Memory Performance In Older Adults Research Articles

Proactive interference and concurrent inhibitory processes do not differentially affect item and associative recognition: Implication for the age-related associative memory deficit

ABSTRACTPrevious studies have suggested an associative deficit hypothesis [Naveh-Benjamin, M. (2000). Adult age differences in memory performance: Tests of an associative deficit hypothesis. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 1170–1187] to explain age-related episodic memory declines. The hypothesis attributes part of the deficient episodic memory performance in older adults to a difficulty in creating and retrieving cohesive episodes. In this article, we further evaluate this hypothesis by testing two alternative processes that potentially mediate associative memory deficits in older adults. Four experiments are presented that assess whether failure of inhibitory processes (proactive interference in Experiments 1 and 2), and concurrent inhibition (in Experiments 3 and 4) are mediating factors in age-related associative deficits. The results suggest that creating conditions that require the operation of inhibitory processes, or that interfere with such processes, cannot simulate associative memory deficit in older adults. Instead, such results support the idea that associative memory deficits reflect a unique binding failure in older adults. This failure seems to be independent of other cognitive processes, including inhibitory and other resource-demanding processes.

Naturalistic Assessment of Everyday Memory Performance Among Older Adults

Background/Study Context: Memory performance in everyday life (EDL) and its change through aging is still unclear because laboratory results are often not transferable to real-life situations. Therefore, a naturalistic memory task was designed to investigate memory performance in older adults in a representative task design.Methods: The memory performance of 23 older (70.28 ± 4.65 years) and 20 younger adults (24.89 ± 3.16 years) was assessed by using four established tasks of short-term and working memory (Digit Simple Span, Digit Complex Span, Grid Simple Span, and Grid Complex Span) that differed in difficulty and domain (verbal vs. visual-spatial). To simulate an EDL context, a “Supermarket” was constructed within the laboratory.Results: The results showed that memory performance presents alterations in older adults. This was especially true for the “Supermarket” task, in which the younger adults showed benefits in the common environment as opposed to older adults. A factor analysis showed that the four memory laboratory tasks measured different memory processes as compared with the EDL task.Conclusion: These findings suggest that memory performance in EDL is a different construct than when it is measured in the laboratory and that memory alterations in older adults are especially pronounced in EDL tasks. Following these findings, the authors recommend an EDL approach to measure memory performance further to the well-established laboratory approaches.

Retrospective cues based on object features improve visual working memory performance in older adults

Research with younger adults has shown that retrospective cues can be used to orient top-down attention toward relevant items in working memory. We examined whether older adults could take advantage of these cues to improve memory performance. Younger and older adults were presented with visual arrays of five colored shapes; during maintenance, participants were presented either with an informative cue based on an object feature (here, object shape or color) that would be probed, or with an uninformative, neutral cue. Although older adults were less accurate overall, both age groups benefited from the presentation of an informative, feature-based cue relative to a neutral cue. Surprisingly, we also observed differences in the effectiveness of shape versus color cues and their effects upon post-cue memory load. These results suggest that older adults can use top-down attention to remove irrelevant items from visual working memory, provided that task-relevant features function as cues.

Memory improvement via slow-oscillatory stimulation during sleep in older adults

We examined the intriguing but controversial idea that disrupted sleep-dependent consolidation contributes to age-related memory decline. Slow-wave activity during sleep may help strengthen neural connections and provide memories with long-term stability, in which case decreased slow-wave activity in older adults could contribute to their weaker memories. One prediction from this account is that age-related memory deficits should be reduced by artificially enhancing slow-wave activity. In young adults, applying transcranial current oscillating at a slow frequency (0.75 Hz) during sleep improves memory. Here, we tested whether this procedure can improve memory in older adults. In 2 sessions separated by 1 week, we applied either slow-oscillatory stimulation or sham stimulation during an afternoon nap in a double-blind, crossover design. Memory tests were administered before and after sleep. A larger improvement in word-pair recall and higher slow-wave activity was observed with slow-oscillatory stimulation than with sham stimulation. This is the first demonstration that this procedure can improve memory in older adults, suggesting that declarative memory performance in older adults is partly dependent on slow-wave activity during sleep.

Memory for sequences of events impaired in typical aging.

Typical aging is associated with diminished episodic memory performance. To improve our understanding of the fundamental mechanisms underlying this age-related memory deficit, we previously developed an integrated, cross-species approach to link converging evidence from human and animal research. This novel approach focuses on the ability to remember sequences of events, an important feature of episodic memory. Unlike existing paradigms, this task is nonspatial, nonverbal, and can be used to isolate different cognitive processes that may be differentially affected in aging. Here, we used this task to make a comprehensive comparison of sequence memory performance between younger (18–22 yr) and older adults (62–86 yr). Specifically, participants viewed repeated sequences of six colored, fractal images and indicated whether each item was presented “in sequence” or “out of sequence.” Several out of sequence probe trials were used to provide a detailed assessment of sequence memory, including: (i) repeating an item from earlier in the sequence (“Repeats”; e.g., ABADEF), (ii) skipping ahead in the sequence (“Skips”; e.g., ABDDEF), and (iii) inserting an item from a different sequence into the same ordinal position (“Ordinal Transfers”; e.g., AB3DEF). We found that older adults performed as well as younger controls when tested on well-known and predictable sequences, but were severely impaired when tested using novel sequences. Importantly, overall sequence memory performance in older adults steadily declined with age, a decline not detected with other measures (RAVLT or BPS-O). We further characterized this deficit by showing that performance of older adults was severely impaired on specific probe trials that required detailed knowledge of the sequence (Skips and Ordinal Transfers), and was associated with a shift in their underlying mnemonic representation of the sequences. Collectively, these findings provide unambiguous evidence that the capacity to remember sequences of events is fundamentally affected by typical aging.

DNA Methylation in the Apolipoprotein-A1 Gene is Associated with Episodic Memory Performance in Healthy Older Individuals

DNA methylation variation has been implicated in memory, cognitive performance, and dementia. Plasma apolipoprotein-A1 (ApoA1) levels may act as a biomarker of age-associated cognitive performance and decline. To estimate the heritability of plasma ApoA1 protein levels; to examine DNA methylation variation within the APOA1 gene; and to investigate whether APOA1 methylation is associated with plasma ApoA1 levels and episodic memory performance. Heritability of ApoA1 protein levels in Older Australian Twins Study (OATS) was assessed using structural equation modelling. APOA1 methylation levels were assayed in two cohorts of cognitively normal older individuals. The methylation status of 12 CpGs in 24 twin pairs from OATS was assayed using the Illumina 450K methylation array. Candidate CpGs were assayed in 454 individuals from Sydney Memory and Ageing Study (Sydney MAS) using pyrosequencing. Regression analyses assessed associations between APOA1 methylation levels, ApoA1 plasma levels, and memory performance. No significant heritability was observed for ApoA1 protein levels. APOA1 candidate-gene analyses revealed CpG sites associated with memory performance in the twin study (p < 0.050). Replication of an association between methylation of a specific CpG (cg03010018) in APOA1 and memory performance was observed in Sydney MAS (β = -0.145, p = 0.010). Methylation of this CpG site was also significantly correlated with ApoA1 protein levels (β = 0.161, p = 0.019). However, no relationship between a composite memory domain score and methylation was observed (p = 0.389). Findings demonstrated that epigenetic control of APOA1 expression and DNA methylation levels are associated with episodic memory performance in older adults.

Age Alters the Effects of Emotional Valence on False Memory: Using the Simplified Conjoint Recognition Paradigm

Previous research has revealed robust differences between young and older adults' accurate emotional memory. Typically, negative emotion prompts memory performance in young adults, while positive emotion benefits memory performance in older adults. Relatively, much less efforts have been devoted to investigating how emotion divergently influences false memory in older adults compared to young adults. The main purpose of the present study is to explore, first, how age alters the effects of emotional valence on false memory; and second, what are the cognitive mechanisms for the interaction effect of age and emotional valence on false memory. The Fuzzy Trace Theory(FTT) uses verbatim memory trace and gist memory trace to interpret individuals' false memory, especially false memory under the framework of Deese-Roediger-Mc Dermott(DRM) paradigm. According to recent research, we proposed some flaws of traditional paradigms(such as the Remember-Know paradigm) in the area of false memory; and we also argued that it would be critical to include response bias in addition to verbatim and gist memory trace to investigate false memory. To fulfill this need, the simplified conjoint recognition(SCR) paradigm, combined with a statistical method of multinomial processing tree model, was used in the present study to investigate false memory and its associated cognitive mechanisms. A sample of 34 young adults(aged 23 ± 2 years) and 28 older adults(aged 68 ± 5 years) completed the SCR task. In the task, the Cornell/Cortland emotion word lists, along with neutral word lists adopted from previous research, were implemented as experimental materials. The results displayed a significant interaction effect of emotional valence and age on false memory(i.e. false alarm). Specifically, positive emotion decreased older adults' false memory, while negative emotion decreased young adults' false memory.The method of multinomial processing tree model was further employed to model, parameterize and inference the cognitive mechanisms related to the effect of emotional valence on false memory within young and older group. It was found that negative emotion contributed to a lower level of false memory in young adults by lowering their response bias toward negative words. As to older adults, positive emotion boosted retrieval of verbatim memory trace and hampered retrieval of gist memory trace, then led to less false memory for positive words. Our study uncovered interesting age-related differences in emotional false memory; it also confirmed the necessity of a simultaneous consideration of verbatim memory trace, gist memory trace and response bias when investigating false memory.

The Dynamic Effects of Age-Related Stereotype Threat on Explicit and Implicit Memory Performance in Older Adults

While an awareness of age-related changes in memory may help older adults gain insight into their own cognitive abilities, it may also have a negative impact on memory performance through a mechanism of stereotype threat (ST). The consequence of ST is under-performance in abilities related to the stereotype. Here, we examined the degree to which explicit and implicit memory were affected by ST across a wide age-range. We found that explicit memory was affected by ST, but only in an Early Aging group (mean age 67.83), and not in a Later Aging group (mean age 84.59). Implicit memory was not affected in either the Early or Later Aging group. These results demonstrate that ST for age-related memory decline affects memory processes requiring controlled retrieval while sparing item encoding. Furthermore, this form of ST appears to dissipate as aging progresses. These results have implications for understanding psychological development across the span of aging.

Dairy intake is associated with memory and pulsatility index in heart failure

Purpose/Aim: Past work shows an inconsistent relationship between dairy intake and cognition in healthy older adults. A cross-sectional design was conducted to examine dairy consumption, cognitive dysfunction, and cerebral blood flow in a sample of older adults with heart failure (HF) to clarify their association in this population at high risk for adverse neurocognitive outcomes. Materials and Methods: A total of 86 older adults with HF (70.39 ± 9.51 years; 33.1% female) underwent neuropsychological testing, transcranial Doppler (TCD) sonography to quantify cerebral blood flow. Dairy intake was quantified using a brief self-report questionnaire. Results: Partial correlations between the dairy consumption questionnaire and neuropsychological tests were conducted adjusting for HF severity, age, and sex. Contrary to expectations, results showed greater dairy intake was associated with poorer memory (r = −0.21, p = 0.01) and higher pulsatility index in the medial cerebral artery (r = −0.17, p = 0.05). Conclusion: Results suggest that greater dairy intake was associated with poorer memory performance in older adults with HF. Several possible explanations for these findings exist, including the contribution of high-fat dairy to underlying physiological processes that promote vascular cognitive impairment. Prospective studies employing objective measures specific to high and low fat dairy are needed to clarify this possibility.

Neural correlates associated with successful working memory performance in older adults as revealed by spatial ICA.

To investigate which neural correlates are associated with successful working memory performance, fMRI was recorded in healthy younger and older adults during performance on an n-back task with varying task demands. To identify functional networks supporting working memory processes, we used independent component analysis (ICA) decomposition of the fMRI data. Compared to younger adults, older adults showed a larger neural (BOLD) response in the more complex (2-back) than in the baseline (0-back) task condition, in the ventral lateral prefrontal cortex (VLPFC) and in the right fronto-parietal network (FPN). Our results indicated that a higher BOLD response in the VLPFC was associated with increased performance accuracy in older adults, in both the baseline and the more complex task condition. This ‘BOLD-performance’ relationship suggests that the neural correlates linked with successful performance in the older adults are not uniquely related to specific working memory processes present in the complex but not in the baseline task condition. Furthermore, the selective presence of this relationship in older but not in younger adults suggests that increased neural activity in the VLPFC serves a compensatory role in the aging brain which benefits task performance in the elderly.

Effects of resveratrol on memory performance, hippocampal functional connectivity, and glucose metabolism in healthy older adults.

Dietary habits such as caloric restriction or nutrients that mimic these effects may exert beneficial effects on brain aging. The plant-derived polyphenol resveratrol has been shown to increase memory performance in primates; however, interventional studies in older humans are lacking. Here, we tested whether supplementation of resveratrol would enhance memory performance in older adults and addressed potential mechanisms underlying this effect. Twenty-three healthy overweight older individuals that successfully completed 26 weeks of resveratrol intake (200 mg/d) were pairwise matched to 23 participants that received placebo (total n = 46, 18 females, 50-75 years). Before and after the intervention/control period, subjects underwent memory tasks and neuroimaging to assess volume, microstructure, and functional connectivity (FC) of the hippocampus, a key region implicated in memory functions. In addition, anthropometry, glucose and lipid metabolism, inflammation, neurotrophic factors, and vascular parameters were assayed. We observed a significant effect of resveratrol on retention of words over 30 min compared with placebo (p = 0.038). In addition, resveratrol led to significant increases in hippocampal FC, decreases in glycated hemoglobin (HbA1c) and body fat, and increases in leptin compared with placebo (all p < 0.05). Increases in FC between the left posterior hippocampus and the medial prefrontal cortex correlated with increases in retention scores and with decreases in HbA1c (all p < 0.05). This study provides initial evidence that supplementary resveratrol improves memory performance in association with improved glucose metabolism and increased hippocampal FC in older adults. Our findings offer the basis for novel strategies to maintain brain health during aging.

Aerobic exercise increases hippocampal volume in older women with probable mild cognitive impairment: a 6-month randomised controlled trial

BackgroundMild cognitive impairment (MCI) is a well-recognised risk factor for dementia and represents a vital opportunity for intervening. Exercise is a promising strategy for combating cognitive decline by improving brain...

Only social feedback reduces age-related prospective memory deficits in “Virtual Week”

Prospective memory, or remembering to do things in the future, is crucial for independent living in old age. Although there is evidence of substantial age-related deficits in memory for intentions, older adults have demonstrated the ability to compensate for their deficits in everyday life. The present study investigated feedback as a strategy for facilitating prospective memory in the elderly. Young and older adults played a computer-based task, Virtual Week, in which they had to remember to carry out life-like intentions. After each virtual day, specific feedback on prospective memory performance was automatically provided on the computer screen that participants either proceeded through by themselves (non-social feedback) or were taken through by an experimenter (social feedback). The control group received no feedback. We found that, compared with no-feedback group, only social feedback substantially reduced the age-related deficit in prospective memory. Older adults significantly benefited from feedback provided by the experimenter on the tasks of intermediate difficulty. Unexpectedly, prospective memory with non-social feedback was not only worse than with social feedback, but it was not any better than without any feedback at all. The results extended previous findings on the effectiveness of feedback in improving the memory performance of older adults to include memory for intentions. Despite the feedback meeting the critical recommendations of being specific, objective, and well-targeted, it was ineffective when the feedback displayed on the computer was not introduced by the experimenter. This has implications for computerized training tasks where automated feedback is considered crucial.

Muscle tension induced after learning enhances long-term narrative and visual memory in healthy older adults

Arousing events are better remembered than mundane events. Indeed, manipulation of arousal, such as by muscle tension, can influence memory even when it occurs shortly after learning. Indeed, our founding study showed this approach can raise delayed memory performance in older adults to a level comparable to that of unaided young adults. Yet, systematic studies, especially those investigating different modalities or types of memory, have not been done. This study investigated the effects of a brief bout of isometric exercise via handgrip on narrative and visuospatial episodic memory in healthy elders. Forty-seven participants completed the Logical Memory subtest of the Wechsler Memory Scales III (LM) and the Benton Visual Retention Test (BVRT), followed alternately by no treatment and by moderately squeezing a sand-filled latex ball for 1-min (counterbalanced order and test forms). Isometric exercise significantly increased both positive and negative affect ratings. Retention was tested 2weeks later. Delayed recall and recognition of LM was enhanced by arousal relative to control, as was recognition of the BVRT. The results extend past findings that muscle tension induced after learning modulates memory consolidation, extending findings in elders to suggest that a simple form of isometric exercise can have practical effects, such as aiding memory for stories and images.

Examining the relationship between subjective and objective memory performance in older adults: a meta-analysis.

Are the beliefs that older adults hold about their memory abilities associated with their scores on lab-based memory tasks? A review of the aging literature suggests that the correlation between subjective and objective memory is inconsistent, with some studies reporting significant effects and others reporting null results. A meta-analysis was conducted to quantitatively summarize the relationship between subjective memory, defined as general predictions about memory, and objective memory performance in older adults, and to examine the conditions under which this relationship may be strongest. This meta-analysis included 53 studies, each of which included a normatively aging older adult sample. Overall, the association between subjective and objective memory was small (r = .062, SE = 0.014) but reliably greater than zero. Moderator analyses were conducted to better understand the parameters of this effect. Age, years of education, gender, depression symptoms, length and format of subjective memory measures, and type of objective memory were significantly correlated with effect size. These results caution against relying on general subjective memory belief measures as a substitute for objective assessments of memory.

Longitudinal associations of subjective memory with memory performance and depressive symptoms: between-person and within-person perspectives.

Clinical diagnostic criteria for memory loss in adults typically assume that subjective memory ratings accurately reflect compromised memory functioning. Research has documented small positive between-person associations between subjective memory and memory performance in older adults. Less is known, however, about whether within-person fluctuations in subjective memory covary with within-person variance in memory performance and depressive symptoms. The present study applied multilevel models of change to 9 waves of data from 27,395 participants of the Health and Retirement Study (HRS; mean age at baseline = 63.78; SD = 10.30; 58% women) to examine whether subjective memory is associated with both between-person differences and within-person variability in memory performance and depressive symptoms and explored the moderating role of known correlates (age, gender, education, and functional limitations). Results revealed that across persons, level of subjective memory indeed covaried with level of memory performance and depressive symptoms, with small-to-moderate between-person standardized effect sizes (0.19 for memory performance and -0.21 for depressive symptoms). Within individuals, occasions when participants scored higher than usual on a test of episodic memory or reported fewer-than-average depressive symptoms generated above-average subjective memory. At the within-person level, subjective memory ratings became more sensitive to within-person alterations in memory performance over time and those suffering from functional limitations were more sensitive to within-person alterations in memory performance and depressive symptoms. We take our results to suggest that within-person changes in subjective memory in part reflect monitoring flux in one's own memory functioning, but are also influenced by flux in depressive symptoms.

Enhanced cerebral bioenergetics with dietary ketosis in Mild Cognitive Impairment

BACKGROUND: Metabolic disturbance is associated with risk for neurodegeneration, and cerebral glucose hypometabolism is prominent in Alzheimer’s disease (AD). Ketone metabolism can compensate for glucose hypometabolism and confers other benefits pertinent to neurodegeneration, among them reduction of oxidative stress and AD pathological factors, suggesting its potential as a therapeutic intervention. In a prior controlled trial, we showed that six weeks’ carbohydrate restriction induced ketogenesis and produced improvements in metabolic parameters and memory performance in older adults with Mild Cognitive Impairment (MCI). Those benefits were attributed to the correction of hyperinsulinemia and to the presumed enhancement of cerebral bioenergetic function associated with ketone metabolism. OBJECTIVE: To assess the effect of dietary ketosis on cerebral metabolites in older adults with MCI. METHODS: We enrolled a sample of five MCI participants in a ketogenic dietary regimen and performed pre- and postintervention proton magnetic resonance spectroscopy to investigate changes in neurochemical metabolites. We also assessed cognitive function and metabolic and anthropometric factors. RESULTS: We observed a significant increase in myo-inositol (p = 0.02) and trends for increases in N-acetyl-aspartate (p = 0.09) and creatine + phosphocreatine (p = 0.11) after six weeks on the ketogenic regimen. Working memory (p = 0.01) and long-term memory (p = 0.07) performances also improved. CONCLUSIONS: This study offers novel, preliminary evidence of cerebral bioenergetic enhancement with mild dietary ketosis in aging humans. Further investigation in controlled trials is warranted to assess the preventive and treatment implications of this intervention for age-related memory decline and dementia.

Memory Performance in Older Adults Before and After Temporal Lobectomy for Pharmacoresistant Epilepsy

Little is known about the effects of epilepsy surgery on memory in older adults. The purpose of this study was to determine if older adults exhibit greater memory decline than younger adults after anterior temporal lobectomy (ATL). Patients 55 years and older at time of surgery (23 left, 14 right ATL, range 55–66 years) were compared to patients age 25–35 years (44 left, 33 right ATL) to assess differences in preoperative to postoperative change in WMS-III index scores. Repeated-measures ANOVAs and ANCOVAs revealed that older patients did not demonstrate greater decline than younger patients across any of the memory indices. Rather, in the left ATL group, older patients showed less decline than younger patients on the Auditory Delayed Memory Index. Similarly, in the right ATL group, older patients showed less decline than younger patients on the Visual Delayed Memory Index. These patterns were also apparent in frequency of individual change. Results provide preliminary evidence that older adults who are good candidates for ATL are not at greater risk for memory decline when measured at 7 months postoperatively.

The effects of exercise on memory performance in older adults with probable mild cognitive impairment: A 6-month randomized controlled trial

The effects of exercise on memory performance in older adults with probable mild cognitive impairment: A 6-month randomized controlled trial

Differential involvement of knowledge representation and executive control in episodic memory performance in young and older adults.

Craik and Bialystok (2006, 2008) postulated that examining the evolution of knowledge representation and control processes across the life span could help in understanding age-related cognitive changes. The present study explored the hypothesis that knowledge representation and control processes are differentially involved in the episodic memory performance of young and older adults. Young and older adults were administered a cued-recall task and tests of crystallized knowledge and executive functioning to measure representation and control processes, respectively. Results replicate the classic finding that executive and cued-recall performance decline with age, but crystallized-knowledge performance does not. Factor analysis confirmed the independence of representation and control. Correlation analyses showed that the memory performance of younger adults was correlated with representation but not with control measures, whereas the memory performance of older adults was correlated with both representation and control measures. Regression analyses indicated that the control factor was the main predictor of episodic-memory performance for older adults, with the representation factor adding an independent contribution, but the representation factor was the sole predictor for young adults. This finding supports the view that factors sustaining episodic memory vary from young adulthood to old age; representation was shown to be important throughout adulthood, and control was also important for older adults. The results also indicated that control and representation modulate age-group-related variance in episodic memory.