Prospective memory in an air traffic control simulation: External aids that signal when to act.

At work and in our personal life we often need to remember to perform intended actions at some point in the future, referred to as Prospective Memory. Individuals sometimes forget to perform intentions in safety-critical work contexts. Holding intentions can also interfere with ongoing tasks. We applied theories and methods from the experimental literature to test the effectiveness of external aids in reducing prospective memory error and costs to ongoing tasks in an air traffic control simulation. Participants were trained to accept and hand-off aircraft and to detect aircraft conflicts. For the prospective memory task, participants were required to substitute alternative actions for routine actions when accepting target aircraft. Across two experiments, external display aids were provided that presented the details of target aircraft and associated intended actions. We predicted that aids would only be effective if they provided information that was diagnostic of target occurrence, and in this study, we examined the utility of aids that directly cued participants when to allocate attention to the prospective memory task. When aids were set to flash when the prospective memory target aircraft needed to be accepted, prospective memory error and costs to ongoing tasks of aircraft acceptance and conflict detection were reduced. In contrast, aids that did not alert participants specifically when the target aircraft were present provided no advantage compared to when no aids were used. These findings have practical implications for the potential relative utility of automated external aids for occupations where individuals monitor multi-item dynamic displays. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Focal/nonfocal cue effects in prospective memory: Monitoring difficulty or different retrieval processes?

We investigated whether focal/nonfocal effects (e.g., Einstein et al., 2005) in prospective memory (PM) are explained by cue differences in monitoring difficulty. In Experiment 1, we show that syllable cues (used in Einstein et al., 2005) are more difficult to monitor for than are word cues; however, initial-letter cues (in words) are similar in monitoring difficulty to word cues (Experiments 2a and 2b). Accordingly, in Experiments 3 and 4, we designated either an initial letter or a particular word as a PM cue in the context of a lexical decision task, a task that presumably directs attention to focal processing of words but not initial letters. We found that the nonfocal condition was more likely than the focal condition to produce costs to the lexical decision task (task interference). Furthermore, when task interference was minimal or absent, focal PM performance remained relatively high, whereas nonfocal PM performance was near floor (Experiment 4). Collectively, these results suggest that qualitatively different retrieval processes can support prospective remembering for focal versus nonfocal cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control of cost in prospective memory: Evidence for spontaneous retrieval processes.

To examine the processes that support prospective remembering, previous research has often examined whether the presence of a prospective memory task slows overall responding on an ongoing task. Although slowed task performance suggests that monitoring is present, this method does not clearly establish whether monitoring is functionally related to prospective memory performance. According to the multiprocess theory (McDaniel & Einstein, 2000), monitoring should be necessary to prospective memory performance with nonfocal cues but not with focal cues. To test this hypothesis, we varied monitoring by presenting items that were related (or unrelated) to the prospective memory task proximal to target events. Notably, whereas monitoring proximal to target events led to a large increase in nonfocal prospective memory performance, focal prospective remembering was high in the absence of monitoring, and monitoring in this condition provided no additional benefits. These results suggest that when monitoring is absent, spontaneous retrieval processes can support focal prospective remembering. (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)     

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)     

Neural correlates of age-related declines in the formation and realization of delayed intentions.

Neural correlates of age-related declines in prospective memory were studied by using event-related brain potentials (ERPs) in a task in which individuals formed and later realized simple intentions. The behavioral data revealed that prospective responding was less accurate and slower in older than in younger adults. The electrophysiological data revealed age-related differences in the amplitude of modulations of the ERPs associated with the encoding of intentions, the detection of cues, and disengagement from the ongoing activity. These findings support the hypothesis that age-related declines in prospective memory result from a reduction in the efficiency with which older adults encode intentions and detect cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age and individual differences in prospective memory during a "Virtual Week": The roles of working memory, vigilance, task regularity, and cue focality.

Young (ages 18–22 years) and older (ages 61–87 years) adults (N = 106) played the Virtual Week board game, which involves simulating common prospective memory (PM) tasks of everyday life (e.g., taking medication), and performed working memory (WM) and vigilance tasks. The Virtual Week game includes regular (repeated) and irregular (nonrepeated) PM tasks with cues that are either more or less focal to other ongoing activities. Age differences in PM were reduced for repeated tasks, and performance improved over the course of the week, suggesting retrieval was more spontaneous or habitual. Correlations with WM within each age group were reduced for PM tasks that had more regular or focal cues. WM (but not vigilance) ability was a strong predictor of irregular PM tasks with less focal cues. Taken together, these results support the hypothesis that habitual and focally cued PM tasks are less demanding of attentional resources (specifically, WM), whereas tasks that are more demanding of controlled attentional processes produce larger age differences, which may be attributable to individual differences in WM. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Event-Based Prospective Memory Following Severe Closed-Head Injury.

Twenty-four severe closed-head injury (CHI) participants and 24 controls completed event-based prospective memory tasks concurrently with an ongoing working memory task. The event cue was either integrated with the ongoing working memory task (focal cue) or peripheral to it. Prospective remembering was poorer for the CHI group in both the focal- and peripheral-cue conditions. The groups did not differ on the ongoing task. The peripheral cue and the integrated focal cue also did not differ in ability to trigger prospective remembering. The results suggest that, even with highly salient event cues, severe CHI participants (> 1 year postinjury) are more likely than controls to exhibit prospective memory failures. The data revealed a link between CHI participants' prospective memory failures and momentary lapses of intention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The dynamics of intention retrieval and coordination of action in event-based prospective memory.

Event-based prospective memory requires responding to cues in the environment that are associated with a previously established intention. Some researchers believe that intentions reside in memory with an above baseline level of activation, a phenomenon called the intention superiority effect. The authors of this study predicted that intention superiority would be masked by additional cognitive processes associated with successful event-based prospective memory. These additional processes include noticing the cue, retrieving the intention, and coordinating intention execution with the ongoing activity, In 3 experiments, intention superiority was demonstrated by faster latencies to the ongoing activity on failed prospective trials and the existence of the additional processes was demonstrated by slower latencies on successful trials. This study demonstrates the importance of investigating the microstructure of the cognitive components involved with processing and responding to an event-based prospective memory cue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ongoing task delays affect prospective memory more powerfully than filler task delays.

The effect of delay on prospective memory (PM) is mixed. Research has typically shown that PM either decreases or remains unchanged as the time increases between intention formation and encounter with a PM cue. However, the results of one study demonstrated that PM sometimes increases with increasing delays (Hicks, Marsh, & Russell, 2000). Hicks et al. hypothesised that increasing the delay may afford an opportunity for people to spontaneously rehearse the intention, or to be reminded of the intention. In the present work, we tested delays of 6 minutes, 21 minutes, and 36 minutes. Two factors were orthogonally manipulated between-subjects. One was the duration of the filler task that came between intention formation and the beginning of the ongoing task in which PM cues were embedded. The second was the duration of the ongoing task prior to the presentation of the first PM cue. Lengthening the ongoing task delay decreased PM. However, lengthening the filler task nominally increased PM. These results suggest that delays within the ongoing task replicate the effects traditionally found in retrospective memory work. In contrast, delays between intention formation and the beginning of the ongoing task may not have straightforward effects on PM retrieval. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

On the Relationship Between Effort Toward an Ongoing Task and Cue Detection in Event-Based Prospective Memory.

In recent theories of event-based prospective memory, researchers have debated what degree of resources are necessary to identify a cue as related to a previously established intention. In order to simulate natural variations in attention, the authors manipulated effort toward an ongoing cognitive task in which intention-related cues were embedded in 3 experiments. High effort toward the ongoing task resulted in decreased prospective memory only when the cognitive processing required to identify the cue was similar to the cognitive processing required to complete the ongoing activity. When the required processing was different for the 2 tasks, cue detection was not affected by manipulated effort, despite there being an overall cost to decision latencies in the ongoing tasks from possessing the intention. Resource allocation policies and factors that affect them are proposed to account for ongoing vs. prospective memory task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Focal and nonfocal prospective memory performance in very mild dementia: A signature decline.

Objective: In a recent study, performance on a certain kind of prospective memory task (PM), labeled focal PM, was sensitive to the very early stages of Alzheimer's disease (AD; Duchek, Balota, & Cortese, 2006). This study sought to replicate and extend these findings by investigating both focal and nonfocal PM, as well as possible influences of alleles of the apolipoprotein E (ApoE) gene. Method: Thirty-five healthy older adults and 33 adults in the very earliest stages of AD, as determined by the clinical dementia rating scale, completed both focal and nonfocal PM tasks. Performance on these tasks has been linked to qualitatively different cognitive processes (Scullin, McDaniel, Shelton, & Lee, 2010), thereby providing leverage to illuminate the specific processes that underlie PM failures in very early AD. Approximately half of the adults in each group were ApoE e4 carriers and half were noncarriers. We also obtained participants' scores on a battery of standard psychometric tests. Results: There was a significant interaction between the type of PM task and dementia status, p p2 = .12, demonstrating that the AD-related decline was more robust for focal than for nonfocal PM. Further, focal PM performance significantly discriminated between the very earliest stages of AD and normal aging, explaining variance unique to that explained by typical psychometric indices. ApoE status, however, was not associated with PM performance. Conclusion: The pronounced deficit observed in the focal PM task suggests that spontaneous retrieval processes may be compromised in very early AD. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

When goals collide: The interaction between prospective memory and task switching.

The neural correlates of prospective retrieval mode, and the basis of the interaction between prospective memory (PM) and task switching, were examined using event-related brain potentials (ERPs). In two experiments individuals performed pure and mixed blocks of trials where they indicated whether or not a word was a noun or a verb or contained one or two vowels based upon a cue that was presented before the target stimulus. Experiment 1 revealed that prospective retrieval mode was associated with slow wave activity over the frontal and posterior regions of the scalp that differed in topography depending upon whether the PM cues were embedded in pure or mixed blocks of trials. This experiment also revealed that the neural correlates of task set configuration, but not cue encoding, were sensitive to PM load. These data indicate that PM load may effect task switching by influencing an individual's ability to maintain multiple task sets in working memory and to efficiently implement a given task set to guide task performance. Additionally, task switching may effect PM by influencing the degree to which individuals rely on stimulus-independent and stimulus-oriented processing to support the realization of delayed intentions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Age-related decline in prospective memory: The roles of cue accessibility and cue sensitivity.

In two experiments the authors evaluated the hypothesis that age-related decline in prospective memory reflects momentary lapses of intention (MLIs), and explored two factors, cue sensitivity and accessibility, that may contribute to MLIs. MLIs were reliably greater than zero in Experiment 1, indicating that performance fluctuated over the course of the task. Analysis of the response latency data (RL) revealed that older adults demonstrated elevated RL for missed prospective cues and were much slower to respond correctly to prospective cues than younger adults. These findings indicate preserved cue sensitivity in later adulthood and an age-related decline in cue accessibility. Experiment 2 demonstrated that cue sensitivity did not result from an orienting response to the perceptual novelty associated with the prospective cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Go with the flow: How to master a nonlinear multiple-cue judgment task.

The authors examined the cognitive processes that participants use in linear and nonlinear multiple-cue judgment tasks, hypothesizing that people are unable to use explicit cue abstraction in a nonlinear task, instead turning to exemplar memory. Experiment 1 confirmed that people are unable to use cue abstraction in nonlinear tasks but failed to confirm the hypothesized, spontaneous shift to exemplar memory. Instead, the participants appeared to be trapped in persistent and futile attempts to abstract the cue-criterion relations. Only after being instructed to rely on exemplar memory in Experiment 2 did they master the nonlinear task. The results suggest that adaptive shifts of representation need not occur spontaneously and that analytical thought may sometimes harm performance in nonlinear tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cost of remembering to remember in event-based prospective memory: Investigating the capacity demands of delayed intention performance.

Prospective memory tasks are often accomplished during the performance of other activities. Despite the dual-task nature of prospective memory, little attention has been paid to how successful prospective memory performance affects ongoing activities. In the first 2 experiments, participants performing an embedded prospective memory task had longer response times on nonprospective memory target trials of a lexical decision task than participants performing the lexical decision task alone. In the prospective memory groups, longer lexical decision response times were associated with better prospective memory performance (Experiments 1, 2, and 3), a pattern not demonstrated with an embedded retrospective memory task (Experiment 2). The results of Experiment 3 suggest that the retrieval of a delayed intention, or the prospective component, can require capacity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The age prospective memory paradox: Young adults may not give their best outside of the lab.

Previous research has identified the age prospective memory paradox of age-related declines in laboratory settings in contrast to age benefits in naturalistic settings. Various factors are assumed to account for this paradox, yet empirical evidence on this issue is scarce. In 2 experiments, the present study examined the effect of task setting in a laboratory task and the effect of motivation in a naturalistic task on prospective memory performance in young and older adults. For the laboratory task (Experiment 1, n = 40), we used a board game to simulate a week of daily activities and varied features of the prospective memory task (e.g., task regularity). For the naturalistic task (Experiment 2, n = 80), we instructed participants to try to remember to contact the experimenter repeatedly over the course of 1 week. Results from the laboratory prospective memory tasks indicated significant age-related decline for irregular tasks (p = .006) but not for regular and focal tasks. In addition, in the naturalistic task, the age benefit was eliminated when young adults were motivated by incentives (F     

Overcoming misinformation effects in eyewitness memory: effects of encoding time and event cues

Eyewitness memory is often distorted when misleading information is presented to subjects after encoding. Three experiments explored ways to overcome these misinformation effects. In Experiment 1, subjects viewed slides of a robbery, at a rate of four or seven seconds per slide. Five minutes later subjects were given a recognition test with few (1-3) or numerous (6-13) event cues. Providing numerous retrieval cues improved overall performance, but did not reduce the effects of misinformation. With week-long delays (Experiment 2) numerous retrieval cues did eliminate misinformation effects, but only when subjects viewed slides at the slower rate (seven seconds per slide). Experiment 3 essentially replicated this pattern, using a modified test to eliminate any biasing effects of distractors. Given adequate encoding and numerous retrieval cues, misinformation effects were eliminated, suggesting that under some conditions misinformation makes event memory inaccessible, but not unavailable.     

Investigating dissociations among memory measures: Support for a transfer-appropriate processing framework.

In three experiments subjects performed one of five tasks after an initial study phase. Results showed that performance on conceptually driven retention tasks (those requiring the processing of meaning) was consistently dissociated from that on data-driven tasks (those relying more on analysis of physical features). Performance on conceptually driven tasks of free recall, semantic cued recall, and a task of answering general knowledge questions was enhanced most when target items had been generated rather than read at study (Experiment 1) and when subjects formed mental images of item referents at study (Experiment 3). Conversely, the data driven tasks of word fragment completion and recall using graphemic cues were performed best when subjects read rather than generated items at input (Experiment 1) and when the physical features of study and test items matched in terms of modality (Experiment 2) and typography (Experiment 3). These findings indicate that dissociations among memory tasks are better explained in terms of the degree of overlap between mental operations at study and test than in terms of various memory systems underlying different tasks. (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)