Prospective Memory Monitoring Research Articles

When is context used to guide prospective memory monitoring?

Monitoring the environment for prospective memory (PM) targets can be attentionally demanding, such as searching for a pharmacy to pick up medication while driving in traffic. It is therefore optimal to increase monitoring in contexts when the probability of encountering a PM target is high (e.g., business plaza) and decrease monitoring in contexts when the probability is low (e.g., residential area), referred to as strategic monitoring. In some instances, though, identifying whether the context is appropriate for monitoring can be attentionally demanding. For example, when contextual information varies unpredictably, it may be easier to continuously monitor rather than dynamically increase and decrease monitoring on a moment-by-moment basis. The current study extends previous research by showing that participants strategically monitor when the ongoing task automatically orients attention to contextual information (i.e., focal context cues), regardless of the difficulty of checking for PM targets (Experiment 1). In contrast, when ongoing task processing does not orient attention to contextual information (i.e., nonfocal context cues), participants only strategically monitor when the demands of target checking are high (Experiment 2). These findings suggest that the decision to utilize context to adjust monitoring is driven by a cost-benefit analysis that weighs the perceived efforts of context identification relative to the expected benefit of not having to check for PM targets on half of the trials. When the perceived effort of identifying context on each trial is outweighed by the benefit of reducing target checking on a subset of trials, strategic monitoring occurs.

Effect of social importance on prospective memory monitoring cost: An event-related potential study

Effect of social importance on prospective memory monitoring cost: An event-related potential study

External Time Monitoring in Time-Based Prospective Memory: An Integrative Framework.

We propose a new integrative framework of external time monitoring in prospective memory (PM) tasks and its relation with performance. Starting from existing empirical regularities andour theoretical analysis, theframework predicts that external monitoring in PM tasks comprises a first stage of loose monitoring to keep track of the passage of time, and a subsequent stage of finer-grained monitoring, based on interval reduction, to meet the PM deadline. Following our framework, we predicted and observed in three different datasets (N = 375): (1) a marked increase in external monitoring frequency in the final part of the period of the PM task, well captured by a proportional rate exponential growth function; (2) a positive association between individual compliance with this monitoring pattern and PM performance; (3) a positive relation between monitoring frequency in the time window immediately preceding the PM deadline and PM performance at the individual level; and (4) good individual compliance with an interval reduction pattern in external monitoring, especially in the time window closer to the PM deadline. These results support the proposed integrative framework, which has the potential to foster future research on external monitoring in PM and in other fields of cognitive science.

Eye tracking reveals two components of monitoring in prospective memory

Eye tracking reveals two components of monitoring in prospective memory

Prospective memory monitoring and aftereffects of deactivated intentions across the lifespan

The purpose of this study was to compare, across the lifespan, different costs that can occur in a prospective memory task. Specifically, we were interested in investigating the costs of responding to both activated (i.e., monitoring costs) and deactivated intentions (i.e., aftereffects). In two experiments, children, younger, and older adults performed an event-based prospective memory task consisting of four blocks (a baseline block, a prospective memory block without the occurrence of prospective memory cues, a prospective memory block with the occurrence of prospective memory cues, and a deactivation block in which unexpected no-more-relevant prospective memory cues occurred). The results revealed that monitoring costs and aftereffects were present in all age groups. Although children engaged in monitoring, their prospective memory performance was lower than for young and older adults. Moreover, aftereffects of responding to deactivated intentions were more pronounced in children and older adults. In Experiment 2, we were interested in examining whether these costs would be modulated by the type of prospective memory cues (semantic vs. perceptual). In fact, aftereffects were modulated by cue type with semantic cues producing higher costs than perceptual cues. These outcomes shed light on the different sources and the extent of cognitive costs resulting from responding to activated and deactivated intentions across the lifespan.

Investigating prospective memory via eye tracking: No evidence for a monitoring deficit in older adults

Prospective memory (PM) refers to remembering to perform intended actions in the future. Older adults in particular have been shown to be negatively affected by PM tasks that require a high amount of attentional resources (i.e., nonfocal tasks). This age-related PM deficit has been attributed to reduced target monitoring in this age group older adults. However, this conclusion was based on indirect measures of monitoring, such as costs of the ongoing task.The present study set out to 1) investigate older adults' PM target monitoring by, for the first time, employing a direct measure (i.e., eye tracking), 2) assess differences in monitoring between PM tasks that differ in their focality, and 3) examine whether differences in PM monitoring can indeed explain older adults' reduced PM performance in nonfocal tasks.Results demonstrate that while older, but not younger adults, showed reduced performance in a nonfocal PM task, overt monitoring (eye movements) of these groups did not differ between focality conditions. Further analyses showed that older adults' performance was still reduced on the strategically more demanding task after controlling for overt target monitoring (i.e., including only trials in which the participant monitored).In contrast to indirect measures of cue monitoring, our findings illustrate that older adults' deficits on nonfocal PM tasks cannot (exclusively) be explained by reduced monitoring. Instead, processing that takes place after target monitoring are discussed as possible mechanisms underlying older adults' reduced PM performance in nonfocal tasks.

Aging and strategic prospective memory monitoring.

Monitoring the environment for the occurrence of prospective memory (PM) targets is a resource-demanding process that produces cost (e.g., slowing) to ongoing activities. Prior research has shown that older adults are able to monitor strategically, which involves the activation of monitoring when contextually appropriate and deactivation of monitoring when it is not thereby affording conservation of limited-capacity attentional resources. However, the time course and efficiency with which these processes operate with increased age are unknown. In the current study, participants performed an ongoing lexical decision task in which words/nonwords were blocked by font color in sets of ten trials (ten red trials followed by ten blue trials). Importantly, participants were informed that PM targets ("TOR" syllable) would only occur in red trials. Replicating previous work, both younger and older adults were successfully able to disengage monitoring upon encountering the unexpected (i.e., blue) context. However, while younger adults completely disengaged monitoring in the unexpected context, older adults continued to show monitoring across the majority of trials. Additionally, younger, but not older, adults showed a re-engagement of monitoring at the end of the unexpected context in preparation for the upcoming expected context. These findings suggest that while strategic monitoring generally remains intact with increased age, the disengagement and preparatory re-engagement of strategic monitoring may operate less optimally for older adults.

Prospective memory under acute stress: The role of (output) monitoring and ongoing-task demands.

Prospective memory (PM) refers to the ability to postpone retrieval and execution of intended actions until the appropriate situation (PM cue) has come, while engaging in other ongoing activities or tasks. In everyday live we often perform PM tasks in stressful situations. While it has been shown that acute stress does not impair PM-cue identification and intention retrieval, little is known about acute stress effects on PM performance and memory for having performed an action (output monitoring) under varying ongoing-task demands. Here we investigated this in eighty healthy participants who performed event-based PM tasks during low- and high-demanding ongoing working memory tasks after having undergone either a standardized stress induction (Maastricht Acute Stress Test) or a standardized control protocol. Successful stress induction in the stress group compared to the no-stress group was confirmed by increased salivary cortisol, an indicator of stress-related hypothalamus-pituitaryadrenal axis activity, throughout the event-based PM tasks. Nevertheless, not-only PM-cue identification but also output monitoring remained fully intact after stress induction. The absence of these effects was independent of ongoing-task demands. Nonetheless, we replicated recent findings of a stress-induced reduction in performance cost of monitoring for PM-cue occurrences. Taken together our findings suggest that acute stress alters PM monitoring by enhancing selective attention, decreasing PM response thresholds or by shifting performance towards more automatic processes in PM, while not affecting PM-cue identification and output monitoring.

Age differences in cue utilization during prospective and retrospective memory monitoring.

Memory monitoring is an inferential process that we use to evaluate and make judgments about the contents of our memory. Prior work has shown age-related similarity in prospective monitoring of ongoing memory processes, but age-related deficits when retrospectively monitoring the source of memories. In the current study, we examined how extrinsic and intrinsic cues influence age differences in these 2 forms of memory monitoring. Two experiments were conducted in which young and older adults made prospective judgments of learning (JOLs) to monitor ongoing memory processes as well as retrospective source judgments during retrieval. The emotional valence of words (positive, negative, and neutral) served as an intrinsic cue across experiments. Extrinsic importance cues were manipulated via item-based directed forgetting cues (to-be-remembered versus to-be-forgotten cues) in Experiment 1 and value-based cues (+10 versus -10 cues) in Experiment 2. Results provide novel evidence for age-related similarity in use of extrinsic and intrinsic cues during prospective memory monitoring via JOLs. By contrast, during retrospective source monitoring, older but not young adults showed a bias to attribute positive items to extrinsic cues with higher importance, even when those attributions were inaccurate. These findings suggest that the age-related tendency to favor positive information may lead to systematic errors in retrospective monitoring, which has implications for the credibility of older adults' source judgments when monitoring memory for emotional events. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Stress and prospective memory: What is the role of cortisol?

Studies investigating effects of acute stress on Prospective Memory (PM) so far yielded heterogeneous findings. Although results were commonly attributed to stress-induced changes in cortisol, past research did not disentangle effects of cortisol from the effects of sympathetic nervous system (SNS) activation and cognitive reappraisal. The present study therefore aimed at investigating the mere effect of cortisol on PM tasks that differently involve prefrontal brain regions (nonfocal vs. focal PM tasks) via a placebo-controlled oral pharmacological intake of 10 mg hydrocortisone mimicking physiological responses to stress. Contrary to our prediction, enhanced levels of cortisol did not affect PM accuracy and monitoring costs, neither for the focal nor the nonfocal PM tasks. These results suggest that changes of cortisol levels do not underlie potential stress effects on PM. Further exploratory results revealed that PM performance was higher in the 3 pm than in the 1 pm placebo group. This means that PM performance, independently of effects of cortisol, seem to vary throughout the day.

Hemisphere-specific effects of prefrontal theta-burst stimulation on visual recognition memory accuracy and awareness.

BackgroundThe prefrontal cortex has been implicated in episodic memory and the awareness of memory. Few studies have probed the nature and necessity of its role via brain stimulation. There are uncertainties regarding whether the hemisphere of stimulation predicts effects on memory and whether effects of stimulation are format‐specific, with most previous studies utilizing verbal/semantic stimuli.ObjectiveOur primary objective was to determine if theta‐burst transcranial magnetic stimulation (TBS) to prefrontal cortex modulates visual memory accuracy, visual memory awareness, or both, and whether these effects depend on brain hemisphere.MethodsWe administered TBS to 12 individuals in either left prefrontal, right prefrontal, or a sham location on three separate days. We then administered a visual associative‐memory task incorporating global‐level awareness judgments and feeling‐of‐knowing (FOK) judgments on test trials for which retrieval failed.ResultsOverall memory accuracy significantly improved after right hemisphere TBS compared to sham. Simultaneously, subjects were relatively underconfident after right TBS, suggesting minimal awareness of memory accuracy improvements. The correspondence between FOKs and later recognition accuracy suggested a pattern of disruption in prospective memory monitoring accuracy after left TBS.ConclusionsOur findings provide unique evidence for improved visual memory accuracy after right prefrontal TBS. These results also suggest right prefrontal lateralization for visual memory and left‐hemisphere specialization for item‐level prospective memory awareness judgments. Taken together, these results provided continued support for noninvasive stimulation to prefrontal cortex as a means of potentially improving memory and causally influencing prospective memory awareness.

Characterising monitoring processes in event-based prospective memory: Evidence from pupillometry

In event-based prospective memory (PM) paradigms, participants are engaged in an ongoing task (e.g. lexical decision) while maintaining an intention to produce a special response if they encounter pre-defined targets (e.g. animal words). This leads to slowed response times even on nontarget trials, which might be caused by: (A) a periodic or intermittent process that occurs transiently to check whether the current stimulus is a target, and/or (B) a sustained monitoring process maintained throughout task performance rather than being time-locked to stimulus presentation. These processes are hard to distinguish, seeing as the key difference between them occurs in the gap between trials. Processes occurring in these gaps cannot be measured directly by behavioural methods. Here we measured pupil size as a continuous index of intention-related processing in an event-based prospective memory task. Participants performed a lexical decision task while remembering intentions based on either specific target words or categories (e.g. animal words). In two experiments, response times were slowed during PM conditions. Pupil size was significantly increased in the category but not the specific-word condition. This effect was sustained throughout task performance rather than occurring transiently when stimuli were presented. Therefore there was no evidence for a transient pupillometric response associated with nontarget checking, although there was a strong transient response when targets were presented in either PM condition. These results provide evidence for a sustained PM monitoring process that occurs even in the gaps between trials.

Aging and the strategic use of context to control prospective memory monitoring.

Monitoring the environment for the occurrence of prospective memory (PM) targets is a resource-demanding process that produces cost to ongoing activities. The current study investigated younger and older adults' ability to monitor strategically, which involves the heightening and relaxation of monitoring when it is contextually appropriate thereby affording conservation of limited-capacity attentional resources. Participants performed a lexical-decision task in which words or nonwords were presented in upper or lower locations of the screen. The specific condition was correctly informed that PM targets ("tor" syllable) would occur only in word trials (simple cue; Experiment 1), in word trials in the upper location (complex cue; Experiments 2 and 3A), or in red trials in the upper location (complex cue; Experiment 3B), whereas the nonspecific condition was told that targets could appear in any context. The results showed that older adults generally exhibited similar monitoring patterns as younger adults. When context varied randomly on each trial, younger and older adults in the specific condition utilized simple (Experiment 1) but not complex (Experiment 2) contextual cues to reduce monitoring in unexpected contexts relative to the nonspecific condition. Notably, younger but not older adults were able to use the location dimension of the complex cue to reduce monitoring in unexpected (lower) contexts. When context varied more predictably (i.e., changed every eight trials), both younger and older adults were able to monitor strategically in response to the complex contextual cue (Experiments 3A and 3B). Together these findings suggest that context-sensitive PM monitoring processes generally remain intact with increased age. (PsycINFO Database Record

Context cue focality influences strategic prospective memory monitoring.

Monitoring the environment for the occurrence of prospective memory (PM) targets is a resource-demanding process that produces cost (e.g., slower responding) to ongoing activities. However, research suggests that individuals are able to monitor strategically by using contextual cues to reduce monitoring in contexts in which PM targets are not expected to occur. In the current study, we investigated the processes supporting context identification (i.e., determining whether or not the context is appropriate for monitoring) by testing the context cue focality hypothesis. This hypothesis predicts that the ability to monitor strategically depends on whether the ongoing task orients attention to the contextual cues that are available to guide monitoring. In Experiment 1, participants performed an ongoing lexical decision task and were told that PM targets (TOR syllable) would only occur in word trials (focal context cue condition) or in items starting with consonants (nonfocal context cue condition). In Experiment 2, participants performed an ongoing first letter judgment (consonant/vowel) task and were told that PM targets would only occur in items starting with consonants (focal context cue condition) or in word trials (nonfocal context cue condition). Consistent with the context cue focality hypothesis, strategic monitoring was only observed during focal context cue conditions in which the type of ongoing task processing automatically oriented attention to the relevant features of the contextual cue. These findings suggest that strategic monitoring is dependent on limited-capacity processing resources and may be relatively limited when the attentional demands of context identification are sufficiently high.

Supplemental Material for Aging and the Strategic Use of Context to Control Prospective Memory Monitoring

Supplemental Material for Aging and the Strategic Use of Context to Control Prospective Memory Monitoring

Involvement of the anterior cingulate cortex in time-based prospective memory task monitoring: An EEG analysis of brain sources using Independent Component and Measure Projection Analysis.

ObjectiveTime-based prospective memory (PM), remembering to do something at a particular moment in the future, is considered to depend upon self-initiated strategic monitoring, involving a retrieval mode (sustained maintenance of the intention) plus target checking (intermittent time checks). The present experiment was designed to explore what brain regions and brain activity are associated with these components of strategic monitoring in time-based PM tasks.Method24 participants were asked to reset a clock every four minutes, while performing a foreground ongoing word categorisation task. EEG activity was recorded and data were decomposed into source-resolved activity using Independent Component Analysis. Common brain regions across participants, associated with retrieval mode and target checking, were found using Measure Projection Analysis.ResultsParticipants decreased their performance on the ongoing task when concurrently performed with the time-based PM task, reflecting an active retrieval mode that relied on withdrawal of limited resources from the ongoing task. Brain activity, with its source in or near the anterior cingulate cortex (ACC), showed changes associated with an active retrieval mode including greater negative ERP deflections, decreased theta synchronization, and increased alpha suppression for events locked to the ongoing task while maintaining a time-based intention. Activity in the ACC was also associated with time-checks and found consistently across participants; however, we did not find an association with time perception processing per se.ConclusionThe involvement of the ACC in both aspects of time-based PM monitoring may be related to different functions that have been attributed to it: strategic control of attention during the retrieval mode (distributing attentional resources between the ongoing task and the time-based task) and anticipatory/decision making processing associated with clock-checks.

The strategic control of prospective memory monitoring in response to complex and probabilistic contextual cues.

Participants use simple contextual cues to reduce deployment of costly monitoring processes in contexts in which prospective memory (PM) targets are not expected. This study investigated whether this strategic monitoring pattern is observed in response to complex and probabilistic contextual cues. Participants performed a lexical decision task in which words or nonwords were presented in upper or lower locations on screen. The specific condition was informed that PM targets ("tor" syllable) would occur only in words in the upper location, whereas the nonspecific condition was informed that targets could occur in any location or word type. Context was blocked such that word type and location changed every 8 trials. In Experiment 1, the specific condition used the complex contextual cue to reduce monitoring in unexpected contexts relative to the nonspecific condition. This pattern largely was not evidenced when the complex contextual cue was probabilistic (Experiment 2). Experiment 3 confirmed that strategic monitoring is observed for a complex cue that is deterministic, but not one that is probabilistic. Additionally, Experiments 1 and 3 demonstrated a disadvantage associated with strategic monitoring-namely, that the specific condition was less likely to respond to a PM target in an unexpected context. Experiment 3 provided evidence that this disadvantage is attributable to impaired noticing of the target. The novel findings suggest use of a complex contextual cue per se is not a boundary condition for the strategic, context-specific allocation of monitoring processes to support prospective remembering; however, strategic monitoring is constrained by the predictive utility of the complex contextual cue.

A fresh pair of eyes on prospective memory monitoring.

Remembering to complete one's future intentions is termed prospective memory. We employed a new eyetracking paradigm to concretely observe the impact of environmental cues on strategic monitoring within a visual prospective memory task. Participants worked on a continuous living-count task comprising images, while simultaneously being asked to respond to a prospective memory target when it appeared. Importantly, the prospective memory target appeared in a different area of the participant's visual field than did the continuous task, which is consistent with prospective memory in many real-world situations, and further allows for a clear index of strategic monitoring processes. Subtle cues in the form of semantically related images were embedded in the continuous task to prompt monitoring for the prospective memory target. Overt strategic monitoring was operationalized as the number of times participants fixated on the designated target area, and cue-driven monitoring was defined by the number of fixations on the prospective memory target region directly after fixating on a related cue. Overt strategic monitoring for the prospective memory target was directly observed for participants in the prospective memory condition, and cue-driven monitoring was also observed in these participants, since they were more likely to initiate monitoring immediately after fixating on a semantically related cue, relative to an unrelated cue. This psychophysiological approach afforded precise measurement of the strategic monitoring process and revealed how contextual cues in the environment interact with the cognitive mechanisms supporting prospective memory.

Modeling criterion shifts and target checking in prospective memory monitoring.

Event-based prospective memory (PM) involves remembering to perform intended actions after a delay. An important theoretical issue is whether and how people monitor the environment to execute an intended action when a target event occurs. Performing a PM task often increases the latencies in ongoing tasks. However, little is known about the reasons for this cost effect. This study uses diffusion model analysis to decompose monitoring processes in the PM paradigm. Across 4 experiments, performing a PM task increased latencies in an ongoing lexical decision task. A large portion of this effect was explained by consistent increases in boundary separation; additional increases in nondecision time emerged in a nonfocal PM task and explained variance in PM performance (Experiment 1), likely reflecting a target-checking strategy before and after the ongoing decision (Experiment 2). However, we found that possible target-checking strategies may depend on task characteristics. That is, instructional emphasis on the importance of ongoing decisions (Experiment 3) or the use of focal targets (Experiment 4) eliminated the contribution of nondecision time to the cost of PM, but left participants in a mode of increased cautiousness. The modeling thus sheds new light on the cost effect seen in many PM studies and suggests that people approach ongoing activities more cautiously when they need to remember an intended action.

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

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