key mechanisms of Alzheimer’s disease (AD), although their interactive effects have yet to be fully examined. Objective: The current study examined 1) the influence of pulse pressure (PP) and inflammatory markers on AD protein levels and 2) links between protein biomarkers and cognitive function in older adults with and without mild cognitive impairment (MCI). Methods: This study included 218 ADNI (81 cognitively normal [CN], 137 MCI) participants who underwent lumbar punctures, apolipoprotein E (APOE) genotyping, and cognitive testing. Cerebrospinal (CSF) levels of eight pro-inflammatory markers were used to create an inflammation composite, and amyloid-beta 1–42 (Aβ 42), phosphorylated tau (p-tau), and total tau (t-tau) were quantified. Results: Multiple regression analyses controlling for age, education, and APOE ɛ4 genotype revealed significant PP x inflammation interactions for t-tau (B = 0.88, p = 0.01) and p-tau (B = 0.84, p = 0.02); higher inflammation was associated with higher levels of tau within the MCI group. However, within the CN group, analyses revealed a significant PP x inflammation interaction for Aβ 42 (B = –1.01, p = 0.02); greater inflammation was associated with higher levels of Aβ 42 (indicative of lower cerebral amyloid burden) in those with lower PP. Finally, higher levels of tau were associated with poorer memory performance within the MCI group only (p s <  0.05). Conclusion: PP and inflammation exert differential effects on AD CSF proteins and provide evidence that vascular risk is associated with greater AD pathology across our sample of CN and MCI older adults.


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