Effects of distinctive context on memory for objects and their locations in young and elderly adults

Reducing age-related Memory Deficits: The Roles of Environmental Support and self-initiated Processing Activities

BACKGROUND

The notion that memory performance in older adults can be boosted by information provided by the environment was proposed by Craik (1983). The suggestion was that age-related memory deficits can be attenuated and sometimes even eliminated by a complementary combination of environmental support and consciously controlled self-initiated activities.

OBJECTIVE

The objective of the present article was to review the subsequent empirical and theoretical work on the topics of environmental support and self-initiated ativities as they relate to the effects of aging on human memory.

DISCUSSION

The notion of schematic support from the person's knowledge base is introduced and its relevance discussed. In addition, the effects of various types of support on encoding and retrieval processes in older adults are desribed, and the increasing theoretical importance of executive processes in reducing age-related memory deficits is discussed.

CONCLUSION

As one main conclusion, it is suggested that self-initiated control processes interact with both information provided by the environment and by the person's knowledge base to improve the effectiveness of encoding and retrieval processing in older adults.

Aggregate context effects in music processing

Control of stimulus confounds is an ever-present, and ever-important, aspect of experimental design. Typically, researchers concern themselves with such control on a local level, ensuring that individual stimuli contain only the properties they intend for them to represent. Significantly less attention, however, is paid to stimulus properties in the aggregate, aspects that, although not present in individual stimuli, can nevertheless become emergent properties of the stimulus set when viewed in total. This paper describes two examples of such effects. The first (Case Study 1) focuses on emergent properties of pairs of to-be-performed tones on a piano keyboard, and the second (Case Study 2) focuses on emergent properties of short, atonal melodies in a perception/memory task. In both cases these sets of stimuli induced identifiable tonal influences despite being explicitly created to be devoid of musical tonality. These results highlight the importance of monitoring aggregate stimulus properties in one's research, and are discussed with reference to their implications for interpreting psychological findings quite generally.

Visual Acuity does not Moderate Effect Sizes of Higher-Level Cognitive Tasks

BACKGROUND/STUDY CONTEXT

Declining visual capacities in older adults have been posited as a driving force behind adult age differences in higher-order cognitive functions (e.g., the "common cause" hypothesis of Lindenberger & Baltes, 1994, Psychology and Aging, 9, 339-355). McGowan, Patterson, and Jordan (2013, Experimental Aging Research, 39, 70-79) also found that a surprisingly large number of published cognitive aging studies failed to include adequate measures of visual acuity. However, a recent meta-analysis of three studies (La Fleur and Salthouse, 2014, Psychonomic Bulletin & Review, 21, 1202-1208) failed to find evidence that visual acuity moderated or mediated age differences in higher-level cognitive processes. In order to provide a more extensive test of whether visual acuity moderates age differences in higher-level cognitive processes, we conducted a more extensive meta-analysis of topic.

METHODS

Using results from 456 studies, we calculated effect sizes for the main effect of age across four cognitive domains (attention, executive function, memory, and perception/language) separately for five levels of visual acuity criteria (no criteria, undisclosed criteria, self-reported acuity, 20/80-20/31, and 20/30 or better).

RESULTS

As expected, age had a significant effect on each cognitive domain. However, these age effects did not further differ as a function of visual acuity criteria.

CONCLUSION

The current meta-analytic, cross-sectional results suggest that visual acuity is not significantly related to age group differences in higher-level cognitive performance-thereby replicating La Fleur and Salthouse (2014). Further efforts are needed to determine whether other measures of visual functioning (e.g., contrast sensitivity, luminance) affect age differences in cognitive functioning.

Outsourcing Memory in Response to an Aging Population

With baby boomers entering old age and longevity increasing, policymakers have focused on the physical, social, and health needs of older persons. We urge policymakers to consider cognitive aging as well, particularly normal, age-related memory decline. Psychological scientists attribute memory decline mainly to cognitive overload stemming from age-related reductions in sensory capacities, speed of cognitive processing, and the ability to filter out irrelevant information. Even in the absence of decline, however, memory is imperfect and forgetting can be especially consequential for older adults. For example, forgetting to take prescription medicines is an age-related problem largely because older adults tend to ingest many more prescription drugs. We propose that policymakers focus on increasing environmental support for memory that can reduce the burden on cognitive resources and thus improve recall. In providing environmental support, policymakers need to pay careful attention to potential age-related changes in physical and cognitive capacity, as well as behavior.

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.

A multifaceted prospective memory intervention to improve medication adherence: design of a randomized control trial

Adherence to prescribed antihypertensive agents is critical because control of elevated blood pressure is the single most important way to prevent stroke and other end organ damage. Unfortunately, nonadherence remains a significant problem. Previous interventions designed to improve adherence have demonstrated only small benefits of strategies that target single facets such as understanding medication directions. The intervention described here is informed by prospective memory theory and performance of older adults in laboratory-based paradigms and uses a comprehensive, multifaceted approach to improve adherence. It incorporates multiple strategies designed to support key components of prospective remembering involved in taking medication. The intervention is delivered by nurses in the home with an education control group for comparison. Differences between groups in overall adherence following the intervention and 6 months later will be tested. Systolic and diastolic blood pressure levels also will be examined between groups and as they relate to adherence. Intra-individual regression is planned to examine change in adherence over time and its predictors. Finally, we will examine the association between executive function/working memory and adherence, predicting that adherence will be related to executive/working memory in the control group but not in the intervention group.

Assessment of spatial memory in mice

Improvements in health care have greatly increased life span in the United States. The focus is now shifting from physical well-being to improvement in mental well-being or maintenance of cognitive function in old age. It is known that elderly people suffer from cognitive impairment, even without neurodegeneration, as a part of 'normal aging'. This 'age-associated memory impairment' (AAMI), can have a devastating impact on the social and economic life of an individual as well as the society. Scientists have been experimenting to find methods to prevent the memory loss associated with aging. The major factor involved in these experiments is the use of animal models to assess hippocampal-based spatial memory. This review describes the different types of memory including hippocampal-based memory that is vulnerable to aging. A detailed overview of various behavioral paradigms used to assess spatial memory including the T-maze, radial maze, Morris water maze, Barnes maze and others is presented. The review also describes the molecular basis of memory in hippocampus called as 'long-term potentiation'. The advantages and limitations of the behavioral models in assessing memory and the link to the long-term potentiation are discussed. This review should assist investigators in choosing suitable methods to assess spatial memory in mice.

The amount of retrieval support modulates age effects on episodic memory: evidence from event-related potentials

This experiment was designed to explore the impact of age and amount of retrieval support on episodic memory and its electrophysiological correlates. Event-related potentials (ERPs) were recorded while young and older participants performed a word-stem cued-recall task in a low-support condition (LSC) in which the stem was composed of three letters, and a high-support condition (HSC) in which the cue consisted of four letters. Behavioral analyses showed that recall in the older group was less accurate than in the young group in the LSC, but no age differences were observed in the HSC. In the LSC, old/new ERP effects at frontal and parietal sites were later and less sustained for the older adults. Furthermore, the parietal old/new effect was symmetrically distributed for older adults, whereas it was predominant over the left hemisphere for their younger counterparts. In addition, young participants demonstrated early and long-lasting frontal and parietal effects in the HSC but with predominance over the right hemisphere, whereas the older adults exhibited a frontal effect and an early and long-lasting parietal effect becoming predominant over the left hemisphere. No age differences in the time course of the parietal old/new effect were observed in this more supportive condition. In addition, in the last period, the left parietal effect was greater for the older group. This study suggests that episodic memory performance and ERP correlates of recall processes are more similar between young and older adults when increased support is provided at retrieval.

Generation and associative encoding in young and old adults: the effect of the strength of association between cues and targets on a cued recall task

The generation effect (i.e., better recall of the generated items than the read items) was investigated with a between-list design in young and elderly participants. The generation task difficulty was manipulated by varying the strength of association between cues and targets. Overall, strong associates were better recalled than weak associates. However, the results showed different generation effect patterns according to strength of association and age, with a greater generation effect for weak associates in younger adults only. These findings suggest that generating weak associates leads to more elaborated encoding, but that elderly adults cannot use this elaborated encoding as well as younger adults to recall the target words at test.

Monitoring Eye Movements to Investigate the Picture Superiority Effect in Spatial Memory

Spatial memory is usually better for iconic than for verbal material. Our aim was to assess whether such effect is related to the way iconic and verbal targets are viewed when people have to memorize their locations. Eye movements were recorded while participants memorized the locations of images or words. Images received fewer, but longer, gazes than words. Longer gazes on images might reflect greater attention devoted to images due to their higher sensorial distinctiveness and/or generation with images of an additional phonological code beyond the visual code immediately available. We found that words were scanned mainly from left to right while a more heterogeneous scanning strategy characterized encoding of images. This suggests that iconic configurations tend to be maintained as global integrated representations in which all the item/location pairs are simultaneously present whilst verbal configurations are maintained through more sequential processes.

Reliance on Visible Speech Cues During Multimodal Language Processing: Individual and Age Differences

The current study demonstrates that when a strong inhibition process is invoked during multimodal (auditory-visual) language understanding: older adults perform worse than younger adults, visible speech does not benefit language-processing performance, and individual differences in measures of working memory for language do not predict performance. In contrast, in a task that does not invoke inhibition: adult age differences in performance are not obtained, visible speech benefits language performance, and individual differences in working memory predict performance. The results offer support for a framework for investigating multimodal language processing that incorporates assumptions about general information processing, individual differences in working memory capacity, and adult cognitive aging.

Pointing to an allocentric and egocentric remembered target in younger and older adults

Previous reports have shown that older adults have difficulties in maintaining allocentric information in memory but not egocentric information. The present study evaluated pointing accuracy in younger and older adults for egocentric and allocentric task. The task was to localize and maintain one, two, or four target locations. Target(s) were presented with or without a surrounding white square in a dimly lit environment. Despite previous postulations, the results of the present study revealed that older adults were able to point to remembered egocentric and allocentric targets as accurately as younger adults regardless of task difficulty. However, older adults took more time pointing to allocentric targets as compared to younger adults. The longer movement time was caused by a lengthening of the deceleration phase, suggesting that during pointing, older adults rely more on visual information surrounding the target than younger adults.

Impact of aging on hippocampal function: plasticity, network dynamics, and cognition

Aging is associated with specific impairments of learning and memory, some of which are similar to those caused by hippocampal damage. Studies of the effects of aging on hippocampal anatomy, physiology, plasticity, and network dynamics may lead to a better understanding of age-related cognitive deficits. Anatomical and electrophysiological studies indicate that the hippocampus of the aged rat sustains a loss of synapses in the dentate gyrus, a loss of functional synapses in area CA1, a decrease in the NMDA-receptor-mediated response at perforant path synapses onto dentate gyrus granule cells, and an alteration of Ca(2+) regulation in area CA1. These changes may contribute to the observed age-related impairments of synaptic plasticity, which include deficits in the induction and maintenance of long-term potentiation (LTP) and lower thresholds for depotentiation and long-term depression (LTD). This shift in the balance of LTP and LTD could, in turn, impair the encoding of memories and enhance the erasure of memories, and therefore contribute to cognitive deficits experienced by many aged mammals. Altered synaptic plasticity may also change the dynamic interactions among cells in hippocampal networks, causing deficits in the storage and retrieval of information about the spatial organization of the environment. Further studies of the aged hippocampus will not only lead to treatments for age-related cognitive impairments, but may also clarify the mechanisms of learning in adult mammals.

There's Got to be a Better Way(finding System)

Aging brings additional challenges to the task of finding one's way around a complex built environment.

Circadian rhythms, aging and memory

In human beings and animal models, cognitive performance is often impaired in natural and experimental situations where circadian rhythms are disrupted. This includes a general decline in cognitive ability and fragmentation of behavioural rhythms in the aging population of numerous species. There is some evidence that rhythm disruption may lead directly to cognitive impairment; however, this causal link has not been made for effects due to aging. We have tested this link by examining rhythms and performance on contextual conditioning with the conditioned place preference task, in elderly, age-matched hamsters. Young healthy hamsters developed a preference for a context that is paired with the opportunity to engage in wheel-running (experiment 1). Aged animals with consolidated locomotor rhythms developed similar degrees of preference, whereas the age-matched hamsters with fragmented rhythms did not (experiment 2). The degree of preference was also correlated with activity amplitude. These results support the notion that age-related rhythm fragmentation contributes to the age-related memory decline.

Circadian rhythms, aging and memory

In human beings and animal models, cognitive performance is often impaired in natural and experimental situations where circadian rhythms are disrupted. This includes a general decline in cognitive ability and fragmentation of behavioural rhythms in the aging population of numerous species. There is some evidence that rhythm disruption may lead directly to cognitive impairment; however, this causal link has not been made for effects due to aging. We have tested this link by examining rhythms and performance on contextual conditioning with the conditioned place preference task, in elderly, age-matched hamsters. Young healthy hamsters developed a preference for a context that is paired with the opportunity to engage in wheel-running (experiment 1). Aged animals with consolidated locomotor rhythms developed similar degrees of preference, whereas the age-matched hamsters with fragmented rhythms did not (experiment 2). The degree of preference was also correlated with activity amplitude. These results support the notion that age-related rhythm fragmentation contributes to the age-related memory decline.

Age-related differences in spatial memory: effects of structural and organizational context

The authors examined effects of structural and organizational spatial context on younger and older adults' memory for an arrangement of dollhouse furniture pieces. For half of the participants, landmark objects (Experiment 1) and a floor plan beneath the array (Experiment 2) served as structural context during study and replacement. Organizational context was varied by grouping items randomly or as 6 rooms in a prototypical house. Two study and replacement trials were given. In Experiment 1, landmark structural cues improved younger adults' performance, whereas both age groups benefited from the floor plan in Experiment 2. In both experiments, positive effects of organizational context and trial occurred. Higher order interactions further revealed that structural and organizational context effects varied in size across trials, suggesting that both age groups used spatial contextual cues more effectively with practice. Implications of these results for current views on cognitive compensation in adulthood are discussed.

Spatial memory in young and older adults: environmental support and contextual influences at encoding and retrieval

Previous studies have demonstrated the existence of an "unequal facilitation" effect in spatial memory. In those experiments, the provision of appropriate environmental support for recall was shown to enhance the recall performance of older adults more than that of young adults. In some cases, this process resulted in parity of performance between the two age groups. The present study evaluated the relative contribution of environmental support to the unequal facilitation effect at encoding and retrieval in a spatial memory task. Results, indicate that, although the provision of environmental support at both encoding and retrieval is necessary for optimal recall across the adult life span, the primary influence of such support for recall in the elderly derives from its presence at encoding.

Visual and semantic support for paired-associates recall in young and older adults

A paired-associates task was used to investigate the degree to which young and older adults benefit from visual and semantic support for recall. Respondents were asked to recall pictorial or verbal items that were either semantically related or unrelated. As has been previously observed in spatial memory tasks, older adults benefited to a greater degree from pictorial materials than did young adults, but only for semantically related items. No such effect was observed for unrelated items. In a second experiment, the imposition of a speed requirement at retrieval eradicated the unequal recall facilitation effect for the older participants. The results of this study are consistent with Craik's (1986) environmental support theory and suggest a link between visuospatial loss and cognitive speed loss in the normal aging process.

Category superiority effects in young and elderly adults

Recent research indicates that some elderly persons experience an age-related visual processing deficit, for which they may attempt to compensate through the use of relational information. This hypothesis was tested, using the category superiority effect as a model system. In studies of young adults, the category superiority effect has been shown to be confined to relatively abstract stimulus materials such as verbal items, and to be absent for more concrete representations such as photographs of actual objects. However, it was predicted that, contrary to the data from young adults, a category superiority effect would be present in elderly adults for both verbal and pictorial stimuli, because elderly people would be expected to use category information to compensate for imageric deficits. This prediction was confirmed, consistent with the hypothesis.

Effects of retention interval length on young and elderly adults' memory for spatial information

Adult age differences in spatial memory following retention intervals of various lengths were examined in 47 young and 56 elderly subjects who recalled spatial information following either a 3-, 15-, or 30-min retention interval. The elderly adults were significantly less accurate than the young adults following the 30-min retention interval only; there was no statistically significant effect of age at the 3-min and 15-min retention intervals. It is concluded that younger adults experience greater temporal stability of spatial memory than do older adults, and the relevance of the present findings for Craik's environmental support hypothesis is discussed.

Feature memory and binding in young and older adults

Intact memory for complex events requires not only memory for particular features (e.g., item, location, color, size), but also intact cognitive processes for binding the features together. Binding provides the memorial experience that certain features belong together. The experiments presented here were designed to explicate these as potentially separable sources of age-associated changes in complex memory-namely, to investigate the possibility that age-related changes in memory for complex events arise from deficits in (1) memory for the kinds of information that comprise complex memories, (2) the processes necessary for binding this information into complex memories, or (3) both of these components. Young and older adults were presented with colored items located within an array. Relative to young adults, older adults had a specific and disproportionate deficit in recognition memory for location, but not for item or for color. Also, older adults consistently demonstrated poorer recognition memory for bound information, especially when all features were acquired intentionally. These feature and binding deficits separately contribute to what have been described as older adults' context and source memory impairments.

Asymmetrical memory decline in normal aging and dementia

We assessed whether age-associated memory impairments and the memory impairment of Alzheimer's disease (AD) is comparable in the verbal and nonverbal domains. Subjects incidentally learned the identity and location of a group of objects and later verbally recalled the objects as well as recalling their previous spatial location. Comparison subject (younger subjects for experiment 1, and older subjects for experiment 2) were tested after retention intervals that equated their performance with that of the index subjects. We found that memory does not change uniformly with age. Verbal memory is more affected than nonverbal memory. This asymmetrical pattern is a feature of normal aging and does not appear to be due to a degenerative process such as Alzheimer's disease.

Age-related Deficits in Intentional Memory for Spatial Location in Small-scale Space: A Meta-Analysis and Methodological Critique

Le but de cette méta-analyse était d'estimer l'effet du vieillissement sur la mémoire intentionnelle de locations dans un espace de petite dimension. Les résultats de 22 études, représentant au total 1 598 sujets, ont été comparés grâce aux indices suivante: (a) d (Cohen, 1988), (b) omega2 (Hays, 1963), et (c) Proportion des sujets classifiés. La méta-analyse suggére que l'effet du vieillissement est «large» (e.g., d moyen de 0.81), et que cet effet est proportionnel au nombre de dimensions de l'espace utilisé. Toutefois, la validité de ces conclusions est incertaine lorsqu'on considére les limites méthodologiques des études recensées. En particulier, moins de la moitié de ces études ont mentionné avoir contrôlé l'effet possible de variables telles que (a) l'acuité visuelle, et (b) la durée de la phase de rappel. Il est proposé que compte de ces variables exogénes.

Adult age differences in spatial memory: effects of structural context and practice

We examined the effect of structural context on memory for spatial location in young and elderly women in two studies. Subjects studied and later reconstructed an array of visually identical objects that were positioned in a three-dimensional Plexiglas matrix. For half the subjects, small household objects were interspersed in the array to serve as spatial landmark cues during encoding and replacement. All subjects received two study and replacement trials. The results indicated that (a) older women remembered fewer locations than younger women but benefited more from landmark cues to location, (b) performance improved on the second replacement trial for the young but not for the older women, and (c) both age groups appeared to use similar processing strategies that were based on the vertical dimension of space. These results suggest that structural context enhances older adults' retention of three-dimensional spatial information. The implications of these data for the conceptual distinction between structural and organizational aspects of spatial context are discussed.

Differential effects of age on subpopulations of hippocampal theta cells

The possible contribution of age-related changes in the firing properties of hippocampal theta cells to spatial learning deficits was addressed in the present study. The behavioral correlates of theta cells in strata oriens, pyramidale, and granulosum were compared as young and old rats performed a radial maze spatial working memory task. Behaviorally, the old animals made significantly more errors on the maze and required more time to solve the task than did young animals. Firing rates were compared in four different locomotion states: still, running radially inward and radially outward, and forward motion. The discharge rates of theta cells in strata pyramidale and granulosum were significantly modulated by these movements in both age groups. Stratum oriens theta cells recorded from young animals, on the other hand, were not movement-sensitive, while similar cells from old animals demonstrated exaggerated responses to movement. In old animals, the mean discharge rates were higher in stratum granulosum and lower in stratum oriens than in the young rats. The discharge rates of cells in stratum pyramidale did not differ between age groups. These region specific changes in the firing characteristics of hippocampal theta cells are likely to have important consequences for information processing in this structure.

Importance of basic and applied research from the viewpoints of investigators in the psychology of aging

In this series of presentations, the importance and practical implications of many different research programs in the psychology of aging is presented from the viewpoints of the investigators themselves. These scientists discuss the implications and significance of their work for society as it affects other scientists, policy-makers, the media, and the public. The discussions make clear that the many of the problems associated with aging are essentially behavioral problems which can be prevented through behavioral change in the early as well as later years of the lifespan.