Attention and the acquisition of new knowledge: their effects on older adults' associative memory deficit

Older adults experience a selective associative memory deficit by demonstrating intact item memory relative to impaired associative memory when compared with younger adults. Age-related deficits in associative memory have been suggested to arise from declines in attentional resources, and the role of attention during encoding and retrieval in associative memory for words and their spatial locations was investigated in the current experiment. Additionally, the tendency of younger and older adults to use knowledge acquired during encoding to improve their associative memory judgments through a strategic associative memory process was also investigated. Younger and older adults studied a list of words with each word belonging to one of four categories, which followed one of four mathematical probability structures for their presentation. Older adults exhibited intact item memory and impaired associative memory relative to full attention younger adults. In addition, both older and younger adults demonstrated an ability to engage in strategic associative memory, by learning and later using the probability structure introduced at study to guide their associative memory judgments. In contrast, dividing the attention of younger adults during encoding impaired item memory, associative memory and strategic associative memory, whereas dividing attention at retrieval did not result in similar deficits. These data add to a growing body of literature demonstrating older adults to exhibit a selective associative memory deficit that is not simulated by dividing the attention of younger adults at encoding or retrieval. Furthermore, younger and older adults maintain the ability to use new knowledge to guide their associative judgments.     

Paying attention to binding: Further studies assessing the role of reduced attentional resources in the associative deficit of older adults

The present experiments investigated whether the observed associative deficit in older adults' episodic memory is mediated by a reduction of attentional resources. Using a dual-task procedure, younger and older participants studied lists of word pairs either under full attention or while performing a concurrent task. Both experiments showed that dividing attention did not cause a greater impairment to memory for associations than to memory for items in either age group. Furthermore, an analysis of concurrent task performance revealed that older adults' attentional costs for both learning and binding items were not larger than for learning items alone, relative to younger adults. These data provide support for a multicausal interpretation of older adults' memory deficits in which common, depleted attentional resources may be a mechanism that reduces memory for components of an episode in both older and younger adults under divided attention at encoding. In addition, older adults have a unique deficit in memory for the associations between the components, which does not seem to be resource dependent.     

Does strategic memory training improve the working memory performance of younger and older adults?

The paper examines the effect of strategic training on the performance of younger and older adults in an immediate list-recall and a working memory task. The experimental groups of younger and older adults received three sessions of memory training, teaching the use of mental images to improve the memorization of word lists. In contrast, the control groups were not instructed to use any particular strategy, but they were requested to carry out the memory exercises. The results showed that strategic training improved performance of both the younger and older experimental groups in the immediate list recall and in the working memory task. Of particular interest, the improvement in working memory performance of the older experimental group was comparable to that of the younger experimental group.     

Retrieval practice and elaborative encoding benefit memory in younger and older adults

Retrieval practice has been identified as a powerful tool for promoting retention. Few studies have examined whether retrieval practice enhances performance in older adults as it does in younger adults. Younger and older adults learned unrelated word pairs and were administered a test after a short (10 min) and long (2 day) delay. Encoding condition was manipulated between subjects, with participants studying the pairs twice, studying them once and taking an immediate test with feedback, or encoding them twice under different deep encoding conditions. In both age groups, equivalent benefits of testing relative to restudy were found. Deep processing also improved memory relative to restudy, suggesting that one factor that might benefit retention is varying the type of encoding task (either by testing or by providing a different instructional manipulation) to increase the accessibility of cues. Retrieval practice can support older adults’ memory and is a viable target for training.     

Source Monitoring: ERP Evidence for Greater Reactivity to Nontarget Information in Older Adults

Event-Related Potentials (ERPs) were collected concurrently with stimulus presentation during a source monitoring task. Younger adults were less likely than older adults to make source monitoring errors and their ERP records showed far greater discrimination between target stimuli and familiar but nontarget foils. Older adults not only made more source errors but produced high amplitude late positivities to the nontarget foils even when these foils were correctly rejected. Under divided attention conditions, younger adults performance was similar to that of the older adults both behaviorally and electrophysiologically. These data illustrate the role that attentional resources play in the ability to inhibit response tendencies and suggest that age differences in source monitoring may be more related to attentional control than inefficiencies in the encoding of contextual information. As well, they suggest that the ERP late positivity may represent a more general response to item salience rather than serve as an index of recollection as is the current view.     

Elucidating the effects of ageing on remembering perceptually distorted word pairs

We investigated the effects of age, background babble, and acoustic distortion of the word itself on serial position memory in a series of experiments involving six different auditory environments (quiet, and 12-talker background babble presented between, overlapping, or concurrent with word presentation or with two kinds of distortion applied to the words). To control for hearing, the level of babble or distortion was adjusted so that younger and older adults could hear the words equally well. Although the presence of continuous and word-flanking background babble adversely affected memory in the early serial positions in both age groups, only older adults' memory was adversely affected in the later serial positions. Moreover, younger adults' memory was not affected by acoustic word distortion, whereas one of the two types of temporal distortion adversely affected memory for later serial positions in older adults. The exact pattern of impairment and its interaction with age suggests that memory in older adults is more affected than that in younger adults in complex listening situations because they either need more time or have to employ more attentional resources to segregate different auditory streams, thereby depleting the pool of resources available for memory encoding.     

A double dissociation of implicit and explicit memory in younger and older adults

This study examined whether age-related differences in cognition influence later memory for irrelevant, or distracting, information. In Experiments 1 and 2, older adults had greater implicit memory for irrelevant information than younger adults did. When explicit memory was assessed, however, the pattern of results reversed: Younger adults performed better than older adults on an explicit memory test for the previously irrelevant information, and older adults performed less well than they had on the implicit test. Experiment 3 investigated whether this differential pattern was attributable to an age-related decline in encoding resources, by reducing the encoding resources of younger adults with a secondary task; their performance perfectly simulated the pattern shown by the older adults in the first two experiments. Both older and younger adults may remember irrelevant information, but they remember it in different ways because of age-related changes in how information is processed at encoding and utilized at retrieval.     

The effectiveness of updating metacognitive knowledge in the elderly: evidence from metamnemonic judgments of word frequency

Accurate metacognitive knowledge is vital for optimal performance in self-regulated learning. Yet older adults have deficiencies in implementing effective learning strategies and knowledge updating and consequently may not learn as effectively from task experience as younger adults. Here we assess the ability of older adults to update metacognitive knowledge about the effects of word frequency on recognition. Young adults have been shown to correct their misconceptions through experience with the task, but the greater difficulty older adults have with knowledge updating makes it unclear whether task experience will be sufficient for older adults. The performance of older adults in this experiment qualitatively replicates the results of a comparison group of younger subjects, indicating that both groups are able to correct their metacognitive knowledge through task experience. Older adults seem to possess more effective and flexible metacognition than sometimes suggested.     

Judgments of origin and generation effects: comparisons between young and elderly adults

In 2 experiments, young and elderly adults were required to both read words, and generate words by completing word fragments. Subjects were then required to recognize those words that had been presented earlier; for those words that they recognized they judged whether the items had initially been presented in read or generate form. Generation effects (better memory for words that were generated as compared with words that were read) of similar magnitude were observed for both young and older adults. The older adults were consistently less accurate than the younger adults in their judgments of origin. In addition, the young adults exhibited a bias to respond "read" for these judgments. In contrast, the older adults either exhibited a neutral response bias or were biased to respond "generate." Age-related differences in the encoding or retrieval of information about cognitive operations do not provide a good account of the results. Alternative accounts are described.     

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.     

Patterns of On-line Resource Allocation to Narrative Text by Younger and Older Readers

Younger and older adults read narrative texts word by word for immediate recall. There were no age differences in recall performance, showing that older adults were effective in narrative memory. Analysis of reading times demonstrated the existence of interindividual variability in sensitivity to text demands, which was predictive of subsequent memory performance. Contrary to the view that older readers do not encode text analytically, for these naturalistic narratives both younger and older adults optimized memory through the allocation of processing resources to the construction of a proposition-based representation of content. Overall, attentiveness to narrative structure also facilitated narrative memory, but this relationship was more reliable among older readers.     

How the measurement of memory processes can affect memory performance: the case of remember/know judgments

Relatively little attention has been paid thus far in memory research to the effects of measurement instruments intended to assess memory processes on the constructs being measured. The current article investigates the influence of employing the popular remember/know (R/K) measurement procedure on memory performance itself. This measurement procedure was extensively used in the past to assess the respective contributions of 2 processes to memory judgments, one based on familiarity and the other on recollection. Two experiments using unrelated word pairs showed that the use of an R/K procedure can alter memory performance. Specifically, the R/K procedure improved associative memory among older but not younger adults compared to conditions in which participants were not asked to provide R/K judgments. Such an effect was not observed in item memory performance. Potential mechanisms mediating these differential memory measurement effects are outlined, and the measurement effects' implications for memory and cognitive research are discussed.     

Effects of Perceptual and Conceptual Processing on Memory for Words and Voice: Different Patterns for Young and Old

In two experiments younger and older adults listened to a list of words presented auditorily by two speakers. The subjects processed each word either perceptually (voice judgements) or conceptually (pleasantness judgements), and were then given memory tasks for the words and the presenting voice. In the word-recognition task the two age groups benefited equally from conceptual as opposed to perceptual processing. In the voice memory task, however, conceptual processing improved performance relative to perceptual processing in the younger subjects (significantly so in Experiment 1), but conceptual processing was associated with decreased performance in the older group (significantly so in Experiment 2). These results suggest that whereas older subjects exhibit a trade-off in memory for item and attribute information, younger subjects exhibit a pattern of support, in which conceptual processing benefits memory for both items and their attributes.     

Comparing the effects of aging and background noise on short-term memory performance

Paired associate recall was tested as a function of serial position for younger and older adults for five word pairs presented aurally in quiet and in noise. In Experiment 1, the addition of noise adversely affected recall in young adults, but only in the early serial positions. Experiments 2 and 3 suggested that the recall of older adults listening to the words in quiet was nearly equivalent to that of younger adults listening in noise. In Experiment 4, we determined the signal-to-noise ratio (S/N) such that, on average, younger and older adults were able to correctly hear the same percentage of words when words were presented one at a time in noise. In Experiment 5, younger adults were tested under this S/N. Compared with older adults from Experiment 3, younger adults in this experiment recalled more words at all serial positions. The results are interpreted as showing that encoding in secondary memory is impaired by aging and noise either as a function of degraded sensory representations, or as a function of reduced processing resources.     

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.     

Age differences in recollection: three patterns of enhanced encoding

Memory encoding conditions can be manipulated in a variety of ways, and many of these methods result in improved recollection for both younger and older adults relative to baseline conditions. Previous results have shown differential age-related patterns of improvement, however, with some manipulations giving equal improvement to young and old participants, some benefiting older adults more, and others benefiting younger adults more. In 2 experiments, the authors show that presenting pictures with words benefited older more than younger participants, word generation benefited both groups equally, and an encoding condition requiring novel integrative processing benefited younger more than older adults. The authors discuss these results in terms of the enhanced elaboration afforded and processing demanded by differential combinations of age groups and encoding conditions.     

Age-related differences in the specificity of verbal encoding

A communication paradigm was used as an analogue to cued recall to separate age-related differences in encoding and retrieval. Younger and older adults (senders) generated a series of one-word clues that would enable other subjects (receivers) to generate a designated target word. Clue and target generation tasks, analogous to the encoding and retrieval components of cued recall, were conducted in the context of either a strong or a weak associate of the target. Clues generated by older senders were less effective than clues generated by younger senders in enabling receivers to generate targets, especially when clues or targets were generated in the context of a weak associate. A deficit among older receivers was also obtained, especially when a weak-rather than a strong-associate context word was given to the receiver. Older adults experience difficulty with encoding and retrieval tasks that require processing of context-specific information that is not part of the generic information typically associated with a stimulus.     

Aging and conditional probability judgments: a global matching approach

Age differences in bias in conditional probability judgments were investigated based on predictions derived from the Minerva-Decision Making model (M. R. P. Dougherty, C. F. Gettys, & E. E. Ogden, 1999), a global matching model of likelihood judgment. In this study, 248 younger and older adults completed frequency judgment and conditional probability judgment tasks. Age differences in the frequency judgment task are interpreted as an age-related deficit in memory encoding. Older adults' stronger biases in the probability judgment task point to age differences in criterion setting. Age-related biases were eliminated when age groups were equated on memory encoding by means of study time manipulation. The authors conclude that older adults' stronger judgment biases are a function of memory impairment.     

Aging and stereotype suppression

Recent work in social cognitive aging has suggested that older adults are more likely than younger adults to activate and use stereotypic information, even when they intend not to. Furthermore, evidence suggests that older adults have difficulty altering their interpretation of a situation, even when it has become clear that their initial interpretation is incorrect. In the current study, younger and older adults read a series of narratives in which a character had a sex-stereotyped occupation (e.g., a plumber is stereotypically male), and the character's gender was either consistent or inconsistent with that stereotype. Explicit labeling of gender was also varied. Results revealed that with explicit labeling, older adults were able to discount their stereotypes and avoid processing difficulties when subsequent stereotype-inconsistent information was encountered. These data suggest that when counter-stereotypic information is explicitly provided at encoding, older adults are no more likely than younger adults to rely on stereotypes, and are similarly capable of altering their interpretation of a situation when information suggests that interpretation is incorrect. These findings indicate that although older adults are more prone to the influence of unwanted stereotypes, this effect can be averted and judgments can be made more egalitarian by providing older adults with explicit stereotype contradiction at encoding.     

Recency judgments as a function of word frequency: A framing effect and frequency misattributions

The effects of word frequency on judgments of recency of item presentation were examined in two experiments. Subjects in Experiment 1 were presented two mixed lists of high- and low-frequency words followed by a list assignment task for recognized items. It was found that subjects were biased toward assigning low-frequency words to the more recently presented list. Subjects in Experiment 2 were presented a single mixed list of high- and low-frequency words followed by either a relative recency of presentation judgment task or a relative primacy of presentation judgment task. Each word pair on the tests contained one high-frequency word and one low-frequency word. It was found that, for the recency judgment task, subjects were biased to select the low-frequency item as having been presented more recently. However, on the parallel primacy judgment task, there were no effects of word frequency; moreover, overall accuracy levels were higher with primacy than with recency instructions. We interpret the effects of word frequency on recency judgments in Experiments 1 and 2 in terms of a misattribution of frequency-related differences in recollection-based recognition. The finding that recency and primacy instructions produced different patterns of results provides further evidence (Flexser & Bower, 1974) for an effect on performance of the way in which the temporal judgment task was framed.