Implementation intentions and imagery: individual and combined effects on prospective memory among young adults

Prospective memory (PM) has been found to benefit from implementation intentions (i.e., “when I see X, I will do Y”). However, to date, it is unclear whether implementation intentions must incorporate imagery in order to produce a positive effect on PM, or whether the verbal statement alone is sufficient. It is also equivocal whether the use of visual imagery alone improves PM, absent an intentional statement. The present study investigated the individual influences of implementation intentions and imagery, as well as their combined effect, on PM. A total of 64 undergraduates were placed into one of four instructional conditions—read-only, implementation intention, imagery, or combined—and were then tested on a laboratory PM task. The results revealed that participants in the implementation intention, imagery, and combined groups completed significantly more PM tasks than did participants in the read-only group, but they did not differ from one another. Combining implementation intentions and imagery, however, did not improve PM performance over either strategy alone. Additionally, the implementation intention and imagery groups outperformed the read-only group on a secondary ongoing digit detection task. The results of this study suggest that implementation intentions do not require imagery to be effective in improving PM, and that imagery alone has positive effects on PM. Finally, the results of the ongoing digit detection task suggest that the use of implementation intentions and imagery might provide for automatic identification and processing of environmental cues.     

Implementation intentions about nonfocal event-based prospective memory tasks

Implementation intentions are detailed and systematic plans that are developed during intention formation. We compared two different implementation intentions to standard event-based prospective memory instructions using three different kinds of intentions. Two of these intentions involved nonfocal cues whereas the remaining intention was about specific, focal cues. Implementation intentions dramatically increased detection performance for the nonfocal intentions. Because the exact cues could not be specified during intention formation, we argue that cue salience and that strengthening the cue to target action association are not very viable mechanisms to explain all instances of the beneficial consequences of forming implementation intentions.     

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.     

Implementation intentions facilitate prospective memory under high attention demands

An implementation intention is a planning technique that involves specifying a situation for initiating an intended action and linking these specific cues to the intention. In two experiments with young adults, we found significant increases in prospective memory with implementation intentions. With an implementation intention, but not with standard instructions, prospective memory performance was maintained under demanding attentional conditions (Experiment 2). Ongoing task performance did not decline, however, in relation with a no prospective memory control. Positive effects were not observed when the imagery component of the implementation intention was isolated from the verbal component. We suggest that implementation intention planning (relative to standard instructions) increases the likelihood that people will encode a robust associative link between the target cue and the intended action, thereby promoting reflexive triggering of the intended action on presentation of the target cue.     

Age differences in prospective memory for everyday life intentions: A diary approach

The age benefit found in many naturalistic prospective memory (PM) tasks has been taken as evidence that PM performance in real life may be spared from aging. However, this conclusion lacks empirical confirmation. Hence, the aim of the present study was to examine possible age differences in the content of everyday PM intentions and their performance. Everyday PM was assessed in young and older adults using a diary approach. Results confirmed a general age benefit for real-life PM tasks. Importantly, this finding was qualified by revealing that the benefit only held true for specific types of intentions such as health and social intentions. Further, moderation analyses showed that the relationships between cognitive functioning and everyday PM were different for young and older adults. While better inhibition, short-term and long-term memory were related with successful PM performance in the young, this was not the case in the older adults. The present findings suggest that the age benefit found in naturalistic experimenter-given tasks extends to real-life PM performance, but may differ depending on the type of intention. Furthermore, cognitive functioning predicts performance in the young, but not in the older adults.     

Priming effects in prospective memory

Abstract

The objective of this study was to examine whether an increased activation of knowledge structures facilitates memory for future actions. Priming effects were manipulated by giving subjects a category fluency task for half of the target categories used in the subsequent prospective memory task. In this task, younger and older adults performed an action whenever an instance of a given semantic category occurred in the context of a free association task. The degree of retrieval support was varied by using typical and atypical category instances as targets. Although reliable priming effects were observed for both age groups, the magnitude of priming interacted with the degree of retrieval support. Older adults showed priming effects for typical targets only, whereas the opposite pattern of results was obtained for younger adults. These findings indicate that, in addition to retrieval-related factors, the operations performed at the time of planning also contribute to optimal prospective remembering.     

Fan effects in event-based prospective memory

Three experiments investigated whether event-based prospective memory was affected by the associative fan of the cues to be detected. The associative fan was operationally defined as the number of associates paired with event-based cues in a paired associate learning phase. Subsequent to the paired associate learning, participants were given a lexical decision task in which event-based cues were embedded. The results from Experiments 1 and 2 confirmed that a larger associative fan significantly reduced event-based cue detection. The third experiment confirmed that the absolute strength of an association does not affect performance, rather the number of associations does. As an ancillary issue, the authors tested whether cue detection was affected by the familiarity of the background words used in the lexical decision task. No consistent evidence for a discrepancy plus search model of prospective memory was found.     

Fan effects in event-based prospective memory

Three experiments investigated whether event-based prospective memory was affected by the associative fan of the cues to be detected. The associative fan was operationally defined as the number of associates paired with event-based cues in a paired associate learning phase. Subsequent to the paired associate learning, participants were given a lexical decision task in which event-based cues were embedded. The results from Experiments 1 and 2 confirmed that a larger associative fan significantly reduced event-based cue detection. The third experiment confirmed that the absolute strength of an association does not affect performance, rather the number of associations does. As an ancillary issue, the authors tested whether cue detection was affected by the familiarity of the background words used in the lexical decision task. No consistent evidence for a discrepancy plus search model of prospective memory was found.     

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.     

Committing to implementation intentions: Attention and memory effects for selected situational cues

Two studies tested whether forming implementation intentions (Gollwitzer, Am Psychol 54:493?C503 in 1999) results in a heightened activation of specified situational cues. Going beyond prior studies, participants of the present studies specified these opportunities on their own (i.e., the action cues were not assigned by the experimenter), and activation level was assessed by attraction of attention and recall performance rather than lexical decisions. In Study 1, situational cues associated with the where and when to act on an everyday life goal attracted more attention than non-specified cues when presented to the non-attended channel in a dichotic listening task. In Study 2, the recall of specified cues was better than that of non-specified cues both 15?min after forming implementation intentions and after a delay of 2?days. Importantly, goal commitment and implementation intention commitment moderated this effect.     

Varying the importance of a prospective memory task: differential effects across time- and event-based prospective memory

Only few studies have addressed the issue of task importance in prospective memory. Most of them, but not all, have shown that perceived task importance does improve prospective memory performance. However, there is little understanding of (1) the conditions under which importance of the prospective memory task makes a difference in performance and (2) the mechanisms by which perceived task importance has an effect on prospective memory performance. The present study reports two experiments that manipulate task importance in a time-based and an event-based prospective memory paradigm. Results show that importance has an effect on the time-based but not on the event-based task. Further analyses of the performance in the cover tasks as well as the monitoring behaviour indicate that importance improves prospective memory to the degree the task requires the strategic allocation of attentional resources.     

Prospective memory and aging: The effects of working memory and prospective memory task load

Abstract

A person's level of engagement in other actions may influence whether a prospective action is correctly performed. This study used a computerized prospective memory task in which participants remembered to perform an action when a specified background pattern appeared while they simultaneously performed a verbal working memory task. Amount of engagement in the working memory task was manipulated by increasing the number of words to be recalled. Prospective memory load was manipulated by varying the number of prospective targets. Older adults performed more poorly than younger adults on the prospective memory task under higher working memory load and also higher prospective load. Participants with lower working memory load performed better on the prospective task, regardless of age. There were no significant age differences in the absolute accuracy of performance postdictions (post experiment performance awareness). Age differences were also found with a second prospective memory task in which participants were told to write the day of the week (DOW) on the top of answer sheets for tasks performed later in the experiment. No significant correlations were observed between the two prospective memory tasks for either age group.     

False prospective memory responses as indications of automatic processes in the initiation of delayed intentions

To analyze the role of automatic processes in the fulfilment of delayed intentions, we extended a typical prospective memory setting with a context signal to indicate whether the intended action is to be carried out or not. Building on dual-process models of cognition, we hypothesized that automatic and controlled processes are in opposition when the action is to be suppressed, because automatic processes trigger the associated response whereas controlled processes exert inhibition. Experiment 1 demonstrates the occurrence of false prospective memory responses to cues with the "suppress" signal. Experiment 2 shows that the rate of false prospective memory responses is sensitive to a manipulation that strengthens the role of automatic processes in prospective memory. The findings support the use of false prospective memory responses for the study of automatic processes in the execution of delayed intentions.     

Importance effects on performance in event-based prospective memory tasks

In the present study we manipulated the importance of performing two event-based prospective memory tasks. In Experiment 1, the event-based task was assumed to rely on relatively automatic processes, whereas in Experiment 2 the event-based task was assumed to rely on a more demanding monitoring process. In contrast to the first experiment, the second experiment showed that importance had a positive effect on prospective memory performance. In addition, the occurrence of an importance effect on prospective memory performance seemed to be mainly due to the features of the prospective memory task itself, and not to the characteristics of the ongoing tasks that only influenced the size of the importance effect. The results suggest that importance instructions may improve prospective memory if the prospective task requires the strategic allocation of attentional monitoring resources.     

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.     

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.     

The effects of working memory resource availability on prospective memory: a formal modeling approach

The PAM theory of event-based prospective memory (Smith, 2003; Smith & Bayen, 2004a) proposes that successful prospective memory performance demands upon the interaction of preparatory attentional processes and retrospective memory processes. The two experiments in the current study represent the first application of a formal model to investigate the sensitivity of these underlying processes to variations in working memory resource availability. Multinomial modeling of data from prospective-memory tasks showed that working memory span influenced preparatory attentional processes and retrospective-memory processes.     

Interrupting recognition memory: Tests of familiarity-based accounts of the revelation effect

The revelation effect is a puzzling phenomenon in which items on a recognition test are more likely to be judged as "old" when they are immediately preceded by a problem-solving task, such as anagram solution. The present experiments were designed to evaluate Westerman and Greene's (1998) and Hicks and Marsh's (1998) familiarity-based accounts of this effect. We found comparable revelation effects when probes were preceded by an anagram or a numerical addition task and when subjects performed either one or two of these tasks. Taken together, the results do not support familiarity-based accounts of the revelation effect but are consistent with a proposed decision-based interpretation (i.e., criterion flux), in which it is assumed that the revelation task displaces the study list context in working memory, leading subjects to adopt a more liberal recognition decision criterion, thereby increasing the hit and false alarm rates.     

Prospective memory for future intentions: Some comparisons with memory for past events

Abstract

Memory for future intentions was compared with memory for past activities by asking members of a film society to retrieve names of films they intended to see later on in a Season and films they had seen earlier. Memory for films that had been seen showed the usual recency effect, while retrieval of films to be seen showed an analogous proximity effect in that films to be seen sooner were more accessible. It was also found that recall of past films was inversely related to the total number of such films, but was unrelated to the average time interval since they were seen. In a similar fashion, retrievability of future films was inversely related to the total number of such films and was unrelated to when they were to be seen. There was a small but significant correlation between an individual's ability to retrieve the names of past and future films. Taken together, these correspondences suggest that similar empirical laws may govern the retrieval of stored information about past events and future intentions. Possible interpretations of the proximity effect and its theoretical implications are discussed.     

Interrupting recognition memory: Tests of a criterion-change account of the revelation effect

The revelation effect is evidenced by an increase in positive recognition responses when the test probe is immediately preceded by an unrelated problem-solving task. As an alternative to familiarity-based explanations of this effect (Hicks & Marsh, 1998; Westerman & Greene, 1998), Niewiadomski and Hockley (2001) proposed a decision-based account in which it is assumed that the problem-solving task displaces the study list context in working memory, leading subjects to adopt a more liberal recognition criterion. In the present study, we show that the revelation effect is seen when the stimulus materials are pure lists of very rare words or nonwords. In contrast, for mixed lists of common words and very rare words or nonwords, the revelation effect is found for common words but disappears for very rare words and nonwords. We argue that, in mixed lists, the liberal decision bias following the revelation task and the criterion changes between common words and very rare words and nonwords serve to offset each other.