Differential effects of age on item and associative measures of memory: A meta-analysis.

In this meta-analysis, the authors evaluated recent suggestions that older adults' episodic memory impairments are partially due to a reduced ability to encode and retrieve associated/bound units of information. Results of 90 studies of episodic memory for both item and associative information in 3,197 young and 3,192 older adults provided support for the age-related associative/binding deficit suggestion, indicating a larger effect of age on memory for associative information than for item information. Moderators assessed included the type of associations, encoding instructions, materials, and test format. Results indicated an age-related associative deficit in memory for source, context, temporal order, spatial location, and item pairings, in both verbal and nonverbal material. An age-related associative deficit was quite pronounced under intentional learning instructions but was not clearly evident under incidental learning instructions. Finally, test format was also found to moderate the associative deficit, with older adults showing an associative/binding deficit when item memory was evaluated via recognition tests but not when item memory was evaluated via recall tests, in which case the age-related deficits were similar for item and associative information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in temporal and item memory.

Three experiments tested whether the relationship between age differences in temporal and item memory depends on the degree to which the item memory measure relies on memory for context. The authors predicted a stronger relationship of temporal memory to free recall than to recognition memory. Results showed that age differences in temporal memory could be eliminated after controlling for free recall but not recognition memory performance. Under some conditions recognition memory accounted for a significant portion of age-related variance in temporal memory. These results challenge past research that has interpreted age differences in temporal and item memory as independent and suggest that a generalized decline in context memory may underlie reduced performance in older adults on all types of memory tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aging and prospective memory on recognition of item and associative information.

Older adults typically perform worse than younger adults on tasks of associative, relative to item, memory. One account of this deficit is that older adults have fewer attentional resources to encode associative information. Previous researchers investigating this issue have divided attention at encoding and then have examined whether associative and item recognition were differentially affected. In the current study, we used a different cognitive task shown to tax attentional resources: event-based prospective memory. Although older adults demonstrated worse associative, relative to item, memory, the presence of the prospective memory task at encoding decreased item and associative memory accuracy to the same extent in both age groups. These results do not support the resource account of age-related associative deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effects of Aging and Divided Attention on Memory for Item and Associative Information.

The present study examined how aging and divided attention influence memory for item and associative information. Older adults and younger adults working under full-attention conditions and younger adults working under divided-attention conditions studied unrelated word pairs. Memory for item information was measured by later recognition of the 2nd word in the pair, and associative information was measured by recognition of the entire pair. Both older adults in the full-attention condition and younger adults in the divided-attention condition performed more poorly than younger adults in the full-attention condition, with the deficit in associative information being greater than the deficit in item information. In addition, a differentially greater associative decrement was found for the older adults, as shown by their heightened tendency to make false-alarm responses to re-paired (conjunction) distractors. The results are discussed in terms of an age-related reduction in processing resources compounded by an age-related increase in older adults' reliance on familiarity in associative recognition memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative and strategic components of episodic memory: A life-span dissociation.

The authors investigated the strategic component (i.e., elaboration and organization of episodic features) and the associative component (i.e., binding processes) of episodic memory and their interactions in 4 age groups (10-12, 13-15, 20-25, and 70-75 years of age). On the basis of behavioral and neural evidence, the authors hypothesized that the two components are functionally related but follow different life-span gradients. In a fully crossed design, age differences in recognition memory for single words versus word pairs (associative demand manipulation) were examined under instructions that emphasized item, pair, or elaborative-pair encoding (strategy manipulation). As predicted, the results showed that the strategic and associative components follow different life-span trajectories. Relative to younger adults, children's difficulties in episodic memory primarily reflected lower levels of strategic functioning. In contrast, older adults showed impairments in both strategic and associative components. The authors conclude that the comparison of strategic and associative components of episodic memory across the life span helps to delineate the two components' unique and interactive contributions to episodic memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Item and associative memory in amnestic mild cognitive impairment: Performance on standardized memory tests.

The earliest neuroanatomical changes in amnestic mild cognitive impairment (aMCI) involve the hippocampus and entorhinal cortex, structures implicated in the integration and learning of associative information. The authors hypothesized that individuals with aMCI would have impairments in associative memory above and beyond the known impairments in item memory. A group of 29 individuals with aMCI and 30 matched control participants were administered standardized tests of object-location recall and symbol-symbol recall, from which both item and associative recall scores were derived. As expected, item recall was impaired in the aMCI group relative to controls. Associative recall in the aMCI group was even more impaired than was item recall. The best group discriminators were measures of associative recall, with which the sensitivity and specificity for detecting aMCI were 76% and 90% for symbol-symbol recall and were 86% and 97% for object-location recall. Associative recall may be particularly sensitive to early cognitive change in aMCI, because this ability relies heavily on the medial temporal lobe structures that are affected earliest in aMCI. Incorporating measures of associative recall into clinical evaluations of individuals with memory change may be useful for detecting aMCI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in item manipulation span: The case of letter-number sequencing.

The authors report 2 experiments in which they examined age differences in working memory tasks involving complex item manipulation (i.e., letter-number sequencing). In Experiment 1, age differences on tasks involving item manipulation were not greater than age differences on tasks requiring recall of items in the order in which they appeared, suggesting that older adults do not have difficulty with item manipulation per se. In Experiment 2, slower presentation rates increased age differences in item manipulation spans, although age differences at the fastest rate may be attributed to differences in strategy use. In both experiments, age differences were largest when participants were most likely to be remembering familiar sequences, suggesting that older adults may have difficulties dampening the representations of such sequences once they are activated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using maintenance rehearsal to explore recognition memory.

We examined associative and item recognition using the maintenance rehearsal paradigm. Our intent was to control for mnemonic strategies; to produce a low, graded level of learning; and to provide evidence of the role of attention in long-term memory. An advantage for low-frequency words emerged in both associative and item recognition at very low levels of learning. This early emergence casts doubt on explanations based on the traditional concept of recollection. A comparison of false alarms supports a role for item information or the joint use of cues but not familiarity in producing associative false alarms. We may also have found a way to measure the amount of attention being paid to a to-be-learned item or pair, independently of memory performance on the attended item. This result may be an important step in determining whether coherent theories about the role of attention in long- and short-term memory can be created. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dual-Process Models of Associative Recognition in Young and Older Adults: Evidence From Receiver Operating Characteristics.

In 3 experiments, young and older adults studied lists of unrelated word pairs and were given confidence-rated item and associative recognition tests. Several different models of recognition were fit to the confidence-rating data using techniques described by S. Macho (2002, 2004). Concordant with previous findings, item recognition data were best fit by an unequal-variance signal detection theory model for both young and older adults. For both age groups, associative recognition performance was best explained by models incorporating both recollection and familiarity components. Examination of parameter estimates supported the conclusion that recollection is reduced in old age, but inferences about age differences in familiarity were highly model dependent. Implications for dual-process models of memory in old age are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Interference and facilitation in spatial working memory: Age-associated differences in lure effects in the n-back paradigm.

Working memory (WM) declines prominently during normal aging. The mechanisms underlying this decline are not fully understood. The authors analyzed performance on 2 versions of a 2-back spatial WM task to assess younger and older adults' responses to lures (i.e., nontarget items that match an item earlier in the sequence but not at the current target lag). Results demonstrate lure interference effects that are particularly pronounced among older adults. At the same time, however, older adults showed facilitation for targets. Taken together, these findings suggest that the contribution of familiarity signals to WM performance increases during normal aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative deficit in recognition memory in a lifespan sample of healthy adults.

Advanced age is associated with decrements in episodic memory, which are more pronounced in memory for associations than for individual items. The associative deficit hypothesis (ADH) states that age differences in recognition memory reflect difficulty in binding components of a memory episode and retrieving bound units. To date, ADH has received support only in studies of extreme age groups, and the influence of sex, education, and health on age-related associative deficit is unknown. We address those issues using a verbal paired-associate yes–no recognition paradigm on a lifespan sample of 278 healthy, well-educated adults. In accord with the ADH, greater age was associated with lower hit and greater false alarm rates and more liberal response bias on associative recognition tests. Women outperformed men on recognition of items and associations, but among normotensive participants, women outperformed men only on memory for associations and not on item recognition. Thus, although supporting ADH in a large lifespan sample of healthy adults, the findings indicate that the effect may be partially driven by an age-related increase in liberal bias in recognition of associations. Sex differences and health factors may modify the associative deficit regardless of age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in prefrontal cortical activity in working memory.

Working memory (WM) declines with advancing age. Brain imaging studies indicate that ventral prefrontal cortex (PFC) is active when information is retained in WM and that dorsal PFC is further activated for retention of large amounts of information. The authors examined the effect of aging on activation in specific PFC regions during WM performance. Six younger and 6 older adults performed a task in which, on each trial, they (a) encoded a 1- or 6-letter memory set, (b) maintained these letters over 5-s, and (c) determined whether or not a probe letter was part of the memory set. Comparisons of activation between the 1- and 6-letter conditions indicated age-equivalent ventral PFC activation. Younger adults showed greater dorsal PFC activation than older adults. Older adults showed greater rostral PFC activation than younger adults. Aging may affect dorsal PFC brain regions that are important for WM executive components. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do young and older adults rely on different processes in source memory tasks? A neuropsychological study.

Source memory has consistently been associated with prefrontal function in both normal and clinical populations. Nevertheless, the exact contribution of this brain region to source memory remains uncertain, and evidence suggests that processes used by young and older adults may differ. The authors explored the extent to which scores on composite measures of neuropsychological tests of frontal and medial temporal function differentially predicted the performance of young and older adults on source memory tasks. Results indicated that a frontal composite measure, consistently associated with source memory performance in older adults, was unrelated to source memory in young adults, although it was sensitive to a demanding working memory task. The memory composite score, however, predicted performance in the young group. In addition, item and source memory were correlated in young but not older people. Findings are discussed in terms of age-related differences in working memory and executive functions, and differential binding processes necessary for item and source memory. The requirement to integrate item and source information at encoding appears to place greater demands on executive or working memory processes in older adults than in younger adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of age in four alternative forced-choice item and associative recognition tasks.

Seventy-three young and 84 older adults were taught interactive imagery as a strategy for learning word pairs. In the control condition, participants viewed word pairs 1 at a time and formed an interactive image for each. In the experimental condition, participants first formed individual mental images for both the cue and the target and then formed an interactive image for the pair. Participants in both conditions then completed 4 alternative forced-choice item and associative recognition tasks that avoid influences of age differences in retrieval strategies such as recall-to-reject. Unlike findings with typical yes–no recognition tests, associative recognition was superior to item recognition in the control condition. This effect was attenuated in the experimental condition. Older adults had poorer recognition memory for both associative and item tests, with a larger age difference for recognizing new associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related associative deficits are absent with nonwords.

Words and nonwords were used as stimuli to assess item and associative recognition memory performance in young and older adults. Participants were presented with pairs of items and then tested on both item memory (old/new items) and associative memory (intact/recombined pairs). For words, older participants performed worse than young participants on item and associative tests but to a greater extent on the latter. In contrast, for nonwords, older participants performed equally worse than young participants on item and associative tests. This is the first study to demonstrate that a manipulation of stimulus novelty can alter age-related associative deficits. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Binding and strategic selection in working memory: A lifespan dissociation.

Working memory (WM) shows a gradual increase during childhood, followed by accelerating decline from adulthood to old age. To examine these lifespan differences more closely, we asked 34 children (10–12 years), 40 younger adults (20–25 years), and 39 older adults (70–75 years) to perform a color change detection task. Load levels and encoding durations were varied for displays including targets only (Experiment 1) or targets plus distracters (Experiment 2, investigating a subsample of Experiment 1). WM performance was lower in older adults and children than in younger adults. Longer presentation times were associated with better performance in all age groups, presumably reflecting increasing effects of strategic selection mechanisms on WM performance. Children outperformed older adults when encoding times were short, and distracter effects were larger in children and older adults than in younger adults. We conclude that strategic selection in WM develops more slowly during childhood than basic binding operations, presumably reflecting the delay in maturation of frontal versus medio-temporal brain networks. In old age, both sets of mechanisms decline, reflecting senescent change in both networks. We discuss similarities to episodic memory development and address open questions for future research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of emotional valence and arousal upon memory trade-offs with aging.

Attention can be attracted faster by emotional relative to neutral information, and memory also can be strengthened for that emotional information. However, within visual scenes, often there is an advantage in memory for central emotional portions at the expense of memory for peripheral background information, called an emotion-induced memory trade-off. The authors examined how aging impacts the trade-off by manipulating valence (positive, negative) and arousal (low, high) of a central emotional item within a neutral background scene and testing memory for item and background components separately. They also assessed memory after 2 study–test delay intervals, to investigate age differences in the trade-off over time. Results revealed similar patterns of performance between groups after a short study–test delay, with both age groups showing robust memory trade-offs. After a longer delay, young and older adults showed enhanced memory for emotional items but at a cost to memory for background information only for young adults in negative arousing scenes. These results emphasize that attention and consolidation stage processes interact to shape how emotional memory is constructed in young and older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential age effects for implicit and explicit conceptual associative memory.

Older adults show disproportionate declines in explicit memory for associative relative to item information. However, the source of these declines is still uncertain. One explanation is a generalized impairment in the processing of associative information. A second explanation is a more specialized impairment in the strategic, effortful recollection of associative information, leaving less effortful forms of associative retrieval preserved. Assessing implicit memory of new associations is a way to distinguish between these viewpoints. To date, mixed findings have emerged from studies of associative priming in aging. One factor that may account for the variability is whether the manipulations inadvertently involve strategic, explicit processes. In two experiments we present a novel paradigm of conceptual associative priming in which subjects make speeded associative judgments about unrelated objects. Using a size classification task, Experiment 1 showed equivalent associative priming between young and older adults. Experiment 2 generalized the results of Experiment 1 to an inside/outside classification task, while replicating the typical age-related impairment in associative but not item recognition. Taken together, the findings support the viewpoint that older adults can incidentally encode and retrieve new meaningful associations despite difficulty with the intentional recollection of the same information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of pure pair repetition on younger and older adults' associative memory.

Although aging causes relatively minor impairment in recognition memory for components, older adults' ability to remember associations between components is typically significantly compromised, relative to that of younger adults. This pattern could be associated with older adults' relatively intact familiarity, which helps preserve component memory, coupled with a marked decline in recollection, which leads to a decline in associative memory. The purpose of the current study is to explore possible methods that allow older adults to rely on pair familiarity in order to improve their associative memory performance. Participants in 2 experiments were repeatedly presented with either single items or pairings of items prior to a study list so that the items and the pairs were already familiar during the study phase. Pure pair repetition (the effects of pair repetition after the effects of item repetition are taken into account) increased associative memory for older and younger adults. Findings based on remember and know judgments suggest that familiarity but not recollection is involved in mediating the repetition effect. (PsycINFO Database Record (c) 2011 APA, all rights reserved)