Time-based Prospective Memory Task Research Articles

Time-based prospective memory performance in young children

Time-based prospective memory refers to the ability to remember to execute a delayed intention after a specific time. In this study, for the first time, a time-based prospective memory task was applied in a sample of 42 kindergarten children (age range: 62 to 87 months) while simultaneously playing a game of Memory/Pairs as the continuous ongoing activity. Significant age differences were identified, as prospective task performance was positively correlated with age. Still, even the youngest children were able to perform the time-based memory task at a basic level. In addition, time-based prospective memory performance was associated with processing speed and working memory. These findings indicate that already by kindergarten age, children are able to remember to carry out a delayed intention on their own initiative. Yet, this ability still develops over time. A possible mechanism in time-based prospective memory development might be seen in the development of working memory resources.

Time-Based Prospective Memory Performance and Time-Monitoring in Children with ADHD

The current study investigated prospective memory (PM) performance in children with attention deficit/hyperactivity disorder (ADHD) and controls and aimed at exploring possible underlying factors of PM performance. Twenty-two children with ADHD and 39 age- and ability-matched typically developing children performed a computerized time-based PM task. As predicted, children with ADHD had fewer correct PM responses than controls. Neither differences in overall ongoing task performance nor, remarkably, differences in overall frequency and accuracy of time monitoring were found. Exploratory analyses suggest that individual differences in time monitoring in the final interval before target times may be related to PM performance in ADHD.

Time-based prospective memory impairment in patients with thalamic stroke.

The role of the thalamus in memory is potentially very complex. However, most studies on the memory impairments of thalamic lesions have focused on retrospective memory, rarely on prospective memory. To explore the effect of thalamic lesions on event-based prospective memory (EBPM) and time-based prospective memory (TBPM), respectively, and to verify the hypothesis that the thalamus is involved in the prospective memory, EBPM and TBPM tasks were administered to 18 thalamic stroke patients and 18 age- and education-matched healthy controls. In the EBPM task, subjects were asked to perform an action whenever particular words were presented. In the TBPM task, subjects were asked to perform an action at certain times. Compared with the performance of healthy controls on EBPM and TBPM tasks (EBPM, 4.3 +/- 1.5; TBPM, 5.4 +/- 1.0), there was a significant difference in the performance of thalamic stroke patients in the TBPM tasks (2.4 +/- 1.6), but no difference was found in EBPM tasks (3.7 +/- 1.1). These results may indicate that the thalamus is involved in PM and particularly in TBPM.

Are Older Adults More Social Than Younger Adults? Social Importance Increases Older Adults' Prospective Memory Performance

ABSTRACT The purpose of this study was to explore the influence of social importance on prospective remembering in younger and older adults as a possible factor contributing to the age-prospective memory paradox. Using a between-subjects design, 40 younger and 40 older adults worked on a time-based prospective memory task in which social importance was varied. Overall, younger adults outperformed older adults in the prospective memory task. Importantly, in contrast to younger adults, older adults' prospective memory performance was significantly better in the social importance condition than in the standard condition. This interaction was not reflected in participants' time-monitoring behaviour. Findings are discussed in the context of recent prospective memory theories.

Prospective Memory in the Nursing Environment: Effects of Type of Prospective Task and Prospective Load

A nurse's working environment may place high demands on both event-based and time-based prospective memory (PM), leading to forgetting. In the field of nursing, forgetting can have serious consequences and put a patient's life in danger. To better understand the role of prospective load (quantity of PM tasks in memory) in nursing, the current study will examine the effects of type of PM task being performed (event-based or time-based) and quantity of PM tasks (n = 1 or 4) on performance of an ongoing task and PM task(s). A novel paradigm will be used to capture naturalistic elements of the nursing environment. Forty registered nurses will complete a representative documentation task in a full-scale mock-up patient room, while also remembering to perform 1 or 4, event-based or time-based PM task(s). Results from this study can be used to further the literature on prospective load, explain possible causes of nursing error, and inform the design of memory technology aides.

Motivation, depression, and naturalistic time-based prospective remembering

This study investigated the effect of a motivational manipulation on naturalistic time-based prospective memory (PM) task performance. The association between depression and PM task performance was also investigated. First-year psychology students were required to send mobile phone text messages (SMSs) at a specific time 3 days and 6 days after an initial meeting. During the delay period participants recorded details of the retrieval whenever they remembered the SMS task. Participants given the incentive of extra course credit (motivation condition) outperformed their counterparts on the PM tasks, and showed a greater increase in the reported frequency of self-initiated retrievals on target days. Depression was negatively correlated with PM task performance. The findings suggest that motivational instructions impact the controlled processes underlying PM.

Time-related processes in time-based prospective memory and in time-interval production

Time-based prospective memory tasks require the retrieval of previously formed plans (e.g., call me on my mobile phone) either at a specified time (e.g., at 3 p.m.) or after a specified period of time has elapsed (e.g., in 3 min). In the present study, we investigated whether the same time-related processes are recruited for a short-duration time-based prospective memory task and for a time-interval production task. In a dual-task paradigm, we required young adult participants to make category-membership decisions, while they were simultaneously engaged either in a time-based prospective memory tasks or in a time-interval production task. Under one set of conditions, participants were instructed to allocate attention equally to the two tasks, whereas in another set of conditions, they allocated attention primarily to the time-relevant task. The findings revealed that time estimates were not affected by the attention allocation manipulation, although it influenced performance on the concurrent category membership decision making task, and as expected time estimates were more accurate on the prospective memory task than on the time-production task. Based on the preponderance of the findings, we suggest that timing is managed by different mechanisms and/or strategies on time-interval production tasks and on short-duration time-based prospective memory tasks.

Global impairment of prospective memory following acute alcohol

Whilst the deleterious effects of alcohol on retrospective remembering have been widely documented, no study has yet objectively determined alcohol's effects on prospective memory (PM)--remembering to do something in the future. With this aim, the present study determined the acute effects of alcohol upon PM using a laboratory measure that simulates the PM tasks in everyday life--'Virtual Week'--both (a) in its standard form with regular, irregular, event-based and time-based PM tasks; and (b) an adapted version which enabled exploration of how future event simulation at encoding impacted upon subsequent PM. Forty healthy volunteers were administered 0.6 g/kg ethanol or a matched placebo in a double-blind fashion and completed the two versions of Virtual Week along with prose recall (to tap retrospective memory) and an executive function task. Alcohol acutely produced global impairments across all (regular, irregular, event-based and time-based) PM tasks. It also produced impairments of episodic memory which positively correlated with PM performance of irregular tasks. Future-event simulation tended to enhance PM in the placebo but not in the alcohol group. These findings on an objective measure of PM suggest that 4-5 units of alcohol will compromise PM abilities in everyday life.

Time-Based Prospective Memory in Children With Autism Spectrum Disorder

AbstractIn this study, for the first time, prospective memory was investigated in 11 school-aged children with autism spectrum disorders and 11 matched neurotypical controls. A computerised time-based prospective memory task was embedded in a visuospatial working memory test and required participants to remember to respond to certain target times. Controls had significantly more correct prospective memory responses than the autism spectrum group. Moreover, controls checked the time more often and increased time-monitoring more steeply as the target times approached. These differences in time-checking may suggest that prospective memory in autism spectrum disorders is affected by reduced self-initiated processing as indicated by reduced task monitoring.

Frontal lobe involvement in a task of time-based prospective memory

Time-based prospective memory (PM) has been found to be negatively affected by aging, possibly as a result of declining frontal lobe (FL) function. Despite a clear retrospective component to PM tasks, the medial temporal lobes (MTL) are thought to play only a secondary role in successful task completion. The present study investigated the role of the FLs and MTLs in time-based PM, as well as their involvement in clock monitoring, plan generation, and time estimation, each of which may play a role in the execution of time-based PM tasks. Based upon their scores on composite measures of FL and MTL function, 32 older adults were divided into four groups, and were then tested on a time-based laboratory PM task. Overall age effects were also assessed and each of the four groups was compared to a group of 32 younger adults. High-frontal functioning participants demonstrated better prospective memory than low-frontal functioning participants, and were not distinguishable from younger adults. Older adults with high-MTL scores performed significantly better than those with low-MTL scores, but only if they were also high in FL function. FL function, but not MTL function, predicted patterns of clock monitoring, quality of plans generated to assist in time-based PM performance, and the accuracy of time estimation. Again, on each of these measures the performance of the high-frontal group was equivalent to that of the younger adults. The results of this study suggest that it is not aging per se that disrupts PM performance, but it is instead primarily the diminished frontal function seen in a subset of older adults.

Prospective memory in normal aging and Alzheimer's disease

Remembering to implement intented activities such as remembering to take medications is referred to as prospective memory (PM). Studies on aging and PM show important variations in the magnitude of the effect of age. One explanation, derived from the multiprocess framework, proposes that age differences depend on retrieval processing. It is thought to be automatic for event-based PM tasks by contrast to self-initiated processing for time-based PM tasks. Older adults generally perform worse than younger ones in laboratory tasks. PM tasks show pronounced age-related deficits, particularly in tasks demanding high level of controlled strategies (e.g. in time-based tasks versus in event-based tasks or, in low salience cue condition versus high salience cue condition in event-based tasks). However, age differences in PM tasks settings differ substantially across studies: some of them show that older adults perform as well as younger ones in event-based PM tasks, especially in ecological ones. Developmental psychologists have investigated this topic, and suggested that several factors could potentially be responsible for the age-related differences observed in MP. These differences could be related to the characteristics of PM cues (e.g. the strength of the association between PM cues and intended actions), the complexity or demands of the ongoing task, or the involvement of planning processes, in other words, the involvement of executive functions. PM deficits are important in mild Alzheimer's disease, even more important than episodic memory or executive functions deficits. This article presents a critical review of cognitive and neuropsychological studies that examined whether these factors or other partly mediate the older adults deficits in prospective memory, which are more important than those observed in episodic memory. The variability of results between studies points to the concept complexity.

Predictors of prospective memory in adults with traumatic brain injury

Previous studies have established that prospective memory is commonly affected following traumatic brain injury (TBI). This study examines whether demographic factors, injury severity and site, executive function, and metacognitive factors predict prospective memory performance in adults with TBI, using a cross-sectional multivariate correlational model. Prospective memory of 44 adults (mean age = 30 years) with severe TBI was measured by the Cambridge Prospective Memory Test (CAMPROMPT) time-based and event-based scores. Using stepwise multiple regression, the time-based score was predicted by the Controlled Oral Word Association Test (COWAT) Animals subtest score, length of post-traumatic amnesia (PTA) and use of note-taking on the CAMPROMPT. The event-based score was predicted by length of PTA and COWAT Animals score. Therefore, patients with longer periods of PTA and executive function impairment may be expected to display poorer prospective memory. Note-taking was associated with improved performance on time-based prospective memory tasks.

The Relative Importance of Suboperations of Prospective Memory

An event-based and a time-based prospective memory (PM) task, a script generation task, several working memory tasks, an incidental retrospective memory task, and a screen clock were implemented on the computer in one integrated procedure lasting between one and two hours. The procedure was designed to simulate four working days and four nights for a white-collar employee. Sixty-eight normal participants completed the task. Time-based prospective memory (self-injecting and going to bed at preordained times of day) shared unique variance with clock checking, but hardly at all with incidental retrospective memory. On the other hand, event-based prospective memory (answering a faint telephone cue as quickly as possible) shared unique variance with incidental retrospective memory of formally task irrelevant context and less with clock checking. The latter correlational dissociation of event-based versus time-based PM by retrospective memory reached significance, inspiring the idea that administrative versus clerical work might each impose its own type of PM demands. In both types of PM, low-level abilities (use of external aids and incidental encoding of context, respectively) seem to be critical for good performance, more so than for high-order executive functions. Our software is offered to the readership to explicitate these findings further or for other research pursuits.

Levodopa improves time-based prospective memory in Parkinson's disease

The present study was aimed at investigating the effect of acute levodopa administration on the performance of a group of individuals with Parkinson's disease (PD) on a time-based prospective memory task. Twenty PD patients and 15 healthy controls were administered a task that required executing three actions after 10 min had elapsed in three consecutive trials. Scores were computed for correct recall of the intention to perform the actions and for correct execution of the actions. PD participants were evaluated after a 12-hr drug wash-out in two conditions: (1) after levodopa administration ("on"); (2) without drug administration ("off"). In the "on" condition, PD patients were significantly more accurate in retrieving the intention to perform the actions than in the "off" condition and their performance was actually comparable to that of healthy controls. The increased accuracy in complying with the prospective memory task following levodopa medication supports the idea that dopamine depletion plays a role in the prospective memory deficits observed in PD patients.

Prefrontal cortex involvement in the event-based prospective memory: Evidence from patients with lesions in the prefrontal cortex

Primary objective: The aim of the present study was to investigate the event-based prospective memory (EBPM) and time-based prospective memory (TBPM) in patients with lesion in prefrontal cortex (PFC) and test the hypothesis that the prefrontal cortex is involved in the prospective memory (PM) network.Research design: The performance of patients with lesion in PFC (n= 30) was compared with that of a demographically matched control group (n= 30).Methods and procedures: A neuropsychological battery of tests including EBPM and TBPM tasks were administered to both groups.Main outcome and results: The group with lesion in PFC were significantly impaired in EBPM, but insignificantly impaired in TBPM tasks. There was no difference in performance of EBPM and TBPM tasks between the patients with lesion in the left and the right PFC.Conclusions: These results suggest that the patients with lesion in PFC were impaired in EBPM, but not in TBPM, implying that EBPM and TBPM may have different neural substrates. It is possible that PFC is more selectively involved in EBPM, but less in TBPM.

Dopaminergic Modulation of Prospective Memory in Parkinson’s Disease

Growing interest is present in literature on the study of prospective memory functioning in Parkinson’s disease (PD). Current data indicate that prospective memory may be impaired in PD and a relationship with general executive dysfunctioning has been suggested. However, although the dopamine dependency of cognitive dysfunction in PD has been widely investigated, poor is known on the dopaminergic modulation of PM. In the present study we explored the effect of acute administration of levodopa on the performance of a PD sample (n = 20) in a time-based prospective memory task. PD patients were evaluated in the morning after a 12-hour therapy wash-out in two experimental conditions: i) after levodopa assumption (“on”); (ii) without drug administration (“off”). The experimental task required to execute three uncorrelated actions after 10' for three consecutive trials. Distinct scores for the spontaneous recall of the intention to perform the actions (prospective component) and for the correct execution of the actions (retrospective component) have been computed. Results showed that in the “off”condition PD patients were selectively impaired on the prospective component of the task. However, L-dopa administration significantly improved PD patients’ performance actually restoring the prospective memory deficit. These results support a critical role of dopaminergic modulation in prospective memory processes in PD patients, possibly through the replacement of dopamine levels in fronto-striatal pathways.

Characteristics of prospective memory deficits in HIV-seropositive substance-dependent individuals: Preliminary observations

The construct of “prospective memory” (PM) refers to a type of episodic memory for a future intention or “remembering what one must do.” This function has been proposed as a candidate mechanism underlying behaviors of critical importance in HIV disease, including adherence with medication regimens and continued engagement in risk behavior. We administered tasks of time-based and event-based prospective memory and control tasks of retrospective and working memory to 31 HIV-seropositive and 35 HIV-seronegative substance-dependent individuals (SDIs). We found that compared with HIV− controls HIV+ participants showed deficits in time-based but not event-based PM. Retrospective, but not working, memory performance correlated significantly with time-based PM performance. In addition, performance on the time-based PM task was a significant predictor of scores on a self-report measure of risky sexual and injection practices. These preliminary data provide new and unique findings regarding the components of executive function mediated by prefrontal cortical systems that are impaired among HIV+ SDIs and their relevance to “real-world” behaviors.

Is time-based prospective remembering mediated by self-initiated rehearsals? Role of incidental cues, ongoing activity, age, and motivation.

The present research examined self-reported rehearsal processes in naturalistic time-based prospective memory tasks (Study 1 and 2) and compared them with the processes in event-based tasks (Study 3). Participants had to remember to phone the experimenter either at a prearranged time (a time-based task) or after receiving a certain text message (an event-based task) and record the details of occasions when they thought about this intention during a 7-day delay interval. The rehearsal and retrieval of time-based tasks was mediated by more automatic than deliberate self-initiated processes. Moreover, the number of reported rehearsals without any apparent triggers was reliably higher in time- than in event-based tasks. Additional findings concern the effects of age, motivation, and ongoing activities on rehearsal and prospective memory performance.

Differential involvement of regions of rostral prefrontal cortex (Brodmann area 10) in time- and event-based prospective memory

Rostral prefrontal cortex (approximating Brodmann area 10) has been shown repeatedly to have a role in the maintenance and realization of delayed intentions that are triggered by event cues (i.e., event-based prospective memory). The cerebral organization of the processes associated with the use of time cues (time-based prospective memory) has however received less attention. In two positron emission tomography (PET) studies we therefore examined brain activity associated with time- and event-based prospective memory tasks. In the time-based condition of the first study, young healthy volunteers were asked to make a prospective response based on their self-estimation of the passage of time while engaged in an attention-demanding ongoing activity. In the time-based condition of the second study, participants had a clock available in the ongoing task display and did not need to estimate the time for the prospective response. In the event-based condition of both studies, participants were asked to make a prospective response when prospective cues were presented in ongoing trials. Both studies showed activation differences in rostral prefrontal cortex according to whether the task was time- or event-based. In study one, an area of left superior frontal gyrus was more active in the time-based condition. In study two, three rostral prefrontal regions were more active in the time-based condition: right superior frontal gyrus, anterior medial frontal lobe and anterior cingulate gyrus. A region in left superior frontal gyrus, different from the area found in the first study, was more active in the event-based condition. These results indicate involvement of multiple brain regions of rostral prefrontal cortex in time- and event-based prospective memory. The results are interpreted as reflecting the differing processing demands made by event- or time-based prospective memory tasks, and the differing demands of time-based tasks according to whether a clock is present as an aid.

Time monitoring and executive functioning in children and adults

This study examined time-based prospective memory performance in relation to individual and developmental differences in executive functioning. School-age children and young adults completed six experimental tasks that tapped three basic components of executive functioning: inhibition, updating, and mental shifting. Monitoring performance was examined in a time-based prospective memory task in which participants indicated the passing of time every 5 min while watching a movie. Separate analyses of the executive functioning data yielded a two-factor solution for both age groups, with the updating and inhibition tasks constituting a common factor and the shifting tasks constituting a separate factor. Both children and adults showed accelerating monitoring functions with low rates of clock checking during the early phase of each 5-min interval. However, compared with adults, children needed more clock checks for obtaining the same level of response accuracy. Executive functioning had selective effects on time-based prospective memory performance. In both children and adults, monitoring performance was related to the inhibition and updating components, but not to the shifting component, of executive functioning. We conclude that difficulties in temporary maintenance and updating of working memory contents may create discontinuities in sense of time, leading to an increased reliance on external cues for time keeping.