An implementation intention strategy can improve prospective memory in older adults with very mild Alzheimer's disease

Time-Based and Event-Based Prospective Memory in Mild Cognitive Impairment and Alzheimer's Disease Patients: A Systematic Review and Meta-analysis

Prospective memory (PM) is the ability to remember to perform planned actions in a future moment and it is of fundamental importance for an independent and autonomous lifestyle from development to late adulthood. Deficits in episodic memory and executive functions, which are involved in PM are characteristic features of mild cognitive impairment (MCI) and Alzheimer's disease (AD). Considering that the number of older adults is drastically increasing over the next decades, it is of great interest to understand how PM decline in healthy older adults and patients with different degree of cognitive decline. The present meta-analysis included 46 studies investigating PM performance in AD patients (17 studies) and people with MCI (24 studies); 5 studies included both clinical conditions in the same article. The 46 studies contributed a total of 63 independent samples and 129 effect sizes from 4668 participants (2115 patients and 2553 controls). Unlike previous reviews of the literature, our results with a larger and updated sample of studies confirmed lower PM abilities in AD compared to MCI and controls, although we did not observe conclusive differences between event-based and time-based PM in patients. Surprisingly, PM deficits shown by MCI and AD patients have decreased across years, in parallel to a reduction of the evidence of publication bias and an increase in the number of observations per task. We propose the use of more reliable research designs as one plausible explanation for the reduction of PM impairments.

Improving children's ability to remember intentions: a literature review on strategies to improve prospective memory during childhood

Children often fail to remember executing intentions because prospective memory (PM) does not completely develop until late adolescence or young adulthood. PM failures are often observed in children and can have negative consequences on their everyday lives. Thus, in the last 50 years, various strategies to support children's PM have been designed and evaluated, such as prompting children to use different encoding modalities, such as verbal, visual, and enacted modalities, or encoding strategies, such as implementation intentions, episodic future thinking (EFT), and performance predictions, as well as providing children with verbal and visual reminders. However, not all these interventions have shown to efficiently enhance PM performance during childhood. The present literature review is aimed at summarizing these interventions and critically examining their effectiveness from a developmental perspective and by considering underlying mechanisms. The type of PM task (event-, time-, and activity-based), cognitive resource demands, and processing overlaps are also considered. Finally, directions for future research and possible applications in everyday life will be discussed.

Fostering cognitive performance in older adults with a process- and a strategy-based cognitive training

       The present study investigates the impact of process-based and strategy-based cognitive training to boost performance in healthy older adults. Three groups trained with either a dichotic listening training (process-based training, n = 25), an implementation intention strategy training (strategy-based training, n = 23), or served as a non-contact control group (n = 30). Our results demonstrated that training participants improved their performance in the trained tasks (process-based training: d = 3.01, strategy-based training: d = 2.6). For untrained tasks, the process-based training group showed significant working memory (d = .58) as well as episodic memory task improvement (d = 1.19) compared to the strategy-based training and to the non-contact control group (all d < .03). In contrast, in the strategy-based training group there was a tendency towards some performance gain in a fluid intelligence test (d = .92). These results indicate that cognitive training can be tailored to improve specific cognitive abilities.

The effects of implementation intentions on prospective memory in young and older adults

Prospective memory (PM) is the ability to perform a planned action at a future time, while carrying on with other unrelated tasks. Implementation Intentions (II) is a promising metacognitive strategy for improving PM in older adults, though its generalization and longer-term effects are not well-understood. We examined the effects of II on PM in 48 community-dwelling older adults (77% female, M_age = 71.52) and 59 young adults (75% female, M_age = 19.86). Participants were randomly allocated to a conventional instruction or II group and administered a laboratory-based PM task in the first session. In the second session, participants returned to complete a similar but new laboratory-based PM task and an ecological PM task without prompts to use a strategy. We found strong age effects on PM performance whereby older adults performed worse than young adults across all PM tasks. While the overall facilitation effect of II was not statistically significant, there was a trend that this strategy facilitated PM performance on the laboratory-based PM task in the first session for older adults with a medium sized effect (d = 0.37). The generalization and longer-term effect of II were not significant for either the similar laboratory-based or the ecological PM task. These results suggest that a single-session II intervention may not be sufficient to elicit transfer to other similar new PM tasks in healthy populations.

Reducing age-related Memory Deficits: The Roles of Environmental Support and self-initiated Processing Activities

BACKGROUND

The notion that memory performance in older adults can be boosted by information provided by the environment was proposed by Craik (1983). The suggestion was that age-related memory deficits can be attenuated and sometimes even eliminated by a complementary combination of environmental support and consciously controlled self-initiated activities.

OBJECTIVE

The objective of the present article was to review the subsequent empirical and theoretical work on the topics of environmental support and self-initiated ativities as they relate to the effects of aging on human memory.

DISCUSSION

The notion of schematic support from the person's knowledge base is introduced and its relevance discussed. In addition, the effects of various types of support on encoding and retrieval processes in older adults are desribed, and the increasing theoretical importance of executive processes in reducing age-related memory deficits is discussed.

CONCLUSION

As one main conclusion, it is suggested that self-initiated control processes interact with both information provided by the environment and by the person's knowledge base to improve the effectiveness of encoding and retrieval processing in older adults.

Prospective Memory Training in Older Adults: A Systematic Review and Meta-Analysis

Prospective memory (PM), which enables one to remember to carry out delayed intentions, is crucial for everyday functioning. PM commonly deteriorates upon cognitive decline in older adults, but several studies have shown that PM in older adults can be improved by training. The current study aimed to summarise this evidence by conducting a qualitative systematic analysis and quantitative meta-analysis of the effects of PM training in older adults, for which systematic searches were conducted across seven databases (Cochrane Library, Embase, PubMed, PsycInfo, Web of Science, CINAHL and Scopus). Forty-eight studies were included in the qualitative analysis, and 43% of the assessed PM training interventions showed positive gains in enhancing PM. However, the methodological quality varied across the studies, with 41% of the non-randomised control trials (non-RCTs) rated as having either serious or critical risk of bias. Therefore, only 29 RCTs were included in the subsequent quantitative meta-analysis. We found a significant and moderate immediate efficacy (Hedges' g = 0.54) of PM training in enhancing PM performance in older adults, but no significant long-term efficacy (Hedges' g = 0.21). Two subgroup analyses also revealed a robust training efficacy across the study population (i.e., healthy and clinical population) and the number of training sessions (i.e., single session and programme-based). Overall, this study provided positive evidence to support PM training in older adults. Further studies are warranted to explore the mechanisms by which PM training exerts its effects, and better-quality RCTs are needed to provide more robust evidence supporting our findings.

Keeping Your Glass Half Full: Cognitive Strategy Intervention for Older Adults

When older adults experience memory dysfunction it often compromises their confidence. Older adults’ confidence in their memory can be improved through interventions designed to teach strategies for improving everyday memory functioning. The present study examines the efficacy of a five-session cognitive strategy program designed to be optimistic and inclusive for older adults living in a residential community. The memory self-efficacy of participants in the intervention group improved significantly relative to a control group. Additionally, participants’ knowledge of memory strategies improved overall after completion of this program. Such findings highlight the benefits of practical cognitive-behavioral interventions for bolstering older adults’ confidence and knowledge of memory strategies.

A Systematic Review of Prospective Memory Interventions Across Stages of Dementia-Related Disorders

BACKGROUND

There is a critical need to develop effective interventions for cognitive impairments associated with dementia-related disorders (i.e., Alzheimer's disease, frontotemporal dementia, mild cognitive impairment). Prospective memory (PM), or the ability to create and carry out future intentions, is one cognitive domain that is impaired in individuals with dementia-related disorders. Effective treatment of PM could significantly improve daily functioning, level of independence, and quality of life.

OBJECTIVE

To date, there have been a number of studies investigating potential interventions, but these interventions have not been comprehensively reviewed and compared across the stages of dementia-related disorders, as is the aim of the current review.

METHODS

This review examined 21 studies on the success of intervention strategies for prospective memory in patients with dementia-related disorders.

RESULTS

All the studies demonstrated positive effects of intervention on PM abilities, but there are questions concerning ecological validity, length of positive effects on PM, and a lack of diversity of interventions across the different stages of dementia-related disorders.

CONCLUSION

Future research should address these issues by incorporating daily functioning activities and caregiver support into the intervention process, as well as investigating these interventions at more severe stages of dementia-related disorders.

Implementation intentions speed up young adults’ responses to prospective memory targets in everyday life

Prospective memory (PM), which is the ability to remember to do something in the future, is vitally important for successful everyday functioning. Although young adults demonstrate high PM abilities in laboratory settings, their abilities to complete intended actions in naturalistic settings are surprisingly low. The present study tested the effectiveness of various encoding techniques in improving young adults’ performance in everyday life. Ninety-two participants were asked to remember to take photographs of receipts for a duration of seven days. The task instructions were either given alone or followed by: (a) the if-then statement, (b) visualising the task, or (c) the combination of the if-then statement plus visualisation. The if-then statement alone significantly speeded up responses to the prospective memory targets, i.e., less time elapsed between getting a receipt and taking a photograph of it. With no effect of the if-then statement on the proportion of correct PM responses, the results may suggest that the if-then statement strengthened the PM cue-intention association but did not influence the PM cue saliency.

Effectiveness of a Visual Imagery Training Program to Improve Prospective Memory in Older Adults with and without Mild Cognitive Impairment: A Randomized Controlled Study

Prospective memory (PM) problems in aging and, to a greater extent, in mild cognitive impairment (MCI), compromise functional independence. This study examined the effectiveness of a cognitive training program based on visual imagery to improve PM among older adults with and without MCI. Participants were older adults, 24 with MCI and 24 cognitively healthy (HOA). Half of them (12 MCI and 12 HOA) were randomly assigned to the PM training program, the other half to the no-training control group. All participants also completed a pre- and post-test evaluation, including neuropsychological tests, questionnaires, and the Ecological Test of Prospective Memory (TEMP). There was no significant effect of the intervention on the TEMP total, event-based or time-based scores for either the MCI or HOA groups. However, the trained MCI group committed fewer false alarms (i.e., more efficient identification of prospective cues) in the event-based condition of the TEMP at post-test. On the other hand, all trained participants performed better than control participants on retrospective memory tests, which suggests that visual imagery-based training is more effective to improve retrospective memory than PM. Possible explanations for these results are explored.

How did I remember to do that? Self-reported strategy use for laboratory prospective memory tasks

The role of metacognition in prospective memory (PM) has received relatively little attention. This study combined data from several experiments to identify the strategy repertoire employed during a classic laboratory PM task and to determine whether self-reported strategy was related to performance. Participants (N = 668) completed either a focal or nonfocal PM task embedded in an ongoing lexical decision task. The results indicated that participants reported the same strategy repertoire regardless of PM task focality. Participants who reported using a strategy performed better than those who did not report using one, and this was especially true under nonfocal conditions. Self-reported strategy use was also associated with more cost to the ongoing task when the opportunity to complete the PM task was present. These findings add to what is known about the metacognitive components of PM and underscore the need for additional research in this area.

The general facilitation effect of implementation intentions on prospective memory performance in patients with schizophrenia

INTRODUCTION

Prospective memory (PM) refers to remembering to execute a planned intention in the future. It can be divided into event- and time-based, according to the nature of the PM cue. Event-based PM cues can be classified as focal or non-focal. Patients with schizophrenia (SCZ) have been found to be impaired in both event- and time-based PM. PM has been found to be improved by implementation intentions, which is an encoding strategy in the format of "if X then Y". This study examined the effect of implementation intentions on a non-focal event-based and a time-based PM task in patients with SCZ.

METHODS

Forty-two patients with SCZ and 42 healthy controls were allocated to either an implementation intention or a control PM instruction condition and were asked to complete two PM tasks.

RESULTS

Implementation intentions was found to improve performance in both the non-focal event-based and time-based PM tasks in patients with SCZ and healthy controls, with no costs to the ongoing task. The improvement in time-based PM performance in the implementation intentions condition was partially mediated by the frequency of clock checking behaviour.

CONCLUSIONS

Implementation intentions can facilitate PM performance in patients with SCZ and has the potential to be used as a clinical intervention tool.

Improving Prospective Memory in Healthy Older Adults and Individuals with Very Mild Alzheimer's Disease

OBJECTIVES

To test the utility of a memory-encoding strategy for improving prospective memory (PM), the ability to remember to execute future goals (e.g., remembering to take medications), which plays an important role in independent living in healthy older adults and those with very mild Alzheimer's disease (AD).

DESIGN

Participants were randomly assigned to an encoding strategy condition or a standard encoding condition.

SETTING

A longitudinal study conducted at an Alzheimer's disease research center. Testing took place at the center and in a university testing room.

PARTICIPANTS

Healthy older adults (Clinical Dementia Rating (CDR) = 0.0, n = 38) and those classified as being in the very mild stage of AD (CDR = 0.5, n = 34).

INTERVENTION

A simple strategy ("If I see Cue X, then I will perform Intention Y") was used to strengthen PM encoding and reduce the probability of forgetting to execute one's future plans.

MEASUREMENTS

PM was assessed using Virtual Week, a laboratory task that requires the simulation of common PM tasks (the types of tasks performed in everyday life), such as taking one's medication at breakfast.

RESULTS

The encoding strategy significantly reduced PM failures in healthy older adults and those with very mild AD and was effective regardless of the individual's episodic memory ability.

CONCLUSION

This encoding strategy was successful in reducing PM errors in healthy older adults and those with mild AD with a range of memory abilities.

Cognitive and neural plasticity in older adults' prospective memory following training with the Virtual Week computer game

Prospective memory (PM) – the ability to remember and successfully execute our intentions and planned activities – is critical for functional independence and declines with age, yet few studies have attempted to train PM in older adults. We developed a PM training program using the Virtual Week computer game. Trained participants played the game in 12, 1-h sessions over 1 month. Measures of neuropsychological functions, lab-based PM, event-related potentials (ERPs) during performance on a lab-based PM task, instrumental activities of daily living, and real-world PM were assessed before and after training. Performance was compared to both no-contact and active (music training) control groups. PM on the Virtual Week game dramatically improved following training relative to controls, suggesting PM plasticity is preserved in older adults. Relative to control participants, training did not produce reliable transfer to laboratory-based tasks, but was associated with a reduction of an ERP component (sustained negativity over occipito-parietal cortex) associated with processing PM cues, indicative of more automatic PM retrieval. Most importantly, training produced far transfer to real-world outcomes including improvements in performance on real-world PM and activities of daily living. Real-world gains were not observed in either control group. Our findings demonstrate that short-term training with the Virtual Week game produces cognitive and neural plasticity that may result in real-world benefits to supporting functional independence in older adulthood.

Enhancing prospective memory in mild cognitive impairment: The role of enactment

INTRODUCTION

Prospective memory (PM) is a fundamental requirement for independent living which might be prematurely compromised in the neurodegenerative process, namely in mild cognitive impairment (MCI), a typical prodromal Alzheimer's disease (AD) phase. Most encoding manipulations that typically enhance learning in healthy adults are of minimal benefit to AD patients. However, there is some indication that these can display a recall advantage when encoding is accompanied by the physical enactment of the material. The aim of this study was to explore the potential benefits of enactment at encoding and cue-action relatedness on memory for intentions in MCI patients and healthy controls using a behavioral PM experimental paradigm.

METHOD

We report findings examining the influence of enactment at encoding for PM performance in MCI patients and age- and education-matched controls using a laboratory-based PM task with a factorial independent design.

RESULTS

PM performance was consistently superior when physical enactment was used at encoding and when target-action pairs were strongly associated. Importantly, these beneficial effects were cumulative and observable across both a healthy and a cognitively impaired lifespan as well as evident in the perceived subjective difficulty in performing the task.

CONCLUSIONS

The identified beneficial effects of enacted encoding and semantic relatedness have unveiled the potential contribution of this encoding technique to optimize attentional demands through an adaptive allocation of strategic resources. We discuss our findings with respect to their potential impact on developing strategies to improve PM in AD sufferers.