Prospective memory in Parkinson disease during a virtual week: effects of both prospective and retrospective demands

Prospective memory functions in traumatic brain injury: The role of neuropsychological deficits, metamemory and impaired self-awareness

A large body of evidence suggests that individuals with traumatic brain injury (TBI) have significant difficulties with prospective memory (PM), the memory for future intentions. However, the processes underlying this cognitive deficit remain unclear. This study aimed to gather further evidence regarding PM functions in TBI and clarify the role of neuropsychological deficits, metamemory, and mood disorders. We used a laboratory-based clinical measure, the Virtual Week, to examine PM function in 18 patients with TBI and 18 healthy control subjects. Measures of attention, processing speed, executive functions, episodic memory, and self-report questionnaires were also administered. In line with prior literature, our findings indicate that individuals with TBI had a consistent deficit compared to controls across all PM tasks. In previous studies, TBI patients had more severe impairment on time-based tasks; nevertheless, our results show that across all participants event-based tasks were easier to perform compared to time-based only when the retrospective memory demand was high. The patients were not only impaired on the prospective component of PM but also failed to recognise the content of their task (the retrospective component). Interestingly, the TBI group did not report higher levels of everyday memory problems, anxiety and depression compared to the control group. These measures also failed to correlate with PM and recognition memory performance. This study found that besides the neuropsychological deficits, a global impairment in PM functioning is present in individuals with TBI across various task types, tasks low and high in retrospective demands, and event versus time-based.

Communication-related aspects of prospective memory: an exploratory factor analysis of prospective memory questionnaires

PURPOSE

Prospective memory (PM) questionnaires are frequently used to evaluate perceptions of PM skills in daily life. This study aimed to systematically investigate communication-specific attributes using pre-existing PM self-rating questionnaires to inform clinicians and researchers about the role of PM in cognitive communicative evaluations.

METHODS

PM-related items from three questionnaires (i.e., Prospective Memory Questionnaire, Comprehensive Assessment of Prospective Memory, and Prospective and Retrospective Memory Questionnaire) were compiled and embedded in Google Forms and distributed to 70 Speech-Language Pathologists (SLPs) with expertise in Cognitive Communicative Disorders across India. Participants first identified items related to communication, and were then contacted to rate the communication-related PM items using a Likert scale for their degree of appropriateness. Responses from 40 SLPs were obtained and subjected to item-content validity index (i-CVI) and exploratory factor analysis (EFA).

RESULTS

Of the 114 PM items, 28 received ratings over 50% for their relevance to communication. Of the 28 items, 21 had an i-CVI score greater than 0.8. After the removal of overlapping content, 14 items were finalized and subjected to EFA, which resulted in four factors: PM failure due to loss of communicative content, PM failure due to loss of communicative intent, PM cost due to ongoing interference, and PM failure linked to the priority of communicative intent.

CONCLUSION

This study highlights communication-related aspects of PM that can be used as a framework for SLPs to assess and research PM skills.

The Weekly Calendar Planning Activity to Assess Functional Cognition in Parkinson Disease

The Weekly Calendar Planning Activity (WCPA) may improve understanding of functional cognition in people with Parkinson disease (PwPD) without dementia. We aimed to determine if WCPA performance (a) discriminates between PwPD with and without cognitive impairment and healthy controls and (b) correlates with other indicators of cognition and daily function. This was a cross-sectional study. Parkinson disease (PD) participants without dementia were divided into normal cognition (PD-NC, n = 25) and possible mild cognitive impairment (PD-MCI, n = 21) groups. Their WCPA performance was compared with that of a normative sample (n = 196) and correlated with neuropsychological test performance and self-reported cognition and participation. Both the PD-MCI and PD-NC groups had impaired WCPA performance. WCPA performance correlated with executive function, processing speed, and self-reported cognition and participation. The WCPA can detect functional cognitive deficits in PwPD without dementia and can inform occupational therapy interventions to support functional cognition, occupational performance, and participation in this population.

The effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on the cognitive and motor functions in rodents: A systematic review and meta-analysis

Memory and motor deficits are commonly identified in Parkinson's disease (PD). 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is transformed to MPP+ via monoamine oxidase B (MAOB), which causes oxidative stress and destroys dopaminergic (DA) neurons in substantia nigra pars compacta (SNc) and is widely used to create animal models of PD. However, to-date, a comprehensive analysis of the MPTP effects on various aspects of PD does not exist. Here, we provide a systematic review and meta-analysis on the MPTP effects on memory and motor functions by analyzing 51 studies on more than one thousand animals mainly including rats and mice. The results showed that in addition to motor functions such as coordination, balance and locomotor activity, MPTP significantly affects various mnemonic processes including spatial memory, working memory, recognition memory, and associative memory compared with the control group with some differences between systemic and intra-nigral injections on spatial memory, familiar object recognition, and anxiety-like behaviors. Nevertheless, our analysis failed to find systematic relationship between MPTP injection protocol parameters reported and the extent of the induced PD symptoms that can be a cause of concern for replicability of MPTP studies.

Prospective Memory Training for Healthy Older Adults: A Systematic Review

OBJECTIVES

This review systematically synthesizes existing evidence of prospective memory training for healthy older adults (> 55 years). Existing prospective memory training include strategy-based, process-based and combined regimens. Strategy-based training focuses on different mnemonics to compensate for aging declines in prospective memory. Process-based training aims to restore related cognitive processes to support prospective memory. Combined training utilizes both strategy-based and process-based regimens to enhance prospective memory performance.

METHODS

A total of 349 studies were identified from the Cochrane Library, EBSCO, PsycINFO and PubMed databases.

RESULTS

Using predefined inclusion and exclusion criteria, 11 studies were included in the review. There were six studies of strategy-based training, two studies of process-based training and three studies of combined training.

CONCLUSIONS

Overall, strategy-based training appears to facilitate prospective memory for healthy older adults. However, it is impossible to draw conclusions for process-based and combined training due to the preliminary nature of current evidence.

CLINICAL IMPLICATIONS

Mental imagery or the use of external aids can be useful strategy-based approaches to facilitate prospective memory in older adults. Strategy-based training should target multiple prospective memory phases simultaneously to encourage transfers. Further studies will be required to draw conclusions on the effectiveness of process-based and combined training.

Prospective memory impairment in neurological disorders: implications and management

Prospective memory is a core neurocognitive ability that refers to memory for future intentions, such as remembering to take medications and to switch off appliances. Any breakdown in prospective memory, therefore, has serious implications for the ability to function independently in everyday life. In many neurological disorders, including Parkinson disease and dementia, prospective memory deficits are common even in the earliest stages and typically become more severe with disease progression. Consequently, clinical assessment of prospective memory is of critical importance. This article provides an overview of the various manifestations and neural bases of prospective memory deficits. To facilitate clinical decision-making, validated measures of this construct are identified and their suitability for clinical practice is discussed, focusing in particular on clinical sensitivity and psychometric properties. The article concludes by reviewing the approaches that can be used to rehabilitate different types of prospective memory impairment, and algorithms to guide the evaluation and treatment of these impairments are provided.

Instruments Measuring Prospective Memory: A Systematic and Meta-Analytic Review

OBJECTIVE

To identify the available measures to assess prospective memory (PM) abilities, to describe their content, and to quantitatively summarize the effects of various diseases on PM depending on the type of assessment.

METHOD

Three databases (PsycInfo, PsycArticles and PubMed) were searched up to June 2019 to identify the existing PM measures. The identified PM measures were classified according to the type of assessment: test batteries, single-trial procedures, questionnaires, and experimental procedures. The characteristics and psychometric properties were presented. PM performances were compared between patients with various diseases and controls depending on the type of assessment.

RESULTS

Most of the 16 measures identified evaluated both event- and time-based tasks, were linked to functional outcomes, showed empirical evidences regarding validity and reliability, and provided parallel versions. To a slightly lesser extent, few measures provided normative data, translations/adaptation into another language, cutoff scores for diagnostic purposes, qualitative scoring, parallel version, and external aids during the test. Compared to healthy controls, patients had significantly poorer performances when PM was assessed with experimental procedures. Heterogeneous data precluded the interpretation of a summary effect for test batteries, single-trial procedures, and questionnaires. Planned subgroup analyses indicated consistent PM impairment for patients compared to controls for three test batteries. However, PM complaints did not differ between patients and controls.

CONCLUSIONS

These results suggest that the use of PM test batteries and experimental procedures are relevant for detecting performance variations in diverse clinical populations. Clinical implications and directions for future research are discussed.

A meta-analytic review of prospection deficits in Parkinson's disease

Parkinson's disease (PD) is one of the most common neurodegenerative disorders, and is associated with prominent motor deficits. However, neurocognitive impairment is also a common clinical feature that can contribute greatly to the overall disease burden. In the current study, a meta-analysis was conducted to gain a clearer understanding of how PD affects one of the most functionally important domains of cognition: prospection. The results indicate that, relative to controls, PD is associated with a large deficit in the capacity to engage in planning (g = -0.81, K = 25) and a moderate-sized deficit in prospective memory (g = -0.57, K = 16). Sub-analyses indicated that these deficits are evident for both time and event-based prospective memory, as well as for prospective memory tasks that have relatively limited ecological validity. Significant impairment was also evident for both medicated and non-medicated PD sub-groups, but for planning, these deficits were substantially greater in the unmedicated sub-group. The theoretical and practical implications of these findings are discussed.

Prospective Memory Is a Key Predictor of Functional Independence in Older Adults

OBJECTIVES

Prospective memory (PM), the ability to execute delayed intentions, has received increasing attention in neuropsychology and gerontology. Most of this research is motivated by the claim that PM is critical for maintaining functional independence; yet, there is a dearth of empirical evidence to back up the claims. Thus, the present study tested whether PM predicts functional independence in older adults using validated behavioral performance measures for both PM and functional independence.

METHODS

Fifty-eight healthy older adults performed a computerized PM paradigm, the Virtual Week task, as well as a timed version of an instrumental activities of daily living (TIADL) task. Furthermore, we assessed vocabulary, processing speed, and self-reported prospective remembering.

RESULTS

TIADL scores correlated significantly with performance in the Virtual Week task, vocabulary, and processing speed. Hierarchical linear regressions revealed that vocabulary and Virtual Week performance were significant predictors for TIADL. However, self-reported PM scores did not predict everyday functioning.

CONCLUSIONS

The findings indicate that PM is an important cognitive ability for successful and independent everyday life beyond vocabulary. Moreover, the results show a substantial incremental contribution of intact PM performance for the prediction of everyday functioning by using objective PM measures. (JINS, 2018, 24, 640-645).

Encoding strategy training and self-reported everyday prospective memory in people with Parkinson disease: a randomized-controlled trial

Objective To compare the effects of laboratory-based training in implementation intentions (II; experimental strategy) and verbal rehearsal (VR; control strategy) on self-reported everyday prospective memory among people with Parkinson disease (PD) and to investigate potential correlates of change in self-reported everyday prospective memory in response to this training. Method This was a randomized-controlled trial. Participants with mild to moderate PD without dementia underwent one session of training in either II (n = 25) or VR (n = 27). Then they were instructed to use their strategy as much as possible in their everyday lives to help them remember to do things. The Prospective and Retrospective Memory Questionnaire Prospective Scale (PRMQ-Pro) administered at baseline and one month after training assessed training-related change in self-reported everyday prospective memory. Baseline depressive symptoms, perceptions of the strategy (credibility, expectancy), prospective memory-related awareness, global cognition, and disease severity were correlated to PRMQ-Pro Change scores (post minus pre) to determine their association with response to training. Results The VR group's PRMQ-Pro scores declined from pre to post training, while the II group's remained stable (p = .03). This effect was driven by change in self-cued everyday prospective memory tasks. Higher baseline depressive symptoms, treatment expectancy, and global cognition related to better response to training in the II group (rs ≤ -.40, ps ≤ .05). Conclusions II training may prevent everyday prospective memory decline among people with PD. In addition, people with higher depression, stronger expectations of improvement from strategy training, or better global cognition may benefit the most from II training.

Psychometric properties of the Actual Week test: a naturalistic prospective memory task

OBJECTIVE

Prospective memory is the ability to 'remember to remember' and a facet of memory important to everyday functioning. For older adults, prospective memory slips are a common concern. In the present study, we conducted an initial validation of a paper-and-pencil adaptation of the Actual Week test, and reported on internal consistency, inter-rater and test-retest reliability, convergent and divergent validity, as well as veridicality of the task.

METHOD

Fifty-eight healthy, community-dwelling older adults were recruited from a larger randomized controlled trial and tested at baseline. The Actual Week test was a naturalistic five-day prospective memory task where participants were assigned eight hypothetical tasks to remember per day for five days. Tasks were either time-cued or event-cued and regular (i.e. occurring daily) or irregular (i.e. varied each day). The proportion of tasks that were recorded as on time and accurate was used as the primary measure of performance.

RESULTS

The Actual Week test had good internal consistency (Kuder-Richardson: r > .8), intra-test (intraclass correlation: α > .9) and test-retest reliability (r = .76). There was also evidence for convergent and divergent validity. Task performance was associated with age, but not years of education or sex.

CONCLUSION

The Actual Week test demonstrated strong psychometric qualities and promising evidence for validity as a performance-based measure of everyday prospective memory in older adults. Avenues for future studies include extending the evidence for convergent validity and evaluating feasibility and utility with other clinical populations.

Improving Prospective Memory in Persons With Parkinson Disease: A Randomized Controlled Trial

BACKGROUND

Prospective memory (PM) is essential for productive and independent living and necessary for compliance with prescribed health behaviors. Parkinson disease (PD) can cause PM deficits that are associated with activity limitations and reduced quality of life. Forming implementation intentions (IIs) is an encoding strategy that may improve PM in this population.

OBJECTIVE

To determine the effect of IIs on PM performance in PD.

METHODS

This was a laboratory-based randomized controlled trial. Participants with mild to moderate PD without dementia (n = 62) performed a computerized PM test (Virtual Week) under standard instructions. One week later they were randomly allocated to perform it again while using either IIs or a rehearsal (RR) encoding strategy.

RESULTS

PM performance was better with the use of both strategies relative to standard instructions. This effect was larger for tasks with event-based compared with time-based cues. In addition, IIs resulted in a larger effect than RR for the nonrepeated tasks.

CONCLUSIONS

Strategies that support full encoding of PM cues and actions can improve PM performance among people with PD, particularly for tasks with cues that are readily available in the environment. IIs may be more effective than RR for nonrepeated tasks, but this finding warrants verification. Future work should address transfer of strategy use from the laboratory to everyday life. Targeted strategies to manage PM impairment could improve function and quality of life and significantly affect clinical care for people with PD.

Event-based prospective memory in patients with Parkinson's disease: the effect of emotional valence

The present study investigated the effect of Parkinson’s disease (PD) on prospective memory (PM) tasks by varying the emotional content of the PM actions. Twenty-one older adults with PD and 25 healthy older adults took part in the present study. Participants performed three virtual days in the Virtual Week task. On each virtual day, participants performed actions with positive, negative or neutral content. Immediately following each virtual day, participants completed a recognition task to assess their retrospective memory for the various PM tasks. PD patients were less accurate than the control group at both PM accuracy and recognition task accuracy. The effect of emotional valence was also evident, indicating that all participants were more accurate on positive PM tasks than both negative and neutral. This study confirmed PM impairment in PD patients and extended previous research showing how positive emotional stimuli can influence PM performance.

Time-based prospective memory functioning in mild cognitive impairment associated with Parkinson's disease: relationship with autonomous management of daily living commitments

OBJECTIVE

Prospective memory (PM), that is, the ability to keep in memory and carry out intentions in the future, is reported to be impaired in individuals with Parkinson's disease (PD). PM failure may be also associated with reduced daily living functioning in these patients. Little is known, however, about the relationship between mild cognitive impairment (MCI) and time-based PM functioning in PD patients and the possible impact of PM deficits on patients' autonomy in daily living. Here we aimed to investigate whether MCI associated with PD affects time-based PM. We also wished to determine whether PM impairment accounts for reduced autonomous management of medication in these patients.

METHOD

The study included 48 PD patients with MCI, 33 PD patients without cognitive disorders (PDN) and 20 healthy controls. The time-based PM procedure required that subjects perform an action after a fixed time. The PM procedure was incorporated in the standard neuropsychological assessment. One score was computed for the ability to retrieve the intention (prospective component) and one for remembering the action to be executed (retrospective component). The Pill Questionnaire was administered to assess the ability to manage medication.

RESULTS

PD patients with MCI performed less accurately in the PM procedure than HC and tended to perform poorer than PDN. Moreover, in PD patients with MCI, accuracy on the prospective component of the PM task and performance on the Modified Card Sorting Test significantly predicted the ability to manage medication.

CONCLUSIONS

RESULTS document that reduced efficiency of time-based PM processes in PD is specifically related to the presence of MCI. The same data indicate that PM weakness may be associated with impaired daily living functioning and decreased autonomy.

PROspective MEmory Training to improve HEart failUre Self-care (PROMETHEUS): study protocol for a randomised controlled trial

Background

Cognitive impairment is seen in up to three quarters of heart failure (HF) patients and has a significant negative impact on patients’ health outcomes. Prospective memory, which is defined as memory to carry out future intentions, is important for functional independence in older adults and involves application of multiple cognitive processes that are often impaired in HF patients. The objective of this study is to examine the effects of prospective memory training on patients’ engagement in HF self-care and health outcomes, carer strain and quality of life.

Methods/design

The proposed study is a randomised, controlled trial in which 200 patients diagnosed with HF, and their carers will be recruited from 3 major hospitals across Melbourne. Eligible patients with HF will be randomised to receive either: 1) The Virtual Week Training Program - a computerised prospective memory (PM) training program (intervention) or 2) non-adaptive computer-based word puzzles (active control). HF patients’ baseline cognitive function will be compared to a healthy control group (n = 60) living independently in the community. Patients will undergo a comprehensive assessment of PM, neuropsychological functioning, self-care, physical, and emotional functioning. Assessments will take place at baseline, 4 weeks and 12 months following intervention. Carers will complete measures assessing quality of life, strain, perceived control in the management of the patients’ HF symptoms, and ratings of the patients’ level of engagement in HF self-care behaviours.

Discussion

If the Virtual Week Training Program is effective in improving: 1) prospective memory; 2) self-care behaviours, and 3) wellbeing in HF patients, this study will enhance our understanding of impaired cognitive processes in HF and potentially is a mechanism to reduce healthcare costs.

Trial registration

Australian New Zealand Clinical Trials Registry #366376; 27 May 2014. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366376&isClinicalTrial=False.

Prospective memory impairment in chronic heart failure

Although cognitive deficits are common in patients with chronic heart failure (CHF), no study to date has investigated whether these deficits extend to the capacity to execute delayed intentions (prospective memory, PM). This is a surprising omission given the critical role PM plays in correctly implementing many important CHF self-care behaviors. The present study aimed to provide the first empirical assessment of PM function in people with CHF. The key dependent measure was a laboratory measure of PM that closely simulates PM tasks in daily life - Virtual Week. A group comparison design was used, with 30 CHF patients compared to 30 demographically matched controls. Background measures assessing executive functions, working memory, and verbal memory were also administered. The CHF group exhibited significant PM impairment, with difficulties generalizing across different types of PM tasks (event, time, regular, irregular). The CHF group also had moderate deficits on several of the background cognitive measures. Given the level of impairment remained consistent even on tasks that imposed minimal demands on memory for task content, CHF-related difficulties most likely reflects problems with the prospective component. However, exploratory analyses suggest that difficulties with retrospective memory and global cognition (but not executive control), also contribute to the PM difficulties seen in this group. The implications of these data are discussed, and in particular, it is argued that problems with PM may help explain why patient engagement in CHF self-care behaviors is often poor.

Dopamine D1 and D5 receptors modulate spike timing-dependent plasticity at medial perforant path to dentate granule cell synapses

Although evidence suggests that DA modulates hippocampal function, the mechanisms underlying that dopaminergic modulation are largely unknown. Using perforated-patch electrophysiological techniques to maintain the intracellular milieu, we investigated how the activation of D1-type DA receptors regulates spike timing-dependent plasticity (STDP) of the medial perforant path (mPP) synapse onto dentate granule cells. When D1-type receptors were inhibited, a relatively mild STDP protocol induced LTP only within a very narrow timing window between presynaptic stimulation and postsynaptic response. The stimulus protocol produced timing-dependent LTP (tLTP) only when the presynaptic stimulation was followed 30 ms later by depolarization-induced postsynaptic action potentials. That is, the time between presynaptic stimulation and postsynaptic response was 30 ms (Δt = +30 ms). When D1-type receptors were activated, however, the same mild STDP protocol induced tLTP over a much broader timing window: tLTP was induced when -30 ms ≤ Δt ≤ +30 ms. The result indicated that D1-type receptor activation enabled synaptic potentiation even when postsynaptic activity preceded presynaptic stimulation within this Δt range. Results with null mice lacking the Kv4.2 potassium channel and with the potassium channel inhibitor, 4-aminopyridine, suggested that D1-type receptors enhanced tLTP induction by suppressing the transient IA-type K(+) current. Results obtained with antagonists and DA receptor knock-out mice indicated that endogenous activity of both D1 and D5 receptors modulated plasticity in the mPP. The DA D5 receptors appeared particularly important in regulating plasticity of the mPP onto the dentate granule cells.

Prospective memory in adults with high-functioning autism spectrum disorders: exploring effects of implementation intentions and retrospective memory load

This study examined, for the first time, the impact of implementation intentions on prospective memory (PM) performance in adults with autism spectrum disorders (ASD) and further explored the role of retrospective memory for PM in ASD. PM was assessed with Virtual Week, a computerized game simulating upcoming everyday-life tasks. Twenty-seven adults with ASD and 27 age- and ability-matched controls were included. Half of the participants were instructed to form implementation intentions (i.e., encoding PM tasks in form of if-then statements), while the rest received simple PM instructions. Results provide first tentative evidence for beneficial effects of implementation intentions and PM tasks with low demands on retrospective memory for adults with ASD's PM. Overall, results point to the importance of planning and retrospective memory for successful prospective remembering in ASD.

Effects of cognitive training with and without aerobic exercise on cognitively demanding everyday activities

We investigated the potential benefits of a novel cognitive-training protocol and an aerobic exercise intervention, both individually and in concert, on older adults' performances in laboratory simulations of select real-world tasks. The cognitive training focused on a range of cognitive processes, including attentional coordination, prospective memory, and retrospective-memory retrieval, processes that are likely involved in many everyday tasks, and that decline with age. Primary outcome measures were 3 laboratory tasks that simulated everyday activities: Cooking Breakfast, Virtual Week, and Memory for Health Information. Two months of cognitive training improved older adults' performance on prospective-memory tasks embedded in Virtual Week. Cognitive training, either alone or in combination with 6 months of aerobic exercise, did not significantly improve Cooking Breakfast or Memory for Health Information. Although gains in aerobic power were comparable with previous reports, aerobic exercise did not produce improvements for the primary outcome measures. Discussion focuses on the possibility that cognitive-training programs that include explicit strategy instruction and varied practice contexts may confer gains to older adults for performance on cognitively challenging everyday tasks.

Prospective memory performance of patients with Parkinson's disease depends on shifting aptitude: evidence from cognitive rehabilitation

This study investigated the effect of cognitive training aimed at improving shifting ability on Parkinson's disease (PD) patients' performance of prospective memory (PM) tasks. Using a double-blind protocol, 17 PD patients were randomly assigned to two experimental arms. In the first arm (n=9) shifting training was administered, and in the second (placebo) arm (n=8), language and respiratory exercises. Both treatments consisted of 12 sessions executed over 4 weeks. PM and shifting measures (i.e., Trail Making Test and Alternate Fluency Test) were administered at T0 (before treatment) and T1 (immediately after treatment). A mixed analysis of variance was applied to the data. To evaluate the effects of treatment, the key effect was the interaction between Group (experimental vs. placebo) and Time of Assessment (T0 vs. T1). This interaction was significant for the accuracy indices of the PM procedure (p<.05) and for the performance parameters of the shifting tasks (p ≤.05). Tukey's HSD tests showed that in all cases passing from T0 to T1 performance significantly improved in the experimental group (in all cases p ≤.02) but remained unchanged in the placebo group (all p consistently>.10). The performance change passing from T0 to T1 on the Alternate Fluency test and the PM procedure was significantly correlated (p<.05). Results show that the cognitive training significantly improved PD patients' event-based PM performance and suggest that their poor PM functioning might be related to reduced shifting abilities.

Prospective memory impairment in long-term opiate users

RATIONALE

Opiate use is associated with a range of neurological and cognitive deficits. However, to date, no studies have assessed whether these cognitive deficits extend to the ability to perform intended actions in the future (i.e. prospective memory). Reduced ability in this area might be anticipated due to impaired executive functions and episodic memory associated with long-term opiate use.

OBJECTIVES

The main objectives of this study are to assess the performance of long-term opiate users on a laboratory measure of prospective memory which closely simulates the types of prospective memory tasks encountered in everyday life ('Virtual Week') and to investigate the extent to which prospective memory performance is related to executive functions and episodic memory ability.

METHODS

Twenty-six long-term heroin users enrolled in an opiate substitution program, and 30 controls with no previous history of drug use were tested on Virtual Week. Retrospective memory and executive functions were also assessed.

RESULTS

Long-term opiate users were significantly impaired on prospective memory performance compared with controls (p = 0.002, η(2) p = 0.17), and these deficits did not vary as a function of prospective memory task type (regular, irregular, event, time). The findings also suggest that retrospective memory difficulties contribute to the prospective memory difficulties seen in opiate users (r s  = 0.78, p < 0.001) but that executive dysfunction is less influential.

CONCLUSIONS

Prospective memory is sensitive to long-term opiate use. Importantly, opiate users suffer from generalised deficits in prospective memory, regardless of the task demands, which may have significant implications for day-to-day functioning. These results may therefore contribute to the development of clinical intervention strategies to reduce the negative impact of prospective memory failures in daily life.

Prospective memory training in older adults and its relevance for successful aging

In research on cognitive plasticity, two training approaches have been established: (1) training of strategies to improve performance in a given task (e.g., encoding strategies to improve episodic memory performance) and (2) training of basic cognitive processes (e.g., working memory, inhibition) that underlie a range of more complex cognitive tasks (e.g., planning) to improve both the training target and the complex transfer tasks. Strategy training aims to compensate or circumvent limitations in underlying processes, while process training attempts to augment or to restore these processes. Although research on both approaches has produced some promising findings, results are still heterogeneous and the impact of most training regimes for everyday life is unknown. We, therefore, discuss recent proposals of training regimes aiming to improve prospective memory (i.e., forming and realizing delayed intentions) as this type of complex cognition is highly relevant for independent living. Furthermore, prospective memory is associated with working memory and executive functions and age-related decline is widely reported. We review initial evidence suggesting that both training regimes (i.e., strategy and/or process training) can successfully be applied to improve prospective memory. Conceptual and methodological implications of the findings for research on age-related prospective memory and for training research in general are discussed.

A Virtual Week study of prospective memory function in autism spectrum disorders

Prospective memory (PM) refers to the implementation of delayed intentions, a cognitive ability that plays a critical role in daily life because of its involvement in goal-directed behavior and consequently the development and maintenance of independence. Emerging evidence indicates that PM may be disrupted in autism spectrum disorders (ASDs), potentially contributing to the functional difficulties that characterize this group. However, the degree, nature, and specificity of ASD-related impairment remains poorly understood. In the current study, children between 8 and 12 years of age who were diagnosed with ASDs (n=30) were compared with typically developing children (n=30) on a child-appropriate version of the Virtual Week board game. This measure provides an opportunity to investigate the different sorts of PM failures that occur. The ASD group showed significant PM impairment on measures of time-based (but not event-based) prospective remembering. However, only a subtle difference emerged between regular and irregular PM tasks, and group differences were consistent across these tasks. Because regular and irregular tasks differentially load retrospective memory, these data imply that the PM difficulties seen in ASDs may primarily reflect a monitoring deficit and not an encoding and memory storage deficit. PM performance was poorer under conditions of high ongoing task absorption, but the magnitude of this effect did not vary as a function of group. In both groups, time-based (but not event-based) PM difficulties were associated with functional outcomes in daily life, but only an inconsistent association with executive control emerged.

Prospective memory in Parkinson's disease: a meta-analysis

Prospective memory (PM) refers to the ability to remember to carry out an intended action in the future and it is pervasive in our daily living. A failure to execute an intended action (e.g., take medication) at the appropriate juncture in future (e.g., after dinner) can negatively affect our daily functioning and at times, may have devastating effects (e.g., forgetting to turn off the gas stove before leaving the house). Patients with Parkinson's disease (PD) exhibit widespread cognitive deficits including deficits in PM. The present study provides a meta-analytic review of PM in PD. Results across nine studies indicated time and event-based PM to be similarly impaired in PD, with time-based PM compromised to a slightly larger extent (Hedges' g = -0.71) as compared to event-based PM (Hedges' g = -0.55). The impairment in PM is more likely due to failure in self-initiated retrieval of intention to be executed, rather than forgetting the content of the intention itself. Furthermore, factors such as intervening task complexity and the mediating role of other executive functions have also been proposed to be responsible for impaired PM in PD.

Prospective memory and chronic heart failure

Background

Patients with chronic heart failure (CHF) experience a number of debilitating symptoms, which impact on activities of daily living and result in poor quality of life. Prospective memory, which is defined as memory to carry out future intentions, has not been investigated in this group. However, emerging evidence suggests CHF patients have difficulties with cognitive processes related to prospective memory. Self-care, which partly relies on prospective memory, is essential in symptom management and preventing acute clinical deterioration. This study aims to measure prospective memory in CHF patients, and examine the relationship between prospective memory and CHF self-care.

Methods/Design

A comprehensive neuropsychological assessment will be conducted to assess a range of cognitive functions and psychopathology. The primary focus will be an assessment of prospective memory using a well-established behavioral measure; Virtual Week. Thirty CHF patients attending a nurse-led management program will be recruited from three hospital sites in Melbourne, Australia and their self-care behaviors will be assessed using the Self-care Chronic Heart Failure Index (SCHFI), a validated self-report tool. An additional 30 healthy controls, matched on age, gender, and IQ will be recruited from the general community.

Discussion

This is a group comparison study that will provide an evaluation of the prospective memory abilities of CHF patients. The findings of this research will provide insight into whether prospective memory may be hindering patients’ ability to perform adequate self-care.