Event-based Prospective Memory Task Research Articles

Impact of inhibitory load on remembering delayed intentions in autism

Objective:Research on prospective memory (PM) in autism spectrum disorders (ASD) is scarce and inconsistent. Differences in results have been attributed to differences in executive control demands of the respective PM tasks. However, so far no study has systematically and experimentally manipulated executive control load. The present study set out to explore the impact of varying inhibitory control demands on PM performance in ASD.Method:Twenty-two adults with ASD and 22 age-, gender- and cognitive ability-matched controls were asked to work on a computerised word categorization task into which an event-based PM task was embedded. In addition, they were required to work on a task that put either low or high load on inhibitory resources.Results:With regards to the event-based PM task, no significant effects emerged. Controls outperformed individuals with ASD on the ongoing task performance and ongoing task performance varied with inhibition load. Similarly, inhibition load affected performance on the inhibition task; here, no group effects were found.Conclusion:Findings suggest spared event-based PM performance in ASD regardless of inhibition load. However, results might be limited by ceiling effects and future studies are needed to investigate to explore inhibition effects using more difficult tasks.

Errorless learning of prospective memory tasks: An experimental investigation in people with memory disorders

The term prospective memory (PM) refers to memory for future intentions. PM problems are frequent in people with cognitive impairment and, because they are central to the realisation of many everyday goals, are important in rehabilitation. Event-based PM tasks (EBPM) are environmentally-cued and have primarily mnemonic demands, whereas time-based PM tasks (TBPM) require self-initiated retrieval, and have greater executive demands. Errorless learning (EL) is an encoding method that results in superior retrospective memory compared with “errorful” learning (EF). As this EL advantage (ELA) likely stems from its reduced explicit memory demands, and there is no such advantage for executive tasks, a greater ELA for EBPM than TBPM was predicted. Fourteen adults with neurological memory impairment completed PM tasks under four counterbalanced conditions: EL of EBPM, EL of TBPM, EF of EBPM, and EF of TBPM. A significant ELA was observed for EBPM (d = .63), but not TBPM (d = –.01). These results extend the evidence for EL within cognitive rehabilitation, by showing for the first time that the method can benefit future action in addition to retrospective memory. The clinical implications are also clear: errorless learning techniques may be usefully employed to support completion of day-to-day EBPM tasks.

Event-based prospective memory deficits in individuals with high depressive symptomatology: Problems controlling attentional resources?

Depression has been found to be related to neurocognitive deficits in areas important to successful prospective memory (PM) performance, including executive function, attention, and retrospective memory. However, research specific to depression and PM has produced a mixed pattern of results. The current study further examined the task conditions in which event-based PM deficits may emerge in individuals with high depressive symptomatology (HDS) relative to individuals with low depressive symptomatology (LDS) and the capacity of HDS individuals to allocate attentional resources to event-based PM tasks. Sixty-four participants (32 HDS, 32 LDS) were required to make a PM response when target words were presented during an ongoing lexical decision task. When the importance of the ongoing task was emphasized, response time costs to the ongoing task, and PM accuracy, did not differ between the HDS and LDS groups. This finding is consistent with previous research demonstrating that event-based PM task accuracy is not always impaired by depression, even when the PM task is resource demanding. When the importance of the PM task was emphasized, costs to the ongoing task further increased for both groups, indicating an increased allocation of attentional resources to the PM task. Crucially, while a corresponding improvement in PM accuracy was observed in the LDS group when the importance of the PM task was emphasized, this was not true for the HDS group. The lack of improved PM accuracy in the HDS group compared with the LDS group despite evidence of increased cognitive resources allocated to PM tasks may have been due to inefficiency in the application of the allocated attention, a dimension likely related to executive function difficulties in depression. Qualitatively different resource allocation patterns may underlie PM monitoring in HDS versus LDS individuals.

Metamemory prediction accuracy for simple prospective and retrospective memory tasks in 5-year-old children

It is well documented that young children greatly overestimate their performance on tests of retrospective memory (RM), but the current investigation is the first to examine children’s prediction accuracy for prospective memory (PM). Three studies were conducted, each testing a different group of 5-year-olds. In Study 1 (N=46), participants were asked to predict their success in a simple event-based PM task (remembering to convey a message to a toy mole if they encountered a particular picture during a picture-naming activity). Before naming the pictures, children listened to either a reminder story or a neutral story. Results showed that children were highly accurate in their PM predictions (78% accuracy) and that the reminder story appeared to benefit PM only in children who predicted they would remember the PM response. In Study 2 (N=80), children showed high PM prediction accuracy (69%) regardless of whether the cue was specific or general and despite typical overoptimism regarding their performance on a 10-item RM task using item-by-item prediction. Study 3 (N=35) showed that children were prone to overestimate RM even when asked about their ability to recall a single item—the mole’s unusual name. In light of these findings, we consider possible reasons for children’s impressive PM prediction accuracy, including the potential involvement of future thinking in performance predictions and PM.

Do Inhibitory Control Demands Affect Event-Based Prospective Memory Performance in ADHD?

Objective: Empirical evidence on prospective memory (PM) in ADHD is inconsistent. Differential findings have been related to differential executive control demands. This study aimed at exploring the impact of inhibitory control on event-based PM performance in ADHD. Method: Eighteen adults with ADHD and 18 controls performed a word categorization task with an embedded event-based PM task. In addition, participants performed an acoustically presented task that put either low or high loads on inhibitory control processes. Results: Inhibitory load did not differentially affect PM performance: Across both inhibitory load conditions, individuals with ADHD showed reduced PM performance when compared with controls. Moreover, inhibitory load did not influence PM performance across both groups. Conclusion: Possibly, full inhibitory control resources are not necessary during the entire duration of an event-based PM task, but may suffice to be employed after cue detection when needing to interrupt the ongoing task. (J. of Att. Dis. 2019; 23(1) 51-56)

Diminished time-based, but undiminished event-based, prospective memory among intellectually high-functioning adults with autism spectrum disorder: Relation to working memory ability.

Objective: Prospective memory (PM) is the ability to remember to carry out an intended action. Working memory is the ability to store information in mind while processing potentially distracting information. The few previous studies of PM in autism spectrum disorder (ASD) have yielded inconsistent findings. Studies of working memory ability in ASD have suggested a selective impairment of “visual working memory.” However, it remains unclear whether any such impairment is the result of diminished (domain-specific; visual/verbal) storage capacity or diminished (domain-general) processing capacity. We aim to clarify these issues and explore the relation between PM and working memory in ASD. Method: Seventeen adults with ASD and 17 age- and IQ-matched comparison participants completed experimental measures of both event-based (perform action x when event y occurs) and time-based (perform action a at time b) PM, plus a self-report measure of PM skills. Participants also completed a working memory test battery. Results: Participants with ASD self-reported diminished PM skill, and showed diminished performance on the time-based, but not event-based, PM task. On the working memory test battery, visual but not verbal storage capacity was diminished among participants with ASD, as was processing ability. Whereas visual storage was associated with event-based PM task performance among comparison participants, verbal storage was associated among ASD participants. Conclusions: ASD appears to involve a selective deficit in time-based PM and a selective difficulty with aspects of working memory that depend on the storage of visual information. However, event-based PM may be achieved through compensatory strategies in ASD.

The Influence of Ongoing Task Change on Event-based Prospective Memory in Patients with Mild Cognitive Impairment

With the increasing of aging and life expectancy, more attention was drawn to Alzheimer's disease. Mild cognitive impairment and its effects have come to the vision of scholars due to it's high risk of Alzheimer's disease. Previous studies about mild cognitive impairment have focused on the executive function, visual spatial, episodic memory, language skills etc. Recent researches indicated that the performance of prospective memory was worse in patients with mild cognitive impairment than that in normal elder. In the literatures, In the literatures, few studies had been found to explore the influence of ongoing task change on event-based prospective memory in patients with mild cognitive impairment. This research mainly focused on two questions:(1) the difference of prospective memory between individuals with mild cognitive impairment and normal elderly;(2) the influence of ongoing task change on prospective memory in the two groups. We recruited 96 participants and followed a 2(group: mild cognitive impairment patients, normal elderly) × 3(ongoing task change: non-change, order-change, random-change) between-subjects design to address the above issues. Firstly, two groups of the participants were screened—mild cognitive impairment / normal elderly by measuring Activities of Daily Living(ADL), Mini-Mental State Examination(MMSE) and Clinical Dementia Rating(CDR). Then, the classic paradigm of prospective memory was applied to test the event-based prospective memory performance in the two groups. The ongoing task required participants to judge the outline or the color of stick drawings. The event-based prospective memory task needed participants to press the space key whenever they saw any of the three target cues. The dependent variables were the accuracy and response latency of the event-based prospective memory tasks as well as the ongoing tasks. The results suggested that:(1) prospective memory performance of the patients with mild cognitive impairment was significantly lower than that of the normal elderly. That is, remarkable impairment appeared in patients with mild cognitive impairment;(2) for the patients with mild cognitive impairment, response latency of prospective memory and ongoing task was significantly decreased with the changing of ongoing tasks. The results supported the strategic process theory of prospective memory. It proves that the deficits in executive function might cause the prospective memory failures in patients with mild cognitive impairment.

Intention Retrieval and Deactivation Following an Acute Psychosocial Stressor

We often form intentions but have to postpone them until the appropriate situation for retrieval and execution has come, an ability also referred to as event-based prospective memory. After intention completion, our cognitive system has to deactivate no-more-relevant intention representations from memory to avoid interference with subsequent tasks. In everyday life, we frequently rely on these abilities also in stressful situations. Surprisingly, little is known about potential stress effects on these functions. Therefore, the present study aimed to examine the reliability of event-based prospective memory and of intention deactivation in conditions of acute psychosocial stress. To this aim, eighty-two participants underwent the Trier Social Stress Test, a standardized stress protocol, or a standardized control situation. Following this treatment, participants performed a computerized event-based prospective memory task with non-salient and focal prospective memory cues in order to assess prospective memory performance and deactivation of completed intentions. Although the stress group showed elevated levels of salivary cortisol as marker of a stress-related increase in hypothalamus-pituitary-adrenal axis activity throughout the cognitive testing period compared to the no-stress group, prospective memory performance and deactivation of completed intentions did not differ between groups. Findings indicate that cognitive control processes subserving intention retrieval and deactivation after completion may be mostly preserved even under conditions of acute stress.

Episodic future thinking as a predictor of children’s prospective memory

The primary goal of this study was to investigate the relationship among retrospective memory, episodic future thinking, and event-based prospective memory performance in preschool, first-grade, and second-grade children. A total of 160 children took part in the experiment. The study included participants from four age groups: 4-year-olds, 5-year-olds, 6-year-olds, and 7-year-olds. Participants were administered a recognition memory task, a task to test the ability to pre-experience future events, and an event-based prospective memory task. Data were submitted to correlational analyses, analyses of variance (ANOVAs), and logistic regression analyses. Results showed that, overall, all of these abilities improve with age and are significantly correlated with one another. However, when partialling out age and retrospective memory, episodic future thinking and prospective memory performance remained correlated. Logistic regression further showed that age and episodic future thinking abilities were significant predictors of prospective memory performance independent of retrospective memory abilities.

Importance Effects on Age Differences in Performance in Event-Based Prospective Memory

Background: Most laboratory-based studies on prospective memory show a decline with increasing age. Theoretical explanations for age differences focus on the allocation of attentional resources to support prospective remembering. The recruitment of prospective memory target monitoring seems to be influenced by perceived task importance. Objective: In the present study, we investigated the influence of task importance on the magnitude of age differences in event-based prospective memory. Methods: Healthy younger (n = 25) and older (n = 25) adults were instructed a priori to prioritize either the ongoing or the prospective memory task before performing an event-based prospective memory task. Results: We found an interaction between age and task importance: instructed higher importance of the ongoing task compared to the prospective memory task component produced significant age-related declines in prospective remembering. By contrast, if older adults treated the prospective memory task component as more important than the ongoing task, they achieved equivalent levels of prospective memory performance as their younger counterparts, but did so at a cost to ongoing task performance. Conclusions: The present data indicate that task importance is one of the factors determining the presence or absence of age deficits in prospective remembering. Findings are discussed in the context of limited processing resources in old age and theoretical frameworks of event-based prospective memory.

What was I supposed to do? Effects of individual differences in age and anxiety on preschoolers’ prospective memory

Prospective memory (PM) refers to remembering to perform a previously planned action at the appropriate time or in the appropriate context. The present study investigated the effects of individual differences in age and trait anxiety on PM performance in 3–5- and 5–7-year-olds. Two types of PM measures were used: an event-based task, requiring ongoing activity interruption across two conditions (with/without memory aid), and an activity-based task, requiring PM action implementation after the main activity was finalized. On the event-based PM task, we found that: all children benefited from the external memory aid; the 5–7-year-old group outperformed the 3–5-year-olds; and higher levels of anxiety negatively affected only the younger age group. On the activity-based PM task, we found no significant age-group differences, while higher anxiety negatively predicted children’s PM performance. Findings support and extend the literature on early PM development, revealing the benefits of external cueing and the potential detrimental effects of anxiety.

Age, Focal Processing, and Monitoring in Event-Based Prospective Memory

While there is some consensus that prospective memory (PM) declines with age, the reasons for differences in performance across age groups are not fully understood. This experiment examines two factors that are likely to affect the magnitude of observed age group differences: type of PM task and whether participants monitor the task environment for the opportunity to complete the PM task. Younger and older adults were engaged in an ongoing test of short-term memory and were asked to perform one of two different event-based PM tasks. Younger adults performed better than older adults on both focal and nonfocal PM tasks. In addition, younger adults were able to perform both types of tasks equally well, but older adults were more successful on the focal task than on the nonfocal task. Age group differences in self-reported PM monitoring were also evident and were related to performance. These findings and their implications for current theoretical conceptions of PM aging are discussed.

Predictive Value of Prospective Memory for Remission in First-Episode Schizophrenia

The study examined the rate of remission in individuals experiencing a first episode of schizophrenia (FES) in China and explored predictors of remission in the acute phase of the illness. Fifty-five FES patients were randomly treated with risperidone, olanzapine, or aripiprazole at therapeutic doses for 8 weeks, and their clinical profiles and cognition were assessed using standardized assessment instruments at entry and the end of the study. Of the 55 patients, 30 (54.5%) remitted by the end of the 8-week study. In univariate analyses, shorter duration of untreated psychosis, higher scores on both the time-based prospective memory (TBPM) and event-based prospective memory tasks and the Hopkins Verbal Learning Test-revised, and less severe negative symptoms were significantly associated with remission. In stepwise multiple logistic regression analyses, only higher scores on the TBPM significantly predicted remission. Individuals having higher scores reflecting better TBPM at baseline were more likely to achieve remission after 8 weeks of optimized antipsychotic treatment. TPBM may be useful in helping clinicians identify those FES patients most likely to achieve a favorable treatment response.

Adult age differences in interference from a prospective-memory task: a diffusion model analysis

People often slow down their ongoing activities when they must remember an intended action, known as the cost or interference effect of prospective memory (PM). Only a few studies have examined adult age differences in PM interference, and the specific reasons underlying such differences are not well understood. The authors used a model-based approach to reveal processes underlying PM interference and age differences in these processes. Older and younger adults first performed a block of an ongoing lexical decision task alone. An embedded event-based PM task was added in a second block. Simultaneously accounting for the changes in response time distributions and error rates induced by the PM task, Ratcliff's (Psychological Review 85:59-108, 1978) diffusion model was used to decompose the nonlinear combination of speed and accuracy into psychologically meaningful components. Remembering an intention not only reduced processing efficiency in both age groups, but also prolonged peripheral nondecision times and induced response cautiousness. Overall, the findings suggest that there are multiple, but qualitatively similar factors underlying PM task interference in both age groups.

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

This study investigated the effect of Parkinson's disease (PD) on event-based prospective memory tasks with varying demand on (1) the amount of strategic attentional monitoring required for intention retrieval (prospective component), and (2) the retrospective memory processes required to remember the contents of the intention or the entire constellation of prospective memory tasks. Twenty-four older adults with PD and 28 healthy older adults performed the computerized Virtual Week task, a multi-intention prospective memory paradigm that simulates everyday prospective memory tasks. The Virtual Week included regular (low retrospective memory demand) and irregular (high retrospective memory demand) prospective memory tasks with cues that were focal (low strategic monitoring demand) or less focal (high strategic monitoring demand) to the ongoing activity. For the regular prospective memory tasks, PD participants were impaired when the prospective memory cues were less focal. For the irregular prospective memory tasks, PD participants were impaired regardless of prospective memory cue type. PD participants also had impaired retrospective memory for irregular tasks, which was associated with worse prospective memory for these tasks during the Virtual Week. When retrospective memory demands are minimized, prospective memory in PD can be supported by cues that reduce the executive control demands of intention retrieval. However, PD-related deficits in self-initiated encoding or planning processes have strong negative effects on the performance of prospective memory tasks, with increased retrospective memory demand.

A pilot fMRI study of event-based prospective memory in healthy adults

Objective To investigate the neural mechanism of prospective memory(PM) using functional magnetic resonance imaging (fMRI). Methods Fifteen healthy volunteers were enrolled, and all subjects were scanned with fMRI while performing the event-based PM tasks (double-task paradigm, including the ongoing task and PM task). And the image data were preprocessed and analyzed by using SPM8 software. Results (1) Compared to the control task, bilateral rostral prefrontal cortex (x, y, z=6/-2, 54/42, -8/-12, t=3.71), right somatosensory association area (x, y, z=14, -62, 64, t=4.64), superior temporal gyrus (x, y, z=42, -46, 16, t=3.95) and right paracentral lobule (x, y, z=10, -22, 76, t=4.01) were activated significantly by the ongoing task (P<0.001). (2) Bilateral rostral prefrontal cortex (x, y, z=-2/6, 42/54, -12/-12, t=3.28) and paracentral lobule (x, y, z=-30/10, -22/-22, 72/76, t=4.25), left postcentral gyrus (x, y, z=-38, -46, 64, t=3.13) and middle occipital gyrus (x, y, z=-30, -70, 0, t=3.97) were activated significantly by the PM task (P<0.001). Conclusion Rostral prefrontal cortex (BA 10 area) is the major area of prospective memory, and medial BA10 area may be involved in the monitoring of external cues.The present study supports the gateway hypotheses of prospective memory. Key words: Prospective Memory; Prefrontal Cortex; Brodmann Area 10

Increased prospective memory interference in normal and pathological aging: different roles of motor and verbal processing speed

ABSTRACT This is a study on prospective memory (PM) and the PM interference effect in normal and pathological aging. One hundred and seven subjects, including 41 healthy young adults, 40 non-demented older adults and 26 patients with mild Alzheimer's disease (AD) participated in this study using a laboratory event-based PM task. PM task performance was comparable between the non-demented older and young adults, but impaired in the AD patients. The PM interference effect increased progressively from the healthy young adults, the non-demented older adults, to the AD patients. Path analysis revealed that the possible mechanism mediating the increased PM interference was the slow motor processing speed in normal aging, while it was the slow verbal speed in pathological aging. It is suggested that different neuropsychological mechanisms may underpin the affected performance of PM task in normal and pathological aging.

Electrophysiological Correlates of Strategic Monitoring in Event-Based and Time-Based Prospective Memory

Prospective memory (PM) is the ability to remember to accomplish an action when a particular event occurs (i.e., event-based PM), or at a specific time (i.e., time-based PM) while performing an ongoing activity. Strategic Monitoring is one of the basic cognitive functions supporting PM tasks, and involves two mechanisms: a retrieval mode, which consists of maintaining active the intention in memory; and target checking, engaged for verifying the presence of the PM cue in the environment. The present study is aimed at providing the first evidence of event-related potentials (ERPs) associated with time-based PM, and at examining differences and commonalities in the ERPs related to Strategic Monitoring mechanisms between event- and time-based PM tasks.The addition of an event-based or a time-based PM task to an ongoing activity led to a similar sustained positive modulation of the ERPs in the ongoing trials, mainly expressed over prefrontal and frontal regions. This modulation might index the retrieval mode mechanism, similarly engaged in the two PM tasks. On the other hand, two further ERP modulations were shown specifically in an event-based PM task. An increased positivity was shown at 400–600 ms post-stimulus over occipital and parietal regions, and might be related to target checking. Moreover, an early modulation at 130–180 ms post-stimulus seems to reflect the recruitment of attentional resources for being ready to respond to the event-based PM cue. This latter modulation suggests the existence of a third mechanism specific for the event-based PM; that is, the “readiness mode”.

Clinical Measures of Prospective Memory in Amnestic Mild Cognitive Impairment

Recent research has established that individuals with amnestic mild cognitive impairment (aMCI) have impaired prospective memory (PM); however, findings regarding differential deficits on time-based versus event-based PM have been less clear. Furthermore, the diagnostic utility of PM measures has received scant attention. Healthy older adults (n = 84) and individuals with aMCI (n = 84) were compared on the Cambridge Prospective Memory Test (CAMPROMPT) and two single-trial event-based PM tasks. The aMCI participants showed global impairment on all PM measures. Measures of retrospective memory and complex attention predicted both time and event PM performance for the aMCI group. Each of the PM measures was useful for discriminating aMCI from healthy older adults and the time- and event-based scales of the CAMPROMPT were equivalent in their discriminative ability. Surprisingly, the brief PM tasks were as good as more comprehensive measures of PM (CAMPROMPT) at predicting aMCI. Results indicate that single-trial PM measures, easily integrated into clinical practice, may be useful screening tools for identifying aMCI. As PM requires retrospective memory skills along with complex attention and executive skills, the interaction between these skills may explain the global PM deficits in aMCI and the good discriminative ability of PM for diagnosing aMCI.

Affective state and event-based prospective memory

Event-based prospective memory tasks require the realisation of a delayed intention at the occurrence of a specific target event. The present research investigates how performance in this kind of prospective memory task is influenced by the current affective state. By manipulating participants’ mood during intention realisation we tested two competing models of mood effects on memory (i.e., a capacity consuming account and a processing style account). Furthermore, we manipulated the valence of the target event to investigate mood-congruency effects in prospective memory. No evidence was found for a mood-congruency effect, but the results showed that prospective memory performance increased with a sad mood. This effect is consistent with recent theories on mood-dependent processing-style regulation, postulating that a sad mood produces a more analytic and detailed processing style whereas a happy mood produces a more global and less detailed processing style.