Proactive interference in working memory is related to adult age and cognitive factors: cross-sectional and longitudinal evidence from the Betula study

ABSTRACT

In working memory (WM), successful maintenance of information is affected by interference. Older adults may be especially susceptible to the effects of interference, which may cause age-related cognitive impairments. A relative score of IC was derived from cross-sectional (n = 869) and longitudinal (n = 443) data to investigate (1) if IC is reduced in normal aging, (2) if individual differences in IC related to individual performance in other cognitive domains, and (3) if 5-year change in IC is related to change in general cognition. Older age was associated with reduced IC, but no decline in IC occurred over 5 years. Also, the ability to control interference in WM was related to performance in episodic memory, verbal fluency, and block design. We also found that IC mediates the relationship between age and cognition, suggesting that age-related cognitive decline is linked to IC. Finally, we demonstrate that change in IC was related to decline in episodic memory.     

轻度认知损伤的语义记忆研究述评

轻度认知损伤（Mild cognitive impairment,MCI）是介于正常老化与痴呆之间的过渡阶段,表现为与年龄和教育程度不相称的认知功能减退。本文回顾了近期有关MCI语义记忆的研究,分析比较了各研究的实验任务及结果,得出MCI患者存在一定程度的由多种原因造成的语义记忆损伤,语义记忆测验对MCI的早期筛查和转归预测有重要作用。最后指出将来的研究需要将包括语义记忆成分在内的多种认知测验相结合,以便及早发现有可能发展为痴呆的危险个体并开展相应干预。     

Decision-making competence in younger and older adults: which cognitive abilities contribute to the application of decision rules?

Older adults perform worse than younger adults when applying decision rules to choose between options that vary along multiple attributes. Although previous studies have shown that general fluid cognitive abilities contribute to the accurate application of decision rules, relatively little is known about which specific cognitive abilities play the most important role. We examined the independent roles of working memory, verbal fluency, semantic knowledge, and components of executive functioning. We found that age-related decline in applying decision rules was statistically mediated by age-related decline in working memory and verbal fluency. Our results have implications for theories of aging and decision-making.     

Influences of preclinical dementia and impending death on the magnitude of age-related cognitive deficits

The authors examined the influence of preclinical dementia and impending death on the cross-sectional relationship between age and performance in tasks assessing episodic memory, visuospatial skill, and verbal fluency. Increasing age was associated with a general decrease in cognitive performance. In addition, those who were to be diagnosed with dementia or had died by a 3-year follow-up, were older, and performed at a lower level than the remaining sample across all cognitive tasks at baseline. Nevertheless, removal of the preclinical dementia and impending death groups from the original sample affected the cross-sectional age-cognition relations relatively little. This pattern of findings suggests that the biological aging process exerts negative influences on cognitive functioning beyond those resulting from disease and mortality.     

Word-list-learning performance in younger and older adults: intra-individual performance variability and false memory

We investigated the word-list-learning performance of younger and older adults over 4 consecutive days at different times of day to study age-related differences in consistency of performance over time and the influence of circadian variation on performance. Eighteen younger (M age, 23.4 years) and 18 older (M age, 73.3 years) men and women participated. The start time of testing alternated between morning and early evening across the 4 days of testing. On each test day, participants learned a different list of 15 unrelated words over four learning trials. As expected, younger adults performed better than older adults on immediate recall, delayed recall, and recognition. Contrary to our expectations, time of day did not significantly influence recall or recognition performance in either the older or younger adults. Older adults did show a greater incidence of false memory (i.e., previously learned list intrusions in free recall and false alarms in recognition) than younger adults. Older adults also exhibited greater intra-individual performance variability on the measures of false memory across test days. This variability was not related to circadian variation. False memory and variability of performance have both been linked to frontal systems dysfunction. The findings presented here are consistent with the notion that changes in cognition with aging in part reflect age-related decline in frontal lobe function.     

Category and Attribute Knowledge Deterioration in Alzheimer's Disease

A prevalent theory regarding the deterioration of semantic memory in Alzheimer's disease is that it is a bottom-up process. If this is true, performance on tests of attribute knowledge should decline more rapidly than performance on tests of categorical knowledge as dementia severity increases. In the present study, a convincing pattern of findings to either support or reject the theory failed to emerge. This raised questions regarding the ability to separate attribute and categorical knowledge, and whether one can be tested without influence of the other. Questions also were raised regarding the additional cognitive processes needed to complete tasks of semantic memory.     

情景记忆成功年老化的神经机制

随着年龄的增长,大部分老年人的情景记忆会出现衰退,但也会有一部分老年人的情景记忆表现出成功的年老化,即记忆成绩较好或随增龄的衰退程度较小。脑保持理论、神经去分化理论、认知储备理论以及神经补偿理论分别从不同角度解释了情景记忆成功年老化的神经机制。基于选择性优化与补偿模型对现有理论进行整合,发现情景记忆成功年老化可能与个体的认知储备水平直接相关：高认知储备的老年人能够对情景记忆相关的脑区和脑网络进行优化且具备更强的神经补偿能力,因而其脑功能(比如,神经表征和神经加工通路的特异性)可能会保持地更好。未来研究需要更多地采用纵向设计来考察各理论之间的关系及其影响因素,从而更好地解释记忆成功年老化的神经机制并为提升老年人的脑与认知健康提供支持。     

Effects of context expectation on prospective memory performance among older and younger adults

This experiment examined the impact of context expectation on prospective memory (PM) performance among older and younger adults. Participants responded to PM target words embedded in an ongoing lexical decision task (LDT). Older and younger adults performed similarly on the PM task. Regardless of age, PM was significantly better for participants in the correct context expectation condition and significantly worse in the incorrect context expectation condition relative to participants who held no expectations about the context in which targets would appear. Participants’ LDT response latencies were used to assess cost of the PM task to the ongoing task. Latencies were discernibly longer in the LDT block where the PM targets were expected compared to the block where they were not expected. The findings provide new information about how context can be used to support PM aging and suggest that contextual information can be equally beneficial for older and younger adults.     

Musculoskeletal pain complaints and performance on cognitive tasks over the adult life span

The present study aimed at comparing participants with and without self reported musculoskeletal pain in a normal population with regard to performance on a range of tests for episodic memory, semantic memory, and other cognitive functions and to see if expected differences interacted with age. The results showed that participants with pain performed worse on a range of tasks as compared to participants without pain, and that these differences occurred regardless of age. The most robust effects of pain were displayed on tests for vocabulary and construction ability as these were the only effects that remained significant after controlling for years of education and reported depression in separate analyses. When depression and education were controlled for in the same analysis, even these effects were eliminated, suggesting interplay between pain, depressive status, and educational level in the negative effects on cognitive functioning.     

Modeling memory decline in older adults: the importance of preclinical dementia, attrition, and chronological age

This longitudinal study examined memory loss in a sample of 391 initially nondemented older adults. Analyses decomposed observed memory loss into decline associated with preclinical dementia, study attrition, terminal decline, and chronological age. Measuring memory as a function of only chronological age failed to provide an adequate representation of cognitive change. Disease progression accounted for virtually all of the memory loss in the 25% of the sample that developed diagnosable dementia. In the remainder of the sample, both chronological age and study attrition contributed to observed memory loss. These results suggest that much of memory loss in aging adults may be attributable to the progression of preclinical dementia and other nonnormative aging processes that are not captured by chronological age.     

Word-List-Learning Performance in Younger and Older Adults: Intra-Individual Performance Variability and False Memory

ABSTRACT

We investigated the word-list-learning performance of younger and older adults over 4 consecutive days at different times of day to study age-related differences in consistency of performance over time and the influence of circadian variation on performance. Eighteen younger (M age, 23.4 years) and 18 older (M age, 73.3 years) men and women participated. The start time of testing alternated between morning and early evening across the 4 days of testing. On each test day, participants learned a different list of 15 unrelated words over four learning trials. As expected, younger adults performed better than older adults on immediate recall, delayed recall, and recognition. Contrary to our expectations, time of day did not significantly influence recall or recognition performance in either the older or younger adults. Older adults did show a greater incidence of false memory (i.e., previously learned list intrusions in free recall and false alarms in recognition) than younger adults. Older adults also exhibited greater intra-individual performance variability on the measures of false memory across test days. This variability was not related to circadian variation. False memory and variability of performance have both been linked to frontal systems dysfunction. The findings presented here are consistent with the notion that changes in cognition with aging in part reflect age-related decline in frontal lobe function.     

The Executive Decline Hypothesis of Cognitive Aging: Do Executive Deficits Qualify as Differential Deficits and Do They Mediate Age-Related Memory Decline?

This paper reports the results of two studies which investigated whether aging is associated with a differential deficit in executive function, compared with deficits in general cognitive ability (Wechsler Adult Intelligence Scale-Revised performance). Further, the studies investigated the specificity of the executive decline hypothesis of memory and aging by examining whether declines in executive function mediate age-related memory decline over and above the variance in memory accounted for by general cognitive ability. The results of Study 1 showed no consistent evidence of a differential decline in executive function among a sample of participants aged between 18 and 75 years. The results of Study 2 indicated a differential decline in one indicator of executive function, the Modified Card Sorting Test, among an older sample aged between 60 and 89 years. Both studies demonstrated that measures of executive function accounted for age-related variance in free recall, recognition, and serial recall, even after controlling for general cognitive ability. However, in Study 1, once variance attributed to speed of processing was taken into account, executive function did not contribute further to the age-related variance.     

Different storage and retrieval deficits in normal aging and mild cognitive impairment: a multinomial modeling analysis

The authors compared patients with mild cognitive impairment with healthy older adults and young control participants in a free recall test in order to locate potential qualitative differences in normal and pathological memory decline. Analysis with an extended multitrial version of W. H. Batchelder and D. M. Riefer's (1980) pair-clustering model revealed globally decelerated learning and an additional retrieval deficit in patients with mild cognitive impairment but not in healthy older adults. Results thus suggest differences in memory decline between normal and pathological aging that may be useful for the detection of risk groups for dementia, and they illustrate the value of model-based disentangling of processes and of multitrial tests for early detection of dementia.     

Type 2 Diabetes Mellitus and Cognitive Performance in a Population-Based Sample of the Oldest Old: Impact of Comorbid Dementia

We examined the relationship between type 2 diabetes mellitus and cognitive function in a population-based sample of very old people. The sample comprised 338 persons, aged 80-93 years (mean age 83.5 years), of whom 70 persons had type 2 diabetes mellitus. Measures of cognitive functioning included tests of perceptual speed, visuo-spatial ability, inductive reasoning, short-term memory, semantic memory, episodic memory, and the Mini-Mental State Examination. Regression analyses showed that type 2 diabetes mellitus duration was related to test performance across all cognitive domains, with the exception of short-term memory, such that longer duration was associated with lower test performance. When cases with dementia were excluded from the sample, further analyses showed that diabetes duration was not associated with cognitive test performance. This indicates that diabetes is not related to lower cognitive function in the general population of non-demented old people. Diabetes, however, increases the risk for cerebrovascular incidents, like stroke, that may contribute to vascular dementia.     

Aging and inhibition of a prepotent motor response during an ongoing action

Inhibitory functions are key mechanisms underlying age related decline (Park & Gutchess, 2000, in: Cognitive aging: A primer. Hove: Psychology Press), yet few studies have investigated their impact on everyday tasks involving action as well as cognition. Using an everyday-based go/no-go task we devised a motor analogy of traditional neuropsychological tests to investigate in 134 older (aged 60-88) and 133 younger adults (aged 20-59) the ability to inhibit a prepotent motor response during an ongoing action. Older adults produced more inhibition failures as expected, but more strikingly inhibitory errors were not all or none; even when the inappropriate response was successfully inhibited, difficulties controlling ongoing movements emerged from as young as people in their 40s. The ability to inhibit therefore does not ensure control of ongoing tasks, and traditional cognitive tests may be unable to detect such difficulties. Furthermore, performance did not covary with education or action speed. Implications for neuropsychological theory and assessing/enhancing functional ability are discussed.     

Cognitive changes in pregnancy: mild decline or societal stereotype?

This research compared pregnant and non‐pregnant women's perceptions of cognitive change and their performance on 13 sensitive memory and attention tasks (Study 1) and two complex driving simulation tasks (Study 2). The pregnant, but not the non‐pregnant, women rated their cognitive abilities as worse than before, but only two performance measures from Study 1 differentiated the two groups (speed of language processing and attentional switching). Study 3 examined beliefs about pregnancy‐related cognitive decline. Women and men with and without immediate experience of pregnancy rated pregnant women's cognitive abilities as slightly worse than before pregnancy. Memory ratings were worse from women and from those with immediate experience of pregnancy. It is concluded that there may be some mild effects of pregnancy on performance of some specific cognitive functions but that cultural expectations based on a stereotype of cognitive decline also contribute to pregnant women's perception of cognitive change. Copyright © 2008 John Wiley & Sons, Ltd.     

Explaining age differences in temporal working memory

To determine the cognitive mechanisms underlying age differences in temporal working memory (WM), the authors examined the contributions of item memory, associative memory, simple order memory, and multiple item memory, using parallel versions of the delayed-matching-to-sample task. Older adults performed more poorly than younger adults on tests of temporal memory, but there were no age differences in nonassociative item memory, regardless of the amount of information to be learned. In contrast, a combination of associative and simple order memory, both of which were reduced in older adults, completely accounted for age-related declines in temporal memory. The authors conclude that 2 mechanisms may underlie age differences in temporal WM, namely, a generalized decline in associative ability and a specific difficulty with order information.     

Characteristics of 12th-grade students seriously deficient in spatial ability

When spatial ability was regressed on a measure of general intelligence in a large national sample of 12th-graders, there was a distinct downturn in the regression line at about -2 SD units. A bimodal distribution of spatial ability was found among these low scoring students, suggesting 2 qualitatively different types of individuals. Relative to students of expected spatial ability, those below expected in spatial ability were high on verbal skills and low on performance skills. Students unexpectedly low in spatial ability performed relatively well on cognitive tests that required answering unambiguous questions by retrieving information directly from long term memory, whereas they performed relatively poorly on tests requiring inference and perception of relations among novel stimuli. Students unexpectedly low in spatial ability performed especially poorly at tests involving visual-spatial perception skills. Results were similar for both sexes. The relatively poor performance of those unexpectedly low in spatial ability does not appear to be related to health problems, personality, interest differences, or biographical data. An organic impairment possibly related to lateralization represents a reasonable causal hypothesis for these data.     

Hypertension differentially impacts cognition in men and women in early midlife

The current study aimed to understand how sex differences in the timing of hypertension onset contribute to early midlife risk for cognitive decline that may differ by sex and whether sex-dependent advantages in normotensive populations are influenced by the presence of hypertension. One hundred and ninety-five adults aged 45–55 from the New England Family Study underwent neuropsychological testing to assess attention, executive function, and memory. Physician-diagnosed hypertension status was self-reported via questionnaire. Mid-adulthood hypertension was associated with worse performance on measures of attention and memory, but the cognitive domains impacted varied by sex. Hypertension was associated with only attention in men, whereas in women it was associated with attention and associative and working memory. Sex differences in midlife cognitive performance found in normotensive adults were attenuated in those with hypertension. Our results underscore the importance of accounting for sex when assessing the impact of hypertension on midlife cognition that could be indicative of later decline and risk for cognitive impairment and dementia, given hypertension is an independent risk factor.