Event-based Prospective Memory Research Articles

Interoceptive sensitivity predicts performance of event-based prospective memory: Evidence from cardiovascular reactivity

Interoceptive sensitivity predicts performance of event-based prospective memory: Evidence from cardiovascular reactivity

Is prospective memory related to depression and anxiety? A hierarchical MPT modelling approach

Prospective memory (PM) refers to remembering to perform an action in the future. One hundred and twenty-nine students completed a laboratory event–based PM task as well as depression and anxiety questionnaires. The data were analysed with the beta-MPT version of the multinomial processing tree model of event-based PM. Thereby, the prospective and retrospective components of PM were estimated for each participant and were then correlated with depression and anxiety. State anxiety was negatively correlated with the prospective component of PM. Neither depression nor trait anxiety were related to either component of PM.

Study on prospective memory in schizophrenia patients with alexithymia

Objective To investigate the event-based prospective memory(EBPM)and time-based prospective memory(TBPM)in schizophrenia patients with alexithymia, and to provide theoretical basis for early intervention and treatment. Methods According to inclusion standard, 30 schizophrenia patients with alexithymia and 30 schizophrenia patients without alexithymia matched in age, gender and education were assessed with a neuropsychological battery of tests including EBPM and TBPM tasks. Results In the EBPM task, there was no significant difference between schizophrenia patients with and without alexithymia (3.80±0.85 vs 4.10±0.71, t=-1.485, P=0.143). A statistically significant in TBPM was observed between schizophrenia patients with and without alexithymia (3.33±1.09 vs 3.93±0.83, t=-2.397, P=0.02). Conclusion The schizophrenia patients with alexithymia have more severe time-based prospective memory impairment than those without alexithymia. Key words: Alexithymia; Schizophrenia; Prospective Memory

Fitting an ex-Gaussian function to examine costs in event-based prospective memory: Evidence for a continuous monitoring profile

Event-based prospective memory (PM) tasks require individuals to remember to perform a deferred action when a target event occurs. PM task requirements can slow ongoing task responses on non-target trials (‘costs’) under conditions where the defining features of targets are non-focal to the ongoing task, which is indicative that individuals have allocated some form of cognitive control process to the PM task. Recent fits of the ex-Gaussian mathematical function to non-target trial response distributions by prior studies have indicated that these control processes are transiently allocated. In the current paper, fits of the ex-Gaussian function to data reported by Loft and Humphreys (2012) demonstrate a shift in the entire response time distribution (μ) and an increase in skew (τ) for a non-focal PM condition required to remember to make a PM response if presented with category exemplars, compared to a control condition. This change in μ is indicative of a more continuous PM monitoring profile than that reported by prior studies. In addition, within–subject variability in μ was reliably correlated with PM accuracy, suggesting that these control processes allocated on a regular basis were functional to PM accuracy. In contrast, when the ongoing task directed attention to the defining features of targets (focal PM) there was a trend level increase in μ, but the within–subject variability in μ was not correlated with PM accuracy, consistent with the theoretical premise that focal PM tasks are not as dependent on cognitive control as non-focal PM tasks.

Ecological Assessment of Executive Functions: A New Virtual Reality Paradigm

Acquired brain injury (ABI) can lead to a constellation of higher-order executive problems, which can impact significantly on everyday behaviour. While some neuropsychological assessments are able to measure these impairments objectively, increasingly, clinicians are finding that a subset of their patients passes these tests while still exhibiting difficulties in day-to-day living. Calls have therefore been made to develop assessments that are more sensitive and that are more ecologically valid. In this study, in Experiment 1, a multiple errands task (MET) based around a business office was created to assess concurrently nine aspects of executive functioning (planning, prioritisation, selective-thinking, creative-thinking, adaptive-thinking, multi-tasking, action-based prospective memory (PM), event-based PM and time-based PM). This new paradigm, the Jansari assessment of Executive Functions (JEF©) showed a significant difference between six individuals with ABI and matched healthy controls; further, it showed that across the nine constructs there was a range of performance. In Experiment 2, JEF©was recreated in a virtual environment resembling a computer game, and it was found that this version significantly differentiated between 17 individuals with ABI and 30 healthy controls. These results suggest that the virtual version of JEF©could be used as a new assessment of executive function. The profile of performance across the nine constructs for each individual provides a wealth of objective information that could potentially inform targeted rehabilitation.

Exploring the Relationship between Planning and Prospective Memory

Articulatory suppression / manipulations of working memory (i.e., poetic language) were examined in relation to planning and prospective memory, memory for actions to be performed in the future. Two experiments were conducted to explore these individual difference measures. Experiment 1 required participants to answer 90 trivia questions and complete embedded time- and event-based prospective memory tasks. The 36 participants were divided into three equal groups: no working memory (WM) load, low WM load, and high WM load. Results from that experiment were surprising because prospective memory performance did not vary by type (event-based versus time-based) and WM load did not influence prospective performance. Experiment 2 required participants to do an errand-planning task and complete embedded time- and event-based prospective memory tasks. The 36 participants, who did not participate in Experiment 1, were also divided into three groups that varied by WM load: no WM load, low WM load, and high WM load. One interesting finding was prospective memory performance correlated with a measure of planning: the Tower of Hanoi task. These experiments, their findings, and general implications are discussed.

Allowing brief delays in responding improves event-based prospective memory for young adults living with HIV disease

Event-based prospective memory (PM) tasks require individuals to remember to perform an action when they encounter a specific cue in the environment, and they have clear relevance for daily functioning for individuals with HIV. In many everyday tasks, not only must the individual maintain the intent to perform the PM task, but the PM task response also competes with the alternative and more habitual task response. The current study examined whether event-based PM can be improved by slowing down the pace of the task environment. Fifty-seven young adults living with HIV performed an ongoing lexical decision task while simultaneously performing a PM task of monitoring for a specific word (which was focal to the ongoing task of making lexical decisions) or syllable contained in a word (which was nonfocal). Participants were instructed to refrain from making task responses until after a tone was presented, which occurred at varying onsets (0–1600 ms) after each stimulus appeared. Improvements in focal and nonfocal PM accuracy were observed with response delays of 600 ms. Furthermore, the difference in PM accuracy between the low-demand focal PM task and the resource-demanding nonfocal PM task was reduced by half across increasingly longer delays, falling from 31% at 0-ms delay to only 14% at 1600-ms delay. The degree of ongoing task response slowing for the PM conditions, relative to a control condition that did not have a PM task and made lexical decisions only, also decreased with increased delay. Overall, the evidence indicates that delaying the task responses of younger HIV-infected adults increased the probability that the PM relevant features of task stimuli were adequately assessed prior to the ongoing task response, and by implication that younger HIV infected adults can more adequately achieve PM goals when the pace of the task environment is slowed down.

Rule monitoring ability predicts event-based prospective memory performance in individuals with TBI.

Numerous studies have demonstrated that prospective memory (PM) abilities are impaired following traumatic brain injury (TBI). PM refers to the ability to remember to complete a planned action following a delay. PM post-TBI has been shown to be related to performance on neuropsychological tests of executive functioning and retrospective episodic memory (RM). However, the relative influence of impairments in RM versus executive functioning on PM performance post-TBI remains uninvestigated. In the current study, PM and neuropsychological test performance were examined in 45 persons with a history of moderate to severe TBI at least 1 year before enrollment. Regression analyses examined the relative contributions of RM and executive functioning in the prediction of PM performance on the Rivermead Behavioral Memory Test (RBMT). Results indicated that scores on tests of delayed RM and rule monitoring (i.e., ability to avoid making errors on executive measures) were the strongest predictors of PM. When the interaction between RM impairment and rule monitoring was examined, a positive relationship between PM and rule monitoring was found only in TBI participants with impaired RM. Results suggest that PM performance is dependent upon rule monitoring abilities only when RM is impaired following TBI.

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.

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- and time-triggered remembering: The impact of attention deficit hyperactivity disorder on prospective memory performance in children

The current study examined prospective memory (PM, both time-based and event-based) and time estimation (TR, a time reproduction task) in children with and without attention deficit hyperactivity disorder (ADHD). This study also investigated the influence of task performance and TR on time-based PM in children with ADHD relative to controls. A sample of 69 children, aged 8 to 13years, completed the CyberCruiser-II time-based PM task, a TR task, and the Super Little Fisherman event-based PM task. PM performance was compared with children’s TR abilities, parental reports of daily prospective memory disturbances (Prospective and Retrospective Memory Questionnaire for Children, PRMQC), and ADHD symptomatology (Conner’s rating scales). Children with ADHD scored more poorly on event-based PM, time-based PM, and TR; interestingly, TR did not appear related to performance on time-based PM. In addition, it was found that PRMQC scores and ADHD symptom severity were related to performance on the time-based PM task but not to performance on the event-based PM task. These results provide some limited support for theories that propose a distinction between event-based PM and time-based PM.

Functional correlates of prospective memory in stroke

IntroductionProspective memory is the ability to remember actions to be performed later in time or when a certain event occurs. Multiple cognitive processes are involved in prospective memory, and the degree to which automatic or effortful processes are involved may differ for different types of prospective memory tasks. This study aimed to investigate prospective memory (dys)functioning in stroke patients, and to get more insight in which cognitive processes are involved in time- versus event-based prospective memory. MethodsWe investigated 39 community-dwelling stroke survivors and 53 matched control participants. Assessment included naturalistic and experimental event- and time-based prospective memory tasks, as well as standard neuropsychological measures of (retrospective) memory, processing speed and attention/executive functioning. Results41% of the stroke patients performed significantly worse than control participants on prospective memory tasks. Deficits in prospective memory occurred as frequently as impairments in retrospective memory (33%, χ2(1, N=39)=3.4, p=.066), and more often than impairments in attention/executive functioning (15%, χ2(1, N=39)=5.2, p=.022) and speed of processing (23%, χ2(1, N=39)=6.5, p=.011).Regression analyses showed that event-based (‘focal’) prospective memory is supported by retrospective memory, indicating that it is a relatively simple and automatic process. Time-based (non-‘focal’) prospective memory proved to be a more complex process, requiring active monitoring of the environment. Performance was predicted by speed of processing, attention/executive functioning and retrospective memory. Thirteen percent of the patients suffered from selective prospective memory impairment, which was associated with damage to the superior temporal gyrus. ConclusionsImpairment of prospective memory occurs frequently after stroke. Different cognitive operations are involved in distinct types of prospective memory. Results fit within the multi-process framework of prospective memory and help further specify its contents.

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.

The cognitive cost of event-based prospective memory in children

Prospective memory is the act of remembering to perform an action in the future, often after the presentation of a cue. However, processes involved in remembering the future intention might hinder performance on activities leading up to and surrounding the event in which an intention must be carried out. The current study was designed to assess whether young children who were asked to engage in prospective memory do so at a cost to current cognitive processing. Participants (4-, 5-, and 6-year-olds) either performed a simple ongoing selection task only (control condition) or performed the selection task with an embedded prospective memory task (experimental condition). Results revealed that children in the experimental condition were slower in the execution of the ongoing task relative to children in the control condition, lending support to the theory that children as young as 4years selectively allocate resources in an effort to succeed in multiple tasks.

Task importance affects event-based prospective memory performance in adults with HIV-associated neurocognitive disorders and HIV-infected young adults with problematic substance use.

Two experiments were conducted to examine the effects of task importance on event-based prospective memory (PM) in separate samples of adults with HIV-associated neurocognitive disorders (HAND) and HIV-infected young adults with substance use disorders (SUD). All participants completed three conditions of an ongoing lexical decision task: (1) without PM task requirements; (2) with PM task requirements that emphasized the importance of the ongoing task; and (3) with PM task requirements that emphasized the importance of the PM task. In both experiments, all HIV+ groups showed the expected increase in response costs to the ongoing task when the PM task's importance was emphasized. In Experiment 1, individuals with HAND showed significantly lower PM accuracy as compared to HIV+ subjects without HAND when the importance of the ongoing task was emphasized, but improved significantly and no longer differed from HIV+ subjects without HAND when the PM task was emphasized. A similar pattern of findings emerged in Experiment 2, whereby HIV+ young adults with SUD (especially cannabis) showed significant improvements in PM accuracy when the PM task was emphasized. Findings suggest that both HAND and SUD may increase the amount of cognitive attentional resources that need to be allocated to support PM performance in persons living with HIV infection.

Prospective memory predicts the level of community living skills in schizophrenia

Schizophrenia patients are known to have prospective memory (PM) deficits. There is no robust evidence showing that PM deficits have a major impact on community living skills in schizophrenia. The aim of this study was to examine the association between PM and community living skills in schizophrenia. Forty-four individuals with schizophrenia formed the study sample. Participants׳ psychopathology, prospective and retrospective memory, level of intelligence, and community living skills were measured with standardized instruments. In bivariate analyses, community living skills overall but not self-care correlated with PM total and subscales scores. In multivariate analyses, event-based PM was more predictive than time-based PM of the level of community living skills. In conclusion, PM has a significant impact on community living skills in schizophrenia and attention should be paid to this type of memory disturbance in rehabilitation of schizophrenia.

Event-based prospective memory in children with autism spectrum disorder: The role of executive function

The present study investigated event-based prospective memory (PM) and its cognitive correlates in children with autism spectrum disorder (ASD) compared to age- and ability-matched typically developing (TD) peers. Participants included 25 children with ASD, 25 age-matched TD peers, and 28 ability-matched TD peers. Participants completed one PM task, and several executive functioning tasks assessing working memory (Block Recall Task), inhibitory control (Stroop Task), and cognitive flexibility (Dimensional Change Card Sorting Task). Results indicated that children with ASD had significantly lower scores on the PM task than children in the TD groups. Additionally, PM performance of children with ASD was significantly predicted by their nonverbal IQ, whereas PM performance of TD children was significantly predicted by their inhibitory control. These results provide evidence for the PM deficit in children with ASD and the effect of cognitive functioning, rather than a specific aspect of executive function, on the development of PM.

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.

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 12years 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.