Learning is impaired by activated intentions

Two experiments examined the task interference that sometimes accrues from having an intention. In standard prospective memory tasks, latency is often slower to an ongoing task performed concurrently with having an intention than it is when no intention is given. If the locus of this slowing resulted from different attentional allocation policies in the two cases, we predicted that the process of learning a word list would be impaired if participants had an intention rather than if they did not. Four different event-based prospective memory tasks were used in Experiment 1 to demonstrate that worse free recall of a word list resulted when studied with a concurrent intention than with a control condition that had no intention. In that experiment, linking an intention to a distal context that was to occur after learning did not impair free recall. Two time-based tasks were used in Experiment 2 to demonstrate that possessing a time-based prospective memory also hinders learning, unless the intention is linked to a future context that is expected to occur after the study session. In the latter case, no impairment was obtained.     

The Role of Interruptions and Contextual Associations in Delayed‐Execute Prospective Memory

We conducted three experiments to examine the dynamics of a delayed‐execute prospective memory task involving task interruptions. In the delayed‐execute paradigm, participants must delay a response until some future condition is met. After an intention was formed to a salient cue, an interruption reduced prospective memory relative to a no‐interruption condition. Prospective memory for cues encountered during an interrupting task was worse than for cues occurring before an interruption, but the location of the cue in either the ongoing task or the interruption did not affect prospective memory. Importantly, reinstating the prevailing context after the interruption alleviated the negative influence of the interruption. Providing participants with information about the future context for making the delayed‐execute response also alleviated some of these deficits presumably because participants could encode more specific features of the performance context. These results highlight the potential importance of contextual associations and reminders in completing everyday intentions successfully. Copyright © 2013 John Wiley & Sons, Ltd.     

Effects of context expectation on prospective memory performance among older and younger adults

This experiment examined the impact of context expectation on prospective memory (PM) performance among older and younger adults. Participants responded to PM target words embedded in an ongoing lexical decision task (LDT). Older and younger adults performed similarly on the PM task. Regardless of age, PM was significantly better for participants in the correct context expectation condition and significantly worse in the incorrect context expectation condition relative to participants who held no expectations about the context in which targets would appear. Participants’ LDT response latencies were used to assess cost of the PM task to the ongoing task. Latencies were discernibly longer in the LDT block where the PM targets were expected compared to the block where they were not expected. The findings provide new information about how context can be used to support PM aging and suggest that contextual information can be equally beneficial for older and younger adults.     

Task interference from prospective memories covaries with contextual associations of fulfilling them

One of the current issues in the field of prospective memory concerns whether having an intention produces a cost to other ongoing activities (called task interference). The evidence to date suggests that certain intentions held over the shorter term do interfere with other tasks. Because the cumulative effect of such costs would be prohibitively expensive in everyday life, the present study examined one means by which that interference may be reduced. Participants who formed a specific association to fulfilling an intention in a future context did not exhibit task interference over the intervening period until that context was encountered. This outcome was observed with both an event-based and a time-based prospective memory task. The results suggest that associating intention fulfillment with a specific context can eliminate task interference, and they emphasize the importance of studying intentions that are linked to future contexts versus those that are not.     

Power in Numbers: The Effect of Target Set Size on Prospective Person Memory in an Analog Missing Child Scenario

Efforts to find missing or wanted individuals have been characterized as an example of event‐based prospective memory called prospective person memory. We examined prospective person memory in the context of missing children. Participants studied 4 or 12 mock missing child posters. In Experiment 1, we equated total time per poster and found no difference between conditions in prospective person memory accuracy. In Experiment 2, we equated total time for all posters and found evidence of a decrease in prospective person memory accuracy in the 12‐poster condition. In Experiment 3, we allowed free study and also found a decrease in prospective person memory accuracy. Across all three experiments, we also found evidence of a more liberal response bias in the 12‐poster condition. Results are discussed in terms of both practical and theoretical implications. Copyright © 2012 John Wiley & Sons, Ltd.     

The influence of partial‐match cues on event‐based prospective memory

In event‐based prospective memory tasks people form an intention to respond when an environmental cue signals that conditions are appropriate to fulfil an intended activity. In the ongoing activity the authors embedded partial‐match cues that only partially, but not completely, satisfied the conditions required to make a prospective response. The consequence of encountering these partial‐match cues was to increase responses to appropriate prospective memory cues encountered later. This outcome occurred both with semantic and orthographic cues, but only the former led to longer processing latencies of the partial‐match cues. This asymmetry suggests that partial‐match cues may not need to be processed consciously in order to benefit event‐based prospective memory. A parametric manipulation of the number of partial‐match cues resulted in numerically but not statistically better prospective memory. Consequently, partial‐match cues may function as overt reminders of the intention to respond or they may serve to engage participants in self‐initiated remindings of the intention.     

On the role of imagery in event-based prospective memory

The role of imagery in encoding event-based prospective memories has yet to be fully clarified. Herein, it is argued that imagery augments a cue-to-context association that supports event-based prospective memory performance. By this account, imagery encoding not only improves prospective memory performance but also reduces interference to intention-related information that occurs outside of context. In the current study, when lure words occurred outside of the appropriate responding context, the use of imagery encoding strategies resulted in less interference when compared with a standard event-based intention condition. This difference was eliminated when participants were not given a specific context to associate their intention (i.e., lures occurred within the appropriate responding context). These results support a cue-to-context association account of how imagery operates in certain event-based prospective memory tasks.     

Prospective memory and ageing: Is task importance relevant?

Memory for activities to be performed in the future, i.e., prospective memory, such as remembering to take medication or remembering to give a colleague a message, is a pervasive real‐world memory task that has recently begun to attract the attention of numerous researchers. Age effects in prospective memory have been found particularly in complex paradigms requiring participants to remember to switch between several subtasks in a limited time period (e.g., Kliegel, McDaniel, & Einstein, 2000). Here, most of the older adults try to complete one or two subtasks and to forget the prospective instruction to work on all subtasks. Since recent findings in this context show that one profits from tips regarding the relevant task in complex double tasks, it seems likely that age effects in prospective memory tasks might also be due to the lack of information about the importance of the prospective task. To test this hypothesis, the importance of the prospective task was varied in the present study with 104 young and old participants by providing motivational incentives to interrupt and switch during the introduction phase (plan formation) as well as during the execution phase. Also, interindividual differences regarding nonexecutive as well as executive cognitive resources were analysed, thus allowing estimation of the relationship between these factors and (age‐related) performance in complex prospective remembering. The results show age effects in favour of the younger group in all task components of the complex prospective multitask. In contrast, there was no effect of the present experimental manipulation of motivational incentives. Finally, in regression analyses, intention formation, in particular, was found to be a significant predictor of intention execution, explaining most of the age‐related variance. In sum, our results specifically highlight the fundamental importance of adequately planning the complex intention and do not support the hypothesis that age‐related decrements in performance are reflecting a lack of motivation in the present complex prospective memory paradigm.     

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 Compensatory Role of Implementation Intentions for Young Adults with Low Working Memory Capacity

Many factors improve prospective memory performance both inside and outside of the laboratory, including the detailed planning of the situational cue and intended action (i.e., implementation intentions). In the current study, we obtained measures of working memory capacity and laboratory event‐based prospective memory performance in college‐aged adults. Half of our participants formed an implementation intention in the prospective memory task. Because of evidence that implementation intentions increase the encoding/retrieval efficiency of the prospective memory, it was predicted that forming an implementation intention would serve as a compensatory strategy for those with low working memory ability. Our results supported this hypothesis in that working memory capacity no longer correlated with prospective memory performance when participants employed an implementation intention encoding strategy. These findings suggest that implementation intentions may be an effective way for individuals with low working memory capacity to improve their performance in an attentionally demanding prospective memory task. Copyright © 2015 John Wiley & Sons, Ltd.     

Effects of ongoing task context and target typicality on prospective memory performance: the importance of associative cueing

Two experiments examined whether prospective memory performance is influenced by contextual cues. In our automatic activation model, any information available at encoding and retrieval should aid recall of the prospective task. The first experiment demonstrated an effect of the ongoing task context; performance was better when information about the ongoing task present at retrieval was available at encoding. Performance was also improved by a strong association between the prospective memory target as it was presented at retrieval and the intention as it was encoded. Experiment 2 demonstrated boundary conditions of the ongoing task context effect, which implicate the association between the ongoing and prospective tasks formed at encoding as the source of the context effect. The results of this study are consistent with predictions based on automatic activation of intentions.     

Effects of ongoing task context and target typicality on prospective memory performance: The importance of associative cueing

Two experiments examined whether prospective memory performance is influenced by contextual cues. In our automatic activation model, any information available at encoding and retrieval should aid recall of the prospective task. The first experiment demonstrated an effect of the ongoing task context; performance was better when information about the ongoing task present at retrieval was available at encoding. Performance was also improved by a strong association between the prospective memory target as it was presented at retrieval and the intention as it was encoded. Experiment 2 demonstrated boundary conditions of the ongoing task context effect, which implicate the association between the ongoing and prospective tasks formed at encoding as the source of the context effect. The results of this study are consistent with predictions based on automatic activation of intentions.     

The involvement of executive functions in prospective memory performance of adults

The present study examines the relationship between prospective memory performance and executive functioning. The four phases of the prospective memory process—intention formation, intention retention, reinstantiation of the intention, and intention execution—are assumed to require different amounts of executive processing, most of which is demanded in the phases of intention formation and intention execution. At present, though, it is still unclear whether, and to what extent, prefrontal executive systems are involved in different kinds of prospective memory tasks, as some findings suggest that prospective memory might rather rely on nonstrategic processes that are unlikely to depend on prefrontal executive systems. Therefore, this study focuses on the following questions: (1) to what degree does executive functioning predict prospective memory performance in different standard prospective memory tasks and, furthermore, are certain executive measures better predictors than others; (2) are age‐related effects in different prospective memory measures due to individual differences in executive functioning; and (3) do age‐related differences in prospective memory exist that are not explained by individual differences in executive functioning. In a sample of 80 adults (20‐80 years), we applied four instruments to measure prospective memory: a traditional single‐task paradigm, two more complex tasks—one time‐based and one event‐based—and a highly complex multi‐task paradigm. We further assessed a broadly defined construct of executive functioning using several standard neuropsychological tests. Results showed that executive functioning did not predict performance in the simple single‐task paradigm. However, executive functioning, but not age, predicted performance in the two more complex standard tests of prospective remembering, and both executive functioning and age predicted performance in the most complex paradigm. In sum, the obtained data underline the assumption that frontal/ executive functions are related to prospective memory performance across a range of prospective paradigms. It also seems clear that age differences in prospective memory performance partially depend on age‐related individual differences in frontal/executive functions.     

Implications of MDMA use for prospective memory function and substance use patterns in an Australian sample: A web‐based pilot study

The use of amphetamine type stimulants, particularly MDMA, is a global concern. Little research has been conducted on the association between MDMA use and everyday memory function—prospective memory. Twenty‐five MDMA users, 37 cannabis users, and 43 illicit substance‐naïve controls were assessed on their substance use history and reported prospective memory performance as measured by the Prospective Memory Questionnaire (PMQ) using a web‐based survey. There were significant differences between MDMA users and controls and cannabis users and controls on long‐term episodic subscale of the PMQ. However, given the high prevalence of cannabis co‐use by MDMA users, it was not possible to determine if MDMA use alone is associated with prospective memory performance. The substance use patterns of the sample were evaluated. Alcohol was the most used substance followed by tobacco, cannabis, and MDMA. The incidence of polydrug use was high, with all illicit substance use reporting having used at least two substances in their lifetime. The present study supports previous research into prospective memory deficits associated with substance use, and provides a basis for future research, particularly for elucidation of prospective memory deficits specific to MDMA use and further evaluation of substance use patterns.     

Planning and realization of complex intentions in traumatic brain injury and normal aging

The realization of delayed intentions (i.e., prospective memory) is a highly complex process composed of four phases: intention formation, retention, re-instantiation, and execution. The aim of this study was to investigate if executive functioning impairments are related to problems in the formation, re-instantiation, and execution of a delayed complex intention. In this context, it was another aim of the study to investigate the executive functioning hypothesis of cognitive aging in prospective memory performance. It was, therefore, explored if age-related prospective memory decline leads to similar decrements in the process of prospective remembering as executive functioning-related decline in young patients with traumatic brain injury. A group of patients with traumatic brain injury with retrospective memory within normal limits but impaired executive functions, a group of healthy older and a group of healthy younger adults completed a complex prospective memory task that allows for the separate assessment of the four phases of the prospective memory process. All groups showed a similarly high performance in the intention retention phase, whereas the patients with deficits in executive functioning and the older participants performed worse than the healthy young participants in the intention formation, re-instantiation and execution phases. The importance of executive functioning for prospective remembering in traumatic brain injury and normal aging is discussed.     

前瞻记忆的干扰效应：多重加工的证据

通过2个实验,对背景任务时间充裕和紧迫两种情况下的具体事件意向、类别事件意向、时间点意向、时间段意向四种前瞻记忆任务对背景任务的干扰效应进行考察。结果表明,在背景任务时间充裕情况下,类别事件意向对背景任务有干扰效应,具体事件意向、时间段意向和时间点意向都没有前瞻干扰效应;在背景任务时间紧迫情况下,时间点意向产生了干扰效应,具体事件意向、类别事件意向、时间段意向均无干扰效应。结果支持前瞻记忆的实现依赖多重加工的观点,时间性前瞻记忆并不一定比事件性前瞻记忆产生更大的干扰。     

The effect of perceptual distinctiveness on the prospective and retrospective components of prospective memory in young and old adults.

In two experiments, the effect of perceptual distinctiveness of cues on prospective memory performance was examined. Young and older adults completed a visual search task with embedded prospective memory instructions. On each trial, participants were asked to indicate the position of a target letter in a letter string, unless either of two letters previously identified as prospective memory cues was presented. Each prospective cue was associated with a specific response. Perceptual distinctiveness was manipulated by spatially displacing a single letter. The prospective component (successful detection of the cue) and the retrospective memory component (recalling the correct response when a cue is detected) were measured separately. Perceptual displacement of cues modulated performance of the prospective component but not the retrospective component. Young adults successfully detected a larger proportion of cues (prospective component) than older adults. However, there were minimal effects of age and no effect of cue displacement on participants' ability to recall the intention once they detected a cue (retrospective component performance). Results are discussed within the context of current theoretical models of prospective memory.     

A diffusion model analysis of task interference effects in prospective memory

Holding an intention often interferes with other ongoing activities, indicating that resource-demanding processes are involved in maintaining the intention and noticing the appropriate event to fulfill it. Little is known, however, about the nature of the processes underlying this task interference effect. The goal of the present research was to decompose the processes contributing to the task interference effect by applying the diffusion model (Ratcliff, Psychological Review 85:59–108, 1978) to an event-based prospective memory task. In the first experiment, we validated the interpretation of the response criterion parameter (a) of the diffusion model as reflecting strategies to cope with the anticipated demands of a prospective memory task in the context of the ongoing task. The second experiment served to investigate which underlying processes contribute to the task interference often found with prospective memory tasks. Diffusion model analyses revealed that the task interference effect was due to (1) less efficient processing in the more demanding than in the less demanding prospective memory task and (2) a more conservative response criterion. We suggest that the anticipated demands and the additional processing demands of the prospective memory task jointly contribute to the task interference effect.     

Disentangling executive functions and memory processes in event‐based prospective remembering after brain damage: A neuropsychological study

Successful prospective remembering (PR) comprises at least two components: one retrospective component that refers to the encoding and retrieval of the content of the intention and a second prospective component that involves the retrieval of the intended action at the appropriate moment. Whereas the retrospective component is very similar to memory skills like learning and retention of new information, the prospective component is thought to rely mainly on executive function. Head injuries can disturb PR during both of these stages. To disentangle the relative impact of executive functions and retrospective memory processes on PR we embedded a PR task in a 2‐back verbal working memory paradigm. Fifty‐six neurological patients with brain damage of various aetiologies were divided pre‐experimentally into four groups on the basis of their delayed recall Index in the Wechsler Memory Scale‐Revised (WMS‐R, indicating absence or presence of deficits in retrospective memory functions) and their age‐corrected score in the Behavioural Assessment of the Dysexecutive Syndrome (BADS, indicating absence or presence of deficits in executive functions). Additionally, 19 controls matched for age and education were examined. We found that patients with deficits in executive functions detected fewer cues than any other group irrespective of their retrospective memory performance. However, eight patients with severe anterograde memory deficits could retain neither the intention nor its content. Thus, intactness of the retrospective component seems to be a necessary but not sufficient prerequisite for successful prospective remembering. For the execution of the intended action itself executive functions play a critical role.