Is working memory necessary for implementation intentions to enhance prospective memory in older adults with cognitive problems?

Implementation intentions are an effective strategy for improving prospective memory in older adults. However, their efficacy has never been assessed in older individuals with cognitive problems (i.e., individuals with subjective memory complaints or objective memory impairments). Furthermore, although most authors consider implementation intentions to depend on automatic processes, some studies have shown the necessity of residual preserved controlled processes for implementation intentions to be efficient. We examined the efficacy of implementation intentions in prospective memory in 45 older participants consulting a memory clinic. Half of the participants were instructed to form an implementation intention, the other half receiving standard instructions. Analyses showed that working memory moderated the efficacy of implementation intentions, which were efficient only in individuals with better working memory. These results corroborate the claim that a minimal level of cognitive resources is required for the technique, although implementation intentions might depend principally on automatic processes.     

The development of automatic and controlled inhibitory retrieval processes in true and false recall

In three experiments, we investigated the role of automatic and controlled inhibitory retrieval processes in true and false memory development in children and adults. Experiment 1 incorporated a directed forgetting task to examine controlled retrieval inhibition. Experiments 2 and 3 used a part-set cue and retrieval practice task to examine automatic retrieval inhibition. In the first experiment, the forget cue had no effect on false recall for adults but reduced false recall for children. In Experiments 2 and 3, both tasks caused retrieval impairments for true and false recall, and this occurred for all age groups. Implicit inhibition, which occurs outside of our conscious control, appears early in childhood. However, because young children do not process false memories as automatically as adults, explicit inhibition can reduce false memory output.     

Implementation intention encoding does not automatize prospective memory responding

An implementation intention encoding, one that specifies the concrete situation that is appropriate for initiating an intended action and links that situational cue to the intended action, has been shown to improve prospective memory. One proposed mechanism is that implementation intentions create automatized prospective remembering. This view anticipates that implementation intentions should prevent prospective memory decline in highly cognitively demanding situations. Contrary to this expectation, although implementation intention encoding enhanced prospective memory (Experiments 1 and 2), implementation-intention encoding did not buffer against significant prospective memory decline in high-cognitive-demand conditions (Experiments 1–3), and in Experiment 3, implementation intention encoding produced lower levels of prospective memory performance than did behavioral practice in the high-cognitive-demand situation. We suggest that although implementation intentions may stimulate a strong associative encoding (between an anticipated environmental cue and an intended action), that encoding does not support a completely automatized prospective memory response.     

The interplay of controlled and automatic processing in the expression of spontaneously inferred traits: A PDP analysis

Inferences made about actors influence subsequent processing about those actors. Three experiments conducted in the context of spontaneous trait inference (STI) making demonstrate that such influences occur can either occur via automatic processes or via controlled processes. Results from Experiment 1 demonstrated that processing goals manipulated prior to encoding actor behavior affected the extent to which STIs automatically influenced subsequent responses but did not alter the extent to which STIs influenced those responses via controlled processes. Results from Experiment 2 showed that the extent to which STIs affected subsequent responding via the action of controlled processes were more affected by a delay between exposure to an actor behavior and the response task than the extent to which STIs affected task performance via the action of automatic processes. Finally, results from Experiment 3 showed that participants' subjective experience of awareness of their trait inferences is related to estimates of the extent to which controlled processing is involved in the production of their future responses but not to estimates of the extent to which those responses are affected by automatic processing.     

The cost of event-based prospective memory: salient target events

Evidence has begun to accumulate showing that successful performance of event-based prospective memory (PM) comes at a cost to other ongoing activities. The current study builds on previous work by examining the cost associated with PM when the target event is salient. Target salience is among the criteria for automatic retrieval of intentions according to the multiprocess view of PM. An alternative theory, the preparatory attentional and memory processes theory, argues that PM performance, including retrieval of the intent, is never automatic and successful performance always will come at a cost to other ongoing activity. The 4 experiments reported here used a salient PM target event. In addition, Experiments 3 and 4 were designed to meet the stringent criteria proposed for automatic retrieval of intentions by multiprocess theory, and, yet, in all 4 experiments, delayed intentions interfered with ongoing task performance.     

Commission errors of active intentions: the roles of aging,cognitive load,and practice

Performing an intended action when it needs to be withheld, for example, when temporarily prescribed medication is incompatible with the other medication, is referred to as commission errors of prospective memory (PM). While recent research indicates that older adults are especially prone to commission errors for finished intentions, there is a lack of research on the effects of aging on commission errors for still active intentions. The present research investigates conditions which might contribute to older adults’ propensity to perform planned intentions under inappropriate conditions. Specifically, disproportionally higher rates of commission errors for still active intentions were observed in older than in younger adults with both salient (Experiment 1) and non-salient (Experiment 2) target cues. Practicing the PM task in Experiment 2, however, helped execution of the intended action in terms of higher PM performance at faster ongoing-task response times but did not increase the rate of commission errors. The results have important implications for the understanding of older adults’ PM commission errors and the processes involved in these errors.     

Prospective remembering: Perceptually driven or conceptually driven processes?

Converging experimental operations and several prospective memory tasks were used across three experiments to determine the extent to which prospective remembering is supported by datadriven versus conceptually driven processes. In all experiments, subjects were asked to perform an action when a target item later occurred. When the semantic context changed from encoding to test, prospective memory significantly declined (Experiment 1). When the target event (the item, which in its subsequent appearance in the experiment was the signal to perform the action) was presented as a word (relative to picture presentation, Experiment 2) or was encoded nonsemantically (relative to semantic encoding, Experiment 3), there was a decline in prospective memory performance. Dividing attention during prospective memory retrieval substantially reduced prospective memory performance (Experiment 3). The results of this research indicated that prospective memory is largely conceptually driven, and it behaves more similarly to direct rather than indirect conceptual tests. We suggest that prospective remembering of the type studied here is mediated by a reflexive episodic associative memory system as proposed by Moscovitch (1994).     

Are covert verbal responses mediating false implicit memory?

In the DRM paradigm, illusory memories of a nonpresented word can be induced by the presentation of strong associates to this word. In two experiments, we explored previous findings of false implicit memory of the nonpresented words (McDermott, 1997; McKone & Murphy, 2000). Experiment 1 extended the finding of false priming to the anagram task. Furthermore, participants attributed this "false" influence on performance to the difficulty of the anagrams and judged them as easier to solve for other students. In Experiment 2, articulatory suppression during the study of the associates resulted in nonsignificant levels of false priming, whereas the normal priming effect was in the same range as that observed in Experiment 1. The study replicates and extends findings of false implicit memory to the anagram task and suggests that future studies should examine the role of covert verbal responses in producing false implicit memory.     

Automatic processing influences free recall: converging evidence from the process dissociation procedure and remember-know judgments

Dual-process theories of retrieval suggest that controlled and automatic processing contribute to memory performance. Free recall tests are often considered pure measures of recollection, assessing only the controlled process. We report two experiments demonstrating that automatic processes also influence free recall. Experiment 1 used inclusion and exclusion tasks to estimate recollection and automaticity in free recall, adopting a new variant of the process dissociation procedure. Dividing attention during study selectively reduced the recollection estimate but did not affect the automatic component. In Experiment 2, we replicated the results of Experiment 1, and subjects additionally reported remember–know–guess judgments during recall in the inclusion condition. In the latter task, dividing attention during study reduced remember judgments for studied items, but know responses were unaffected. Results from both methods indicated that free recall is partly driven by automatic processes. Thus, we conclude that retrieval in free recall tests is not driven solely by conscious recollection (or remembering) but also by automatic influences of the same sort believed to drive priming on implicit memory tests. Sometimes items come to mind without volition in free recall.     

Prospective memory: Effects of divided attention on spontaneous retrieval

We examined the effects of divided attention on the spontaneous retrieval of a prospective memory intention. Participants performed an ongoing lexical decision task with an embedded prospective memory demand, and also performed a divided-attention task during some segments of lexical decision trials. In all experiments, monitoring was highly discouraged, and we observed no evidence that participants engaged monitoring processes. In Experiment 1, performing a moderately demanding divided-attention task (a digit detection task) did not affect prospective memory performance. In Experiment 2, performing a more challenging divided-attention task (random number generation) impaired prospective memory. Experiment 3 showed that this impairment was eliminated when the prospective memory cue was perceptually salient. Taken together, the results indicate that spontaneous retrieval is not automatic and that challenging divided-attention tasks interfere with spontaneous retrieval and not with the execution of a retrieved intention.     

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.     

Psychophysiology of prospective memory

Prospective memory involves the self-initiated retrieval of an intention upon an appropriate retrieval cue. Cue identification can be considered as an orienting reaction and may thus trigger a psychophysiological response. Here we present two experiments in which skin conductance responses (SCRs) elicited by prospective memory cues were compared to SCRs elicited by aversive stimuli to test whether a single prospective memory cue triggers a similar SCR as an aversive stimulus. In Experiment 2 we also assessed whether cue specificity had a differential influence on prospective memory performance and on SCRs. We found that detecting a single prospective memory cue is as likely to elicit a SCR as an aversive stimulus. Missed prospective memory cues also elicited SCRs. On a behavioural level, specific intentions led to better prospective memory performance. However, on a psychophysiological level specificity had no influence. More generally, the results indicate reliable SCRs for prospective memory cues and point to psychophysiological measures as valuable approach, which offers a new way to study one-off prospective memory tasks. Moreover, the findings are consistent with a theory that posits multiple prospective memory retrieval stages.     

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.     

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.     

Individual differences in event-based prospective memory: Evidence for multiple processes supporting cue detection

The multiprocess view proposes that different processes can be used to detect event-based prospective memory cues, depending in part on the specificity of the cue. According to this theory, attentional processes are not necessary to detect focal cues, whereas detection of nonfocal cues requires some form of controlled attention. This notion was tested using a design in which we compared performance on a focal and on a nonfocal prospective memory task by participants with high or low working memory capacity. An interaction was found, such that participants with high and low working memory performed equally well on the focal task, whereas the participants with high working memory performed significantly better on the nonfocal task than did their counterparts with low working memory. Thus, controlled attention was only necessary for detecting event-based prospective memory cues in the nonfocal task. These results have implications for theories of prospective memory, the processes necessary for cue detection, and the successful fulfillment of intentions.     

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.     

Retrieval experience in prospective memory: strategic monitoring and spontaneous retrieval

According to the multi-process model of prospective memory (McDaniel & Einstein, 2000), performance in a prospective memory task may be due to spontaneous retrieval processes or due to strategic monitoring. Spontaneous retrieval is typically accompanied by a pop up experience and strategic monitoring by a search experience. In this study we report two experiments with young adults in which we systematically investigated whether retrieval experience differed across experimental conditions. In Experiment 1 some prospective memory targets were preceded by associated primes. We expected that presenting primes would enhance performance by an automatic activation of the intention and hence lead to an increase in pop up experiences. In Experiment 2 half of the participants received instructions containing information about the specific context in which the prospective memory task would occur, whereas the other half of the participants received no such information. We expected that specific context instructions would enhance performance by legitimate anticipation of the prospective memory task and hence would lead to an increase in search experiences. The results confirmed these expectations. They indicate that the assessment of retrieval experience can provide valuable insights into the processes underlying prospective memory performance. They also suggest that retrieval experience can vary systematically across experimental situations as predicted by the multi-process model.     

Delaying execution of intentions: overcoming the costs of interruptions

In real-world settings, execution of retrieved intentions must often be briefly delayed until an ongoing activity is completed (delayed-execute prospective memory tasks). Further, in demanding work settings, the ongoing activity itself can be interrupted. Experiment 1 examined the effects of the delay length (5, 15, 40 s), the presence of an interruption within that delay, and the length of the interruption on prospective memory performance. Delay length did not significantly affect performance, but interruptions produced significant decrements in performance relative to a delay alone. The length of the interruptions (10 vs. 20 s) did not significantly affect performance. Experiment 2 replicated the negative effects of interruptions, and found that these effects could be overcome with a simple external mnemonic. We suggest that in demanding work environments where interruptions are likely, external cues are advisable, especially where prospective memory failures have critical consequences. Copyright © 2004 John Wiley & Sons, Ltd.     

The influence of high and low cue–action association on prospective memory performance

Recent discoveries in the field of prospective memory (PM) show higher accuracy for remembering intentions in which prospective cue and action are strongly associated. In two experiments presented in this paper, participants encoded both high and low association cue–action pairs and were later tested on both prospective and retrospective PM components. Results of both studies show higher PM accuracy for the low association pairs, compared to high association ones, but only for the prospective component (across both Experiments) and only when a high association cue was presented first (Experiment 2). This finding was accompanied by longer study times for the low association pairs and study times were functionally related to later performance (across both Experiments). In the retrospective component, higher accuracy was observed for pairs with high level of association (but only in the first Experiment). Data are discussed in the context of metacognitive processes possibly related to the encoding of an intention as well as cue monitoring in case of PM tasks with high memory load and varying task difficulty.     

Complex Prospective Memory in Children with ADHD

The ability to remember intentions (prospective memory) is fundamental to the organization of goal-directed actions in everyday life. Successful prospective remembering involves forming, retaining, initiating, and executing an intention. Although previous research has demonstrated prospective memory impairments in children with attention deficit/hyperactivity disorder (ADHD), this has largely focused on the intention initiation and execution stages. In this study, we investigate the performance of 20 children with ADHD and 20 matched controls at each of the four stages of prospective memory, using a computer multitask paradigm. Results suggest that children with ADHD may demonstrate difficulties forming delayed intentions, as indicated by impulsive planning, and that this may have further implications for the retention and implementation of these delayed intentions. While children with ADHD showed comparable multitask switching, this appeared to be at the expense of intention execution as they made more performance errors than controls. Implications for day-to-day functioning are discussed.