Prospective memory in young and older adults: The effects of task importance and ongoing task load

Remembering to perform an action in the future, called prospective memory, often shows age-related differences in favor of young adults when tested in the laboratory. Recently Smith, Horn, and Bayen (2012; Aging, Neuropsychology, and Cognition, 19, 495) embedded a PM task in an ongoing color-matching task and manipulated the difficulty of the ongoing task by varying the number of colors on each trial of the task. Smith et al. found that age-related differences in PM performance (lower PM performance for older adults relative to young adults) persisted even when older adults could perform the ongoing task as well or better than the young adults. The current study investigates a possible explanation for the pattern of results reported by Smith et al. by including a manipulation of task emphasis: for half of the participants the prospective memory task was emphasize, while for the other half the ongoing color-matching task was emphasized. Older adults performed a 4-color version of the ongoing color-matching task, while young adults completed either the 4-color or a more difficult 6-color version of the ongoing task. Older adults failed to perform as well as the young adults on the prospective memory task regardless of task emphasis, even when older adults were performing as well or better than the young adults on the ongoing color-matching task. The current results indicate that the lack of an effect of ongoing task load on prospective memory task performance is not due to a perception that one or the other task is more important than the other.     

Effects of age and anxiety on episodic memory: selectivity and variability

Selective age-related differences in source memory relative to item memory, and individual differences in memory performance in relation to anxiety were explored with high- and low-anxious subjects screened from normal young and elderly adults. They were read false facts about the locations of well-known and unknown sights in a male or female voice. Intentional and incidental learning instructions were administered for source memory. Selective age-related deficits in source memory were observed under both encoding conditions. Higher level of anxiety was related to lower memory performance only in the old group; this relation was stronger in source recall. The findings suggest that the presence of such selectivity is unrelated to the tradeoff between item encoding and source encoding. Anxiety affects the variability, and mediates the selectivity of age effects on episodic memory.     

Future thinking improves prospective memory performance and plan enactment in older adults

Efficient intention formation might improve prospective memory by reducing the need for resource-demanding strategic processes during the delayed performance interval. The present study set out to test this assumption and provides the first empirical assessment of whether imagining a future action improves prospective memory performance equivalently at different stages of the adult lifespan. Thus, younger (n?=?40) and older (n?=?40) adults were asked to complete the Dresden Breakfast Task, which required them to prepare breakfast in accordance with a set of rules and time restrictions. All participants began by generating a plan for later enactment; however, after making this plan, half of the participants were required to imagine themselves completing the task in the future (future thinking condition), while the other half received standard instructions (control condition). As expected, overall younger adults outperformed older adults. Moreover, both older and younger adults benefited equally from future thinking instructions, as reflected in a higher proportion of prospective memory responses and more accurate plan execution. Thus, for both younger and older adults, imagining the specific visual–spatial context in which an intention will later be executed may serve as an easy-to-implement strategy that enhances prospective memory function in everyday life.     

Younger and older adults’ prospective memory: the role of delay task difficulty

ABSTRACT

There is mixed evidence on the impact of delay task difficulty on prospective memory (PM) performance and little research has examined this among older adults. The present study examined younger (N = 60) and older (N = 57) adults’ prospective memory (PM) performance after completing an easy or difficult Raven’s matrices task. To assess whether delay difficulty impacted how often participants thought about their PM intention, participants were asked to report on what they thought about during the delay task itself and retrospectively after all tasks were completed. Younger adults outperformed older adults on the PM task; however, delay task difficulty had no impact PM for either age group. Reports of thinking about the intention during the delay task differed by age group depending whether they were online or retrospective, however, overall greater reports of thinking about the intention was positively associated with PM performance.     

Age-related changes in frequency of mind-wandering and task-related interferences during memory encoding and their impact on retrieval

During the performance of cognitive tasks such as memory encoding, attention can become decoupled from the external environment and instead focused on internal thoughts related to the appraisal of the current task (task-related interferences; TRI), or personal thoughts unrelated to the task at hand (mind-wandering; MW). However, the association between the frequency of these thoughts experienced at encoding and retrieval accuracy in young and older adults remains poorly understood. In this study young and older adults encoded lists of words using one of two encoding tasks: judging whether words are man-made/natural (objective task), or whether they are pleasant/neutral (subjective task). We measured the frequency of TRI and MW at encoding, and related them to retrieval accuracy in both age groups. We found that encoding task influenced the type of internal thoughts experienced by young, but not older, adults: young exhibited greater MW in the subjective vs the objective task, and greater TRI in the objective vs subjective encoding task. Second, across both tasks we found marked age-related decreases in both MW and TRI at encoding, and frequency of these thoughts negatively impacted memory retrieval in young adults only. We discuss these findings in relation to current theories of ageing, attention and memory.     

Age related differences in metacognitive control: role of executive functioning

To examine whether aging affects metacognitive control, elderly and young adults carried out a readiness-recall task, in which subjects monitor their own learning procedure, allowing strategy manipulation (study time and rehearsal) to be measured. Age differences were observed in metamemory control performance. Younger adults were found to be better at adjusting study time and rehearsal to the task. Moreover, to determine whether age-related differences in strategy manipulation may mediate age-related differences in memory performance, performance on the readiness-recall task was compared to performance on an experimenter-paced task. Results indicated that younger adults recalled significantly more words in the readiness-recall task than in the experimenter test. This was not the case for older adults. Furthermore, a hierarchical regression analysis revealed that age-related differences in strategy manipulation mediate some age-related differences in memory performance. Our aim was also to determine whether metacognitive control is related to executive functions. Thus, all participants were administered standard neuropsychological tests used to assess executive functioning. Significant partial correlation appeared between metamemory control and executive functioning. Finally, a hierarchical regression analysis indicated that age-related decline in metamemory control may be largely the result of executive limitations associated with aging.     

Effect of distinctive encoding on false recognition,discrimination, and decision criteria in young and elderly adults

In order to examine the effects of distinctive encoding on age-related differences in false memory and decision criteria, we used a standard recognition paradigm and manipulated three encoding conditions: control, general, and distinctive. The results revealed main effects of age and encoding condition on hits and false recognition, and interactions between these variables, with elderly adults benefiting more than young adults from the encoding tasks. In the distinctive encoding condition, the age-related difference on false recognition was eliminated. These findings are discussed in terms of an age-related deficit in self-initiated distinctive processing. Further analyses showed that elderly adults used a more lenient decision criterion than young adults. Distinctive encoding led all subjects to use stringent decision criteria, but did not eliminate age differences.     

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).     

Prospective memory across adolescence: the effects of age and cue focality

The present study examined the role of controlled attention in age differences in event-based prospective memory performance across adolescence. The researchers tested whether presenting the prospective memory cue in or out of focal awareness of the ongoing task (resulting in low versus high demands for controlled attention, respectively) might affect age-related prospective memory performance. In total, 119 Chinese participants ages 13 to 20 took part in this study (60 adolescents: age M = 13.26 years, SD = 0.50; 23 boys; 59 young adults: age M = 19.70 years, SD = 0.87; 19 men). Findings demonstrated a significant interaction, F(1, 114) = 6.41, p < .05. No effect of age on prospective memory performance was revealed when a focal cue was used (F < 1), whereas there was a reliable age effect between adolescents and young adults when nonfocal prospective memory cues were presented, F(1, 59) = 16.13, p < .01. This pattern of results suggests that the interplay of both available resources of controlled attention and working memory, along with specific task demands, may contribute to possible age differences in prospective memory performance across adolescence. Results are discussed in the context of the multiprocess theory of prospective memory.     

Instructional manipulations and age differences in memory: now you see them, now you don't.

The instructions for most explicit memory tests use language that emphasizes the memorial component of the task. This language may put older adults at a disadvantage relative to younger adults because older adults believe that their memories have deteriorated. Consequently, typical explicit memory tests may overestimate age-related decline in cognitive performance. In 2 experiments, older and younger adults performed a memory test on newly learned trivia. In both experiments, age differences were obtained when the instructions emphasized the memory component of the task (memory emphasis) but not when the instructions did not emphasize memory (memory neutral). These findings suggest that aspects of the testing situation. such as experimental instructions, may exaggerate age differences in memory performance and need to be considered when designing studies investigating age differences in memory.     

The effects of age, enactment, and cue-action relatedness on memory for intentions in the Virtual Week task

ABSTRACT The current study investigated the influence of encoding modality and cue-action relatedness on prospective memory (PM) performance in young and older adults using a modified version of the Virtual Week task. Participants encoded regular and irregular intentions either verbally or by physically performing the action during encoding. For half of the intentions there was a close semantic relation between the retrieval cue and the intended action, while for the remaining intentions the cue and action were semantically unrelated. For irregular tasks, both age groups showed superior PM for related intentions compared to unrelated intentions in both encoding conditions. While older adults retrieved fewer irregular intentions than young adults after verbal encoding, there was no age difference following enactment. Possible mechanisms of enactment and relatedness effects are discussed in the context of current theories of event-based PM.     

The effects of age,enactment, and cue-action relatedness on memory for intentions in the Virtual Week task

ABSTRACT

The current study investigated the influence of encoding modality and cue-action relatedness on prospective memory (PM) performance in young and older adults using a modified version of the Virtual Week task. Participants encoded regular and irregular intentions either verbally or by physically performing the action during encoding. For half of the intentions there was a close semantic relation between the retrieval cue and the intended action, while for the remaining intentions the cue and action were semantically unrelated. For irregular tasks, both age groups showed superior PM for related intentions compared to unrelated intentions in both encoding conditions. While older adults retrieved fewer irregular intentions than young adults after verbal encoding, there was no age difference following enactment. Possible mechanisms of enactment and relatedness effects are discussed in the context of current theories of event-based PM.     

The effect of implementation intentions on prospective memory performance across the lifespan

Differences in the amount and availability of cognitive resources may be responsible for age‐related differences in event‐based prospective memory tasks. We hypothesised that a manipulation which reduces resource requirements by enhancing automatic processing will reduce age differences. Implementation intentions are assumed to satisfy this requirement. We tested a total of 563 participants, 185 adolescents, 193 young adults and 185 older adults in order to investigate whether providing participants with implementation intention instructions would improve performance, whether any improvement would vary with age, and whether it would affect the prospective component or the retrospective component. The results showed a benefit of implementation intentions for older adults, but not for adolescents and for young adults. Separate analyses for the prospective and the retrospective components revealed that this effect was based mainly on a performance facilitation of the prospective component. These results suggest that implementation intentions provide a means to reduce age differences in prospective memory. Copyright © 2009 John Wiley & Sons, Ltd.     

Self control of when and how much to test face-name pairs in a novel spaced retrieval paradigm: An examination of age-related differences

ABSTRACT Although the mnemonic benefit of spaced retrieval is well established, the way in which participants naturally space their own retrieval is relatively unexplored. To examine this question, a novel experimental paradigm was developed in which young and healthy older adults were given control over the frequency and timing of retrieval practice in the context of an ongoing reading task. Results showed that both age groups naturally expanded the intervals of their retrieval practice. When instructed, younger adults but not older adults were better able to employ equal spaced retrieval during retrieval practice. However, even under equal spaced retrieval instructions, young adults included an early retrieval attempt prior to equally spacing their retrieval. Although memory performance was equivalent, secondary task performance was reduced in the experimenter-instructed condition compared with the participant-selected condition. The results overall indicate that both younger and older participants naturally monitor their memory and efficiently use testing to titrate the number and timing of retrieval attempts used during the acquisition phase.     

A threat in the elder: the impact of task‐instructions,self‐efficacy and performance expectations on memory performance in the elderly

Widely used explicit memory tasks seem to overestimate age‐related differences in memory performance. Social and personal factors may buffer or undermine the effect of age on memory performance. In two studies, the performance of older adults was compared with the performance of younger adults. Tasks were presented either as memory tasks or non‐memory tasks. Older adults' performance on a memory task improved when the task‐instructions did not explicitly emphasize the memory component of the task. In the first study, results revealed that memory self‐efficacy beliefs play a moderator role on the impact of task‐instruction on memory performance, so that lower levels of memory self‐efficacy correlate with lower performance in the memory emphasizing task condition but not in the orientation emphasizing task condition. In a second study actual performance expectations were measured. For older participants only, expectations were sensitive to task‐instructions and mediated the relation between tasks‐instructions and performances. These findings suggest that observed age‐related differences in memory performance may be significantly exaggerated by the testing situation and by a low memory self‐efficacy and low memory performance expectancies prevalent among older adults. Copyright © 2005 John Wiley & Sons, Ltd.     

Prospective memory in young and older adults: the effects of ongoing-task load

Prospective memory involves remembering to perform intended actions in the future. Previous work with the multinomial model of event-based prospective memory indicated that adult age-related differences in prospective-memory performance were due to the prospective (not the retrospective) component of the task (Smith & Bayen, 2006 , Journal of Experimental Psychology: Learning, Memory, and Cognition, 32, 623). However, ongoing-task performance was also lower in older adults in that study. In the current study with young and older adults, the difficulty of the ongoing task was manipulated by varying the number of colors per trial to create easier and harder versions of the ongoing task for each age group. The easier version included 2 colors per trial for older adults and 4 colors for young adults. The harder version included 4 colors for older adults and 6 colors for young adults. By adjusting the ongoing-task difficulty, older adults were able to perform the ongoing task as well or better than the young adults. Analyses with the multinomial model revealed that making the ongoing task easier for older adults (or more difficult for young adults) did not eliminate age-related differences in prospective-memory performance and the underlying prospective component.     

The first signs of prospective memory

We conducted a study to examine the impact of motivation and length of delay on performance on prospective memory (PM) tasks in 2-year of children. A total of 158 children aged exactly 24 months were asked to perform a naturalistic PM task. Length of delay (10?min; 35?min) and motivation (high; very high) were between-subjects factors. Two thirds of children had to be excluded from the analysis because of poor retrospective memory for the PM task instructions which were no longer remembered at the end of the session. For the children who did remember the instructions, both motivation and delay had significant effects on PM. Also, their PM performance was reliably above zero, even after the long delay. The findings indicate that when children as young as 24 months are able to remember the PM task instructions they can reliably succeed in PM tasks that are intrinsically motivating for them.     

Task coordination and aging: explorations of executive control processes in the task switching paradigm.

A number of models of cognitive aging suggest that older adults exhibit disproportionate performance decrements on tasks which require executive control processes. In a series of three studies we examined age-related differences in executive control processes and more specifically in the executive control processes which underlie performance in the task switching paradigm. Young and old adults were presented with rows of digits and were required to indicate whether the number of digits (element number task) or the value of the digits (digit value task) were greater than or less than five. Switch costs were assessed by subtracting the reaction times obtained on non-switch trials from trials following a task switch. Several theoretically interesting results were obtained. First, large age-related differences in switch costs were found early in practice. Second, and most surprising, after relatively modest amounts of practice old and young adults switch costs were equivalent. Older adults showed large practice effects on switch trials. Third, age-equivalent switch costs were maintained across a two month retention period. Finally, the main constraint on whether age equivalence was observed in task switching performance was memory load. Older adults were unable to capitalize on practice under high memory loads. These data are discussed in terms of their implications for both general and process specific cognitive aging models.     

A double dissociation of implicit and explicit memory in younger and older adults

This study examined whether age-related differences in cognition influence later memory for irrelevant, or distracting, information. In Experiments 1 and 2, older adults had greater implicit memory for irrelevant information than younger adults did. When explicit memory was assessed, however, the pattern of results reversed: Younger adults performed better than older adults on an explicit memory test for the previously irrelevant information, and older adults performed less well than they had on the implicit test. Experiment 3 investigated whether this differential pattern was attributable to an age-related decline in encoding resources, by reducing the encoding resources of younger adults with a secondary task; their performance perfectly simulated the pattern shown by the older adults in the first two experiments. Both older and younger adults may remember irrelevant information, but they remember it in different ways because of age-related changes in how information is processed at encoding and utilized at retrieval.     

Differential effects of age on item and associative measures of memory: a meta-analysis

In this meta-analysis, the authors evaluated recent suggestions that older adults' episodic memory impairments are partially due to a reduced ability to encode and retrieve associated/bound units of information. Results of 90 studies of episodic memory for both item and associative information in 3,197 young and 3,192 older adults provided support for the age-related associative/binding deficit suggestion, indicating a larger effect of age on memory for associative information than for item information. Moderators assessed included the type of associations, encoding instructions, materials, and test format. Results indicated an age-related associative deficit in memory for source, context, temporal order, spatial location, and item pairings, in both verbal and nonverbal material. An age-related associative deficit was quite pronounced under intentional learning instructions but was not clearly evident under incidental learning instructions. Finally, test format was also found to moderate the associative deficit, with older adults showing an associative/binding deficit when item memory was evaluated via recognition tests but not when item memory was evaluated via recall tests, in which case the age-related deficits were similar for item and associative information.