Effect of age on event-based and time-based prospective memory.

The magnitude of age differences on event- and time-based prospective memory tasks was investigated in 2 experiments. Participants performed a working memory task and were also required to perform either an event- or time-based prospective action. Control participants performed either the working memory task only or the prospective memory task only. Results yielded age differences on both prospective tasks. The age effect was particularly marked on the time-based task. Performance of the event-based prospective task, however, had a higher cost to performance on the concurrent working memory task than the time-based task did, suggesting that event-based responding has a substantial attentional requirement. The older adults also made a significant number of time-monitoring errors when time monitoring was their sole task. This suggests that some time-based prospective memory deficits in older adults are due to a fundamental deficit in time monitoring rather than to prospective memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prospective memory impairment in individuals with Parkinson's disease.

This study investigated prospective memory and its relationship to executive and memory functions in persons with Parkinson's disease (PD). Twenty-three individuals with PD and 25 healthy comparison participants participated in the study. In the prospective memory tasks, participants were asked to execute 3 actions after 20 min (time-based condition) or after a timer ring (event-based condition). A score was computed for the correct recall of the intention to perform the actions (prospective component) and for the correct execution of the actions (retrospective component). Participants with PD also received an extensive neuropsychological test battery. PD participants were less accurate than comparison participants in the prospective component of the time-based but not the event-based task. Individuals with PD were also impaired on the retrospective component of both tasks. In the PD group, a general trend toward significant correlations was found between performance level on the prospective memory component of the time-based task and scores on executive and working memory measures. These results document that prospective memory is impaired in PD possibly in relation to a dysregulation of cognitive functions associated with frontal systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metamemory and prospective memory in Parkinson's disease.

Objective: 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. Method: 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. Results: 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. Conclusions: 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. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Normal aging and prospective memory.

We develop a laboratory paradigm for studying prospective memory and examine whether or not this type of memory is especially difficult for the elderly. In two experiments, young and old subjects were given a prospective memory test (they were asked to perform an action when a target event occurred) and three tests of retrospective memory (short-term memory, free recall, and recognition). From the perspective that aging disrupts mainly self-initiated retrieval processes, large age-related decrements in prospective memory were anticipated. However, despite showing reliable age differences on retrospective memory tests, both experiments showed no age deficits in prospective memory. Moreover, regression analyses produced no reliable relation between the prospective and retrospective memory tasks. Also, the experiments showed that external aids and unfamiliar target events benefit prospective memory performance. These results suggest some basic differences between prospective and retrospective memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in event-based prospective memory: A meta-analysis on the role of focal versus nonfocal cues.

Studies of age differences in event-based prospective memory indicate wide variation in the magnitude of age effects. One explanation derived from the multiprocess framework proposes that age differences depend on whether the cue to carry out a prospective intention is focal to ongoing task processing. A meta-analysis of 117 effect sizes from 4,709 participants provided evidence for this view, as age effects were greater when the prospective cue to the ongoing task was nonfocal compared with when it was focal. However, the results only support a weaker but not a stronger prediction of the multiprocess framework, as age impairments were reliably above zero for both types of retrieval cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of prospective memory in typically developing children.

Objective: This study aimed to use specifically designed tasks to capture time-based, activity-based, and event-based prospective memory (PM) performance in typically developing school-age children. Method: Two PM tasks (Fishing Game & Happy Week) were used to examine the developmental patterns of PM in these children. Retrospective memory (RM) was also examined in these tasks. A total of 120 children aged between 7 and 12 years (10 girls and 10 boys in each age band) were recruited. Tests of working memory, inhibition, and IQ were also administered. Results: The age effect on PM accuracy was significant, with improvements identified between ages 7 to 8 and 10 to 11 years. For both tasks, performance on the time-based PM task was significantly poorer than that on the event-based PM task, which in turn was significantly poorer than that on the activity-based PM task. In terms of errors, results indicated that while errors associated with the PM component of the tasks decreased with age, errors associated with the RM component showed an inverted-U shape. The different patterns of errors suggest qualitative as well as quantitative differences in PM development in children. Finally, IQ, working memory, and inhibition were found to relate to PM when age was partialed out. Conclusions: Results of the study highlight the importance of contextual cues, such as activities and events, for prospective remembering in children. In addition, they have provided a general picture of PM development in school-age children and have implications for educators and parents. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The source of adult age differences in event-based prospective memory: A multinomial modeling approach.

Event-based prospective memory involves remembering to perform an action in response to a particular future event. Normal younger and older adults performed event-based prospective memory tasks in 2 experiments. The authors applied a formal multinomial processing tree model of prospective memory (Smith & Bayen, 2004) to disentangle age differences in the prospective component (remembering that you have to do something) and the retrospective component (remembering when to perform the action) of prospective memory performance. The modeling results, as well as more traditional analyses, indicate age differences in the resource-demanding prospective component. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Meta-Analytic Review of Prospective Memory and Aging.

A meta-analysis of prospective memory (PM) studies revealed that in laboratory settings younger participants outperform older participants on tests of both time- and event-based PM (rs=-.39 and -.34, respectively). Event-based PM tasks that impose higher levels of controlled strategic demand are associated with significantly larger age effects than event-based PM tasks that are supported by relatively more automatic processes (rs=-.40 vs. -.14, respectively). However, contrary to the prevailing view in the literature, retrospective memory as measured by free recall is associated with significantly greater age-related decline (r=-.52) than PM, and older participants perform substantially better than their younger counterparts in naturalistic PM studies (rs=.35 and .52 for event- and time-based PM, respectively). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prospective memory functioning in mild cognitive impairment.

Objective: The present study aimed to investigate prospective memory (PM) in persons with mild cognitive impairment (MCI). Method: 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). Results: 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). Conclusions: 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance predictions improve prospective memory and influence retrieval experience.

In retrospective memory, performance predictions have been found to enhance performance on subsequent memory tests. In prospective memory, the influence of metacognitive judgments on performance has not been investigated systematically. In the present study, 140 undergraduate students performed a complex short-term memory task that included a prospective memory task. Half of them gave performance predictions after the prospective memory task instructions. In addition, the specificity of the prospective memory task was manipulated by instructing participants either to perform an action when a word that belongs to the category of musical instruments was presented or to respond when the word “trumpet” was presented. The results showed that performance predictions enhanced performance, but only for the categorical task. Additional analyses of retrieval experience showed that performance predictions lead to an increase in search experiences while cue specificity was accompanied by an increase in pop up experiences. The results indicate that performance predictions can improve prospective performance and thus may be a valuable strategy for assisting prospective memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Age-related deficits in prospective memory: The influence of task complexity.

Younger and older Ss were asked to perform an action whenever target words occurred during a short-term memory task. The difficulty of this prospective memory task was manipulated by varying the delay preceding the occurrence of a target event and by varying the number of different target events. Age-related performance differences emerged when there were several different target events but not when there was 1 target event presented several times. Age-related performance differences, when they occurred, were associated with poorer retrospective memory for the target events. The results were interpreted in terms of a componential analysis of prospective memory, which assumes both similarities and differences between prospective and retrospective memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and prospective memory: The influence of increased task demands at encoding and retrieval.

A feature of prospective memory tasks is that they tend to be embedded into other background activities. Two experiments examined how the demands of these background activities affect age differences in prospective memory. The first experiment showed that increasing the demands of the background activities (by adding a digit-monitoring task) significantly reduced prospective memory performance. Planned comparisons revealed that age differences in prospective memory were reliable only in the more demanding background condition. The second experiment revealed significant prospective memory declines when the demands were selectively increased at encoding for both younger and older adults. When the demands were selectively increased at retrieval, older adults were particularly affected. The authors propose a model that relies on both automatic retrieval processes and working memory resources to explain prospective memory remembering. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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

Objective: 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. Method: 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. Results: 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. Conclusions: 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. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Event-based prospective memory and executive control of working memory

In 5 experiments, the character of concurrent cognitive processing was manipulated during an event-based prospective memory task. High- and low-load conditions that differed only in the difficulty of the concurrent task were tested in each experiment. In Experiments 1 and 2, attention-demanding tasks from the literature on executive control produced decrements in prospective memory. In Experiment 3, attention was divided by different loads of articulatory suppression that did not ultimately lead to decrements in prospective memory. A high-load manipulation of a visuospatial task requiring performance monitoring resulted in worse prospective memory in Experiment 4, whereas in Experiment 5 a visuospatial task with little monitoring did not. Results are discussed in terms of executive functions, such as planning and monitoring, that appear to be critical to successful event-based prospective memory.     

A Multinomial Model of Event-Based Prospective Memory.

Prospective memory is remembering to perform an action in the future. The authors introduce the 1st formal model of event-based prospective memory, namely, a multinomial model that includes 2 separate parameters related to prospective memory processes. The 1st measures preparatory attentional processes, and the 2nd measures retrospective memory processes. The model was validated in 4 experiments. Manipulations of instructions to place importance on either the prospective memory task or the background task (Experiments 1 and 2) and manipulations of distinctiveness of prospective memory targets (Experiment 2) had expected effects on model parameters, as did a manipulation of the difficulty of prospective memory target encoding (Experiments 3 and 4). An alternative model was also evaluated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cognitive processes underlying event-based prospective memory in school-age children and young adults: A formal model-based study.

Fifty children 7 years of age (29 girls, 21 boys), 53 children 10 years of age (29 girls, 24 boys), and 36 young adults (19 women, 17 men) performed a computerized event-based prospective memory task. All 3 groups differed significantly in prospective memory performance, with adults showing the best performance and with 7-year-olds showing the poorest performance. We used a formal multinomial process tree model of event-based prospective memory to decompose age differences in cognitive processes that jointly contribute to prospective memory performance. The formal modeling results demonstrate that adults differed significantly from the 7-year-olds and the 10-year-olds on both the prospective component and the retrospective component of the task. The 7-year-olds and the 10-year-olds differed only in the ability to recognize prospective memory target events. The prospective memory task imposed a cost to ongoing activities in all 3 age groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prospective memory in Parkinson disease across laboratory and self-reported everyday performance.

Prospective memory is a complex cognitive construct ubiquitous in everyday life that is thought to sometimes rely on executive skills commonly affected by Parkinson’s disease (PD). The present study investigated the effect of PD on prospective memory tasks with varying demand on executive control processes, namely on the amount of strategic attentional monitoring required for intention retrieval. Individuals with PD but without dementia and healthy adults performed laboratory event-based prospective memory tasks that varied in whether strategic attentional monitoring (nonfocal condition) or spontaneous processes (focal condition) were primarily involved in intention retrieval. Participants also completed a questionnaire rating their frequency of prospective memory failures in everyday life for both self-cued and environment-cued tasks. PD participants performed worse than non-PD participants in the nonfocal, but not focal, condition of the laboratory task. They also reported more everyday failures than non-PD participants for self-cued, but not environment-cued, prospective memory tasks. Thus, nondemented individuals with PD are preferentially impaired on prospective memory tasks for which higher levels of executive control are needed to support intention retrieval. This pattern is consistent across laboratory and reported real-world performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prospective memory across adolescence: The effects of age and cue focality.

The present study examined the role of controlled attention in age differences in event-based prospective memory performance across adolescence. The researchers tested whether presenting the prospective memory cue in or out of focal awareness of the ongoing task (resulting in low versus high demands for controlled attention, respectively) might affect age-related prospective memory performance. In total, 119 Chinese participants ages 13 to 20 took part in this study (60 adolescents: age M = 13.26 years, SD = 0.50; 23 boys; 59 young adults: age M = 19.70 years, SD = 0.87; 19 men). Findings demonstrated a significant interaction, F(1, 114) = 6.41, p