Effects of repetition and response deadline on associative recognition in young and older adults

The constructive nature of memories in insects: bumblebees as a case study

The view that human memory is constructive implies that recollections are not necessarily an accurate reproduction of past events. An approach to study this constructive nature of memory is by examining memory errors. In this regard, conjunction errors-i.e. incorrect recollection of new stimuli integrated by components from two previously studied stimuli-have attracted important attention in human memory research. Do animals other than humans make conjunction errors? To investigate this issue, a choice task in which training was not involved was used. Bees experienced two to-be-remembered stimuli. At the test, they were presented with four stimuli: one of the original items (i.e. old), an item made by combining two features of the original items (i.e. conjunction), an item containing a previously presented feature and a new one (i.e. feature), and an item integrated solely by new features (i.e. new). Bumblebees remembered the old items. Importantly, when making memory errors, bumblebees selected conjunction and feature lures more often than new items. These results indicate that bumblebees, like humans, spontaneously make memory conjunction errors and suggest that invertebrates' memories might also be constructive in nature. I suggest that focusing on memory errors is a solid avenue to investigate episodic (like) memory in animals.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

Judgments of learning reflect the encoding of contexts, not items: evidence from a test of recognition exclusion

Two sources of evidence seem to be shared by judgments of past recognition and judgments of future performance: item memory or familiarity (i.e., memory for the item independent of the context in which it was experienced) and context memory or recollection (i.e., memory for the context specific to a particular prior encounter). However, there are few studies investigating the link between these two putative memory processes and judgments of learning (JOLs). We tested memory and metamemory using a continuous exclusion procedure - a modified recognition memory task where study events for two classes of items are interleaved with test trials in which the subject must endorse items from one class and reject items from the other. This procedure allowed us to estimate the influences of memory for context and memory for item on JOLs and licenses conclusions about the relative role of item and context information in supporting JOLs. An analysis of forgetting revealed that JOLs reflect both the initial degree of learning and the rate of forgetting, but only of memory for context and not of memory for items. These findings suggest that JOLs are predictive of memory for context-bound episodes, rather than for the semantic content of those episodes.

Older adults can use memory for distinctive objects, but not distinctive scenes, to rescue associative memory deficits

Associative memory deficits in aging are frequently characterized by false recognition of novel stimulus associations, particularly when stimuli are similar. Introducing distinctive stimuli, therefore, can help guide item differentiation in memory and can further our understanding of how age-related brain changes impact behavior. How older adults use different types of distinctive information to distinguish overlapping events in memory and to avoid false associative recognition is still unknown. To test this, we manipulated the distinctiveness of items from two stimulus categories, scenes and objects, across three conditions: (1) distinct scenes paired with similar objects, (2) similar scenes paired with distinct objects, and (3) similar scenes paired with similar objects. Young and older adults studied scene-object pairs and then made both remember/know judgments toward single items as well as associative memory judgments to old and novel scene-object pairs ("Were these paired together?"). Older adults showed intact single item recognition of scenes and objects, regardless of whether those objects and scenes were similar or distinct. In contrast, relative to younger adults, older adults showed elevated false recognition for scene-object pairs, even when the scenes were distinct. These age-related associative memory deficits, however, disappeared if the pair contained an object that was visually distinct. In line with neural evidence that hippocampal functioning and scene processing decline with age, these results suggest that older adults can rely on memory for distinct objects, but not for distinct scenes, to distinguish between memories with overlapping features.

Forgetting of specific and gist visual associative episodic memory representations across time

Associative binding between components of an episode is vulnerable to forgetting across time. We investigated whether these forgetting effects on inter-item associative memory occur only at specific or also at gist levels of representation. In two experiments, young adult participants (n = 90, and 86, respectively) encoded face-scene pairs and were then tested either immediately after encoding or following a 24-hour delay. Tests featured conjoint recognition judgments, in which participants were tasked with discriminating intact pairs from highly similar foils, less similar foils, and completely dissimilar foils. In both experiments, the 24-hour delay resulted in deficits in specific memory for face-scene pairs, as measured using multinomial-processing-tree analyses. In Experiment 1, gist memory was not affected by the 24-hour delay, but when associative memory was strengthened through pair repetition (Experiment 2), deficits in gist memory following a 24-hour delay were observed. Results suggest that specific representations of associations in episodic memory, and under some conditions gist representations, as well, are susceptible to forgetting across time.

Learning facilitates dual-process face recognition regardless of holistic processing

Much evidence suggests that faces are recognized based on their global familiarity in a signal-detection manner. However, experiments drawing this conclusion typically present study lists of faces only once or twice, and the nature of face recognition at higher levels of learning remains unclear. Here, three experiments are reported in which participants studied some faces eight times and others twice and then took a recognition test containing previously viewed faces, entirely new faces, and faces which recombined the parts of previously viewed faces. Three measures converged to suggest that study list repetition increased the likelihood of participants rejecting recombined faces as new by recollecting that their parts were studied but in a different combination, and that manipulating holistic or Gestalt-like processing-a hallmark of face perception-qualitatively preserved its effect on how memory judgments are made. This suggests that face learning causes a shift from the use of a signal-detection strategy to the use of a dual-process strategy of face recognition regardless of holistic processing.

Normal Aging Affects the Short-Term Temporal Stability of Implicit, But Not Explicit, Motor Learning following Visuomotor Adaptation

Normal aging is associated with a decline in memory and motor learning ability. However, the exact form of these impairments (e.g., the short-term temporal stability and affected learning mechanisms) is largely unknown. Here, we used a sensorimotor adaptation task to examine changes in the temporal stability of two forms of learning (explicit and implicit) because of normal aging. Healthy young subjects (age range, 19–28 years; 20 individuals) and older human subjects (age range, 63–85 years; 19 individuals) made reaching movements in response to altered visual feedback. On each trial, subjects turned a rotation dial to select an explicit aiming direction. Once selected, the display was removed and subjects moved the cursor from the start position to the target. After initial training with the rotational feedback perturbation, subjects completed a series of probe trials at different delay periods to systematically assess the short-term retention of learning. For both groups, the explicit aiming showed no significant decrease over 1.5 min. However, this was not the case for implicit learning; the decay pattern was markedly different between groups. Older subjects showed a linear decrease of the implicit component of adaptation over time, while young subjects showed an exponential decay over the same period (time constant, 25.61 s). Although older subjects adapted at a similar rate, these results suggest natural aging selectively impacts the short-term (seconds to minutes) temporal stability of implicit motor learning mechanisms. This understanding may provide a means to dissociate natural aging memory impairments from deficits caused by brain disorders that progress with aging.

The influence of item familiarization on neural discriminability during associative memory encoding and retrieval

Associative memory requires one to encode and form memory representations not just for individual items, but for the association or link between those items. Past work has suggested that associative memory is facilitated when individual items are familiar rather than simultaneously learning the items and their associative link. The current study employed multivoxel pattern analyses (MVPA) to investigate whether item familiarization prior to associative encoding affects the distinctiveness of neural patterns, and whether that distinctiveness is also present during associative retrieval. Our results suggest that prior exposure to item stimuli impacts the representations of their shared association compared to stimuli that are novel at the time of associative encoding throughout most of the associative memory network. While this distinction was also present at retrieval, the overall extent of the difference was diminished. Overall the results suggest that stimulus familiarity influences the representation of associative pairings during memory encoding and retrieval, and the pair-specific representation is maintained across memory phases irrespective of this distinction.

Effects of age differences in memory formation on neural mechanisms of consolidation and retrieval

Episodic memory decline is a hallmark of cognitive aging and a multifaceted phenomenon. We review studies that target age differences across different memory processing stages, i.e., from encoding to retrieval. The available evidence suggests that age differences during memory formation may affect the quality of memory representations in an age-graded manner with downstream consequences for later processing stages. We argue that low memory quality in combination with age-related neural decline of key regions of the episodic memory network puts older adults in a double jeopardy situation that finally results in broader memory impairments in older compared to younger adults.

Quantifying mechanisms of cognition with an experiment and modeling ecosystem

Although there have been major strides toward uncovering the neurobehavioral mechanisms involved in cognitive functions like memory and decision making, methods for measuring behavior and accessing latent processes through computational means remain limited. To this end, we have created SUPREME (Sensing to Understanding and Prediction Realized via an Experiment and Modeling Ecosystem): a toolbox for comprehensive cognitive assessment, provided by a combination of construct-targeted tasks and corresponding computational models. SUPREME includes four tasks, each developed symbiotically with a mechanistic model, which together provide quantified assessments of perception, cognitive control, declarative memory, reward valuation, and frustrative nonreward. In this study, we provide validation analyses for each task using two sessions of data from a cohort of cognitively normal participants (N = 65). Measures of test-retest reliability (r: 0.58-0.75), stability of individual differences (ρ: 0.56-0.70), and internal consistency (α: 0.80-0.86) support the validity of our tasks. After fitting the models to data from individual subjects, we demonstrate each model's ability to capture observed patterns of behavioral results across task conditions. Our computational approaches allow us to decompose behavior into cognitively interpretable subprocesses, which we can compare both within and between participants. We discuss potential future applications of SUPREME, including clinical assessments, longitudinal tracking of cognitive functions, and insight into compensatory mechanisms.

Neural Correlates of Enhanced Memory for Meaningful Associations with Age

Evidence suggests that age differences in associative memory are attenuated for associations that are consistent with prior knowledge. Such knowledge structures have traditionally been associated with the default network (DN), which also shows reduced modulation with age. In the present study, we investigated whether DN activity and connectivity patterns could account for this age-related effect. Younger and older adults underwent functional magnetic resonance imaging as they learned realistic and unrealistic prices of common grocery items. Both groups showed greater activity in the DN during the encoding of realistic, relative to unrealistic, prices. Moreover, DN activity at encoding and retrieval and its connectivity with an attention control network at encoding were associated with enhanced memory for realistic prices. Finally, older adults showed overactivation of control regions during retrieval of realistic prices relative to younger adults. Our findings suggest that DN activity and connectivity patterns (traditionally viewed as indicators of cognitive failure with age), and additional recruitment of control regions, might underlie older adults' enhanced memory for meaningful associations.

How do cognitive and functional impairment relate to the use of anticholinergic medications in hospitalised patients aged 65 years and over?

BACKGROUND

Anticholinergic medications are commonly prescribed to older adults despite their unfavourable pharmacological profile. There are no specific systems in place to alert prescribers about the wide range of medications with anticholinergic properties and their cumulative potential.

AIMS

To examine associations between medications with anticholinergic properties and cognitive and functional impairment in hospitalised patients aged 65 years and older.

METHODS

This descriptive, cross-sectional study included 94 patients admitted to a rehabilitation ward and a geriatric evaluation and management unit. Anticholinergic burden was calculated using the Anticholinergic Risk Scale. The Addenbrooke's Cognitive Examination and the Elderly Symptom Assessment Scale tools were utilised to assess cognitive function and burden of anticholinergic symptoms, respectively.

RESULTS

Medications with anticholinergic properties were taken by 72.3% of patients with level 1 being the most commonly consumed (median 1, IQR = 0-2) medications. There was no association between anticholinergic medication use and cognitive function or anticholinergic symptoms. Increasing age and the hospital length of stay were associated with fewer anticholinergic symptoms (p < 0.001 and p = 0.021, respectively), whereas the total number of medications consumed was linked to a greater burden of anticholinergic symptoms (p < 0.001).

CONCLUSION

A lack of association between anticholinergic medications and cognitive function could be related to duration of exposure to this group of medications and the age sensitivity. Additionally, the total number of medications consumed by patients was linked to a greater burden of anticholinergic symptoms. These findings highlight the need for improved knowledge and attentiveness when prescribing medications in general in this vulnerable population.

Age-related differences in recognition in associative memory

Aging is often accompanied by associative memory changes, although their precise nature remains unclear. This study examines how recognition of item position in the context of associative memory differs between younger and older adults. Participants studied word pairs (A-B, C-D) and were later tested with intact (A-B), reversed (D-C), recombined (A-D), and recombined and reversed (B-C) pairs. When participants were instructed to respond "Old" to both intact and reversed pairs, and "New" to recombined, and recombined and reversed pairs, older adults showed worse recognition for recombined and reversed pairs relative to younger adults (Experiment 1). This finding also emerged when flexible retrieval demands were increased by asking participants to respond "Old" only to intact pairs (Experiment 2). These results suggest that as conditions for flexible retrieval become more demanding, older adults may show worse recognition in associative memory tasks relative to younger adults.

Modeling age differences in effects of pair repetition and proactive interference using a single parameter

In this article, we apply the REM model (Shiffrin & Steyvers, 1997) to age differences in associative memory. Using Criss and Shiffrin's (2005) associative version of REM, we show that in a task with pairs repeated across 2 study lists, older adults' reduced benefit of pair repetition can be produced by a general reduction in the diagnosticity of information stored in memory. This reduction can be modeled similarly well by reducing the overall distinctiveness of memory features, or by reducing the accuracy of memory encoding. We report a new experiment in which pairs are repeated across 3 study lists and extend the model accordingly. Finally, we extend the model to previously reported data using the same task paradigm, in which the use of a high-association strategy introduced proactive interference effects in young adults but not older adults. Reducing the diagnosticity of information in memory also reduces the proactive interference effect. Taken together, the modeling and empirical results reported here are consistent with the claim that some age differences that appear to be specific to associative information can be produced via general degradation of information stored in memory. The REM model provides a useful framework for examining age differences in memory as well as harmonizing seemingly conflicting prior modeling approaches for the associative deficit. (PsycINFO Database Record

The role of stimulus complexity and salience in memory for face-name associations in healthy adults: Friend or foe?

The associative deficit hypothesis (ADH) posits that age-related differences in recognition of associations are disproportionately larger than age differences in item recognition because of age-related difficulty in binding and retrieval of two or more pieces of information in a memory episode. This proposition rests on the observation of disproportionately greater age differences in memory for associations than in recognition of individual items. Although ADH has been supported in experiments with verbal and nonverbal stimuli, the effects of task or stimulus characteristics on its generalizability remain unclear. In a series of experiments, we examined how salience and variability of face stimuli presented in face-name pairs affect age differences in recognition of items and associations. We found that a disproportionate age-related deficit in the recognition of face-name associations emerges when face stimuli are more complex, salient, variable, and distinctive, but not when standardized faces appear within minimal visual context. These findings indicate that age-related associative memory deficits may stem at least in part from age differences in use of stimulus characteristics for contextual support. (PsycINFO Database Record

Repeated study of items with and without repeated context: aging effects on memory discriminability

Presenting items multiple times during encoding is a common way to enhance recognition accuracy. Under such conditions, older adults often show an increase in false recognition that counteracts benefits of repeated study. Using a false-memory paradigm with related study items and related lures, we tested whether repetition within the same encoding task or repetition across two different encoding tasks would be more beneficial to older adults' memory discriminability. Results showed that, compared to items not repeated at study, items repeated in the same context and items repeated across different contexts showed improvements in memory discriminability in both young and older adults. This improvement was primarily reflected in improved recollection responses for both age groups across both repeat study conditions, as compared to no repetition. Importantly, the results demonstrated that repetition can be used to successfully mitigate age-related deficits by increasing memory discriminability and without incurring a cost of false recognition specific to any one age group.

Competing cues: Older adults rely on knowledge in the face of fluency

Consumers regularly encounter repeated false claims in political and marketing campaigns, but very little empirical work addresses their impact among older adults. Repeated statements feel easier to process, and thus more truthful, than new ones (i.e., illusory truth). When judging truth, older adults' accumulated general knowledge may offset this perception of fluency. In two experiments, participants read statements that contradicted information stored in memory; a post-experimental knowledge check confirmed what individual participants knew. Unlike young adults, older adults exhibited illusory truth only when they lacked knowledge about claims. This interaction between knowledge and fluency extends dual-process theories of aging. (PsycINFO Database Record

Familiarity influences on direct and indirect associative memory for objects in scenes

Remembering arbitrary associations, such as unrelated word pairs or object-background pairs, appears to depend on recollection. However, for cases in which the components of an association share pre-existing semantic relations, can familiarity support associative recognition? In two experiments with congruent object-background pairings, we found that participants were successful at direct and indirect associative recognition in both 1000 ms time restriction (speeded) and unlimited response time (non-speeded) test conditions. Because dual-process theory postulates that familiarity is less impacted by speeded responses, relative to recollection, these findings suggest that congruent object-background associations may not necessitate recollection when an arbitrary link is not constructed at encoding. Experiment 3 compared direct associative memory for congruent and incongruent object-background pairs in speeded and non-speeded test conditions. We found that participants in the non-speeded condition performed comparably with congruent and incongruent pairs, whereas those in the speeded condition performed significantly worse on the incongruent pairs than on the congruent pairs. Together, these findings suggest a differential role of familiarity and recollection depending on the types of associations. Implications for dual-process recognition memory models and levels of unitization framework are discussed.

The effects of item familiarity on the neural correlates of successful associative memory encoding

Associative memory is considered to be resource-demanding, requiring individuals to learn individual items and the specific relationships between those items. Previous research has shown that prior studying of items aids in associative memory for pairs composed of those same items, as compared to pairs of items that have not been prelearned (e.g., Kilb & Naveh-Benjamin, 2011). In the present study, we sought to elucidate the neural correlates mediating this memory facilitation. After being trained on individual items, participants were scanned while encoding item pairs composed of items from the pretrained phase (familiarized-item pairs) and pairs whose items had not been previously learned (unfamiliarized-item pairs). Consistent with previous findings, the overall subsequent recollection showed the engagement of bilateral parahippocampal gyrus (PHG) and hippocampus, when compared to subsequent forgetting. However, a direct comparison between familiarized- and unfamiliarized-item pairs showed that subsequently recollected familiarized-item pairs were associated with decreased activity across much of the encoding network, including bilateral PHG, hippocampus, prefrontal cortex, and regions associated with item-specific processing within occipital cortex. Increased activity for familiarized-item pairs was found in a more limited set of regions, including bilateral parietal cortex, which has been associated with the formation of novel associations. Additionally, activity in the right parietal cortex correlated with associative memory success in the familiarized condition. Taken together, these results suggest that prior exposure to items can reduce the demands incurred on neural processing throughout the associative encoding network and can enhance associative memory performance by focusing resources within regions supporting the formation of associative links.

Effects of repetition on age differences in associative recognition

The study reported here examined the effect of repetition on age differences in associative recognition using a paradigm designed to encourage recollection at test. Young and older adults studied lists of unrelated word pairs presented one, two, four, or eight times. Test lists contained old (intact) pairs, pairs consisting of old words that had been studied with other partners (rearranged lures), and pairs consisting of two unstudied words (new lures). Participants gave old/new responses and then indicated whether their responses were based on details that they could recollect or on familiarity. Older adults exhibited an ironic effect of repetition-an increase in false alarms on rearranged lures with more study opportunities-whereas young adults did not. Older adults also claimed to recall details of the study episode for rearranged lures whose constituent words were presented more frequently, but this was not true for young adults. Although both young and older adults said that they based correct rejections of rearranged lures on memory for details of the study episode, this effect was stronger for young adults. The observed age differences are consistent with older adults having reduced use of recollection in associative recognition tasks.

The Interaction Between Memory Trace and Memory Judgment in Age-Related Decline

BACKGROUND/STUDY CONTEXT

Associative memory deficit and executive functioning deficit are two alternative--but nonexclusive--accounts of the episodic memory deficit observed in aging. The first explain the episodic memory decline generally observed in aging by an associative memory deficit (memory decline per se), whereas the second explains it by an executive functioning deficit. This distinction could be critical in early discrimination between healthy aging and very mild Alzheimer's-type dementia.

METHODS

Memory performance was measured in older adults (n = 20) and paired younger participants (n = 20), whereas the facial expression and auditory context (spoken voice) associated with the face were manipulated between study and test. Recollection and familiarity were estimated using a remember/know judgment, and source memory performance was obtained depending on the information to retrieve.

RESULTS

Although no between-group difference was observed for correctly recognized old faces, older participants made more false alarms than younger ones, thus revealing lower discriminability (d'). Facial expression change decreased recognition for all participants, whereas auditory context change decreased recognition only for younger participants. Remember/know judgments revealed age-related deficits in both recollection and familiarity, the relative decrease in familiarity reported by older adults was particularly large in the expression change conditions, and a disadvantage in source memory performance was particularly pronounced when the task was to retrieve auditory context associated with the face at study.

CONCLUSIONS

The present findings show that age-related associative memory differences occur with familiarity as well as recollection and are observed in situations that do not necessarily require conscious retrieval. This age-related decline is more prominent for multimodal (face-auditory context) than for intraitem (face-expression) associations. The value of exploring both memory trace and memory judgment was discussed, and potential applications for the development of neuropsychological tools for memory assessment in aging were highlighted.

Are There Age-Related Differences in the Ability to Learn Configural Responses?

Age is often associated with a decline in cognitive abilities that are important for maintaining functional independence, such as learning new skills. Many forms of motor learning appear to be relatively well preserved with age, while learning tasks that involve associative binding tend to be negatively affected. The current study aimed to determine whether age differences exist on a configural response learning task, which includes aspects of motor learning and associative binding. Young (M = 24 years) and older adults (M = 66.5 years) completed a modified version of a configural learning task. Given the requirement of associative binding in the configural relationships between responses, we predicted older adults would show significantly less learning than young adults. Older adults demonstrated lower performance (slower reaction time and lower accuracy). However, contrary to our prediction, older adults showed similar rates of learning as indexed by a configural learning score compared to young adults. These results suggest that the ability to acquire knowledge incidentally about configural response relationships is largely unaffected by cognitive aging. The configural response learning task provides insight into the task demands that constrain learning abilities in older adults.

The role of familiarity in associative recognition of unitized compound word pairs

This study examined the effect of unitization and contribution of familiarity in the recognition of word pairs. Compound words were presented as word pairs and were contrasted with noncompound word pairs in an associative recognition task. In Experiments 1 and 2, yes–no recognition hit and false-alarm rates were significantly higher for compound than for noncompound word pairs, with no difference in discrimination in both within- and between-subject comparisons. Experiment 2 also showed that item recognition was reduced for words from compound compared to noncompound word pairs, providing evidence of the unitization of the compound pairs. A two-alternative forced-choice test used in Experiments 3A and 3B provided evidence that the concordant effect for compound word pairs was largely due to familiarity. A discrimination advantage for compound word pairs was also seen in these experiments. Experiment 4A showed that a different pattern of results is seen when repeated noncompound word pairs are compared to compound word pairs. Experiment 4B showed that memory for the individual items of compound word pairs was impaired relative to items in repeated and nonrepeated noncompound word pairs, and Experiment 5 demonstrated that this effect is eliminated when the elements of compound word pairs are not unitized. The concordant pattern seen in yes–no recognition and the discrimination advantage in forced-choice recognition for compound relative to noncompound word pairs is due to greater reliance on familiarity at test when pairs are unitized.

Improving associative memory in older adults with unitization

We examined if unitization inherent preexperimentally could reduce the associative deficit in older adults. In Experiment 1, younger and older adults studied compound word (CW; e.g., store keeper) and noncompound word (NCW; e.g., needle birth) pairs. We found a reduction in the age-related associative deficit such that older but not younger adults showed a discrimination advantage for CW relative to NCW pairs on a yes-no associative recognition test. These results suggest that CW compared to NCW word pairs provide schematic support that older adults can use to improve their memory. In Experiment 2, reducing study time in younger adults decreased associative recognition performance, but did not produce a discrimination advantage for CW pairs. In Experiment 3, both older and younger adults showed a discrimination advantage for CW pairs on a two-alternative forced-choice recognition test, which encourages greater use of familiarity. These results suggest that test format influenced young adults' use of familiarity during associative recognition of unitized pairs, and that older adults rely more on familiarity than recollection for associative recognition. Unitization of preexperimental associations, as in CW pairs, can alleviate age-related associative deficits.

The role of reduced working memory storage and processing resources in the associative memory deficit of older adults: simulation studies with younger adults

Previous research indicates that relative to younger adults, older adults show a larger decline in long-term memory (LTM) for associations than for the components that make up these associations. The purpose of the present study was to investigate whether we can impair associative memory performance in young adults by reducing their working memory (WM) resources, hence providing potential clues regarding the underlying causes of the associative memory deficit in older adults. With two experiments, we investigated whether we can reduce younger adults' long-term associative memory using secondary tasks in which either storage or processing WM loads were manipulated, while participants learned name-face pairs and then remembered the names, the faces, and the name-face associations. Results show that reducing either the storage or the processing resources of WM produced performance patterns of an associative long-term memory deficit in young adults. Furthermore, younger adults' associative memory deficit was a function of their performance on a working memory span task. These results indicate that one potential reason older adults have an associative deficit is a reduction in their WM resources but further research is needed to assess the mechanisms involved in age-related associative memory deficits.

Age-related changes in associative memory for emotional and nonemotional integrative representations

Events often include novel combinations of items. Sometimes, through the process of integration, we experience and remember these items as parts of a whole rather than as separate entities. Recent research with younger adults has demonstrated that successfully integrating 2 nonemotional items at encoding, instead of imagining them separately, produces a disproportionately larger associative memory benefit than integrating an emotional and a nonemotional item. In the first study to examine whether age and emotion interact to influence integration, we used 2 measures of integrative success-the ability to successfully retrieve integrations, measured through associative cued recall, and the ability to successfully generate integrated representations at encoding, measured through self report. The cued-recall results (Experiments 1 and 2) revealed that the emotional content of the word pairs interacts to influence the effect of integration on older adults' associative memory, but in the opposite direction of younger adults: Older adults showed no associative retrieval benefit of integration over nonintegration for nonemotional pairs, but they showed a significant integrative benefit for emotional pairs. We also demonstrated (Experiment 2) that encoding time interacts with emotion and integration in different ways for older and younger adults: Putting younger adults under time pressure reduced their success in generating integrated representations at encoding for nonemotional pairs, whereas for older adults it disrupted their ability to generate integrated representations for emotional pairs. We discuss possible age-related differences in the processes used to create emotional and nonemotional integrations.

Familiarity-based memory as an early cognitive marker of preclinical and prodromal AD

There is great interest in the development of cognitive markers that differentiate "normal" age-associated cognitive change from that of Alzheimer's disease (AD) in its prodromal (i.e., mild cognitive impairment; MCI) or even preclinical stages. Dual process models posit that recognition memory is supported by the dissociable processes of recollection and familiarity. Familiarity-based memory has generally been considered to be spared during normal aging, but it remains controversial whether this type of memory is impaired in early AD. Here, we describe findings of estimates of recollection and familiarity in young adults (YA), cognitively normal older adults (CN), and patients with amnestic-MCI (a-MCI). These measures in the CN and a-MCI patients were then related to a structural imaging biomarker of AD that has previously been demonstrated to be sensitive to preclinical and prodromal AD, the Cortical Signature of AD (ADsig). Consistent with much work in the literature, recollection, but not familiarity, was impaired in CN versus YA. Replicating our prior findings, a-MCI patients displayed impairment in both familiarity and recollection. Finally, the familiarity measure was correlated with the ADsig biomarker across the CN and a-MCI group, as well as within the CN adults alone. No other standard psychometric measure was as highly associated with the ADsig, suggesting that familiarity may be a sensitive biomarker of AD-specific brain changes in preclinical and prodromal AD and that it may offer a qualitatively distinct measure of early AD memory impairment relative to normal age-associated change.

Metacognitive awareness of the associative deficit for words and names

Older adults have considerable impairment in associative recognition despite minimal age differences in item recognition. The magnitude of this associative deficit varies by type of stimuli, strategy utilization, and other mediators and moderators ( Old & Naveh-Benjamin, 2008 , Psychology and Aging, 23, 104-118). Name pair stimuli have not been used to test the associative deficit hypothesis (ADH), although tests using name-face stimuli support the ADH. Additionally, metacognitive awareness of the ADH has not been investigated. We tested the ADH with word and name pair stimuli, and predicted that age-related associative deficits would be larger for words than names because names, unlike most common nouns, lack certain semantic properties that could be used to bind pairs of names together. Results supported the ADH for words but not names: Younger and older adults recognized equivalently fewer names on the associative test relative to the item test. As predicted, self-efficacy was higher for younger than older adults. Surprisingly, self-efficacy for the associative test was higher than for the item test but post-test estimates of performance success (postdictions) were higher for the item test than for the associative test, suggesting sensitivity by participants to different task demands in the item and associative tests following recognition attempts. Metacognitive accuracy was better for words than names and for the item test than associative test, and equivalent between age groups. Overall, participants overestimated their name recognition abilities. Our findings extend support for the ADH to a conceptually important and ecologically valid domain (names) and provide new data on metacognitive aspects of the ADH.

Social relevance enhances memory for impressions in older adults

Previous research has demonstrated that older adults have difficulty retrieving contextual material over items alone. Recent research suggests this deficit can be reduced by adding emotional context, allowing for the possibility that memory for social impressions may show less age-related decline than memory for other types of contextual information. Two studies investigated how orienting to social or self-relevant aspects of information contributed to the learning and retrieval of impressions in young and older adults. Participants encoded impressions of others in conditions varying in the use of self-reference (Experiment 1) and interpersonal meaningfulness (Experiment 2), and completed memory tasks requiring the retrieval of specific traits. For both experiments, age groups remembered similar numbers of impressions. In Experiment 1 using more self-relevant encoding contexts increased memory for impressions over orienting to stimuli in a non-social way, regardless of age. In Experiment 2 older adults had enhanced memory for impressions presented in an interpersonally meaningful relative to a personally irrelevant way, whereas young adults were unaffected by this manipulation. The results provide evidence that increasing social relevance ameliorates age differences in memory for impressions, and enhances older adults' ability to successfully retrieve contextual information.

The effects of emotional arousal and gender on the associative memory deficit of older adults

In this study we assessed the potential moderating roles of stimulus type (emotionally arousing) and participants' characteristics (gender) in older adults' associative memory deficit. In two experiments, young and older participants studied lists that included neutral and emotionally arousing word pairs (positive and negative) and completed recognition tests for the words and their associations. In Experiment 1, the majority of the word pairs were composed of two nouns, whereas in Experiment 2 they were composed of adjective-noun pairs. The results extend evidence for older adults' associative deficit and suggest that older and younger adults' item memory is improved for emotionally arousing words. However, associative memory for the word pairs did not benefit (and even showed a slight decline) from emotionally arousing words, which was the case for both younger and older adults. In addition, in these experiments, gender appeared to moderate the associative deficit of older adults, with older males but not females demonstrating this deficit.

Tests of the DRYAD theory of the age-related deficit in memory for context: not about context, and not about aging

Older adults exhibit a disproportionate deficit in their ability to recover contextual elements or source information about prior encounters with stimuli. A recent theoretical account, DRYAD, attributes this selective deficit to a global decrease in memory fidelity with age, moderated by weak representation of contextual information. The predictions of DRYAD are tested here in three experiments. We show that an age-related deficit obtains for whichever aspect of the stimulus subjects' attention is directed away from during encoding (Experiment 1), suggesting a central role for attention in producing the age-related deficit in context. We also show that an analogous deficit can be elicited within young subjects with a manipulation of study time (Experiment 2), suggesting that any means of reducing memory fidelity yields an interaction of the same form as the age-related effect. Experiment 3 evaluates the critical prediction of DRYAD that endorsement probability in an exclusion task should vary nonmonotonically with memory strength. This prediction was confirmed by assessing the shape of the forgetting function in a continuous exclusion task. The results are consistent with the DRYAD account of aging and memory judgments and do not support the widely held view that aging entails the selective disruption of processes involved in encoding, storing, or retrieving contextual information.

Age, criterion flexibility, and associative recognition

OBJECTIVE

The goal of this study was to compare the extent to which young and older adults exhibit flexibility in adjusting decision criteria in response to changes in recognition task difficulty.

METHODS

Forty-eight young and 48 older adults studied a list of word pairs and then took 2 successive tests of associative recognition, an easy test consisting of intact study pairs and new lure pairs and a hard test pitting intact study pairs against rearranged lures. The order of the 2 tests was manipulated, with half of the participants in each age group receiving the easy test first and half receiving the hard test first.

RESULTS

When the easy test preceded the hard test, participants in both age groups adopted a more stringent response criterion on the harder test. When the hard test preceded the easy test, no criterion shift was seen in either age group.

DISCUSSION

These results suggest that older adults have preserved metacognitive abilities with regard to assessing the consequences for accuracy of maintaining a lenient criterion when discrimination between experienced and new information becomes more difficult and further suggests that they can take appropriate action to control error rates under these conditions.

Effects of aging and IQ on item and associative memory

The effects of aging and IQ on performance were examined in 4 memory tasks: item recognition, associative recognition, cued recall, and free recall. For item and associative recognition, accuracy and the response time (RT) distributions for correct and error responses were explained by Ratcliff's (1978) diffusion model at the level of individual participants. The values of the components of processing identified by the model for the recognition tasks, as well as accuracy for cued and free recall, were compared across levels of IQ (ranging from 85 to 140) and age (college age, 60-74 years old, and 75-90 years old). IQ had large effects on drift rate in recognition and recall performance, except for the oldest participants with some measures near floor. Drift rates in the recognition tasks, accuracy in recall, and IQ all correlated strongly. However, there was a small decline in drift rates for item recognition and a large decline for associative recognition and cued recall accuracy (70%). In contrast, there were large effects of age on boundary separation and nondecision time (which correlated across tasks) but small effects of IQ. The implications of these results for single- and dual-process models of item recognition are discussed, and it is concluded that models that deal with both RTs and accuracy are subject to many more constraints than are models that deal with only one of these measures. Overall, the results of the study show a complicated but interpretable pattern of interactions that present important targets for modeling.

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.

Effects of repetition on associative recognition in young and older adults: item and associative strengthening

Young and older adults studied word pairs and later discriminated studied pairs from various types of foils including recombined word-pairs and foil pairs containing one or two previously unstudied words. We manipulated how many times a specific word pair was repeated (1 or 5) and how many different words were associated with a given word (1 or 5) to tease apart the effects of item familiarity from recollection of the association. Rather than making simple old/new judgments, subjects chose one of five responses: (a) Old-Old (original), (b) Old-Old (rearranged), (c) Old-New, (d) New-Old, (e) New-New. Veridical recollection was impaired in old age in all memory conditions. There was evidence for a higher rate of false recollection of rearranged pairs following exact repetition of study pairs in older but not younger adults. In contrast, older adults were not more susceptible to interference than young adults when one or both words of the pair had multiple competing associates. Older adults were just as able as young adults to use item familiarity to recognize which word of a foil was old. This pattern suggests that recollection problems in advanced age are because of a deficit in older adults' formation or retrieval of new associations in memory. A modeling simulation provided good fits to these data and offers a mechanistic explanation based on an age-related reduction of working memory.

Effects of emotion on associative recognition: valence and retention interval matter

In two experiments, we examined the effects of emotional valence and arousal on associative binding. Participants studied negative, positive, and neutral word pairs, followed by an associative recognition test. In Experiment 1, with a short-delayed test, accuracy for intact pairs was equivalent across valences, whereas accuracy for rearranged pairs was lower for negative than for positive and neutral pairs. In Experiment 2, we tested participants after a one-week delay and found that accuracy was greater for intact negative than for intact neutral pairs, whereas rearranged pair accuracy was equivalent across valences. These results suggest that, although negative emotional valence impairs associative binding after a short delay, it may improve binding after a longer delay. The results also suggest that valence, as well as arousal, needs to be considered when examining the effects of emotion on associative memory.

Representational explanations of "process" dissociations in recognition: the DRYAD theory of aging and memory judgments

It is widely assumed that older adults suffer a deficit in the psychological processes that underlie remembering of contextual or source information. This conclusion is based in large part on empirical interactions, including disordinal ones, that reveal differential effects of manipulations of memory strength on recognition in young and old subjects. This article lays out an alternative theory that takes as a starting point the overwhelming evidence from the psychometric literature that the effects of age on memory share a single mediating influence. Thus, the theory assumes no differences between younger and older subjects other than a global difference in memory fidelity--that is, the older subjects are presumed to have less valid representations of events and objects than are young subjects. The theory is articulated through 3 major assumptions and implemented in a computational model, DRYAD, to simulate fundamental results in the literature on aging and recognition, including the very interactions taken to imply selective impairment in older people. The theoretical perspective presented here allows for a critical examination of the widely held belief that aging entails the selective disruption of particular memory processes.

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.

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.

The associative deficit in older adult memory: Recognition of pairs is not improved by repetition

This study used a novel experimental paradigm that combined associative recognition and list discrimination to study the associative deficit in older adults' memory (M. Naveh-Benjamin, 2000). Participants viewed 2 lists of word-face pairs and were tested on recognition of pairs from the second study list. Older and young adults' recognition was increased by repetition of individual items, but repetition of pairs of items increased recognition in young adults only. This provides converging evidence that older adults do not form associative links between items within pairs and supports the hypothesis that an associative deficit contributes to age-related memory decline.

When false recognition is out of control: the case of facial conjunctions

In three experiments, a dual-process approach to face recognition memory is examined, with a specific focus on the idea that a recollection process can be used to retrieve configural information of a studied face. Subjects could avoid, with confidence, a recognition error to conjunction lure faces (each a reconfiguration of features from separate studied faces) or feature lure faces (each based on a set of old features and a set of new features) by recalling a studied configuration. In Experiment 1, study repetition (one vs. eight presentations) was manipulated, and in Experiments 2 and 3, retention interval over a short number of trials (0-20) was manipulated. Different measures converged on the conclusion that subjects were unable to use a recollection process to retrieve configural information in an effort to temper recognition errors for conjunction or feature lure faces. A single process, familiarity, appears to be the sole process underlying recognition of conjunction and feature faces, and familiarity contributes, perhaps in whole, to discrimination of old from conjunction faces.