The effects of attention on age-related relational memory deficits: evidence from a novel attentional manipulation

Divided attention at retrieval does not influence neural correlates of recollection in young or older adults

Age-related decline in episodic memory has been partially attributed to older adults' reduced domain general processing resources. In the present study, we examined the effects of divided attention (DA) - a manipulation assumed to further deplete the already limited processing resources of older adults - on the neural correlates of recollection in young and older adults. Participants underwent fMRI scanning while they performed an associative recognition test in single and dual (tone detection) task conditions. Recollection effects were operationalized as greater BOLD activity elicited by test pairs correctly endorsed as 'intact' than pairs correctly or incorrectly endorsed as 'rearranged'. Detrimental effects of DA on associative recognition performance were identified in older but not young adults. The magnitudes of recollection effects did not differ between the single and dual (tone detection) tasks in either age group. Across the task conditions, age-invariant recollection effects were evident in most members of the core recollection network. However, while young adults demonstrated robust recollection effects in left angular gyrus, angular gyrus effects were undetectable in the older adults in either task condition. With the possible exception of this result, the findings suggest that DA did not influence processes supporting the retrieval and representation of associative information in either young or older adults, and converge with prior behavioral findings to suggest that episodic retrieval operations are little affected by DA.

The age-related associative deficit simulated by relational divided attention: encoding strategy and recollection

According to the associative deficit hypothesis, older adults experience greater difficulty in remembering associations between pieces of information than young adults, despite their relatively intact memory for individual items. It has been demonstrated that this deficit could be simulated by depleting resources for relational processing. The current study examines the possible mechanisms underlying this simulation. Item and associative memory were assessed using a process dissociation paradigm in which word pairs were encoded under full attention (FA) or relational divided attention (DA) conditions across three groups: FA older adults (n = 24), FA young adults (n = 24), and DA young adults (n = 24). Recollection and familiarity were estimated for the associative memory performance. Relative to FA young adults, both older adults and DA young adults showed an associative deficit, and reduced use of recollection and high-level relational encoding strategies. Regression analyses suggested that the effects of age and DA on associative memory were largely driven by the variance in recollection and encoding strategy use. The results suggest that depletion of attentional resources for relational processing impairs associative memory through disrupting the use of effective encoding strategies and recollection, which largely simulates age-related associative deficit.

Dissociating refreshing and elaboration and their impacts on memory

Maintenance of information in working memory (WM) is assumed to rely on refreshing and elaboration, but clear mechanistic descriptions of these cognitive processes are lacking, and it is unclear whether they are simply two labels for the same process. This fMRI study investigated the extent to which refreshing, elaboration, and repeating of items in WM are distinct neural processes with dissociable behavioral outcomes in WM and long-term memory (LTM). Multivariate pattern analyses of fMRI data revealed differentiable neural signatures for these processes, which we also replicated in an independent sample of older adults. In some cases, the degree of neural separation within an individual predicted their memory performance. Elaboration improved LTM, but not WM, and this benefit increased as its neural signature became more distinct from repetition. Refreshing had no impact on LTM, but did improve WM, although the neural discrimination of this process was not predictive of the degree of improvement. These results demonstrate that refreshing and elaboration are separate processes that differently contribute to memory performance.

Age-related changes to oscillatory dynamics during maintenance and retrieval in a relational memory task

In aging, structural and/or functional brain changes may precede changes in cognitive performance. We previously showed that despite having hippocampal volumes similar to those of younger adults, older adults showed oscillatory changes during the encoding phase of a short-delay visuospatial memory task that required spatial relations among objects to be bound across time (Rondina et al., 2016). The present work provides a complementary set of analyses to examine age-related changes in oscillatory activity during maintenance and retrieval of those spatial relations in order to provide a comprehensive examination of the neural dynamics that support memory function in aging. Participants were presented with three study objects sequentially. Following a delay (maintenance phase), the objects were re-presented simultaneously and participants had to determine whether the relative spatial relations among the objects had been maintained (retrieval phase). Older adults had similar task accuracy, but slower response times, compared to younger adults. Both groups showed a decrease in theta (2-7Hz), alpha (9-14Hz), and beta (15-30Hz) power during the maintenance phase. During the retrieval phase, younger adults showed theta and beta power increases that predicted greater task accuracy, whereas older adults showed a widespread decrease in each of the three frequency ranges that predicted longer response latencies. Older adults also showed distinct patterns of behaviour-related activity depending on whether the analysis was time-locked to the onset of the stimulus or to the onset of the response during the test phase. These findings suggest that older adults may experience declines in relational binding and/or comparison processes that are reflected in oscillatory changes prior to structural decline.

Attending to behaviorally relevant moments enhances incidental relational memory

Memory for the items one has recently encountered is sometimes enhanced in divided attention tasks: Attending to behaviorally relevant items, such as a target in a detection task, boosts memory for unrelated background items (e.g., scenes or words). However, a central feature of episodic memory is memory for the spatiotemporal relationship between items and other elements of an event (relational memory), not just the item itself. Three experiments examined whether attending to a behaviorally relevant target-item boosts memory for the relationship between that item, its features, and a background scene. Participants memorized briefly presented scenes. At the same time, they pressed a button if a second unrelated item (a figure or face) was a particular target color (Experiments 1 and 2) or target gender (Experiment 3) rather than a distractor color or gender. Target and distractor items also varied in task-irrelevant features (shape, location, or facial identity). If attending to behaviorally relevant events influences relational memory, then participants should be better able to report both target-defining and irrelevant features of items that appeared with target-paired scenes rather than distractor-paired scenes. This was the case in all experiments: memory was enhanced for the target-paired scenes as well as the association between a scene and features of the paired target-item. Attending to behaviorally relevant moments therefore has broader effects on memory encoding than previously thought. In addition to boosting memory for unrelated background items, attending to targets facilitates relational memory in these tasks.

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

BACKGROUND/STUDY CONTEXT

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

METHODS

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

RESULTS

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

CONCLUSION

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

Relação entre a competência funcional da memória episódica e os fatores associados à independência funcional de idosos saudáveis

OBJETIVO: O objetivo deste estudo foi descrever a relação entre competência funcional da memória episódica e fatores associados à independência de idosos saudáveis do município de Juiz de Fora, Minas Gerais, Brasil. MÉTODOS: Trata-se de estudo transversal, descritivo e exploratório em que 60 idosos saudáveis compuseram a amostra final. Para avaliar a capacidade funcional, foram utilizadas as escalas de Katz e de Lawton & Brody. A memória episódica foi avaliada utilizando-se teste de West & Thorn, validado e adaptado para a população brasileira por Yassuda, Lasca e Neri em 2005. A análise estatística foi realizada por meio do software estatístico Sphinx Léxica e Eureka, versão 5.0. RESULTADOS: Foi encontrada associação estatisticamente significante entre escolaridade e desempenho em tarefa de memória episódica e entre esta e três itens da escala de avaliação das atividades instrumentais de vida diária, embora inconclusiva. CONCLUSÕES: Acredita-se que esses resultados se devam ao fato de existir muitas diferenças entre os estudos com relação à metodologia empregada e a escolha dos instrumentos que avaliam tanto a memória episódica, quanto a capacidade funcional de idosos. Além disso, a hipótese de que no envelhecimento saudável existe uma capacidade de, frente às perdas graduais na memória episódica, compensá-las utilizando outras estratégias e recursos, deve receber atenção de futuras pesquisas.

Reflexive orienting in response to short- and long-duration gaze cues in young, young-old, and old-old adults

Shifting visual focus on the basis of the perceived gaze direction of another person is one form of joint attention. In the present study, we investigated whether this socially relevant form of orienting is reflexive and whether it is influenced by age. Green and Woldorff (Cognition 122:96-101, 2012) argued that rapid cueing effects (i.e., faster responses to validly than to invalidly cued targets) were limited to conditions in which a cue overlapped in time with a target. They attributed slower responses following invalid cues to the time needed to resolve the incongruent spatial information provided by the concurrently presented cue and target. In the present study, we examined the orienting responses of young (18-31 years), young-old (60-74 years), and old-old (75-91 years) adults following uninformative central gaze cues that overlapped in time with the target (Exp. 1) or that were removed prior to target presentation (Exp. 2). When the cue and target overlapped, all three groups localized validly cued targets more quickly than invalidly cued targets, and validity effects emerged earlier for the two younger groups (at 100 ms post-cue-onset) than for the old-old group (at 300 ms post-cue-onset). With a short-duration cue (Exp. 2), validity effects developed rapidly (by 100 ms) for all three groups, suggesting that validity effects resulted from reflexive orienting based on the gaze cue information rather than from cue-target conflict. Thus, although old-old adults may be slow to disengage from persistent gaze cues, attention continues to be reflexively guided by gaze cues late in life.

Aging and individual differences in binding during sentence understanding: evidence from temporary and global syntactic attachment ambiguities

We report an investigation of aging and individual differences in binding information during sentence understanding. An age-continuous sample of adults (N=91), ranging from 18 to 81 years of age, read sentences in which a relative clause could be attached high to a head noun NP1, attached low to its modifying prepositional phrase NP2 (e.g., The son of the princess who scratched himself/herself in public was humiliated), or in which the attachment site of the relative clause was ultimately indeterminate (e.g., The maid of the princess who scratched herself in public was humiliated). Word-by-word reading times and comprehension (e.g., who scratched?) were measured. A series of mixed-effects models were fit to the data, revealing: (1) that, on average, NP1-attached sentences were harder to process and comprehend than NP2-attached sentences; (2) that these average effects were independently moderated by verbal working memory capacity and reading experience, with effects that were most pronounced in the oldest participants and; (3) that readers on average did not allocate extra time to resolve global ambiguities, though older adults with higher working memory span did. Findings are discussed in relation to current models of lifespan cognitive development, working memory, language experience, and the role of prosodic segmentation strategies in reading. Collectively, these data suggest that aging brings differences in sentence understanding, and these differences may depend on independent influences of verbal working memory capacity and reading experience.

Age-related differences in recognition memory for items and associations: contribution of individual differences in working memory and metamemory

Ability to form new associations between unrelated items is particularly sensitive to aging, but the reasons for such differential vulnerability are unclear. In this study, we examined the role of objective and subjective factors (working memory and beliefs about memory strategies) on differential relations of age with recognition of items and associations. Healthy adults (N = 100, age 21 to 79) studied word pairs, completed item and association recognition tests, and rated the effectiveness of shallow (e.g., repetition) and deep (e.g., imagery or sentence generation) encoding strategies. Advanced age was associated with reduced working memory (WM) capacity and poorer associative recognition. In addition, reduced WM capacity, beliefs in the utility of ineffective encoding strategies, and lack of endorsement of effective ones were independently associated with impaired associative memory. Thus, maladaptive beliefs about memory in conjunction with reduced cognitive resources account in part for differences in associative memory commonly attributed to aging.

The Effects of Attention on Age-related Relational Memory Deficits: fMRI Evidence from a Novel Attentional Manipulation

Numerous studies have documented that older adults (OAs) do not perform as well as young adults (YAs) when task demands require the establishment or retrieval of a novel link between previously unrelated information (relational memory: RM). Nonetheless, the source of this age-related RM deficit remains unspecified. One of the most widely investigated factors is an age-related reduction in attentional resources. To investigate this factor, previous researchers have tested whether dividing YAs' attention during encoding equated their RM performance to that of OAs. However, results from these studies failed to replicate the age-related RM impairment observed in aging. The current study investigated whether a reduction in attentional resources for processing of relational information (i.e., relational attention) underlies age-related RM deficits. Using fMRI, we examined whether the effect of reduced attentional resources for processing of relational information is similar to that observed in aging at both behavioral and neural levels. The behavioral results showed that reduced attentional resources for relational information during encoding equated YAs RM performance to that of OAs. Furthermore, the fMRI results demonstrated that both aging, as well as reductions in relational attention in YAs, significantly reduced activity in brain areas associated with successful RM formation, namely, the ventrolateral and dorsolateral PFC, superior and inferior parietal regions, and left hippocampus. Such converging evidence from behavioral and neuroimaging studies suggests that a reduction in attentional resources for relational information is a critical factor for the RM deficit observed in aging.