Age differences in adults' free recall, cued recall, and recognition

Association between telomere length and cognitive function among cognitively unimpaired individuals at risk of Alzheimer's disease

INTRODUCTION

Leukocyte telomere length (LTL) is an objective biomarker of biological aging, and it is proposed to play a crucial role in Alzheimer's disease (AD) risk. We aimed at evaluating the cross-sectional association between LTL and cognitive performance in middle-aged cognitively unimpaired individuals at increased risk of AD.

METHODS

A total of 1520 participants from the ALFA cohort were included. Relative telomere length was measured in leukocytes through qPCR. LTL was residualized against age and sex, and associations with cognitive performance were assessed in short and long groups based on residualized LTL (rLTL). Interactions with sex and genetic risk of AD were tested.

RESULTS

Non-linear associations were found between LTL and episodic memory (EM). Better EM was associated with longer rLTL among women in the short rLTL group.

DISCUSSION

Results suggest a potential role of telomeres in the cognitive aging process with sex-specific patterns.

Take a load off: examining partial and complete cognitive offloading of medication information

Although cognitive offloading, or the use of physical action to reduce internal cognitive demands, is a commonly used strategy in everyday life, relatively little is known about the conditions that encourage offloading and the memorial consequences of different offloading strategies for performance. Much of the extant work in this domain has focused on laboratory-based tasks consisting of word lists, letter strings, or numerical stimuli and thus makes little contact with real-world scenarios under which engaging in cognitive offloading might be likely. Accordingly, the current work examines offloading choice behavior and potential benefits afforded by offloading health-related information. Experiment 1 tests for internal memory performance for different pieces of missing medication interaction information. Experiment 2 tests internal memory and offloading under full offloading and partial offloading instructions for interaction outcomes that are relatively low severity (e.g., sweating). Experiment 3 extends Experiment 2 by testing offloading behavior and benefit in low-severity, medium-severity (e.g., backache), and high-severity interaction outcomes (e.g., heart attack). Here, we aimed to elucidate the potential benefits afforded by partial offloading and to examine whether there appears to be a preference for choosing to offload (i) difficult-to-remember information across outcomes that vary in severity, as well as (ii) information from more severe interaction outcomes. Results suggest that partial offloading benefits performance compared to relying on internal memory alone, but full offloading is more beneficial to performance than partial offloading.

Visual and cognitive functioning among older adults with low vision before vision rehabilitation: A pilot study

Introduction

The occurrence of age-related vision changes is inevitable. However, some of these changes can become pathological. Research indicates that vision and hearing loss is correlated with age-related cognitive decline, and with a higher risk of developing dementia due to Alzheimer's disease. Low vision rehabilitation could possibly be a protective factor against cognitive decline, as it provides the clients with compensatory strategies to overcome their visual deficits.

Objectives and hypothesis

The aim of this pilot study was to assess correlations between visual and cognitive functions in older adults referred for low vision rehabilitation. We hypothesized that more severe impairment of visual acuity and contrast sensitivity would be correlated with more advanced levels of cognitive impairment. The second objective was to examine which of these correlations would remain significant once established variables that influence cognition are statistically removed (e.g., age, education).

Methods

Thirty-eight older adults (age range: 66-97 years old) with a visual impairment (acuity <20/70) were recruited before the onset of their low vision rehabilitation. They underwent vision (reading acuity, reading speed, contrast sensitivity), hearing (audiogram, speech-in-noise perception) and cognitive (global cognition, memory, executive functions) testing, and demographic information was obtained.

Results and discussion

Correlations among global cognition and visual aid use, memory and reading speed, memory and contrast sensitivity, memory, and visual aid use, and between executive functions and contrast sensitivity were significant. Correlations between contrast sensitivity and memory, as well as between global cognition and visual aid use remained significant after controlling for age and education. The present study is relevant to clinicians who are assessing the cognitive status of older adults, such as neuropsychologists, because it highlights the importance of considering low vision when administering neuropsychological tests, especially to persons who have not yet received rehabilitation for their visual impairment.

Age effects in autobiographical memory depend on the measure

Studies examining age effects in autobiographical memory have produced inconsistent results. This study examined whether a set of typical autobiographical memory measures produced equivalent results in a single participant sample. Five memory tests (everyday memory, autobiographical memory from the past year, autobiographical memory from age 11-17, word-cued autobiographical memory, and word-list recall) were administered in a single sample of young and older adults. There was significant variance in the tests' sensitivity to age: word-cued autobiographical memory produced the largest deficit in older adults, similar in magnitude to word-list recall. In contrast, older adults performed comparatively well on the other measures. The pattern of findings was broadly consistent with the results of previous investigations, suggesting that (1) the results of the different AM tasks are reliable, and (2) variable age effects in the autobiographical memory literature are at least partly due to the use of different tasks, which cannot be considered interchangeable measures of autobiographical memory ability. The results are also consistent with recent work dissociating measures of specificity and detail in autobiographical memory, and suggest that specificity is particularly sensitive to ageing. In contrast, detail is less sensitive to ageing, but is influenced by retention interval and event type. The extent to which retention interval and event type interact with age remains unclear; further research using specially designed autobiographical memory tasks could resolve this issue.

Interpretation of familiar metaphors and proverbs by Polish people in middle and late adulthood

BACKGROUND

The ability to understand figurative language, including metaphors and proverbs, decreases with age, although the phenomenon is not universal. Cognitive capacities and education play an important role in the competence connected with figurative language use and comprehension in people during the second half of life.

AIMS

To identify possible similarities and differences in task performance by subjects representing middle adulthood (40-49 and 50-59 years old) and late adulthood (60-69 and 70-92 years old). Additionally, the analyses took into account factors significantly affecting the results, that is, tasks type (metaphors versus proverbs), the way the answer is given (open-ended versus multiple choice) and types of answers (abstract and concrete). This study also aimed to identify some cognitive correlates of task completion.

METHODS & PROCEDURES

A total of 86 Caucasian subjects, aged 40-92 years, participated in this study (M_{whole group} = 62.37, SD = 15.53); the group included 20 subjects aged 40-49 years (M_age = 45.4; SD = 3.05), 20 aged 50-59 years (M_age = 55.50; SD = 2.64), 20 aged 60-69 years (M_age = 64.40; SD = 2.78), and 26 aged 70-92 years (M_age = 79.15; SD = 6.27). A total of 20 well-known Polish metaphors and 20 popular Polish proverbs were used to assess the level of proverb and metaphor comprehension. The Montreal Cognitive Assessment Scale and Vocabulary subtest of the Polish version of WAIS-R were applied to assess the cognitive functions.

OUTCOMES & RESULTS

The results of the analyses suggest that there are differences as well as certain similarities between the groups. At 70+ years of age, the ability to explain and comprehend metaphors and proverbs decreases when compared with younger adults. In the 70+ group, the ability to grasp the meaning of both metaphors and proverbs is similar, unlike in the younger groups which present a better ability to explain and comprehend metaphors than proverbs. The conditions related to the types of tasks, that is, spontaneous interpretation and choice of responses, do not affect scores of the oldest subjects.

CONCLUSIONS

The analysis of response types, that is, abstract versus concrete, shows that, compared with younger groups, people aged 70+ years tend to less frequently provide abstract explanations and more often give concrete (but correct) responses, referring to situational data or examples from everyday life. Moreover, attention, short-term/delayed memory and lexical reserve influence the ability to use and comprehend figurative language to a varied degree.

WHAT THIS PAPER ADDS

What is already known on the subject Studies focusing on metaphor and proverb interpretation by people in middle and late adulthood are rather scarce, and what is more, they provide inconclusive results. Research has shown that the capacities related to attention and memory, as well as language resources and executive functions, all deteriorate in older people, which negatively affects their ability to understand metaphors and proverbs. However, varied methods are applied to assess these skills, which may explain why the related findings are inconsistent. What this paper adds to existing knowledge The novelty of this study lies in the fact that the analyses took into account the type of task (metaphors versus proverbs), the method of responding (open-ended versus multiple-choice) and the nature of the answer (abstract versus concrete). This allowed us to highlight intergroup differences and to show specific characteristics of proverb and metaphor spontaneous interpretation and choice of correct answers. The results were compared among the participants representing relatively narrow age ranges classified as middle and late adulthood. What are the potential or actual clinical implications of this work? Analysis of how people in middle and late adulthood interpret metaphors and proverbs might constitute an element of preliminary screening assessment showing whether a decrease in this capacity is in the normal range or if it reflects a serious cognitive decline. It would be worthwhile if the diagnostic process included varied task designs, that is, both metaphors and proverbs, as well as spontaneous interpretation and multiple-choice, as well as varied types of responses.

The ironic effect of older adults' increased task motivation: Implications for neurocognitive aging

Recent work suggests that most older adults who volunteer to take part in cognitive experiments are more motivated to do well than are undergraduate students. This empirical evidence is echoed by the impressions of cognitive aging researchers. We surveyed a large group (N = 88) of researchers asking about their perceptions of younger and older adults' motivation to take part in lab-based research. Not only were older adults seen as more motivated than younger adults, but researchers thought that the two groups participate for different reasons: younger adults to obtain course credit or monetary compensation, older adults to get a sense of their cognitive health, to further science, and out of curiosity. However, older adults' greater motivation to do well on cognitive tasks may leave them vulnerable to stereotype threat, the phenomenon by which individuals underperform when they are put in a position to either confirm or deny a negative stereotype about their group. In this opinion piece, we argue that most cognitive experiments, not just those designed to measure stereotype threat, likely induce some form of performance-related anxiety in older adults. This anxiety likely leads to greater task-related interference, or thoughts about how one is doing on the task, resulting in poorer performance. We discuss some of the potential implications for our understanding of neurocognitive aging.

The effect of age on the FCSRT-IR and temporary visual memory binding

ABSTRACTBackground:Cognitive markers of early Alzheimer's disease (AD) should be sensitive and specific to memory impairments that are not associated with healthy cognitive aging. In the present study, we investigated the effect of healthy cognitive aging on two proposed cognitive markers of AD: the Free and Cued Selective Reminding Task with Immediate Recall (FCSRT-IR) and a temporary visual memory binding (TMB) task.

METHOD

Free recall and the cost of holding bound information in visual memory were compared between 24 younger and 24 older participants in a mixed, fully counterbalanced experiment.

RESULTS

A significant effect of age was observed on free recall in the FCSRT-IR only and not on the cost of binding in the TMB task.

CONCLUSIONS

Of these two cognitive markers, the TMB task is more likely to be specific to memory impairments that are independent of age.

Contextual representations of negative images modulate intrusion frequency in an intrusion provocation paradigm

BACKGROUND AND OBJECTIVES

To understand how memories of negative events become highly accessible in the context of trauma, we tested the hypothesis that contextual information modulates how easily intrusions can be provoked by perceptual stimuli..

METHODS

Healthy participants viewed pictures depicting trauma scenes either with or without accompanying moderate (i.e. survival, recovery) or severe (i.e. fatality, permanent injury) outcome information. All participants viewed the same depictions of trauma scenes. Involuntary memories for the pictures were assessed using self-report diaries and an adapted version of the Impact of Event Scales (IES). A blurred picture perceptual priming paradigm was adapted to be used as an intrusion provocation task.

RESULTS

The severe outcome group experienced a significantly higher frequency of intrusions on the intrusion provocation task in comparison to both moderate outcome and control (no-context) conditions. The severe outcome condition did not increase intrusions on the self-report diaries or the adapted IES. There was no effect of condition on ratings for the emotionality, self-relevance, valence, or seriousness of the trauma scenes.

LIMITATIONS

The analogue method should not be generalized directly to incidences of real-life trauma. It was unclear why differences in intrusion frequency were found in the provocation task only. The relative amount of individual conceptual and data-driven processing adopted by the participants was not assessed.

CONCLUSIONS

Manipulating contextual information that determines the meaning of sensory-perceptual features for a trauma scene can modulate subsequent intrusion frequency in response to visually similar cues.

Age, Organization, and Memory: Effects of Presentation Rate and Rehearsal Strategy

The relationship between free recall and organization was investigated using a 2(age) × 2(presentation rate) × 2(rehearsal strategy) analysis-of-variance design. A multitrial free-recall task was used with a 16-item list of unrelated words. Young and old adults practiced these materials overtly using either spontaneous (natural) rehearsal or a strategy increasing active rehearsal. Both increased rehearsal activity and increased study time were expected to improve senior adults' memory functioning. Analyses of rehearsal and recall measures indicated that elderly individuals had a general decrement in verbal memory. The role played by organizational strategies appears important only for young adults. For the elderly, both independent variables led to more enriched rehearsal activity and slightly greater subjective organization. No improvement in recall emerged, and large differences associated with age persisted. These findings suggest that organizational deficits do not account for differences in memory as a function of age.

Sex differences in cognitive trajectories in clinically normal older adults

Age effects on cognitive functioning are well-documented, but effects of sex on trajectories of cognitive aging are less clear. We examined cognitive ability across a variety of measures for 1,065 to 2,127 participants (mean baseline age 64.1 to 69.7 years) from the Baltimore Longitudinal Study of Aging who were repeatedly tested over a mean follow-up interval of 3.0 to 9.0 years with a mean of 2.3 to 4.4 assessments. Memory and other cognitive tests were administered at each visit, assessing mental status, verbal learning and memory, figural memory, language, attention, perceptuomotor speed and integration, executive function, and visuospatial ability. Importantly, participants free from cognitive impairment at all time points were used in the analyses. Results showed that for all tests, higher age at baseline was significantly associated with lower scores, and performance declined over time. In addition, advancing age was associated with accelerated longitudinal declines in performance (trend for mental status). After adjusting for age, education, and race, sex differences were observed across most tests of specific cognitive abilities examined. At baseline, males outperformed females on the 2 tasks of visuospatial ability, and females outperformed males in most other tests of cognition. Sex differences in cognitive change over time indicated steeper rates of decline for men on measures of mental status, perceptuomotor speed and integration, and visuospatial ability, but no measures on which women showed significantly steeper declines. Our results highlight greater resilience to age-related cognitive decline in older women compared with men.

The role of font size and font style in younger and older adults' predicted and actual recall performance

We examined how font sizes (18pt., 48 pt.) and font styles (regular, italic, bold) influenced younger and older adults' judgments of learning (JOLs) and recall. In Experiment 1 younger adults gave higher JOLs and obtained higher recall than older adults. However, JOLs and recall varied for both age groups as a function of font size and font style manipulations despite a tendency for both groups to predict higher recall for items in large and in regular and italic styles than for small and bold fonts and achieve higher recall for regular than italic or bold items. No age differences were found in relative accuracy, with near-perfect calibration in absolute accuracy for younger and older adults. Experiment 2 presented a description of Experiment 1 and asked participants to predict recall for the various font size/style combinations. Younger and older adults predicted higher recall for large than small font items, regardless of font style, and higher recall for bold than regular or italic styles, regardless of font size. Memory predictions did not align across experiments, suggesting that memory beliefs combine with processing fluency to affect JOLs and recall.

Memory deficits in aging and neurological diseases

Memory is central to our ability to perform daily life activities and correctly function in society. Improvements in public health and medical treatment for a variety of diseases have resulted in longer life spans; however, age-related memory impairments have been significant sources of morbidity. Loss in memory function is not only associated with aging population but is also a feature of neurodegenerative diseases such as Alzheimer's disease and other psychiatric and neurological disorders. Here, we focus on current understanding of the impact of normal aging on memory and what is known about its mechanisms, and further review pathological mechanisms behind the cause of dementia in Alzheimer's disease. Finally, we discuss schizophrenia and look into abnormalities in circuit function and neurotransmitter systems that contribute to memory impairment in this illness.

Relating traffic, construction, and ventilation noise to cognitive performances and subjective perceptions

The present study investigates the cognitive performance and subjective perceptions in the context of road traffic noise alone and multiple noises, including construction and ventilation noises. A total of 20 university students were exposed to seven noise conditions. Laboratory experiments employed semantic and episodic memory tasks. Self-reports of perception were collected from the participants. It was found that multiple noise sources impaired the free recall of words, and free recall scores were affected by noise type. Significant differences in free recall scores were found when the noise level difference between the individual noise and multiple noise sources was more than 5 dB. In contrast, word comprehension did not mediate the effects of noise on semantic memory. Annoyance caused by multiple noise sources correlated highly with the results of the free recall and word comprehension tasks. Moreover, loudness and roughness were found to account for the annoyance ratings of combinations of road traffic noise with construction or ventilation noises.

Age-related differences according to the associative deficit and the environmental support hypotheses: an application of the formal charm associative memory model

BACKGROUND/STUDY CONTEXT: According to both the associative deficit hypothesis (ADH; Naveh-Benjamin, 2000 , Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 1170-1187) and the environmental support hypothesis (ESH; Craik, 1983 , Philosophical Transactions of the Royal Society of London Series B, 302, 354-359), memory decline with aging can be seen as an impairment of the self-initiated associative memory processes such that supportive encoding and/or retrieval can reduce age-related differences. A formalization of relationships between the ADH and ESH was investigated using the distributed memory model "CHARM" (Composite Holographic Associative Recall-Recognition Model; Metcalfe, 1982 , Psychological Review, 89, 627-661; Metcalfe, 1991 , Psychological Review, 98, 529-543).

METHODS

Empirical data were collected in young and elderly participants on cued recall and recognition tests according to both the level of processing (LOP: phonetic vs. semantic tasks) and the self-generated cueing (elaboration effect: provided vs. self-generated cue) manipulation. These data were compared with those from CHARM simulations that were designed to evaluate the impact of deteriorated associative processes (i.e., ADH) and the role of LOP and elaboration effects (i.e., ESH) in memory performance.

RESULTS

The simulated data were largely consistent with the empirical data, showing that the impairment of associative processes in the CHARM model was accompanied by an increased need for environmental support at encoding (interaction between age, LOP, and elaboration) to reduce memory decline in cued recall tasks, which is somewhat observed in the recognition scores.

CONCLUSION

The overall results from CHARM simulations are in accordance with both the ADH and ESH hypotheses and provide discussion on the formal connections between these two main aging explanations.

Age-related declines in the fidelity of newly acquired category representations

We present a theory suggesting that the ability to build category representations that reflect the nuances of category structures in the environment depends upon clustering mechanisms instantiated in an MTL-PFC-based circuit. Because function in this circuit declines with age, we predict that the ability to build category representations will be impaired in older adults. Consistent with this prediction, we find that older adults are impaired relative to younger adults at learning nuanced category structures that contain exceptions to the rule. Model-based analysis reveals that this deficit arises from older adults' failure to engage clustering mechanisms to separate exception and rule-following items in memory.

Age-related changes in right middle frontal gyrus volume correlate with altered episodic retrieval activity

Age-related deficits in episodic retrieval have been associated with volume reductions in the middle frontal gyrus (MFG). However, it remains unclear how this age-related reduction in MFG volume correlates with neural activity during retrieval. To address this, we conducted in vivo volumetry of the frontal cortex in young and older human adults and found more volume loss on the right than on the left MFG with age. We then examined how left and right MFG volume correlated with fMRI activity during successful retrieval of item, spatial context, and temporal context information in both age groups. In young adults, larger right MFG volume was positively correlated with greater activity in a commonly found episodic retrieval network that included bilateral dorsolateral prefrontal cortex (DLPFC) and bilateral inferior parietal cortex. Within this network, left DLPFC and right inferior parietal cortex activity predicted memory performance. In older adults, a positive structure-function association in DLPFC for either left or right MFG/DLPFC was not observed. Instead, right MFG volume was negatively correlated with activity in several regions in older adults, including the parahippocampal cortex (PHC) and anterior cingulate. Less activity in the PHC region predicted better item memory, and less activity in the anterior cingulate predicted better spatial context accuracy in older adults. We conclude that age-related change in the structure-function association in MFG/DLPFC impacts retrieval activity and performance, and those older adults with larger right MFG volume attempt to compensate for this change by modifying activity in other brain regions to help retrieval performance.

Étude des relations entre des measures d'évaluation subjective et objective de mémoire et des mesures psychosociales chez des personnes âgées entre 55 et 65 ans

A review of the literature shows that only a weak connection exists between objective memory tests and self-evaluation memory questionnaires. The object of the present study was to explore which of the mnemonic, affective or psychosocial factors influence subjective evaluation of the memory function. This study is composed of a self-evaluation memory questionnaire, an ecologic-type objective memory evaluation, two affective state measures, anxiety and depression, and an inventory of life events. Sixty elderly persons took part in the study. They were divided into two groups, with attribution to a group depending on whether or not they considered themselves to have problems with memory Results supported the hypothesis that subjective and objective evaluations of memory comprise different components. Contrary to an objective test, self-evaluation of memory is strongly related to affect rather than being a perfect representation of actual mnemonic ability and this in spite of the ecological character of the memory test.

Contemporary review 2009: cognitive aging

This article addresses key topics in cognitive aging, intending to provide the reader with a brief overview of the current state of research in this growing, multidisciplinary field. A summary of the physiological changes in the aging brain is provided as well as a review of variables that influence cognitive abilities in older age. Normal aging differentially affects various aspects of cognition, and specific changes within various domains such as attention, executive functioning, and memory are discussed. Various theories have been proposed to account for the cognitive changes that accompany normal aging, and a brief examination of these theories is presented in the context of these domain-specific changes.

Influence of age, gender and educational level on performance in the Brief Cognitive Battery-Edu

The Brief Cognitive Battery-Edu (BCB-Edu) contains nine tests, seven of which are related to the memory of drawings, and has good accuracy in the diagnosis of cognitive impairment.

OBJECTIVES

To evaluate the influence of age, gender and educational level on the performance in tests related to memory of drawings of the BCB-Edu in healthy subjects.

METHODS

Participants were adult volunteers; exclusion criteria were illiteracy, neurologic or psychiatric disorders, visual or hearing impairment, untreated chronic clinical conditions, alcoholism, use of drugs, and for those aged 65 or over, an informant report of cognitive or functional impairment. We evaluated 325 individuals (207 women), with a mean age of 47.1 (±16.8) years, ranging from 19 to 81, and a mean of 9.8 (±5.0) schooling-years. Univariate analyses, correlations and logistic regression were employed (α=0.05).

RESULTS

There were significant negative correlations between age and the scores in four of the seven tests. However, schooling-years were positively correlated to the scores, where schooling-years decreased with age in this sample (rho= -0.323; p<0.001). Logistic regression confirmed that gender influenced the learning of drawings, where women performed better, while age influenced incidental memory, immediate memory, learning and delayed recall of the drawings, and schooling-years influenced visual identification, immediate memory, learning, delayed recall and recognition of the drawings.

CONCLUSION

Gender, age and education influence the performance on the memory of drawings of the BCB-Edu, although the extent of these influences differs according to the nature of the test.

Memory for gist and detail information in Alzheimer's disease and mild cognitive impairment

Two experiments examined different forms of gist and detail memory in people with Alzheimer's disease (AD) and those with amnestic mild cognitive impairment (MCI). In Experiment 1, 14 AD, 14 MCI, and 22 control participants were assessed with the Deese-Roediger-McDermott paradigm. Results indicated that false recognition of nonstudied critical lures (gist memory) was diminished in the AD compared with the MCI and control groups; the two latter cohorts performed similarly. In Experiment 2, 14 AD, 20 MCI, and 26 control participants were tested on a text memory task. Results revealed that recall of both macropropositions (gist information) and micropropositions (detail information) decreased significantly in AD and in MCI as compared with control participants. This experiment also revealed that the impairment was comparable between gist and detail memory. In summary, the results were consistent across experiments in the AD but not in the MCI participants. The discrepancy in MCI participants might be explained by differences in the degree of sensitivity of the experimental procedures and/or by the differences in the cognitive processes these procedures assessed.

Age effect in recall performance according to the levels of processing, elaboration, and retrieval cues

The present study was conducted to investigate the incidence of several factors contributing to age-related memory decrement. Variables manipulated include quality (level of processing encoding conditions), the degree of effort and encoding quantitative elaboration (active/passive encoding conditions), and the influence of retrieval support (free-/cued recall conditions). In support of the environmental support hypothesis, middle-old and old subjects benefited more than young ones from cued recall in all the memory tests. Moreover, the results showed a differential (qualitative vs. quantitative) impairment of conceptual processing between the middle-old and the old-age groups. In the middle-olds, age differences were abolished by deep processing in old adults, age differences were attentuated only with deep and active processing associated with retrieval support. These gradual memory impairments are evaluated according to Mandler's model of memory (1979, In L. G. Nilsson [Ed.], Perspective in memory research. Hillsdale: Lawrence-Erlbaum), and the environmental support hypothesis is discussed in terms of the involvement of encoding and retrieval operations required by the memory task.

Adult age differences in the functional neuroanatomy of verbal recognition memory

Adult age differences are frequently observed in the performance of memory tasks, but the changes in neural function mediating these differences are largely unknown. We used (H2)15O positron emission tomography (PET) to measure changes in regional cerebral blood flow (rCBF) during Encoding, Baseline, and Retrieval conditions of a recognition memory task. Twelve young adults (20-29 years) and 12 older adults (62-79 years) participated. During each task condition, participants made a two-choice manual response to each of 64 words. Analyses of the performance data yielded evidence of age-related slowing of encoding and retrieval processes, and an age-related decline in the accuracy of yes/no recognition (d'). The rCBF activation associated with both encoding and retrieval was greater for older adults than for young adults, but this pattern was more clearly evident for memory retrieval. For young adults, rCBF activation during retrieval occurred primarily in right prefrontal cortex, whereas older adults exhibited a more bilateral pattern of prefrontal activation. Regression analyses predicting reaction time in the memory task from regional PET counts confirmed that the neural system mediating memory retrieval is more widely distributed for older adults than for young adults. Both age groups exhibited some decrease in rCBF activation in the second half of the test session, relative to the first half. The practice-related decrease in rCBF activation was more prominent for young adults, suggesting that the older adults' recruitment of additional neural systems reflects a more continual allocation of attention to support task performance.

Nonsteroidal anti-inflammatory drugs and cognitive function: do they have a beneficial or deleterious effect?

Studies suggest that high dose NSAID use may be associated with a reversible impairment of cognition in the elderly. Prolonged NSAID use, on the other hand, may prevent the decline in cognition associated with aging. However, it has yet to be to be definitively determined whether this protection arises from an anti-inflammatory effect that modifies pathways involved in Alzheimer's dementia, or is mediated by a platelet effect that decreases the risk of cerebrovascular disease. Further large-scale, randomised, controlled trials using NSAIDs are needed before patients can be advised that the known risks of NSAIDs are outweighed by their potential long term benefits on cognition. While clinicians await the results of such studies, they should continue to be alert to the possibility of acute CNS adverse effects in their elderly patients who are receiving NSAIDs and to prescribe the minimum dose that is necessary to control pain and inflammation.

Aging and olfactory recognition memory: effect of encoding strategies and cognitive abilities

The effects of two encoding manipulations on recognition memory for odors were examined in 20 young and 20 elderly males. Subjects were instructed to use two different encoding strategies: (1) labeling-plus-definition (i.e., naming the odor and giving a short description) and, (2) life-episode association (i.e., associating a memory of a life-episode with each odor). Results revealed that elderly subjects performed significantly worse than young subjects in the labeling-plus-definition condition, but not in the life-episode task in which they achieved a level of performance not significantly different from the young. Encoding specificity or precision did not significantly impact recognition memory for the odors in either group. Analysis of response bias revealed that, in the label-plus-definition condition, young subjects were more conservative in responding style, while more liberal in their responding in the life-episode condition. In contrast, elderly subjects exhibited nearly identical response bias across both encoding conditions. The results suggest that age-related deficits in olfactory memory may be strategy dependent.

Risk factors for motor vehicle crashes among older drivers in a rural community

OBJECTIVE

To estimate the motor vehicle crash rate in a cohort of older drivers from a rural community and to identify health-related conditions that increase their risk for crash involvement.

DESIGN

Cohort study with 5 years of crash-record surveillance.

SETTING

The Iowa 65+ Rural Health Study, one of four Established Populations for Epidemiologic Studies of the Elderly (EPESE).

PARTICIPANTS

A total of 1791 drivers aged 68 years and older.

MAIN MEASURES

Exposure measures of physical, mental, and sensory well-being from a health interview survey; outcome measure of police-reported crashes maintained by the Iowa Department of Motor Vehicles.

RESULTS

Between 1985 and 1989, 206 drivers were involved in 245 state-recorded crashes. The estimated annual crash involvement rate for these rural older drivers (28 per 1000 driving-years) was about 20% less than the national average for drivers aged 65 years and over (36 per 1,000). An increased risk for motor vehicle crashes was associated with episodes of back pain (Relative Risk = 1.4, P < .05), use of nonsteroidal anti-inflammatory drugs (RR = 1.7, P < .01), and poor performance on a free-recall memory test (RR = 1.4, P < .05).

CONCLUSIONS

If these and other geriatric conditions are confirmed as risk factors for motor vehicle crashes, medical guidelines for license renewal may need updating and health professionals may need new instruments to detect older patients at high risk for unsafe driving.

Knowing but not remembering: adult age differences in recollective experience

Age differences in recollective experience were examined in two experiments in which younger and older adults used their self-generated associations as retrieval cues. When recalling an item, subjects indicated whether they consciously remembered its prior occurrence, or merely knew that it was presented previously. The results of both experiments showed that aging selectively impaired retention accompanied by recollective experience, as measured by remember responses, but had no effects in the absence of recollective experience, as measured by know responses. In Experiment 2, a similar pattern of data was obtained for a group of younger adults by increasing the rate of presentation at study. The results also indicated that judgments of recollective experience were related to type of encoding: Subjects who generated detailed associations reported higher levels of remember responses and lower levels of know responses than did subjects who generated fewer detailed associations. The results are discussed in terms of processes related to perceptual familiarity and contextual detail.

Event-related potentials and repetition priming in young, middle-aged and elderly normal subjects

Although the structure of semantic memory appears to be unaffected with increasing age, there is evidence that older adults are less efficient at accessing stored memory representations. Aging also results in a decline in the ability to use contextual information effectively, suggesting a deficit in episodic memory processes. The present experiment examines the effects of age on memory retrieval of stored representations and the use of contextual information. Event-related potentials (ERP) were recorded to immediate and delayed word repetition during a lexical decision task. Three groups of subjects were tested: young (mean = 27.3 years), middle (mean = 46.7 years) and old (mean = 67.4 years). Behavioral facilitation due to repetition did not significantly differ across groups. With increasing age, the ERP waveform showed a positive shift which began around 300-400 ms post-stimulus and was apparent across all stimulus types and response conditions. This positive shift may reflect an age-related decrease in cortical excitation. Although the onset of the ERP repetition effect was not affected by age, its duration for both immediate and delayed repetition was significantly prolonged. In the light of recent models of ERP word repetition effects, these results suggest that processes related to accessing stored representations in memory are unaffected by age. The extended duration of the repetition effect and the increase in the magnitude of the effect of delayed repetition with age suggest that aging affects processes related to the retrieval and use of contextual information in integrating a stimulus with its context.

The effect of goal-setting and feedback on age differences in secondary memory

Goal-setting and feedback have been found to improve performance on a variety of tasks. The present study applied this finding to an examination of adult age differences in secondary memory. Elderly and young adults completed a free-recall task in which one subgroup established a performance goal for blocks of trials and received feedback on a trial-by-trial basis. A second, comparison subgroup completed the same task without setting goals or receiving feedback. Results indicated that the use of the motivational technique of goal-setting and feedback increased memory performance of both age groups beyond that obtained under standard recall conditions.

Ability to register new information: a memory measure for the aged

Ability to register new information is a necessity for the maintenance of autonomy. Its measurement is especially critical with older patients to distinguish cognitive from other aging losses. This paper introduces the Aronson Shopping List, constructed to assess that ability. It describes a check on the test's reliability and an aspect of construct validity for its use. The subjects were 67 community volunteers aged 62 to 89 yr. Those aged 80 to 89 yr. required more training than members of the two preceding decades. Correlations of learning scores on the Aronson Shopping List with WAIS or WAIS--R subtests and prorated IQs were significant. Alternate form stability/reliability, checked after a mean interval of 11 mo. was .75. Assessing cognitive aging was discussed and related to memory.

Age differences in primary organization or processing variability? Part I: An examination of age and primary organization

We compared young and elderly adults on the ability to serially recall sequences of letters assumed to be stored in secondary memory. The results showed that older adults recalled significantly fewer complete strings than younger adults. However, both age groups exhibited the same pattern of transitional error probabilities (TEPs), indicating that the two groups were chunking information in the same qualitative manner. Interestingly, though, the older adults exhibited higher TEP spikes (indicating stronger chunk bounderies) than did younger adults. These results do not support the view that there are qualitative age differences in primary organization, but the results do indicate that older adults have a secondary memory deficit.

Adult age differences in cross-modal recoding and mental tempo, and older adults' utilization of compensatory task conditions

Free recall performance of younger and older adults was examined in three modes of presentation: visually presented sentences, auditorily presented sentences, and bimodally (visually + auditorily) presented sentences. For all modes, the sentences were presented at slow or fast rates. The main result was a three-way interaction between age, mode, and rate. The younger adults performed at the same level in all three modes at a slow rate of presentation, and at a higher level in the bimodal task than in the unimodal tasks at a fast rate of presentation. The elderly, on the other hand, performed at the highest level in the bimodal task regardless of rate of presentation. In addition, the younger adults outperformed the elderly in all mode by rate combinations; however, attenuated age differences in recall were observed for the bimodally presented sentences at a slow presentation rate. It is suggested that the adult aging process is associated with deficits in cross-modal recoding and rate of processing. Finally, the capability of older adults to utilize compensatory task conditions is discussed.

Age differences in the commonality of free associations

Commonality of associative response provides an index of the organization of semantic memory. The present study investigated age differences in semantic organization by comparing commonality of associative response. Thirty young (M = 20 yrs) and 30 old (M = 72 yrs) adults gave free associations to single stimulus words of high or low linguistic frequency. Controlling statistically for education and verbal skills, it was determined that there were no age differences in the commonality or variability of associates. Results are discussed in reference to developmental trends in the organization of semantic memory.

Priming effects and recognition memory in young and elderly adults

The present study explores the effects of age on the priming of alternate homophone spellings and recognition memory. Sixteen young and sixteen elderly adults were given a general information test, a spelling test, and a test of recognition memory. By embedding the less frequently spelled member of different homophone units (e.g., write vs. right) in the general information questions, certain of the homophones were primed during this task. The effect of this priming was assessed through the subjects' choice of spelling for these words on the spelling test. Recognition memory was assessed by asking subjects to indicate which words from a longer list were presented during the spelling test. As found in prior research priming effects were observed in younger subjects; however, no significant priming effects occurred in the older age group. On the recognition test, homophones were more often correctly recognized than nonhomophones, and priming affected the scores of the young negatively, but had no effects, positive or negative, on the elderly. These results suggest possible differences in the underlying bases of memory loss in aged adults and amnesics.

Age differences in the effects of contextual framework and word- familiarity on episodic memory

The effect of contextual framework on episodic memory for words was investigated by asking young and older adults either to study a list of words for intentional recall, or to place the words into a story context, with subsequent incidental recall. The story context orienting task was no more beneficial for recall than the study task, and this was true for both young and old. Providing the story at both encoding and retrieval, however, was beneficial, but equally so for both age groups. Pre-experimental familiarity with word items in terms of cohort relevance was an important determinant of recall for both age groups.

The systematic use of semantic and acoustic processing by younger and older adults

To examine age differences in semantic and acoustic processing, 80 older and 80 younger adults participated in an incidental learning study. The study compared free recall and semantic and acoustic cued recall performance after five orienting conditions. The younger adults performed better than the older adults, especially after acoustic orienting. Encoding specificity effects occurred at both age levels. The results indicated that both age groups performed better with semantic processing than acoustic processing, but that older adults relied on the semantic information far more than the younger adults.

Age differences in the effect of encoding congruence on incidental free and cued recall

The effect of encoding congruence on incidental free and cured recall was investigated by presenting young and older adults with a list of 24 words, one from each of 24 taxonomic categories. half the subjects from each age group received a congruent orienting task, in which category questions were matched with relevant word instances; the other half from each age group received a non-congruent orienting task, in which category questions were not matched with relevant instances. The age x orienting task x memory interaction indicated that the free recall performance of the young was higher following the congruent orienting, but that of the old was no different following congruent and non-congruent orienting. On cued recall, both age groups performed at the same high level following congruent orienting. The young had a marginally higher level of cued recall than the old following non-congruent orienting. The implications of these findings for processing and production deficiency hypotheses of age-related memory differences were discussed.

Aging and recognition memory: methodological and interpretive problems

The recognition memory and aging literature has been reviewed with the purpose of evaluating the notion that the elderly encode semantic information in a more variable manner than the young. Because of methodological, as well as interpretive problems, only a handful of the investigations may be given serious consideration. It is recommended that future investigators report hits, false alarms, sensitivity and response-bias measures. It is also recommended that a concerted effort be made to equate age groups for response bias, that complete details of experimental procedures be reported and that appropriate statistical tests be made.