Idiom literality judgments in younger and older adults: age-related effects in resolving semantic interference

To study age effects in the resolution of idiomatic semantic ambiguity, we focus on decomposability, the extent to which a literal reading of an idiom's words shares meaning with its figurative interpretation. Younger and older adults judged whether decomposable and nondecomposable idioms and nonidioms had a literal interpretation. Older adults were slower at making literality judgments and more sensitive to conflicts between literal and figurative meanings. The results support claims of decompositional analysis of idioms during later processing stages and of obligatory activation of figurative meanings. They also lend support to research that has shown age-related effects in ambiguity resolution.     

When working memory updating requires updating: Analysis of serial position in a running memory task

This study aimed to investigate updating in working memory (WM), analyzing the effects of task demand and memory resources on serial position curve (SPC), in a running memory task with slow pace presentation and a probed recognition procedure. These task conditions were supposed to produce an easier WM updating task, which may allow evidencing whether the task is performed through an active or a passive updating.     

A comparison of visual working memory and episodic memory performance in younger and older adults

Working memory and episodic memory decline with age. However, as they are typically studied separately, it is largely unknown whether age-associated differences are similar. A task design was developed in which visual working memory and episodic memory performances were measured using the same stimuli, with both tasks involving context binding. A 2-back working memory task was followed by a surprise subsequent recognition memory task that assessed incidental encoding of object locations of the 2-back task. The study compared performance of younger (N=30; M_age=23.5, SD_age=2.9, range=20-29) and older adults (N=29; M_age=72.1, SD_age=6.8, range=62-90). Older adults performed worse than younger adults, without an interaction effect. In younger, but not in older adults, performance on the two tasks was related. We conclude that although age differences (Young>Older) are similar in the working memory and incidental associative memory tasks, the relationship between the two memory systems differs as a function of age group.     

Directed forgetting in working memory: age-related differences

This study explored the effects of ageing on working memory by means of the directed forgetting procedure designed by Reed (1970). Memory for a letter trigram was compared in conditions where it was either presented alone (single-item), or followed by a second trigram to be recalled (interference), or followed by a second trigram to be forgotten (directed forgetting). The results clearly indicated that elderly participants inhibited the no-longer-relevant information less efficiently (recall in the single-item condition - recall in the directed forgetting condition), as predicted by the model of Hasher and Zacks (1988). However, the results also demonstrated that sensitivity to interference (recall in the single-item condition - recall in the interference condition) increased in the condition in which no inhibition was directly required.     

Improving visual spatial working memory in younger and older adults: effects of cross-modal cues

Spatially informative auditory and vibrotactile (cross-modal) cues can facilitate attention but little is known about how similar cues influence visual spatial working memory (WM) across the adult lifespan. We investigated the effects of cues (spatially informative or alerting pre-cues vs. no cues), cue modality (auditory vs. vibrotactile vs. visual), memory array size (four vs. six items), and maintenance delay (900 vs. 1800 ms) on visual spatial location WM recognition accuracy in younger adults (YA) and older adults (OA). We observed a significant interaction between spatially informative pre-cue type, array size, and delay. OA and YA benefitted equally from spatially informative pre-cues, suggesting that attentional orienting prior to WM encoding, regardless of cue modality, is preserved with age. Contrary to predictions, alerting pre-cues generally impaired performance in both age groups, suggesting that maintaining a vigilant state of arousal by facilitating the alerting attention system does not help visual spatial location WM.     

The roles of working memory updating and processing speed in mediating age-related differences in fluid intelligence

This study was conducted to investigate the relative roles of working memory updating (updating) and processing speed in mediating age-related differences in fluid intelligence. A sample of 142 normal adults between 18 and 85 years of age performed a set of updating, processing speed, and fluid intelligence tasks. Hierarchical regression analyses indicated that the proportion of unique age-related variance in updating measures was related to the complexity of speed measures. There was a larger proportion of unique age-related variance in updating measures after controlling for the variance in simpler speed measures. Moreover, structural equation modeling showed that updating mediated almost all the age-related effects on fluid intelligence. These results suggest that updating, but not speed, is the critical mediator between age and fluid intelligence. In addition, the speed mediation of age-related differences in fluid intelligence as indicated by previous studies is at least partially derived from the executive component of speed measures.     

Age differences in working memory updating: The role of interference,focus switching and substituting information

Working memory updating (WMU) tasks require different elements in working memory (WM) to be maintained simultaneously, accessing one of these elements, and substituting its content. This study examined possible developmental changes from childhood to adulthood both in focus switching and substituting information in WM. In addition, possible age-related changes in interference due to representational overlap between the different elements simultaneously held in these tasks were examined. Children (8- and 11-year-olds), adolescents (14-year-olds) and younger adults (mean age = 22 years) were administered a numerical updating memory task, in which updating and focus switching were manipulated. As expected, response times decreased and recall performance increased with age. More importantly, the time needed for focus switching was longer in children than in adolescents and younger adults. On the other hand, substitution of information and interference due to representational overlap were not affected by age. These results suggest that age-related changes in focus switching might mediate developmental changes in WMU performance.     

Spatial updating of multiple targets: Comparison of younger and older adults

When walking without vision, people mentally keep track of the directions and distances of previously viewed objects, a process called spatial updating. The current experiment indicates that while people across a large age range are able to update multiple targets in memory without perceptual support, aging negatively affects accuracy, precision, and decision time. Participants (20 to 80 years of age) viewed one, three, or six targets (colored lights) on the floor of a dimly lit room. Then, without vision, they walked to a target designated by color, either directly or indirectly (via a forward turning point). The younger adults’ final stopping points were both accurate (near target) and precise (narrowly dispersed), but updating performance did degrade slightly with the number of targets. Older adults’ performance was consistently worse than the younger group, but the lack of interaction between age and memory load indicates that the effect of age on performance was not further exacerbated by a greater number of targets. The number of targets also significantly increased the latency required to turn toward the designated target for both age groups. Taken together, results extend previous work showing impressive updating performance by younger adults, with novel findings showing that older adults manifest small but consistent degradation of updating performance of multitarget arrays.     

The focus of attention in working memory: evidence from a word updating task

Three experiments examined the cognitive costs of item switching within working memory with a novel word updating task, thereby extending previous research to the field of linguistic stimuli and linguistic-graphemic updating operations. In Experiments 1 and 2 costs for switching between working memory items were evident on the word level, and they increased with an increasing word set size (Experiment 2). In contrast, a surprisingly similar switch effect on the level of letters was not affected by word set size (Experiment 2). Experiment 3 showed that this effect is not simply based on the need for re-orienting visual spatial attention. To account for the overall picture of results, a recursive model of attentional foci is proposed. Moreover, individual working memory span appears to be associated with the accuracy of item switching, but not with its speed.     

The focus of attention in working memory: Evidence from a word updating task

Three experiments examined the cognitive costs of item switching within working memory with a novel word updating task, thereby extending previous research to the field of linguistic stimuli and linguistic-graphemic updating operations. In Experiments 1 and 2 costs for switching between working memory items were evident on the word level, and they increased with an increasing word set size (Experiment 2). In contrast, a surprisingly similar switch effect on the level of letters was not affected by word set size (Experiment 2). Experiment 3 showed that this effect is not simply based on the need for re-orienting visual spatial attention. To account for the overall picture of results, a recursive model of attentional foci is proposed. Moreover, individual working memory span appears to be associated with the accuracy of item switching, but not with its speed.     

Causal attributions and strategy use in relation to memory performance differences in younger and older adults

A metacognitive hypothesis to explain age differences in adult memory is explored here–that younger and older adults differ in beliefs about memory and strategic processing. The motivational beliefs that adults make for their own memory performances were examined across tests of recall, recognition, face–name learning, and appointment-keeping. Forty-eight older and 48 younger community-living adults were required to report the factors they believed influenced their performance and the memory strategies used for each task. A final questionnaire required subjects to rank order the importance of a list of causal factors. There were significantly more younger adults as compared to older adults who attributed performance to controllable factors (i.e. strategy use), although age differences in beliefs on a more familiar memory task were smaller than on other tasks. Moreover, within age groups, attributions to controllable factors were associated with increased memory performance compared to when memory was attributed to uncontrollable factors (i.e. ability, age). Believing that memory is uncontrollable may undermine the efficient use of effort in cognition, consistent with current metacognitive theory.     

Age-related differences in strategy knowledge updating: blocked testing produces greater improvements in metacognitive accuracy for younger than older adults

Age-related differences in updating knowledge about strategy effectiveness after task experience have not been consistently found, perhaps because the magnitude of observed knowledge updating has been rather meager for both age groups. We examined whether creating homogeneous blocks of recall tests based on two strategies used at encoding (imagery and repetition) would enhance people's learning about strategy effects on recall. Younger and older adults demonstrated greater knowledge updating (as measured by questionnaire ratings of strategy effectiveness and by global judgments of performance) with blocked (versus random) testing. The benefit of blocked testing for absolute accuracy of global predictions was smaller for older than younger adults. However, individual differences in correlations of strategy effectiveness ratings and postdictions showed similar upgrades for both age groups. Older adults learn about imagery's superior effectiveness but do not accurately estimate the magnitude of its benefit, even after blocked testing.     

Time-of-day affects prospective memory differently in younger and older adults

The goal of this study was to investigate the impact of circadian arousal on prospective memory performance as a function of age. We tested a younger (18–34 years) and an older group (56–95 years) of participants on- and off-peak with regard to their circadian arousal patterns in a computer-based laboratory experiment. For the prospective memory task, participants had to press a particular key whenever specific target words appeared in an ongoing concreteness-judgment task. The results showed that prospective memory performance was better on- than off-peak in younger but not older participants. Younger participants consistently outperformed older participants in all conditions. We conclude that prospective remembering underlies time-of-day effects which most likely reflect controlled processes.     

Mechanisms of autobiographical memory retrieval in younger and older adults

In this study, retrieval of autobiographical memories was compared within or without the context of a lifetime period and between younger and older adults. The results of two experiments demonstrated that memories were more accessible for younger and older adults when they were retrieved within a time period context than without such context. However, when the retrieval context was more constrained and limited to cue word memories, the benefit of retrieval context disappeared. The results also suggested that as compared with younger adults, older adults were more likely to selectively retain memories with distinctive characteristics, such as being self-relevant and emotionally intense, particularly when remote memories were involved. Mechanisms of autobiographical memory retrieval in younger and older adults.     

Goals-feedback conditions and episodic memory: Mechanisms for memory gains in older and younger adults

Research has established that challenging memory goals always lead to score increases for younger adults, and can increase older adults' scores under supportive conditions. This study examined beliefs and on-task effort as potential mechanisms for these self-regulatory gains, in particular to learn whether episodic memory gains across multiple trials of shopping list recall are controlled by the same factors for young and old people. Goals with feedback led to higher recall and strategic categorisation than a control condition. Strategy usage was the strongest predictor of gains over trials for both age groups. Age, goal condition, and effort also predicted scores across the entire sample. Older adults' gains, but not younger adults' gains, were affected significantly by the interaction of self-efficacy beliefs and goal condition, and condition interacted with locus of control to predict younger adult gains. These results emphasise the importance of self-regulatory effort and positive beliefs for facilitating goal-related memory gains.     

Divided attention in younger and older adults: effects of strategy and relatedness on memory performance and secondary task costs

Divided attention at encoding leads to a significant decline in memory performance, whereas divided attention during retrieval has relatively little effect; nevertheless, retrieval carries significant secondary task costs, especially for older adults. The authors further investigated the effects of divided attention in younger and older adults by using a cued-recall task and by measuring retrieval accuracy, retrieval latency, and the temporal distribution of attentional costs at encoding and retrieval. An age-related memory deficit was reduced by pair relatedness, whereas strategy instructions benefited both age groups equally. Attentional costs were greater for retrieval than for encoding, especially for older adults. These findings are interpreted in light of notions of an age-related associative deficit (M. Naveh-Benjamin, 2000) and age-related differences in the use of self-initiated activities and environmental support (F. I. M. Craik, 1983, 1986).     

Verbal and pictorial elaborations enhance memory in younger and older adults

Abstract

These studies examined the facilitative role of verbal and pictorial elaborations in younger and older adults' recall of verbal material. During acquisition, subjects studied short sentences under one of several encoding/retrieval conditions where the presence of verbal and pictorial elaborations was systematically varied. Subjects later recalled the target adjectives, given the sentence frames as a prompt. In Experiment 1, explanatory verbal elaborations at study and test enhanced verbal recall for both age groups, but no benefit of pictorial elaborations was observed. In Experiment 2, pictorial elaborations improved recall for both age groups. A significant Age x Encoding Condition interaction effect revealed that the benefit was especially pronounced for the older adults. the implications of these results for understanding the facilitative effects of pictorial illustrations on older adults. recall of verbal material are discussed.     

Self-initiated spatial working memory in young and older adults

The age-related decline in working memory (WM) has been studied extensively. Yet, research has focused mainly on one aspect of memory, in which older adults memorised information provided to them, neglecting the frequent everyday behaviour in which memory is self-initiated (SI), meaning that individuals memorise information they selected themselves. The present study used a modified spatial span task in which young and older adults memorised spatial sequences they constructed themselves, or random sequences provided to them. The results revealed that young and older adults carefully planned and constructed structured spatial sequences, by minimising distances between successive locations, and by selecting sequences with fewer path crossings and with more linear shapes. Older adults constructed sequences that were even more structured in some aspects. Young and older adults benefited from self-initiation to the same extent, showing similar age-related declines in SI and provided spatial WM. Overall, the study shows that older adults have access to metacognitive knowledge on the structure of efficient WM representations that benefit accuracy, and shows that older adults can use strategic encoding processes efficiently when encoding is SI. More generally, SI WM explores an important aspect of behaviour, demonstrating how older adults shape their environment to facilitate cognitive functioning.     

Visual feature binding in younger and older adults: encoding and suffix interference effects

Three experiments investigated younger (18–25 yrs) and older (70–88 yrs) adults’ temporary memory for colour–shape combinations (binding). We focused upon estimating the magnitude of the binding cost for each age group across encoding time (Experiment 1; 900/1500?ms), presentation format (Experiment 2; simultaneous/sequential), and interference (Experiment 3; control/suffix) conditions. In Experiment 1, encoding time did not differentially influence binding in the two age groups. In Experiment 2, younger adults exhibited poorer binding performance with sequential relative to simultaneous presentation, and serial position analyses highlighted a particular age-related difficulty remembering the middle item of a series (for all memory conditions). Experiments 1–3 demonstrated small to medium binding effect sizes in older adults across all encoding conditions, with binding less accurate than shape memory. However, younger adults also displayed negative effects of binding (small to large) in two of the experiments. Even when older adults exhibited a greater suffix interference effect in Experiment 3, this was for all memory types, not just binding. We therefore conclude that there is no consistent evidence for a visual binding deficit in healthy older adults. This relative preservation contrasts with the specific and substantial deficits in visual feature binding found in several recent studies of Alzheimer's disease.