Intact Pairs Research Articles

Differential attentional costs of encoding specific and gist episodic memory representations.

Theories of episodic memory posit that more attentional resources are needed for encoding specific compared to gist representations. This position has been challenged by recent findings of similar divided attention (DA) at encoding costs on both specific and gist representations. However, the disrupting effects of DA on specific representations may emerge under less difficult DA conditions than those under which effects on gist representations emerge. The present study addressed this possibility by manipulating the difficulty of a concurrent DA task (low, intermediate, or high difficulty) during encoding among 176 young adult participants, who encoded face-scene pairs under either full attention or one of the three levels of DA. During retrieval, participants discriminated intact pairs from recombined pairs that varied in how similar they were to studied pairs. Results, interpreted using a multinomial-processing-tree model of specific and gist memory, showed that the disrupting effects of DA on specific representations emerged under less difficult attentional loads (intermediate-demanding condition) compared to those under which gist representations were disrupted (high-demanding condition). These findings reinforce the suggestion of differential attentional demands for specific and gist representations and also provide insights into attentional resource theories of adult age-related cognitive decline. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Spaced Retrieval Practice: Can Restudying Trump Retrieval?

We investigated spaced retrieval and restudying in 3 preregistered, online experiments. In all experiments, participants studied 40 Swahili–English word pair translations during an initial study phase, restudied intact pairs or attempted to retrieve the English words to Swahili cues twice in three spaced practice sessions, and then completed a final cued-recall test. All 5 sessions were separated by 2 days. In Experiment 1, we manipulated the response format during retrieval (covert vs. overt) and the test list structure (blocked vs. intermixed covert/overt retrieval trials). A memory rating was required on all trials (retrieval: “Was your answer correct?”; restudy: “Would you have remembered the correct translation?”). Response format had no effect on recall, but surprisingly, final test performance for restudied items exceeded both the overt and covert retrieval conditions. In Experiment 2, we manipulated the requirement to make a memory rating. If a memory rating was required, final test restudy performance exceeded retrieval performance, replicating Experiment 1. However, the pattern was descriptively reversed if no rating was required. In Experiment 3, the memory rating was removed altogether, and we examined recall performance for items restudied versus retrieved once, twice, or thrice. Performance improved with practice, and retrieval performance exceeded restudy performance in all conditions. The reversal of the typical retrieval practice effect observed in Experiments 1 and 2 is discussed in terms of theories of reactivity of memory judgments.

The formation of specific and gist associative episodic memory representations during encoding: Effects of rate of presentation.

Assessing the time course under which underlying memory representations can be formed is an important question for understanding memory. Several studies assessing item memory have shown that gist representations of items are laid out more rapidly than verbatim representations. However, for associations among items/components, which form the core of episodic memory, it is unclear whether gist representations form more quickly than, or at least in parallel with, verbatim representations, as fuzzy-trace theory predicts, or whether gist is extracted more slowly from inferring the meaning of verbatim representations, as in gist macroprocessor theories. To test these contrasting possibilities, we used a novel associative recognition task in which participants studied face-scene pairs for .75, 1.5, or 4 seconds each, and were later tested on their ability to discriminate intact pairs from foils which varied in how similar they were to originally studied pairs. Across 2 experiments, we found that verbatim memory for associations, measured using a multinomial-processing-tree model, improved from .75 to 1.5 to 4 seconds of presentation time. Paralleling these effects of encoding time on verbatim memory, for gist memory, there were improvements from .75 seconds to 1.5 seconds in both experiment 1 and 2, while improvements from 1.5 seconds to 4 seconds were only evident when the retention interval between study and test was increased (experiment 2). These results provide strong support for the parallel processing framework of fuzzy-trace theory over the slow gist extraction framework of an alternative gist macroprocessor theory. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

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.

Adult age differences in specific and gist associative episodic memory across short- and long-term retention intervals.

Age-related deficits in associative episodic memory have been widely reported, but recent research suggests that some of these deficits occur for highly specific but not gist representations. It remains undetermined whether older adults' deficits in specific associative episodic memory, observed in long-term memory, are also present in short-term memory. We used a continuous associative recognition task to address this question. Fifty young and 50 older adults studied face-scene pairs, with memory tests occurring in both short-term and long-term memory. Memory tests featured intact (old) pairs, related (similar) pairs, and unrelated (dissimilar) pairs. On short-term memory tests, older adults were less accurate in classifying related pairs, which was manifest by age-related reductions in the probability of retrieving specific memory to engage in recollection rejection. However, older adults were capable of remembering specific details in short-term memory for intact probes but were less likely to remember specific details in long-term memory. Finally, older adults were always as capable as younger adults of remembering gist details. Results suggest that older adults do at least partially encode specific representations in short-term memory, and their access to these specific representations is cue dependent-they can do so when there is a large correspondence between encoding and retrieval conditions but are less likely to engage in deeper elaboration at retrieval. This limits their ability to remember specific details of associations to suppress false recognitions in short-term memory and to engage in veridical recognition in long-term memory. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Greater sleep variance related to decrements in memory performance and event-specific neural similarity: a racially/ethnically diverse lifespan sample

Successful memory performance depends on overlap between neural representations at encoding and retrieval. With older age, neural similarity, memory performance, and sleep quality decline. Regardless of age, racial/ethnic minorities tend to experience poor sleep, which may contribute to poor memory. Previous studies have not investigated memory performance, neural similarity, sleep quality, and age in diverse participants. Here, we recruited racially/ethnically diverse adults across the lifespan and examined night-to-night sleep quality in relation to memory performance and encoding-retrieval similarity. We employed item-specific, representational similarity analysis (not confounded by effort, word perception, or differences in electroencephalography signal amplitude) to assess neural similarity for intact and recombined paired associates. Greater sleep variance and poorer memory performance were more strongly associated with older age. Interestingly, sleep variance was positively associated with neural similarity for intact pairs. This relationship was stronger with younger age and for racial/ethnic minorities. For recombined pairs, greater sleep variance was associated with reduced neural similarity. Thus, varied sleep may induce greater reliance on familiarity, while consistent sleep may support recollection.

Unitization congruence moderates the effect of unitization on associative recognition: evidence from event-related potentials

Recently, a growing number of studies have shown that familiarity can promote associative recognition when more than two types of stimuli are combined into a single entity. However, it is not clear why the effect of unitization on associative recognition varies in the different studies. In this study, we examined whether the unitization congruence (UC) between original image pairs and rearranged ones affects associative recognition. Participants were asked to learn relevant and irrelevant picture pairs for the encoding phase, and they needed to distinguish intact pairs from rearranged pairs for the retrieval phase, while event-related potentials (ERPs) were recorded during the whole process. The results of the behavioral experiments showed that the performances of recognition (Prs: hits-false alarms) were higher under the relevant condition than under the irrelevant one for both UC conditions, although this effect was much larger under the inconsistent UC condition than under the consistent one. The ERP results also revealed that there were larger early old/new effect (FN400) and late left parietal old/new effect (LPC) under the relevant condition than under the irrelevant ones, irrespective of its consistency or inconsistency. However, these effects were more significant for inconsistent conditions. These results indicated that UC can moderate the effect of unitization on associative recognition by increasing familiarity and recollection and revealed the need to match the level of unitization of materials arrangements in future studies.

Surgical sterilization impacts on behavior of coyote pairs

Coyotes (Canis latrans) involved in depredation of livestock, an act frequently resulting in human-wildlife conflict, often do so out of necessity for provisioning pups. Surgical sterilization methods such as vasectomy that preserve gonadal hormones have been successful in reducing depredation by free-ranging coyotes while allowing individuals to maintain territoriality and mate fidelity. However, use of these methods remain costly and ineffective for wide-scale use. Given the alternative proposal of using chemical sterilization techniques, we investigated whether the use of hormone-altering sterilization methods impacted behavior of captive coyote pairs (i.e., male-female pair bonds). Our objective was to evaluate behavior and reproductive hormones of mated coyote pairs that had received different surgical sterilization treatments. We assigned mated pairs of captive coyotes to different sterilization treatment groups (vasectomy, spay, neuter, ovary-sparing spay, and intact) and coded their behavior as the time spent in resting versus active (i.e., walking, running, scent communication, and aggressive interactions) behaviors. Additionally, hormone concentrations were analyzed to determine effectiveness of hormone-altering treatment, given the potential role of gonadal hormones in regulating behavior. The study was repeated across three breeding seasons. The top model comparing time spent active versus resting was the null model, although the model that included whether sterilization type altered hormones and year also had a ΔAIC of < 2.0. Testosterone concentrations between neutered and vasectomized or intact males was significantly different, indicating sterilization treatment was successful and the different sterilization techniques impact hormones differently; there were no statistical difference for estradiol or progesterone levels among female treatment groups. No sterilized pairs produced pups, but the intact pairs did. Although there are potentially some differences in behavior across sterilization treatment types, our results suggest sterilization of coyotes holds potential as a future management strategy as behavior did not differ among different treatments. Potential difference across years suggest further research is necessary to determine potential extraneous factors influencing behavior and the effect of treatment on territoriality on free-ranging coyotes.

Evaluating the Contribution of Emotional Valence to Associative Memory: Retrieval Practice Matters

Research has indicated that emotional valence can influence associative memory, but it is less clear whether it still works when the retrieval practice is controlled. The current study combined an associative recognition task with a paradigm of retrieval practice, with negative, neutral, and positive word pairs serving as stimuli. Results revealed that intact pairs possessed higher correct response proportions than rearranged, old+new, and new pairs; the rearranged pairs were more likely to be classified as intact; a negative impairment effect was observed in both learning conditions; the retrieval practice effect was sensitive to the interaction of emotional valence by pair type. We shows that the involvement of the recollection-driven process varies with pair type, providing telling evidence for the dual-process models; the occurrence of negative impairment effect conforms to the account of spontaneous interactive imagery; the contribution of desirable difficulty framework is modulated by the interaction of emotional valence by pair type.

Identification of RAG-like transposons in protostomes suggests their ancient bilaterian origin

BackgroundV(D) J recombination is essential for adaptive immunity in jawed vertebrates and is initiated by the RAG1-RAG2 endonuclease. The RAG1 and RAG2 genes are thought to have evolved from a RAGL (RAG-like) transposon containing convergently-oriented RAG1-like (RAG1L) and RAG2-like (RAG2L) genes. Elements resembling this presumptive evolutionary precursor have thus far only been detected convincingly in deuterostomes, leading to the model that the RAGL transposon first appeared in an early deuterostome.ResultsWe have identified numerous RAGL transposons in the genomes of protostomes, including oysters and mussels (phylum Mollusca) and a ribbon worm (phylum Nemertea), and in the genomes of several cnidarians. Phylogenetic analyses are consistent with vertical evolution of RAGL transposons within the Bilateria clade and with its presence in the bilaterian ancestor. Many of the RAGL transposons identified in protostomes are intact elements containing convergently oriented RAG1L and RAG2L genes flanked by terminal inverted repeats (TIRs) and target site duplications with striking similarities with the corresponding elements in deuterostomes. In addition, protostome genomes contain numerous intact RAG1L-RAG2L adjacent gene pairs that lack detectable flanking TIRs. Domains and critical active site and structural amino acids needed for endonuclease and transposase activity are present and conserved in many of the predicted RAG1L and RAG2L proteins encoded in protostome genomes.ConclusionsActive RAGL transposons were present in multiple protostome lineages and many were likely transmitted vertically during protostome evolution. It appears that RAGL transposons were broadly active during bilaterian evolution, undergoing multiple duplication and loss/fossilization events, with the RAGL genes that persist in present day protostomes perhaps constituting both active RAGL transposons and domesticated RAGL genes. Our findings raise the possibility that the RAGL transposon arose earlier in evolution than previously thought, either in an early bilaterian or prior to the divergence of bilaterians and non-bilaterians, and alter our understanding of the evolutionary history of this important group of transposons.

Under the condition of unitization at encoding rather than unitization at retrieval, familiarity could support associative recognition and the relationship between unitization and recollection was moderated by unitization-congruence.

It is widely accepted that associative recognition can be supported by familiarity through integrating more than two stimuli into a unit, but there are still three unsolved questions: (1) how unitization affects recollection-based associative recognition; (2) whether it is necessary to match the level of unitization (LOU) between original and rearranged pairs, which was term as unitization-congruence (UC); (3) whether unitization can occur at encoding or at retrieval. The purposes of this study are to try to answer these questions. During the encoding phase, the participants were asked to learn compound words and unrelated word pairs, and during the retrieval phase, they needed to distinguish intact pairs from rearranged consistent and rearranged inconsistent pairs with “remember/know” paradigm. The results showed that (1) the role of unitization in recollection was moderated by UC; (2) Under the consistent UC condition, unitization could improve familiarity-based associative recognition without affecting recollection-based associative recognition, while under the inconsistent UC condition, unitization could improve familiarity-based and recollection-based associative recognition simultaneously, these results indicated that it was necessary to match the LOU between original and rearranged pairs; (3) unitization at encoding could support familiarity-based associative recognition, while unitization at retrieval did not. In briefly, unitization at encoding could improve associative recognition and this effect was moderated by UC, while unitization at retrieval did not affect associative recognition.

The effect of unitization on associative recognition was not moderated by the unitization-congruence between original and rearranged picture pairs (UC) for picture stimuli.

It is widely accepted that associative recognition can be supported by familiarity through integrating more than two stimuli into a unit, but the role of unitization in recollection-based associative recognition remains unclear. In this study, we aimed to illustrate how the level of unitization (LOU) affected recollection-based associative recognition and to examine whether the unitization-congruence between original and rearranged picture pairs (UC) could have effect on the relationship between LOU and associative recognition. In encoding, participants were asked to learn related and unrelated picture pairs, and in retrieval, they needed to distinguish intact pairs from rearranged pairs. We also distinguished the LOU of the pairs based on its status at encoding or retrieval separately. The results showed that: (1) LOU-at-encoding could improve associative recognition through increasing recollection-based associative recognition selectively; (2) LOU-at-retrieval could improve associative recognition through increasing familiarity-based and recollection-based associative recognitions; (3) UC did not moderate the relationship between LOU and associative recognition. Hence, in future studies, researchers do not need to pay much attention to the construction of rearranged pairs to ensure that the LOU between original and rearranged picture pairs is matched. It greatly reduces the difficulty of materials selection.

Neural evidence for age-related differences in representational quality and strategic retrieval processes

Mounting behavioral evidence suggests that declines in both representational quality and controlled retrieval processes contribute to episodic memory decline with age. The present study sought neural evidence for age-related change in these factors by measuring neural differentiation during encoding of paired associates and changes in regional blood oxygenation level–dependent activity and functional connectivity during retrieval conditions that placed low (intact pairs) and high (recombined pairs) demands on controlled retrieval processes. Pattern similarity analysis revealed age-related declines in the differentiation of stimulus representations at encoding, manifesting as both reduced pattern similarity between closely related events and increased pattern similarity between distinct events. During retrieval, both groups increased recruitment of areas within the core recollection network when endorsing studied pairs, including the hippocampus and angular gyrus. In contrast, only younger adults increased recruitment of, and hippocampal connectivity with, lateral prefrontal regions during correct rejections of recombined pairs. These results provide evidence for age-related changes in representational quality and in the neural mechanisms supporting memory retrieval under conditions of high, but not low, control demand.

The benefit of generating errors during learning: What is the locus of the effect?

Guessing translations of foreign words (hodei?), before viewing corrective feedback (hodei-cloud), leads to better subsequent memory for correct translations than studying intact pairs (hodei-cloud), even when guesses are always incorrect (Potts & Shanks, 2014), but the mechanism underlying this effect is unknown. Possible explanations fall into two broad classes. One puts the locus of the effect at retrieval: Items studied through a generation process have more potential retrieval cues associated with them, or a more distinctive context, and are therefore more accessible at final test. The other puts the locus at encoding and involves enhanced encoding of the correct answer following the generation of an error compared with passive studying (Potts & Shanks, 2014). In 6 experiments we found support for the proposal that generating errors benefits memory through stimulating curiosity to learn correct answers following an incorrect guess, leading to enhanced processing of targets following generation. In Experiment 1, generating possible translations after seeing correct answers did not produce better memory than studying without generating, suggesting that an element of surprise or anticipation is necessary for generating to benefit memory. Experiments 2a-2c found enhanced recognition memory for targets following generating, suggesting increased focus on targets following a guess. In Experiments 3 and 4, participants rated their curiosity to learn correct answers higher when ratings were given after generating than before, suggesting that the act of generation increases curiosity to learn the answers. These findings imply that enhanced processing of feedback is a key consequence of errorful generation. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Age-related differences in recognition in associative memory

ABSTRACTAging 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.

Transcranial magnetic stimulation of the left angular gyrus during encoding does not impair associative memory performance

ABSTRACTThe left angular gyrus (AG) is thought to play a critical role in episodic retrieval and has been implicated in the recollection of specific details of prior episodes. Motivated by recent fMRI studies in which it was reported that elevated neural activity in left AG during study is predictive of subsequent associative memory, the present study investigated whether the region plays a causal role in associative memory encoding. Participants underwent online transcranial magnetic stimulation (TMS) while encoding word pairs prior to an associative memory test. We predicted that TMS to left AG during encoding would result in reduced subsequent memory accuracy, especially for estimates of recollection. The results did not support this prediction: estimates of both recollection and familiarity-driven recognition were essentially identical for words pairs encoded during TMS to left AG relative to a vertex control site. These results suggest that the left AG may not play a necessary role in associative memory encoding. TMS to left AG did however affect confidence for incorrect ‘intact’ judgments to rearranged pairs and incorrect ‘rearranged’ judgments to intact pairs. These findings suggest that the left AG supports encoding processes that contribute to aspects of subjective mnemonic experience.

Visual integration enhances associative memory equally for young and older adults without reducing hippocampal encoding activation

The ability to remember associations between previously unrelated pieces of information is often impaired in older adults (Naveh-Benjamin, 2000). Unitization, the process of creating a perceptually or semantically integrated representation that includes both items in an associative pair, attenuates age-related associative deficits (Bastin et al., 2013; Ahmad et al., 2015; Zheng et al., 2015). Compared to non-unitized pairs, unitized pairs may rely less on hippocampally-mediated binding associated with recollection, and more on familiarity-based processes mediated by perirhinal cortex (PRC) and parahippocampal cortex (PHC). While unitization of verbal materials improves associative memory in older adults, less is known about the impact of visual integration. The present study determined whether visual integration improves associative memory in older adults by minimizing the need for hippocampal (HC) recruitment and shifting encoding to non-hippocampal medial temporal structures, such as the PRC and PHC. Young and older adults were presented with a series of objects paired with naturalistic scenes while undergoing fMRI scanning, and were later given an associative memory test. Visual integration was varied by presenting the object either next to the scene (Separated condition) or visually integrated within the scene (Combined condition). Visual integration improved associative memory among young and older adults to a similar degree by increasing the hit rate for intact pairs, but without increasing false alarms for recombined pairs, suggesting enhanced recollection rather than increased reliance on familiarity. Also contrary to expectations, visual integration resulted in increased hippocampal activation in both age groups, along with increases in PRC and PHC activation. Activation in all three MTL regions predicted discrimination performance during the Separated condition in young adults, while only a marginal relationship between PRC activation and performance was observed during the Combined condition. Older adults showed less overall activation in MTL regions compared to young adults, and associative memory performance was most strongly predicted by prefrontal, rather than MTL, activation. We suggest that visual integration benefits both young and older adults similarly, and provides a special case of unitization that may be mediated by recollective, rather than familiarity-based encoding processes.

The relational luring effect: Retrieval of relational information during associative recognition.

Here we argue that semantic relations (e.g., works in: nurse-hospital) have abstract independent representations in long-term memory (LTM) and that the same representation is accessed by all exemplars of a specific relation. We present evidence from 2 associative recognition experiments that uncovered a novel relational luring effect (RLE) in recognition memory. Participants studied word pairs, and then discriminated between intact (old) pairs and recombined lures. In the first experiment participants responded more slowly to lures that were relationally similar (table-cloth) to studied pairs (floor-carpet), in contrast to relationally dissimilar lures (pipe-water). Experiment 2 extended the RLE by showing a continuous effect of relational lure strength on recognition times (RTs), false alarms, and hits. It used a continuous pair recognition task, where each recombined lure or target could be preceded by 0, 1, 2, 3 or 4 different exemplars of the same relation. RTs and false alarms increased linearly with the number of different previously seen relationally similar pairs. Moreover, more typical exemplars of a given relation lead to a stronger RLE. Finally, hits for intact pairs also rose with the number of previously studied different relational instances. These results suggest that semantic relations exist as independent representations in LTM and that during associative recognition these representations can be a spurious source of familiarity. We discuss the implications of the RLE for current models of semantic and episodic memory, unitization in associative recognition, analogical reasoning and retrieval, as well as constructive memory research. (PsycINFO Database Record

Effects of repetition on age differences in associative recognition

ABSTRACTThe 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.

Change in Depression Symptomatology and Cognitive Function in Twins: A 10-Year Follow-Up Study.

A complex interrelation exists between change in depression symptomatology and cognitive decline. Studies indicate either that depression is a direct risk factor for cognitive change over time, or vice versa. Longitudinal twin studies provide the possibility to unravel cause and effect of correlated traits. Here, we have applied twin modeling approaches to shed light on the genetic correlation between both level and change of depression symptomatology and cognitive functioning, and to further explore the bidirectionality of any such correlation using assessments of both phenotypes at two occasions 10 years apart. The study included 2,866 Danish twins with a mean age of 56.8 years at intake (range: 45-68 years). Of these, 1,267 were intact pairs. A total number of 1,582 twins (55%), of whom 557 were intact pairs, participated in the follow-up survey. We found stable cross-sectional heritability estimates of approximately 60% for general cognitive abilities and 30% for affective depressive symptoms. There was a considerable decline in the mean cognitive performance over 10 years, whereas the mean affective depression symptoms score was stable and with no genetic contribution to any individual change. Additionally, we saw a small but significant cross-trait correlation at both occasions (-0.11 and -0.09, respectively), but cross-trait cross-occasion analysis revealed no evidence that either of the two traits predicts the other over a 10-year interval. Thus, our study was not able to detect any causal association between change in depressive symptomatology and cognitive decline in middle-aged and elderly people over a 10-year interval.