Age differences in response selection for pure and mixed stimulus-response mappings and tasks

Two experiments examined effects of mixed stimulus-response mappings and tasks for older and younger adults. In Experiment 1, participants performed two-choice spatial reaction tasks with blocks of pure and mixed compatible and incompatible mappings. In Experiment 2, a compatible or incompatible mapping was mixed with a Simon task for which the mapping of stimulus color to location was relevant and stimulus location was irrelevant. In both experiments, older adults showed larger mixing costs than younger adults and larger compatibility effects, with the differences particularly pronounced in Experiment 1 when location mappings were mixed. In mixed conditions, when stimulus location was relevant, older adults benefited more than younger adults from complete repetition of the task and stimulus from the preceding trial. When stimulus location was irrelevant, the benefit of complete repetition did not differ reliably between age groups. The results suggest that the age-related deficit associated with mixing mappings and tasks is primarily due to older adults having more difficulty separating task sets that activate conflicting response codes.     

Adult Age Differences in Divided Attention: Effects of Elaboration During Memory Encoding

The present study used attention operating characteristics (AOCs) to examine whether age differences existed in divided attention (DA) performance when both primary (cued recall) and secondary tasks (letter recall) were analyzed simultaneously. Additionally, to determine if age differences in DA might depend on the amount of elaborative processing required at study, participants either read (low elaboration) or generated (high elaboration) target words. AOC analyses indicated that performance was disrupted most when attention was divided at encoding versus retrieval, and dividing attention had a greater negative impact on older adults’ performance relative to younger adults’. Furthermore, the high elaboration condition was less affected by DA than the low elaboration condition for both age groups. The results indicate that although the ability to divide attention declines with age, some elaborative study strategies may be more resistant to DA effects for both younger and older adults.     

Adult Age Differences in the Access and Deletion Functions of Inhibition

ABSTRACT

This study examined age differences in working memory using a delayed-matching-to-sample (DMTS) task. Based on the inhibitory decline hypothesis, which posits that older adults are more susceptible to interference, age differences were expected to be greater for older adults when irrelevant information was present during encoding. Two experiments tested both the access and deletion functions of inhibition. In both experiments, performance was equated for older and younger participants on a no-interference version of the DMTS task to control for age differences in encoding information into working memory. Results consistently showed equivalent effects of distraction for older and younger adults regardless of the difficulty of the perceptual discrimination of targets and distractors, the degree of processing of the distractors, or the semantic relationship between targets and distractors. These results support theories that propose age differences in encoding to explain age differences in working memory, and are inconsistent with theories that propose that older adults are more susceptible to interference than younger adults.     

A quantitative model-based approach to examining aging effects on information-integration category learning

Information-integration category learning was examined in older and younger adults. Accuracy results indicated that older participants learned less well than younger participants in both linear and nonlinear conditions. Model-based analyses indicated that both groups in the linear condition tended to use information integration but that later in training younger participants were more likely to do so. In contrast, the 2 groups in the nonlinear condition were equally likely to use information integration. Further analysis indicated that younger adults were more accurate than older adults when an information-integration approach was adopted, whereas fewer age-related differences were observed when a rule-based approach was used, suggesting that age can have a negative impact on information-integration category learning processes but less impact on rule-based learning.     

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).     

The effects of presentation rate and retention interval on memory for items and associations in younger adults: A simulation of older adults’ associative memory deficit

Older adults show an associative deficit in episodic memory compared to younger adults. Previous research suggests both strategic and automatic binding deficits contribute to older adults’ poorer memory performance. Using behavioral manipulations designed to affect strategic and automatic binding of associations, three experiments attempted to simulate an associative deficit in younger adults. In these experiments participants learned face-scene pairs and then were given item and associative recognition memory tests. We manipulated the time allotted at encoding and retrieval to simulate strategic deficits, and the length of the retention interval to simulate automatic deficits. Results indicate that both manipulations separately contribute to a differential decline in associative memory, similar to the one shown by older adults, especially as reflected in the differential increase in false alarm rate in the associative memory test more than in the item memory test. Considerations of possible underlying brain mechanisms are discussed.     

Success and failure at dual-task coordination by younger and older adults

Dual-task processing was explored in younger and older adults in 2 experiments that used a tone discrimination and a letter discrimination task. To encourage parallel processing if that was possible, the authors presented the stimuli for the 2 tasks simultaneously, and participants were instructed to withhold their responses until both were ready. The authors found no evidence for parallel processing and no evidence that the management of central processing of dual tasks is qualitatively different in older adults than it is in younger adults. When one response was verbal and the other manual, the 2 responses closely coincided. When both responses were manual, the authors did find that the first response was not delayed enough to coincide with the 2nd and that this underestimation was greater in older adults.     

Age-related differences in visual search in dynamic displays

The authors examined the ability of younger and older adults to detect changes in dynamic displays. Older and younger adults viewed displays containing numerous moving objects and were asked to respond when a new object was added to the display. Accuracy, response times, and eye movements were recorded. For both younger and older participants, the number of eye movements accounted for a large proportion of variance in transient detection performance. Participants who actively searched for the change performed significantly worse than did participants who employed a passive or covert scan strategy, indicating that passive scanning may be a beneficial strategy in certain dynamic environments. The cost of an active scan strategy was especially high for older participants in terms of both accuracy and response times. However, older adults who employed a passive or covert scan strategy showed greater improvement, relative to older active searchers, than did younger adults. These results highlight the importance of individual differences in scanning strategy in real-world dynamic, cluttered environments.     

Heterogeneity in memory training improvement among older adults: A latent class analysis

This study investigated the extent to which older adults' associative memory functioning can be modified through instruction and practice based on individuals' memory status. Here 42 younger adults and 42 older adults performed four tasks that measured strategic and binding aspects of memory. With latent class analysis, two classes of older adults were identified. The first class showed higher memory functioning similar to younger adults, while the second class was characterised by lower memory functioning. A subsequent analysis examined whether the high- and low-performing older adults differ in patterns of gain from receiving instruction and practice on a mnemonic strategy. The results revealed that high-performing older adults, similar to younger adults, showed higher associative memory performance under explicit intentional encoding instruction and after extensive practice of the strategy. In contrast, low-performing older adults benefited more from directed instruction of the strategy. The results are discussed in relation to individual differences in the functional status of mechanisms underlying memory functioning, and how these differences may lead to compensation or magnification of training gain. The present findings highlight the importance of considering differential memory processes to develop specific training paradigms that target the processes that show the most prominent decline.     

Age-related differences in timing with breaks

Two groups of participants differing in age were compared on a time production task during which timing was temporarily interrupted. Produced intervals lengthened with increasing delay before the break occurrence, and the effect was more pronounced in older than in younger adults. A reaction time response to the signal beginning the break period was required also. Older participants responded more slowly to this signal, but they benefited to a greater extent from a lengthening of the time preceding its presentation. These results suggest that performance of older participants is affected by attention sharing and preparation involved in timing with breaks.     

Item-specific processing reduces false recognition in older and younger adults: Separating encoding and retrieval using signal detection and the diffusion model

Our study examined processing effects in improving memory accuracy in older and younger adults. Specifically, we evaluated the effectiveness of item-specific and relational processing instructions relative to a read-only control task on correct and false recognition in younger and older adults using a categorized-list paradigm. In both age groups, item-specific and relational processing improved correct recognition versus a read-only control task, and item-specific encoding decreased false recognition relative to both the relational and read-only groups. This pattern was found in older adults despite overall elevated rates of false recognition. We then applied signal-detection and diffusion-modeling analyses, which separately utilized recognition responses and the latencies to those responses to estimate contributions of encoding and monitoring processes on recognition decisions. Converging evidence from both analyses demonstrated that item-specific processing benefits to memory accuracy were due to improvements of both encoding (estimates of d′ and drift rate) and monitoring (estimates of lambda and boundary separation) processes, and, importantly, occurred similarly in both younger and older adults. Thus, older and younger adults showed similar encoding-based and test-based benefits of item-specific processing to enhance memory accuracy.     

Collaboration reduces the frequency of false memories in older and younger adults

Older (mean age = 74.23) and younger (mean age = 33.50) participants recalled items from 6 briefly exposed household scenes either alone or with their spouses. Collaborative recall was compared with the pooled, nonredundant recall of spouses remembering alone (nominal groups). The authors examined hits, self-generated false memories, and false memories produced by another person's (actually a computer program's) misleading recollections. Older adults reported fewer hits and more self-generated false memories than younger adults. Relative to nominal groups, older and younger collaborating groups reported fewer hits and fewer self-generated false memories. Collaboration also reduced older people's computer-initiated false memories. The memory conversations in the collaborative groups were analyzed for evidence that collaboration inhibits the production of errors and/or promotes quality control processes that detect and eliminate errors. Only older adults inhibited the production of wrong answers, but both age groups eliminated errors during their discussions. The partners played an important role in helping rememberers discard false memories in older and younger couples. The results support the use of collaboration to reduce false recall in both younger and older adults.     

Heterogeneity in memory training improvement among older adults: A latent class analysis

This study investigated the extent to which older adults' associative memory functioning can be modified through instruction and practice based on individuals' memory status. Here 42 younger adults and 42 older adults performed four tasks that measured strategic and binding aspects of memory. With latent class analysis, two classes of older adults were identified. The first class showed higher memory functioning similar to younger adults, while the second class was characterised by lower memory functioning. A subsequent analysis examined whether the high- and low-performing older adults differ in patterns of gain from receiving instruction and practice on a mnemonic strategy. The results revealed that high-performing older adults, similar to younger adults, showed higher associative memory performance under explicit intentional encoding instruction and after extensive practice of the strategy. In contrast, low-performing older adults benefited more from directed instruction of the strategy. The results are discussed in relation to individual differences in the functional status of mechanisms underlying memory functioning, and how these differences may lead to compensation or magnification of training gain. The present findings highlight the importance of considering differential memory processes to develop specific training paradigms that target the processes that show the most prominent decline.     

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

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

Memory for emotionally arousing stimuli: a comparison of younger and older adults

The authors compared emotional memory in younger (aged 18-32 years) and older (aged 59-84 years) adults. Previous researchers who investigated the emotionmemory relationship in younger adults consistently showed that emotional arousal enhances memory for central detail. The present authors' goal was to determine whether a similar effect could be found with older adults. Younger and older adults viewed a series of 12 slides, accompanied by a taped narrative, that showed emotionally arousing or neutral scenes in the middle phase (Slides 5-8). Participants then completed recognition tests that were scored for central detail, peripheral detail, and gist. The results indicated that, although younger adults showed higher performance than older adults did, both groups showed increased memory for central detail. In contrast, the authors found no such enhancement for peripheral detail or gist in either group. These results indicated that the arousal manipulation produced a similar effect on memory in younger and older adults. Furthermore, these results were consistent with the notion of poststimulus elaboration, which is the continued processing of central detail after the termination of an arousing event.     

Exploring the enactment effect from an information processing view: What can we learn from serial position analyses?

The focus of the present article was to analyze processes that determine the enactment and age effect in a multi-trial free recall paradigm by looking at the serial position effects. In an experimental study (see Schatz et al 2010), the performance-enhancing effect of enactive encoding and repeated learning was tested with older and younger participants. As expected, there was a steady improvement of memory performance as a function of repeated learning regardless of age. In addition, enactive encoding led to a better memory performance than verbal encoding in both age groups. Furthermore, younger adults outperformed the elderly regardless of type of encoding. Analyses in the present article show that encoding by enacting seems to profit especially from remembering the last items of a presented list. Regarding age differences, younger outperformed older participants in nearly all item positions. The performance enhancement after task repetition is due to a higher amount of recalled items in the middle positions in a subject performed task (SPT) and a verbal task (VT) as well as the last positions of a learned list in VT.     

Information selectivity in decision making by younger and older adults

Past research has demonstrated that older adults are more likely than younger adults to exhibit information selectivity in decision making. Two alternative explanations have been proposed to account for this age difference. One explanation attributes the increase in information selectivity to older adults' reliance on prior knowledge, whereas the other explanation suggests that it reflects reduced information processing capacity. The aim of this research was to explore the latter explanation by controlling for experiential factors and varying the cognitive demands involved in decision making. Specifically, participants were faced with unfamiliar decision problems, and had to base their decisions on the available information in order to reach a desired goal. In Experiment 1 younger and older participants were required to play a game involving chance. The outcome payoff was varied between three conditions (approach, avoidance, and control). The results indicated that both the younger and the older participants based their decisions on payoff, though the older participants did so to a lesser extent. In Experiment 2 younger and older participants performed a similar decision task but with higher cognitive demands. Specifically, the decision‐making task included two dimensions of information, outcome probability and outcome payoff. The results showed that the younger participants based their decisions on probability and payoff whereas the older participants based their decisions on probability alone. In Experiment 3 younger and older participants made decisions in a sale context and received instructional cue to incorporate payoff information in their decisions. As before, the younger participants utilized probability and payoff, whereas the older participants based their decisions only on probability information. The findings are discussed in terms of age differences in information‐processing capacity, metacognition, motivation, and goal‐setting.     

The effects of aging on selectivity and control in short-term recall

The ability to control encoding and retrieval processing strategically is critical for the efficient use of memory. We examined the ability of younger and older adults to selectively remember words on the basis of their arbitrary point values by using a technique developed by Watkins and Bloom (1999). In the first three experiments, younger subjects recalled more words than did older subjects, but an independent index of recall selectivity showed that older subjects were apparently more successful in selecting higher valued words. However, a fourth experiment showed that this superior selectivity on the part of older adults was attributable to their greater proportional reliance on primary memory recall. Overall, the data suggest that although older adults recall fewer words than do younger adults, they exert as much control over some aspects of encoding.     

A developmental comparison of the effectiveness of encoding tasks.

In Experiment 1, the free-recall performance of young children, college students, and older adults was examined. Subjects encoded words by simply learning them, by studying them in either base or elaborate sentence frames, or by constructing sentences. Overall recall was better for the college students than for the children or for the older adults, and the college students recalled best in the simple learning condition. The young children recalled best in the sentence construction condition; recall by older adults did not vary as a function of the encoding tasks. In Experiment 2, college students and older adults recalled a categorized list, encoding the words by simply learning them, by studying them in elaborate sentence frames, or by completing word fragments. For both age groups, simple learning produced the highest level of recall. These results suggest that organization provides the most effective encoding system and that older adults may need a more obvious basis for organization than do younger adults. Younger and older adults recalled equally well only when organization was discouraged by conceptual processing.     

How does context affect assessments of facial emotion? The role of culture and age

People from Asian cultures are more influenced by context in their visual processing than people from Western cultures. In this study, we examined how these cultural differences in context processing affect how people interpret facial emotions. We found that younger Koreans were more influenced than younger Americans by emotional background pictures when rating the emotion of a central face, especially those younger Koreans with low self-rated stress. In contrast, among older adults, neither Koreans nor Americans showed significant influences of context in their face emotion ratings. These findings suggest that cultural differences in reliance on context to interpret others' emotions depend on perceptual integration processes that decline with age, leading to fewer cultural differences in perception among older adults than among younger adults. Furthermore, when asked to recall the background pictures, younger participants recalled more negative pictures than positive pictures, whereas older participants recalled similar numbers of positive and negative pictures. These age differences in the valence of memory were consistent across culture.