Prospective Memory Costs Research Articles

Prospective memory decision control: A computational model of context effects on prospective memory.

Prospective memory (PM) tasks require remembering to perform a deferred action and can be associated with predictable contexts. We present a theory and computational model, prospective memory decision control (PMDC), of the cognitive processes by which context supports PM. Under control conditions, participants completed lexical decisions. Under PM conditions, participants had the additional PM task of responding to letter strings containing certain syllables. Stimuli were presented in one of two colors, with color potentially changing after each set of four trials. A pretrial colored fixation was presented before each set. Under control and PM standard conditions, fixation color was meaningless. Under PM context conditions, fixation color indicated whether a PM target could occur within the next set. We replicated prior findings of higher PM accuracy for context compared to standard conditions, and the expected variation in PM costs (slowed lexical decisions) as a function of context relevance. PMDC, which formalizes PM as a process of evidence accumulation among ongoing and PM task responses, accounted for the impact of context on PM costs and accuracy via proactive and reactive cognitive control. Increased ongoing task thresholds and decreased PM thresholds in relevant contexts indicated proactive control. With context provision, PM accumulation rates on PM trials increased, as did inhibition of accumulation to competing responses, indicating reactive control. Although an observed capacity-sharing effect explained some portion of PM costs, we found no evidence that participants redirected more capacity from the ongoing to the PM task when contextually cued to relevant contexts. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Distinct monitoring strategies underlie costs and performance in prospective memory

Prospective memory (PM) describes the ability to remember to perform goal-relevant actions at an appropriate time in the future amid concurrent demands. A key contributor to PM performance is thought to be the effortful monitoring of the environment for PM-related cues, a process whose existence is typically inferred from a behavioral interference measure of reaction times. This measure, referred to as “PM costs,” is an informative but indirect proxy for monitoring, and it may not be sufficient to understand PM behaviors in all situations. In this study, we asked participants to perform a visual search task with arrows that varied in difficulty while concurrently performing a delayed-recognition PM task with pictures of faces and scenes. To gain a precise measurement of monitoring behavior, we used eye-tracking to record fixations to all task-relevant stimuli and related these fixation measures to both PM costs and PM accuracy. We found that PM costs reflected dissociable monitoring strategies: higher costs were associated with early and frequent monitoring while lower costs were associated with delayed and infrequent monitoring. Moreover, the link between fixations and PM costs varied with cognitive load, and the inclusion of fixation data yielded better predictions of PM accuracy than using PM costs alone. This study demonstrates the benefit of eye-tracking to disentangle the nature of PM costs and more precisely describe strategies involved in prospective remembering.

Investigating the effects of ongoing-task bias on prospective memory.

Event-based prospective memory (PM) refers to the cognitive processes required to perform a planned action upon encountering a future event. Event-based PM studies engage participants in an ongoing task (e.g., lexical decision-making) with an instruction to make an alternative PM response to certain items (e.g., items containing "tor"). The Prospective Memory Decision Control (PMDC) model, which provides a quantitative process account of ongoing-task and PM decisions, proposes that PM and ongoing-task processes compete in a race to threshold. We use PMDC to test whether, as proposed by the Delay Theory of PM costs, PM can be improved by biasing decision-making against a specific ongoing-task choice, so that the PM process is more likely to win the race. We manipulated bias in a lexical decision task with an accompanying PM intention. In one condition, a bias was induced against deciding items were words, and in another, a bias was induced against deciding items were non-words. The bias manipulation had little effect on PM accuracy but did affect the types of ongoing-task responses made on missed PM trials. PMDC fit the observed data well and verified that the bias manipulation had the intended effect on ongoing-task processes. Furthermore, although simulations from PMDC could produce an improvement in PM accuracy due to ongoing-task bias, this required implausible parameter values. These results illustrate the importance of understanding event-based PM in terms of a comprehensive model of the processes that interact to determine all aspects of task performance.

The Cost of Prospective Memory in Children: The Role of Cue Focality.

Prospective memory (PM) is an essential ability in daily life, since it involves remembering to perform an intention. While PM largely develops during childhood and adolescence, its underlying mechanisms are still poorly understood. In general, age differences in PM have been found with tasks in which the prospective cues are not part of the ongoing activity (non-focal PM tasks). In the present study, we evaluated the cognitive cost produced by a PM task over the ongoing activity by comparing the performance of a single-task condition with that of an ongoing activity condition involving a prospective intention. Specifically, to determine the impact of cue focality on performance as a function of age, we tested two groups of children (6 and 11 years old) in three experimental conditions: single, focal and non-focal prospective cues. In the single-task condition, children were only asked to perform the ongoing task (to categorize images as animal or non-animal). In the focal condition, in addition to performing the ongoing activity, participants were asked to press different keys whenever the image appearing on the screen was a kite or a ball. In the non-focal condition, children were to press the keys if the color of the frame of the screen changed to magenta or gray. Although reaction times were greater for the non-focal conditions in both age groups, the results showed worse performance on the ongoing activity for both the focal and the non-focal conditions (relative to the single-task condition) in the younger children. This difference was less pronounced in older children so that response times for focal and non-focal cues differed from the single condition, but the difference in performance between focal and single task conditions was not reliable. These findings, which are partly in line with the dual process framework (McDaniel et al., 2015), suggest that while non-focal prospective cues compromise attentional control in younger and older children, focal cues seem to rely on less effortful processes in older children.

Proactive control processes in event-based prospective memory: Evidence from intraindividual variability and ex-Gaussian analyses.

The present study implemented an individual differences approach in conjunction with response time (RT) variability and distribution modeling techniques to better characterize the cognitive control dynamics underlying ongoing task cost (i.e., slowing) and cue detection in event-based prospective memory (PM). Three experiments assessed the relation between proactive control ability, ex-Gaussian parameter estimates (μ and τ), intraindividual variability in responding (coefficient of variation, CoV), and PM cue detection. Experiment 1 examined these relations using a standard nonfocal PM paradigm. Experiments 2 and 3 further assessed how PM importance and PM cue focality, respectively, influenced performance. Across all experiments, nonfocal PM was associated with increases in all cost measures, but only μ reliably predicted cue detection. Importance instructions and focal PM cues selectively increased and decreased μ cost, respectively, relative to the standard nonfocal condition. These findings suggest that μ cost may reflect a target-checking process that benefits cue detection and produces slowing throughout the entire ongoing task. Additionally, across all experiments proactive control was positively associated with μ cost and cue detection, and generally negatively associated with variability cost (τ and CoV). These findings suggest that natural variation in proactive control ability may affect reliance on more efficacious monitoring processes that facilitates cue detection. Furthermore, variability in responding may have little influence on successful PM. The results from the current study highlight the utility of RT variability and distribution analyses in understanding PM costs and have important implications for extant theories of PM concerning the cognitive control processes underlying cue detection. (PsycINFO Database Record

Accumulating evidence about what prospective memory costs actually reveal.

Event-based prospective memory (PM) tasks require participants to substitute an atypical PM response for an ongoing task response when presented with PM targets. Responses to ongoing tasks are often slower with the addition of PM demands ("PM costs"). Prominent PM theories attribute costs to capacity-sharing between the ongoing and PM tasks, which reduces the rate of processing of the ongoing task. We modeled PM costs using the Linear Ballistic Accumulator and the Diffusion Decision Model in a lexical-decision task with nonfocal PM targets defined by semantic categories. Previous decision modeling, which attributed costs to changes in caution rather than rate of processing (Heathcote et al., 2015; Horn & Bayen, 2015), could be criticized on the grounds that the PM tasks included did not sufficiently promote capacity-sharing. Our semantic PM task was potentially more dependent on lexical decision resources than previous tasks (Marsh, Hicks, & Cook, 2005), yet costs were again driven by changes in threshold and not by changes in processing speed (drift rate). Costs resulting from a single target focal PM task were also driven by threshold changes. The increased thresholds underlying nonfocal and focal costs were larger for word trials than nonword trials. As PM targets were always words, this suggests that threshold increases are used to extend the time available for retrieval on PM trials. Under nonfocal conditions, but not focal conditions, the nonword threshold also increased. Thus, it seems that only nonfocal instructions cause a global threshold increase because of greater perceived task complexity. (PsycINFO Database Record

Supplemental Material for Accumulating Evidence About What Prospective Memory Costs Actually Reveal

Supplemental Material for Accumulating Evidence About What Prospective Memory Costs Actually Reveal

Hypnosis Attenuates Executive Cost of Prospective Memory

Prospective memory is the ability to formulate and carry out actions at the appropriate time or in the appropriate context. This study aimed to identify the effect of hypnosis on prospective memory performance and to analyze the involvement of executive control processes in intention realization in a hypnotically altered state of consciousness. In 1 experiment, manipulating hypnotic instruction in a within-subject fashion, the authors explored the event-based prospective memory performance of 23 volunteers in 3 conditions: baseline, expectation, and execution. The primary result was that executing prospective memory responses, at the same accuracy rate, produced a significantly lower cost of ongoing responses in terms of response latency in the hypnotic state than in wake condition.

Slow down and remember to remember! A delay theory of prospective memory costs.

Event-based prospective memory (PM) requires a deferred action to be performed when a target event is encountered in the future. Individuals are often slower to perform a concurrent ongoing task when they have PM task requirements relative to performing the ongoing task in isolation. Theories differ in their detailed interpretations of this PM cost, but all assume that the PM task shares limited-capacity resources with the ongoing task. In what was interpreted as support of this core assumption, diffusion model fits reported by Boywitt and Rummel (2012) and Horn, Bayen, and Smith (2011) indicated that PM demands reduced the rate of accumulation of evidence about ongoing task choices. We revaluate this support by fitting both the diffusion and linear ballistic accumulator (Brown & Heathcote, 2008) models to these same data sets and 2 new data sets better suited to model fitting. There was little effect of PM demands on evidence accumulation rates, but PM demands consistently increased the evidence required for ongoing task response selection (response thresholds). A further analysis of data reported by Lourenço, White, and Maylor (2013) found that participants differentially adjusted their response thresholds to slow responses associated with stimuli potentially containing PM targets. These findings are consistent with a delay theory account of costs, which contends that individuals slow ongoing task responses to allow more time for PM response selection to occur. Our results call for a fundamental reevaluation of current capacity-sharing theories of PM cost that until now have dominated the PM literature.

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.

Supplemental Material for Slow Down and Remember to Remember! A Delay Theory of Prospective Memory Costs

Supplemental Material for Slow Down and Remember to Remember! A Delay Theory of Prospective Memory Costs

The specificity of prospective memory costs

A current issue in the field of prospective memory (i.e., memory for intentions) is the extent to which intentions interfere with ongoing activities. A question of interest is whether this interference is specific to stimuli that are relevant to the intention or whether interference is more general in its influence. Participants performed a lexical decision task (LDT) with an embedded prospective memory (PM) task in which they had to remember to press a computer key if a pre-specified target appeared (e.g., GIRL). Results demonstrated a consistent pattern of results. Increased reaction time costs were observed on trials where there was a match between PM targets and non-target ongoing stimuli. That is, when a prospective memory target was a word, then reaction time costs were observed on non-target word LDT trials and there were no costs on non-target nonword trials. Similarly, if a PM target was a nonword (e.g., UEBL) then costs were observed on non-target nonword LDT trials relative to non-target word trials. Evidence from three experiments suggests that task interference is specific to the type of stimulus (word or nonword) that is relevant to the intention. We refer to this finding as a Stimulus Specific Interference Effect (SSIE).