Time-based Tasks Research Articles

Prospective memory and ageing paradox with event-based tasks: A study of young, young-old, and old-old participants

Research on ageing and prospective memory--remembering to do something in the future--has resulted in paradoxical findings, whereby older adults are often impaired in the laboratory but perform significantly better than younger adults in naturalistic settings. Nevertheless, there are very few studies that have examined prospective memory both in and outside the laboratory using the same sample of young and old participants. Moreover, most naturalistic studies have used time-based tasks, and it is unclear whether the prospective memory and ageing paradox extends to event-based tasks. In this study, 72 young (18-30 years), 79 young-old (61-70 years), and 72 old-old (71-80 years) participants completed several event-based tasks in and outside the laboratory. Results showed that the ageing paradox does exist for event-based tasks but manifests itself differently from that in time-based tasks. Thus, younger adults outperformed old-old participants in two laboratory event-based tasks, but there were no age effects for a naturalistic task completed at home (remembering to write the date and time in the upper left corner of a questionnaire). The young and old-old also did not differ in remembering to retrieve a wristwatch from a pocket at the end of the laboratory session. This indicates that the paradox may be due to differences in ongoing task demands in the lab and everyday life, rather than the location per se. The findings call for a concentrated effort towards a theory of cognitive ageing that identifies the variables that do, or do not, account for this paradox.

Effects of Age on Performance of Prospective Memory Tasks Differing According to Task Type, Difficulty and Degree of Interference

In this study we compare the performance of older and younger adults in prospective memory tasks. Our aim is to understand the differences between the performances of cognitively unimpaired older individuals and young people in prospective memory tasks using both events based and time based tasks, as well as to determine whether the prospective memory interference effect in the ongoing task differs according to the age samples. A further objective is to analyze whether the difficulty of the PM task (event-based versus time-based) affects the degree of interference in the ongoing task. Using four different event based prospective memory tasks, we found no differences between the young people and the cognitively unimpaired older individuals (even when increasing the difficulty of the ongoing task), neither in the time-based tasks or the PM interference effect. It was concluded that deterioration in performance on tasks involving the recall of pending intentions is not a problem associated with age but rather with another series of deficits in the cognitive processes.

Exposure to second‐hand smoke damages everyday prospective memory

Prospective memory (PM: remembering future intentions and activities) is critical to everyday remembering. This study compared a group of never-smokers who reported regular exposure to second-hand smoke (the SHS group) with a group of current smokers (the CS group) and a group of never-smokers who reported never having been exposed to SHS (the non-SHS group) on objective PM. An existing groups design was employed to compare the SHS, CS and non-SHS groups. Twenty-four SHS, 27 CS and 28 non-SHS were tested on objective PM. All participants were university undergraduates aged between 18-30 years. All participants were tested individually in a laboratory setting. The Cambridge Prospective Memory Test (CAMPROMPT) was used to assess objective PM. Age, other drug use, mood and IQ were also measured as covariates in the study. The non-SHS group recalled significantly more time-based PM tasks than the SHS group (means = 16.3 versus 13.7, P < 0.001) and significantly more than the CS group (CS mean = 11.6, P < 0.001); and the SHS group recalled significantly more time-based tasks than the CS group (P < 0.002). The non-SHS group recalled significantly more event-based PM tasks than the CS group (means = 15.2 versus 11.3, P < 0.002) with no significant difference between the non-SHS group and SHS group (SHS mean = 14.3, P = 0.234); and the SHS group recalled significantly more event-based tasks than the CS group (P < 0.001). Non-smokers exposed to second-hand smoke may suffer impairment in time-based prospective memory.

Deficits in retrospective and prospective components underlying prospective memory tasks in amnestic mild cognitive impairment

ObjectivesBy use of purer indices of PM and RM components than previous studies and adoption of three PM task types, the present study aimed to investigate the deficits of these two components underlying global impairment at a PM task in individuals with amnestic mild cognitive impairment (aMCI).MethodsNineteen aMCI patients and 22 normal controls were examined on event-, time- and activity-based PM tasks. Separate scores were obtained for initiation of intentions (i.e. PM component) and for the content of the intentions (i.e. RM component).ResultsIndividuals with aMCI achieved lower PM component (but not RM component) scores than NCs across all three PM tasks. Furthermore, there was a trend for greater impairment on activity-based than time-based and event-based PM tasks, but which did not reach significance. In addition, a significant association between PM component and an executive function test was observed in aMCI group. PM task performance, especially activity-based PM task performance and PM component performance, successfully discriminated between aMCI and NC and was able to do so above and beyond the executive function tests.ConclusionsOur finding suggested that the deficits in PM component, related to a disrupted executive control processes, were responsible for the impaired ability of individuals with aMCI to realize delayed intentions.

Time-Based Prospective Memory in Severe Traumatic Brain Injury Patients: The Involvement of Executive Functions and Time Perception

Prospective memory (PM) is the ability to remember to perform a future action at a specified later time, which is investigated through the use of event-based and time-based tasks. Prior investigations have found that PM is impaired following traumatic brain injury (TBI). However, there is limited information regarding the cognitive functions that mediate TBI and PM performance. Thus, this study investigated time-based PM in TBI patients, and the relationship among time-based PM, time perception, and executive functions. To accomplish this objective, 18 severe TBI patients and 18 healthy matched controls performed a time-based PM task, a time reproduction task, and two executive functions (Stroop and n-back) tasks. While both groups increased their monitoring frequency close to the target time, TBI patients monitored more and were less accurate than healthy controls at the target time confirming the time-based PM dysfunction in these patients. Importantly, executive functions, particularly inhibition and updating abilities, were strongly related to time-based PM performance; both time perception and executive functions are involved in time-based prospective memory in controls, whereas, only executive functions appear to be involved in TBI time-based prospective memory performance.

Adaptive power management system for mobile multimedia device

Recently, methods that combine the concepts of dynamic voltage scaling (DVS) and dynamic power management (DPM) approaches have been proposed for a single task. This study proposes adaptive power management system (APMS), which utilises useful features of both DPM and DVS and an existing pattern analysis algorithm, and new break even time-based task partition scheduling (BET-BTPS). APMS splits tasks based on BET to reduce the total power consumption of multiple multimedia applications in a mobile embedded system environment and analyses their usage patterns of peripheral devices and apply the results to their scheduling for further reduction of power consumption. It also takes into account the additional time delay that may occur while invoking and executing a timeslot scheduler to guarantee real-time services for multimedia data streams when the scheduling of APMS is in effect. In order to determine the optimal processor speed that minimises power consumption, the extra consumption required by the scheduler is compared with that reduced by BTPS. The proposed approach demonstrates better performance compared to existing power management schemes not only for single task but multiple tasks.

Positive effects of subclinical depression in prospective memory and ongoing tasks in young and old adults

ABSTRACT Results reported in the literature show that depression can have either negative or neutral effects on prospective memory (PM). The goal of the present study was to broaden the analysis of depression-related effects on PM, with regard to the possibility that subclinical depression may have positive influence on PM. A total of 120 participants from four groups (young/old, subclinically depressed/non-depressed) completed event- and time-based PM tasks embedded in the linear orders task or stories task, respectively. In the event-based PM task no effects of depression were found, whereas depressed participants were more accurate in the time-based PM task, where higher monitoring during the last minute of the task was observed. It was also found that depressed participants built a mental model in the linear orders task more accurately than controls. Results of the present study are discussed with reference to the analytical rumination hypothesis.

Processing Biases for Emotional Faces in 4- to 12-Year-Old Non-Clinical Children: An Exploratory Study of Developmental Patterns and Relationships with Social Anxiety and Behavioral Inhibition

The present study examined (a) processing biases for emotional facial stimuli in a sample of 355 4- to 12-year-old non-clinical children, (b) developmental patterns of such biases, and (c) to what extent biases were related to social anxiety and the temperamental trait of behavioral inhibition in children of various ages. Processing biases were assessed with a dot probe task and a dynamic emotion recognition paradigm (i.e., morph task), whereas children's levels of social anxiety and behavioral inhibition were measured by means of parent-report. Results showed that on the morph task children were generally faster in detecting happy faces compared to angry faces, and this effect was not qualified by age, social anxiety, or behavioral inhibition. Further analyses revealed no significant effect of age on bias scores. However, analyses did reveal two classes in the data with one class mainly consisting of younger children and the other class predominantly composed of older children: Younger children were in general slower, less accurate, and displayed more variance in their scores on the processing biases tasks than older children. Results of this study underline the need of the development and use of more age-appropriate, non-reaction time-based tasks for measuring processing bias in younger children.

Prospective memory, emotional valence and ageing

Emotional factors have been found to be an important influence on memory. The current study investigated the influence of emotional salience and age on a laboratory measure of prospective memory (PM); Virtual Week. Thirty young and 30 old adults completed Virtual Week, in which the emotional salience of the tasks at encoding was manipulated to be positive, negative or neutral in content. For event-based, but not time-based tasks, positivity enhancement in both age groups was seen, with a greater number of positive PM tasks being performed relative to neutral tasks. There was no negativity enhancement effect. Older adults showed generally poorer levels of PM, but they also demonstrated greater beneficial effects of positive valence compared to young. These effects of emotion on PM accuracy do not appear to reflect the retrospective component of the task as a different pattern of emotion effects was seen on the recall of PM content. Results indicate that older adults' difficulties in prospective remembering can be reduced where the tasks to be remembered are positive.

P01-222-Prospective memory performance in Chinese patients with bipolar affective disorder

IntroductionPersons suffering from bipolar affective disorder have a wide range of cognitive deficits, but there have been limited understanding of prospective memory performance. Time-based prospective memory is remembering to perform an action at a specific time, whereas event-based prospective memory is remembering to perform an action when an external cue appears.ObjectivesAssess the time-based and event-based prospective memory performance in Chinese persons diagnosed with bipolar affective disorder.AimsIdentify factors associated with prospective memory performance.MethodsA sample of 40 persons diagnosed with bipolar affective disorder were recruited from a psychiatric outpatient clinic. All participants completed the Cambridge Prospective Memory Test, Rivermead Behavioral Memory Test, Test of Nonverbal Intelligence - Third Edition, the Young Mania Rating Scale and Hamilton Rating Scale for Depression.ResultsThe mean total score of the Cambridge Prospective Memory Test of persons diagnosed with bipolar affective disorder was 24.4 ± 7.0. Time-based prospective memory performance was worse than event-based PM task. The Cambridge Prospective Memory Test total score was associated with the Hamilton Rating Scale for Depression score and Rivermead Behavioral Memory Test score. The performance of time-based prospective memory tasks was associated with the Hamilton Rating Scale for Depression score, and the performance of event-based prospective memory tasks was associated with the Rivermead Behavioral Memory Test total score.ConclusionsPersons diagnosed with bipolar affective disorder are found to have worse time-based than event-based prospective memory performance. The importance for everyday functioning and independent living needs to be explored in future studies.

A differential deficit in time- versus event-based prospective memory in Parkinson's disease.

The aim of the current study was to clarify the nature and extent of impairment in time- versus event-based prospective memory in Parkinson's disease (PD). Prospective memory is thought to involve cognitive processes that are mediated by prefrontal systems and are executive in nature. Given that individuals with PD frequently show executive dysfunction, it is important to determine whether these individuals may have deficits in prospective memory that could impact daily functions, such as taking medications. Although it has been reported that individuals with PD evidence impairment in prospective memory, it is still unclear whether they show a greater deficit for time- versus event-based cues. Fifty-four individuals with PD and 34 demographically similar healthy adults were administered a standardized measure of prospective memory that allows for a direct comparison of time-based and event-based cues. In addition, participants were administered a series of standardized measures of retrospective memory and executive functions. Individuals with PD demonstrated impaired prospective memory performance compared to the healthy adults, with a greater impairment demonstrated for the time-based tasks. Time-based prospective memory performance was moderately correlated with measures of executive functioning, but only the Stroop Neuropsychological Screening Test emerged as a unique predictor in a linear regression. Findings are interpreted within the context of McDaniel and Einstein's (2000) multiprocess theory to suggest that individuals with PD experience particular difficulty executing a future intention when the cue to execute the prescribed intention requires higher levels of executive control.

Metamemory and prospective memory in Parkinson's disease.

Metamemory is integral for strategizing about memory intentions. This study investigated the prospective memory (PM) deficit in Parkinson's disease (PD) from a metamemory viewpoint, with the aim of examining whether metamemory deficits might contribute to PM deficits in PD. Sixteen patients with PD and 16 healthy older adult controls completed a time-based PM task (initiating a key press at two specified times during an ongoing task), and an event-based PM task (initiating a key press in response to animal words during an ongoing task). To measure metamemory participants were asked to predict and postdict their memory performance before and after completing the tasks, as well as complete a self-report questionnaire regarding their everyday memory function. The PD group had no impairment, relative to controls, on the event-based task, but had prospective (initiating the key press) and retrospective (recalling the instructions) impairments on the time-based task. The PD group also had metamemory impairments on the time-based task; they were inaccurate at predicting their performance before doing the task but, became accurate when making postdictions. This suggests impaired metamemory knowledge but preserved metamemory monitoring. There were no group differences regarding PD patients' self-reported PM performance on the questionnaire. These results reinforce previous findings that PM impairments in PD are dependent on task type. Several accounts of PM failures in time-based tasks are presented, in particular, ways in which mnemonic and metacognitive deficits may contribute to the difficulties observed on the time-based task.

Prospective Memory Deficits in Patients with Bipolar Disorder: A Preliminary Study

Prospective memory (PM) is the ability to remember to do something in the future without explicit prompts. To date, little has been known about PM deficits in bipolar disorder (BD). This study examined the nature and correlates of PM in patients with BD. Forty clinically stable BD patients and 40 matched healthy controls formed the study sample. Socio-demographic characteristics, PM, psychosocial functioning, retrospective memory (RM), and IQ were measured in all participants, whereas clinical condition was measured in patients with standardized assessment instruments. Patients performed significantly more poorly on the time-based PM task than controls (10.6 ± 5.0 vs. 14.6 ± 3.0, p < .001). In correlation analyses, older age, lower education, more severe depressive and manic symptoms, poor psychosocial functioning, poor RM, and lower scores in IQ were significantly associated with poor performance in the time-based PM task, whereas poor RM and lower scores in IQ associated with poorer performance in the event-based PM task in patients. In multivariate analyses, severity of depression and older age significantly contributed to poor performance in the time-based PM task, whereas poor RM contributed to poor performance in the event-based PM task in patients. The time-based PM is impaired in BD patients. Depressive symptoms, age, and RM were determinants of certain aspects of impaired PM performance in BD patients.

Do Patients with Schizophrenia and Healthy Elderly People show Similar Patterns of Prospective Memory Performance?

Schizophrenia and normal aging have both been associated with structural and physiological changes in the prefrontal and temporal cortex and impairments in prospective memory (PM). This study aimed to compare PM performance in patients with schizophrenia, healthy older, and healthy younger individuals. Computerized event- and time-based PM tasks were administered to 30 patients with schizophrenia, 30 healthy older adults, and 30 healthy younger adults. The healthy older adults and patients with schizophrenia demonstrated deficits in time-based PM when compared with the healthy younger adults. However, only healthy older adults were found to be impaired in event-based PM when compared with the healthy younger adults. These findings suggest that patients with schizophrenia show a similar pattern of performance on one type but not another type of PM and provide only partial support for the accelerated aging hypothesis of schizophrenia.

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.

Prospective memory functioning in mild cognitive impairment.

The present study aimed to investigate prospective memory (PM) in persons with mild cognitive impairment (MCI). Twenty individuals with MCI (10 with an amnestic profile and 10 with a dysexecutive profile of cognitive impairment) and 20 control subjects (CS) were recruited. In the PM tasks, subjects had to execute three actions after 20 min had elapsed (time-based condition) or after a timer rang (event-based condition). Separate scores were computed for correct recall of the intention to perform the actions (prospective component) and for correct execution of the actions (retrospective component). Although individuals with MCI were less accurate than CS in both prospective (Cohen's d ranged from 1.04 to 2.23) and retrospective (Cohen's d ranged from 0.81 to 1.06) components of the experimental task, they were significantly more impaired in the former than the latter component (Cohen's d = 0.42). Moreover, the deficit in the prospective component of the time-based task was particularly evident in MCI participants presenting with a dysexecutive impairment in respect to amnestic MCI individuals (Cohen's d = 0.99). Results of the present study show that the ability of subjects with MCI to comply effectively with a planned delayed intention is impaired and suggest that dysexecutive disorders are likely responsible for this deficit.

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.

Is Schizophrenia a Syndrome of Accelerated Aging? Evidence from Prospective Memory Performance

Event Abstract Back to Event Is Schizophrenia a Syndrome of Accelerated Aging? Evidence from Prospective Memory Performance Raymond C. Chan1, 2*, Xiaohong Hong3, Zhangjiang Li4, David Shum5, Ya Wang1, 2 and Xin Yu6 1 Chinese Acadamy of Science, Neuropsychology and Applied Cognitive Neuroscience Lab, Institute of Psychology, China 2 Chinese Acadamy of Science, Key Laboratory of Mental Health, Institute of Psychology, China 3 Shantou University, Mental Health Center, China 4 Capital Medical University, Beijing Anding Hospital, China 5 Griffith University, School of Psychology and Griffith Institute for Health and Medical Research, Australia 6 Peking University, Institute of Mental Health, China This study compared prospective memory (PM) performance in schizophrenic patients and healthy younger and older individuals, and to test the accelerated aging hypothesis of schizophrenia. Computerized tests of PM capturing event-and time-based tasks were administered to 30 healthy older people (M = 69.90 years, SD = 7.14 years), 30 schizophrenic patients (M = 27.10 years, SD = 8.28 years), and 30 healthy younger adults (M = 25.47 years, SD = 8.85 years). The findings showed that the healthy older individuals and schizophrenic patients demonstrated deficits in time-based PM as compared to the healthy younger adults. However, schizophrenic patients did not significantly differ from the healthy older individuals in time-based PM, even after controlling for ongoing task performances. In addition, unlike healthy older adults, schizophrenic patients were not found to be impaired in event-based PM as compared to the young adults. Subsequent analyses showed that PM did not correlate with medication level or other clinical symptoms in schizophrenia except for the relation between time-based PM and negative symptoms (r = -0.43, p = 0.018).. Taken together, these findings suggest that, in terms of level of neurocognitive functions, schizophrenia may be a developmental stage analogue to a “mild” grade of aging and support the accelerated aging hypothesis of schizophrenia. Conference: The 20th Annual Rotman Research Institute Conference, The frontal lobes, Toronto, Canada, 22 Mar - 26 Mar, 2010. Presentation Type: Poster Presentation Topic: Psychiatric Citation: Chan RC, Hong X, Li Z, Shum D, Wang Y and Yu X (2010). Is Schizophrenia a Syndrome of Accelerated Aging? Evidence from Prospective Memory Performance. Conference Abstract: The 20th Annual Rotman Research Institute Conference, The frontal lobes. doi: 10.3389/conf.fnins.2010.14.00149 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 01 Jul 2010; Published Online: 01 Jul 2010. * Correspondence: Raymond C Chan, Chinese Acadamy of Science, Neuropsychology and Applied Cognitive Neuroscience Lab, Institute of Psychology, Beijing, China, rckchan@psych.ac.cn Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Raymond C Chan Xiaohong Hong Zhangjiang Li David Shum Ya Wang Xin Yu Google Raymond C Chan Xiaohong Hong Zhangjiang Li David Shum Ya Wang Xin Yu Google Scholar Raymond C Chan Xiaohong Hong Zhangjiang Li David Shum Ya Wang Xin Yu PubMed Raymond C Chan Xiaohong Hong Zhangjiang Li David Shum Ya Wang Xin Yu Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

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.

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.