The failure of deactivating intentions: aftereffects of completed intentions in the repeated prospective memory cue paradigm

We used a newly developed experimental paradigm to investigate aftereffects of completed intentions on subsequent performance that required the maintenance and execution of new intentions. Participants performed an ongoing number categorization task and an additional prospective memory (PM) task, which required them to respond to PM cues that differed from standard stimuli in 1 particular visual feature. Although the feature defining the to-be-acted-upon PM cue changed in each block, the irrelevant PM cue of the previous PM task block was occasionally repeated in the subsequent block. In 4 experiments we found that performance in the ongoing task was substantially slowed for repeated PM cue trials compared to oddball trials, which also differed in a visual feature from standard stimuli but never served as PM cues. This aftereffect decreased as a function of delay after intention completion. These findings indicate that intentions can exhibit persisting activation even after they have been completed and may interfere with the execution of the new relevant task. Possible mechanisms and boundary conditions of this intention deactivation failure are discussed.     

The difficulty of letting go: moderators of the deactivation of completed intentions

Recent studies showed that prospective memory (PM) intentions might not be deactivated directly after completion. The residual activation leads to aftereffects which are reflected as interference in performance when former PM cues of old intentions are interspersed in the new task (i.e., intention deactivation failure, Walser et al., J Exp Psychol Learn Mem Cogn 38(4):1030–1044, 2012). In the present study, we investigated potential mechanisms that might support the deactivation process of completed intentions by manipulating the task demands (e.g., working memory load) between intention completion and measurement of aftereffects. Aftereffects on repeated PM-cue trials were found when working memory load was low (control condition), but were reduced when available resources were sparse (working memory load condition). When participants were asked to reflect upon the to-be-deactivated PM cue, subsequent aftereffects were increased. Further, overall aftereffects were larger for participants low in self-reported action control. Results show that the nature of the filler-task activity determines whether the representation of the completed intention is destabilized (working memory load) or strengthened (intention reflection). The (at least partial) overwriting of completed intention representations by new working memory task representations seems therefore to reflect a supporting factor for the deactivation of completed intentions.     

The importance of cue familiarity and cue distinctiveness in prospective memory

Abstract

Both retrospective cued-memory tasks and event-based prospective memory tasks require that cue and target information be associated, and that aspects of that association be reinstated for successful remembering. These functional similarities between retrospective memory and prospective memory were the bases for the hypothesis that the familiarity and the distinctiveness of the target event (cue) would influence prospective memory performance. Experiment 1, focusing on target familiarity, found a nominal advantage in prospective memory with unfamiliar target events. Experiment 2 showed a significant benefit for unfamiliar target events, as well as for target events that were distinctive relative to the local context. Additionally, prospective memory performance did not reliably correlate with explicit retrospective memory tasks (recall and recognition), but did correlate with an indirect retrospective memory task (word fragment completion). This pattern suggests and helps specify the general view that prospective memory processes may be similar to those involved in both direct and indirect tests of retrospective memory.     

The fate of completed intentions

The goal of this research was to determine whether and how people deactivate prospective memory (PM) intentions after they have been completed. One view proposes that PM intentions can be deactivated after completion, such that they no longer come to mind and interfere with current tasks. Another view is that now irrelevant completed PM intentions exhibit persisting activation, and continue to be retrieved. In Experiment 1, participants were given a PM intention embedded within the ongoing task during Phase 1, after which participants were told either that the PM task had been completed or suspended until later. During Phase 2, participants were instructed to perform only the ongoing task and were periodically prompted to report their thoughts. Critically, the PM targets from Phase 1 reappeared in Phase 2. All of our measures, including thoughts reported about the PM task, supported the existence of persisting activation. In Experiment 2, we varied conditions that were expected to mitigate persisting activation. Despite our best attempts to promote deactivation, we found evidence for the persistence of spontaneous retrieval in all groups after intentions were completed. The theoretical and practical implications of this potential dark side to spontaneous retrieval are discussed.     

The effects of implementation intention strategies on prospective memory cue encoding

Implementation intentions, which include a structured verbal statement and mental imagery, improve prospective memory performance (i.e. remembering to execute delayed intentions). To investigate whether, and how, implementation intention strategies affect encoding processes we had participants complete a thought probe procedure immediately after forming the intention to remember to press Q when seeing fruit words. In Experiment 1, an implementation intention verbal statement (relative to control statement) significantly increased generation of high typicality exemplars (apple, banana, orange). In Experiment 2, an implementation intention imagery procedure (relative to control imagery) produced similar outcomes. In Experiment 3, combining the statement and imagery components of the implementation intention (relative to control statement and imagery) demonstrated even more potent effects (e.g. three-fold increase in fruit exemplars generated). In Experiment 4, we tested whether the control statement versus control imagery procedure differentially affected encoding, but these control procedures showed no significant differences. An interesting, unanticipated finding was that there was significantly less mind wandering in the implementation intention conditions relative to the control conditions. The current experiments provide novel information on the processes operating during intention encoding, and support the classic view that implementation intentions increase the encoding of specific retrieval cues.     

The effect of implementation intentions on prospective memory performance across the lifespan

Differences in the amount and availability of cognitive resources may be responsible for age‐related differences in event‐based prospective memory tasks. We hypothesised that a manipulation which reduces resource requirements by enhancing automatic processing will reduce age differences. Implementation intentions are assumed to satisfy this requirement. We tested a total of 563 participants, 185 adolescents, 193 young adults and 185 older adults in order to investigate whether providing participants with implementation intention instructions would improve performance, whether any improvement would vary with age, and whether it would affect the prospective component or the retrospective component. The results showed a benefit of implementation intentions for older adults, but not for adolescents and for young adults. Separate analyses for the prospective and the retrospective components revealed that this effect was based mainly on a performance facilitation of the prospective component. These results suggest that implementation intentions provide a means to reduce age differences in prospective memory. Copyright © 2009 John Wiley & Sons, Ltd.     

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.     

The role of memory for compounds in cue competition

Revisions of common associative learning models incorporate a within-compound association mechanism in order to explain retrospective cue competition effects (e.g., [Dickinson, A., & Burke, J. (1996). Within-compound associations mediate the retrospective revaluation of causality judgements. Quarterly Journal of Experimental Psychology, 49B, pp. 60-80.]). These models predict a correlation between memory for compounds (as a measure for the strength of within-compound associations) and retrospective cue competition but not forward cue competition. This was indeed found in a study of [Melchers, K. G., Lachnit, H., & Shanks, D. (2004). Within-compound associations in retrospective revaluation and in direct learning: A challenge for comparator theory. Quarterly Journal of Experimental Psychology, 57B, pp. 25-54.]. We argue that a higher-order reasoning account of causal learning can also explain the evidence for the role of within-compound associations in cue competition. Moreover, this account predicts that if making inferences during the learning stage is impeded, a correlation between memory for compounds and forward cue competition should be found as well. The results of a new study confirmed this prediction.     

Event-based prospective memory in depression: The impact of cue focality

This study is the first to compare event-based prospective memory performance in individuals with depression and healthy controls. The degree to which self-initiated processing is required to perform the prospective memory task was varied. Twenty-eight individuals with depression and 32 healthy controls worked on a computerised prospective memory task. Prospective cues were either presented focally or non-focally to the ongoing activity. Collapsing data across both conditions, controls outperformed individuals with depression in the prospective memory task. Overall, participants showed a poorer prospective memory performance in the non-focal condition that required self-initiated processing to a higher degree than the focal condition. Importantly, as revealed by a group by task condition interaction, groups did not differ in the focal condition, whereas, controls outperformed individuals with depression in the non-focal condition. The results are in line with the multiprocess framework of event-based prospective remembering and the cognitive-initiative account of depression-related cognitive deficits.     

Relationship between cue word activation and prospective memory performance

The interaction of cue-word specificity in instructions and cue-word familiarity on prospective performance was examined. Exp. 1 was based on a typical prospective memory paradigm using familiar and unfamiliar cue words. Prospective memory performances under general and specific instruction conditions were compared. In Exp. 2, the relationship found in Exp. 1 was further investigated based on the activation of cue words and prospective memory performance. The experimental results indicated that, when a spontaneous retrieval process was used, unfamiliar cues were more likely to be detected, whereas when only strategic monitoring played a role, familiar cues were more likely to be detected, suggesting that retrieval varied systematically across experimental situations, as predicted by the multiprocess model.     

Implementation intentions and prospective memory among older adults: an investigation of the role of frontal lobe function

Prospective memory (PM) among older adults has been shown to be influenced by frontal lobe (FL) function. An implementation intention (e.g., 'if situation X occurs, I will do Y') is a mnemonic strategy that may be particularly beneficial for individuals with low-FL function, as it has been suggested that implementation intentions produce heightened accessibility to environmental cues, and automatic triggering of previously formed intentions. The present study investigated the effectiveness of implementation intentions among 32 older adults characterized as possessing high- or low-FL function. Participants were placed into one of two conditions: Read-Only or Implementation Intentions, before being tested on a laboratory prospective memory task. Results indicated that older adults with high-FL composite scores demonstrated better PM than those with low-FL scores, and that those who made implementation intentions outperformed those who simply read task instructions. Of particular interest is the finding that high-FL participants benefited from implementation intentions, suggesting that implementation intentions may improve PM of all older adults regardless of FL function. Theoretical underpinnings of implementation intentions are discussed in the context of FL function.     

Effect of delay on children's delay-execute prospective memory performance

To date, little work has been done investigating prospective memory in children, particularly using a delay-execute paradigm. Two experiments were conducted to investigate this issue with children aged 5–11 years. While playing a computer driving game, children's ability to carry out a delayed intention either immediately a target cue appeared or after an additional delay, was assessed. These findings supported the few previous studies in this area by showing that preschool children are able to perform event-based prospective memory tasks. The results also extended these findings by demonstrating the impact of briefly delaying the execution of a retrieved intention, and revealing that there were important improvements in prospective memory performance from early to late childhood. The suggestion is made that executive resources may be responsible for this pattern of performance.     

Effects of delay of prospective memory cues in an ongoing task on prospective memory task performance

To address the mixed results reported in previous studies, the present experiments examined forgetting in prospective memory (PM) by manipulating the delay between the PM instructions and cue presentation in event-based PM tasks. PM performance was measured for delays of 2–20 min in Experiment 1 and for delays of approximately 1–10 min in Experiment 2. Experiment 2 included both focal and nonfocal PM tasks, and speed on the ongoing task was measured to examine evidence for monitoring processes across the delays tested. The results suggest that nonfocal PM performance follows a nonlinear forgetting function (i.e., rapid decline for shorter delays and slower decline for longer delays) when tested over delays from 1 to 20 min. No effect of delay was seen for the focal task tested in Experiment 2 from 1 to 10 min. In Experiment 2, ongoing-task costs were also found for the first delay but not for longer delays, suggesting that monitoring was significantly reduced between 1 and 2.5 min of the ongoing-task trials.     

The development of prospective memory in young schoolchildren: The impact of ongoing task absorption,cue salience,and cue centrality

This study presents evidence that 9- and 10-year-old children outperform 6- and 7-year-old children on a measure of event-based prospective memory and that retrieval-based factors systematically influence performance and age differences. All experiments revealed significant age effects in prospective memory even after controlling for ongoing task performance. In addition, the provision of a less absorbing ongoing task (Experiment 1), higher cue salience (Experiment 2), and cues appearing in the center of attention (Experiment 3) were each associated with better performance. Of particular developmental importance was an age by cue centrality (in or outside of the center of attention) interaction that emerged in Experiment 3. Thus, age effects were restricted to prospective memory cues appearing outside of the center of attention, suggesting that the development of prospective memory across early school years may be modulated by whether a cue requires overt monitoring beyond the immediate attentional context. Because whether a cue is in or outside of the center of attention might determine the amount of executive control needed in a prospective memory task, findings suggest that developing executive control resources may drive prospective memory development across primary school age.     

Age effects in emotional prospective memory: cue valence differentially affects the prospective and retrospective component

While first studies suggested that emotional task material may enhance prospective memory performance in young and older adults, the extent and mechanisms of this effect are under debate. The authors explored possible differential effects of cue valence on the prospective and retrospective component of prospective memory in young and older adults. Forty-five young and 41 older adults performed a prospective memory task in which emotional valence of the prospective memory cue was manipulated (positive, negative, neutral). The multinomial model of event-based prospective memory was used to analyze effects of valence and age on the two prospective memory components separately. Results revealed an interaction indicating that age differences were smaller in both emotional valence conditions. For older adults positive cues improved the prospective component, while negative cues improved the retrospective component. No main effect of valence was found for younger adults on an overt accuracy measure, but model-based analyses showed that the retrospective component was enhanced in the positive compared with the negative cue condition. The study extends the literature in demonstrating that processes underlying emotional effects on prospective memory may differ depending on valence and age.     

The role of memory and restricted context in repeated visual search

Previous studies have shown that the efficiency of visual search does not improve when participants search through the same unchanging display for hundreds of trials (repeated search), even though the participants have a clear memory of the search display. In this article, we ask two important questions. First, why do participants not use memory to help search the repeated display? Second, can context be introduced so that participants are able to guide their attention to the relevant repeated items? Experiments 1-4 show that participants choose not to use a memory strategy because, under these conditions, repeated memory search is actually less efficient than repeated visual search, even though the latter task is in itself relatively inefficient. However, when the visual search task is given context, so that only a subset of the items are ever pertinent, participants can learn to restrict their attention to the relevant stimuli (Experiments 5 and 6).     

Preliminary remarks on type of task and delay in children's prospective memory

This study investigated the extent to which the type of task influences children's prospective memory performance. 80 subjects, aged 7 to 11 yr. participated in an experiment in which the type of task (time-based vs event-based) and the retention interval (5 min. vs 10 min.) varied. The prospective memory task was embedded in a principal task lasting about 15 min. and required subjects perform an action at a given time or in response to a specific cue. Analysis indicated that the delay was associated with prospective memory performance only on a time-based task in which the intention has to be performed after 10 min. but not age. Analysis indicated also that time monitoring was associated with shorter latency between the target time and the execution of the intention on the time-based task. Implications were discussed.     

Prospective remembering in younger and older adults: role of the prospective cue

In these studies, adult age differences in event-based prospective memory were examined using an adapted version of G.O. Einstein and M.A. McDaniel's (1990) task. In Experiments 1-3, we varied prospective cue specificity by assigning a specific target word or an unspecified word drawn from a given taxonomic category. In Experiment 3, we manipulated cue typicality by presenting low or high typicality target words. Results yielded positive effects of cue specificity on prospective performance. Age effects occurred when high typicality target words served as prospective cues (Exps. 1 and 3), but younger and older adults performed comparably with moderate and low typicality words (Exps. 2 and 3). Hierarchical regression analyses indicated that age accounted for a small but significant amount of variance in prospective memory, although the contribution of age was substantially reduced after statistically controlling for recognition memory. Implications of these data for current views on prospective remembering are discussed.     

The role of executive processes in prospective memory tasks

Prospective remembering refers to remembering and acting on behavioural intentions. Three experiments tested the hypothesis that prospective remembering requires the availability of executive processes. It was expected that this is more important when intentions are stated in categorical terms. Type of instruction (specific versus categorical), typicality of the cue in relation to the category specified, and executive load were manipulated. Results showed a general benefit of specific instructions. Furthermore, with categorical instructions, performance was better with typical cues. Although the data suggested that executive processes are responsible for the processing of cues, the load manipulation had no significant effect on the prospective memory measure. Thus, no evidence was found for the hypothesis that prospective remembering requires the availability of executive processes. It is argued that it is a matter of strategic choice whether executive processes are deployed: One does not need to monitor for cues but can choose to rely on bottom‐up processes. Monitoring may be sufficient, but not necessary for successful prospective remembering.     

The role of rehearsals in self-generated prospective memory tasks

In order to inquire into the nature of retrieval in prospective memory in a naturalistic context, we investigated the number and circumstances of rehearsals of different kinds of intentions to be pursued during a single time period. Thirty-six students were given four minutes to generate a list of tasks they were planning to perform over the course of 10 days. During this retention interval, they were provided with pocket-size diaries in which they recorded the details of each occasion they thought about the tasks previously listed. As to the nature of any triggers or cues that prompted rehearsal, the participants were asked to choose one of three alternatives: (1) association with an internal or an external cue that accidently appeared in the surroundings (accidental rehearsals), (2) deliberate thinking, e.g. while planning (self-initiated rehearsals), (3) recollection that spontaneously popped into one's mind for no apparent reason (no-trigger rehearsals). The results showed that thoughts about intended actions appeared more often after accidental cues than for no apparent reason. However, the relative contribution of self-initiated triggers to the rehearsal process was substantial: Most importantly, it was the self-initiated rehearsal that differentiated between executed and unexecuted actions. In addition, the most activated intention resulted in a higher frequency of no-trigger and self-initiated rehearsals than the remaining intentions. Finally, perceived intention importance was positively related to both the number of rehearsals and the likelihood of successful task completion. The results are discussed with regard to which factors may be crucial for the successful performance of participants' own self-generated intentions in a natural setting. The role of deliberate rehearsal in specifying the details of the intended action and its designated retrieval context is highlighted.