Recreational drug use and prospective memory.

Whilst the deleterious effects of alcohol on retrospective remembering have been widely documented, no study has yet objectively determined alcohol's effects on prospective memory (PM)--remembering to do something in the future. With this aim, the present study determined the acute effects of alcohol upon PM using a laboratory measure that simulates the PM tasks in everyday life--'Virtual Week'--both (a) in its standard form with regular, irregular, event-based and time-based PM tasks; and (b) an adapted version which enabled exploration of how future event simulation at encoding impacted upon subsequent PM. Forty healthy volunteers were administered 0.6 g/kg ethanol or a matched placebo in a double-blind fashion and completed the two versions of Virtual Week along with prose recall (to tap retrospective memory) and an executive function task. Alcohol acutely produced global impairments across all (regular, irregular, event-based and time-based) PM tasks. It also produced impairments of episodic memory which positively correlated with PM performance of irregular tasks. Future-event simulation tended to enhance PM in the placebo but not in the alcohol group. These findings on an objective measure of PM suggest that 4-5 units of alcohol will compromise PM abilities in everyday life.

Frontal lobe involvement in a task of time-based prospective memory

Enhancing cue salience improves aspects of naturalistic time-based prospective memory in older adults with HIV disease.

The overall aim of the current thesis was to explore three key components of future-oriented thinking, namely episodic future thinking (EFT), episodic foresight, and prospective memory (PM), in middle childhood. The developmental literature examining each of these future-oriented abilities has generally focused on their emergence in the preschool years, with less known about how these abilities present in middle childhood. In addition, research investigating what cognitive mechanisms may drive these abilities in this age band is limited and findings of those studies that have been conducted are inconsistent. Lastly, the literature has predominantly examined EFT, episodic foresight, and PM in isolation, and research has only just begun to explore interrelations between these future-oriented constructs. The first empirical study therefore aimed to investigate whether EFT ability was associated with age and to examine what cognitive mechanisms may contribute to this skill. The second empirical study aimed to examine, for the first time, whether episodic foresight was associated with age across middle childhood. A second aim of this study was to provide the first investigation of the cognitive mechanisms that may contribute to episodic foresight in this age group, with the particular interest in whether EFT contributed to episodic foresight. The final empirical study aimed to explore whether age was associated with children’s PM performance across event-based and time-based PM tasks. An additional aim of this study was to explore the cognitive abilities that contribute to children’s performance on both event-based and time-based PM tasks, with a particular interest in the contribution of EFT. A single sample of 80 children aged 8 to 12 years were recruited for this research project. Study 1 indicated greater EFT ability was associated with age, consistent with some of the limited studies previously conducted with this age group. Study 1 also demonstrated strong evidence regarding the contribution from episodic memory to children’s EFT and a lack of contribution from executive functions. Study 2 was the first study to examine episodic foresight beyond the preschool years. Results of this study provided the first evidence of an association between age and better episodic foresight performance across the ages of 8 to 12 years. In addition, Study 2 identified age and IQ as significant contributors to successful episodic foresight performance, while retrospective memory, executive functions, and EFT were not found to contribute. The lack of contribution from EFT may have been due to the specific form of episodic foresight task used in this study, which did not require a specific scenario to be envisaged. Further research is now required to investigate whether EFT contributes to other types of episodic foresight task that involve clear scenarios that can be envisaged. The results of Study 3 indicated age was significantly correlated with performance on both event-based and time-based PM tasks. The findings also clearly revealed age, retrospective memory, and EFT were significant contributors to event-based PM performance, while retrospective memory was the only significant contributor to time-based PM performance. Furthermore, the results clearly demonstrated a lack of contribution from executive functions to performance on both task types. Importantly, Study 3 demonstrated that EFT selectively contributed to children’s event-based PM performance. This finding is consistent with the only other study in this age band and used a more comprehensive set of predictors than this previous study. The current research provided novel insights into the profile of children’s future-oriented thinking across the middle childhood period. The findings regarding age-related improvements in EFT, episodic foresight, and PM help to bridge the gap in understanding of the development of these abilities between their emergence in the preschool years and their presentation later in development. Longitudinal research that extends from early childhood to adulthood is now needed to provide a thorough understanding of the developmental trajectory of these abilities across the lifespan. In addition, the current research revealed a clear pattern of results regarding the cognitive mechanisms that contribute to each of these abilities, providing some clarity to the previously mixed findings in the children’s future oriented-thinking literature. Results regarding the inter-relationships between the future-oriented constructs also provided an important extension to current understanding of future-oriented thinking as a broader taxonomy. Furthermore, the current findings bring attention to the need for further theoretical distinction between different forms of episodic foresight and the cognitive processes that contribute to this skill. Overall, the findings from the current thesis have important implications for children’s daily living. In particular, greater understanding of future-oriented thinking in the middle childhood period gained from this thesis may assist in fostering the development of these abilities early in life. This in turn will enable parents and teachers to create reasonable expectations regarding children’s capacity to use these skills in their everyday functioning, thereby maximising success and minimising failure.

HIV infection and older age are each independently associated with lower health-related quality of life (HRQoL) and deficits in prospective memory (PM), which is a distinct aspect of cognition involving the ability to "remember to remember" to do something at a future occasion. The present study investigated associations between PM and HRQoL in 72 older (≥ 50 years) and 41 younger (≤ 40 years) HIV-infected adults. Self-reported PM complaints predicted HRQoL across the entire sample, but there was a significant interaction between performance-based PM and age group on HRQoL, such that lower time-based PM was associated with lower HRQoL only in the younger cohort. Within the younger group, time-based and self-reported PM significantly predicted mental HRQoL independent of other risk factors (e.g. depression). These findings suggest that PM plays a unique role in HRQoL outcomes among younger persons living with HIV infection and support the examination of other age-related factors (e.g. effective use of compensatory strategies) that may regulate the adverse impact of PM on everyday functioning.

Objective: Prospective memory (PM) is the ability to remember to carry out an intended action. Working memory is the ability to store information in mind while processing potentially distracting information. The few previous studies of PM in autism spectrum disorder (ASD) have yielded inconsistent findings. Studies of working memory ability in ASD have suggested a selective impairment of “visual working memory.” However, it remains unclear whether any such impairment is the result of diminished (domain-specific; visual/verbal) storage capacity or diminished (domain-general) processing capacity. We aim to clarify these issues and explore the relation between PM and working memory in ASD. Method: Seventeen adults with ASD and 17 age- and IQ-matched comparison participants completed experimental measures of both event-based (perform action x when event y occurs) and time-based (perform action a at time b) PM, plus a self-report measure of PM skills. Participants also completed a working memory test battery. Results: Participants with ASD self-reported diminished PM skill, and showed diminished performance on the time-based, but not event-based, PM task. On the working memory test battery, visual but not verbal storage capacity was diminished among participants with ASD, as was processing ability. Whereas visual storage was associated with event-based PM task performance among comparison participants, verbal storage was associated among ASD participants. Conclusions: ASD appears to involve a selective deficit in time-based PM and a selective difficulty with aspects of working memory that depend on the storage of visual information. However, event-based PM may be achieved through compensatory strategies in ASD.

The current study examined the effect of a delay on naturalistic time-based prospective memory (PM) tasks. Two experiments were performed to compare PM performance on a texting task with delays of 1 to 6 days after an initial session. In the first experiment, half of the participants were asked to repeat their response with the same delay to test whether requiring a second response (i.e., a repeated PM task, such as taking medication at the same time each day) would affect time-based PM performance. In the second experiment, participants were given an implicit or an explicit reminder several hours before their time to respond to examine the effect of type of reminder on this PM task. The results of both experiments showed a significant decline in PM performance between the 1-day and multi-day delays. Repeating responses (Experiment 1) had no effect on accuracy of the PM task, but in Experiment 2, explicit experimenter-initiated reminders significantly increased time-based PM performance compared with implicit reminders. These results are discussed in the context of previous studies that have tested delay effects on time-based PM and current theoretical descriptions of time-based PM.

ABSTRACTHuman immunodeficiency virus (HIV) disease is commonly associated with deficits in prospective memory (PM), which increase the risk of suboptimal health behaviours, like medication non-adherence. This study examined the potential benefits of a brief future visualisation exercise during the encoding stage of a naturalistic PM task in 60 young adults (aged 19–24 years) with HIV disease. Participants were administered a brief clinical neuropsychological assessment, which included a standardised performance-based measure of time- and event-based PM. All participants were also given a naturalistic PM task in which they were asked to complete a mock medication management task when the examiner showed them the Grooved Pegboard Test during their neuropsychological evaluation. Participants were randomised into: (1) a visualisation condition in which they spent 30 sec imagining successfully completing the naturalistic PM task; or (2) a control condition in which they repeated the task instructions. Logistic regression analyses revealed significant interactions between clinical neurocognitive functions and visualisation. HIV positive (HIV+) participants with intact retrospective learning and/or low time-based PM demonstrated observable gains from the visualisation technique, while HIV+ participants with impaired learning and/or intact time-based PM did not evidence gains. Findings indicate that individual differences in neurocognitive ability moderate the response to visualisation in HIV+ young adults. The extent to which such cognitive supports improve health-related PM outcomes (e.g., medication adherence) remains to be determined.

This study investigated the effects of emotional valence on prospective memory (PM) performance in individuals with traumatic brain injury (TBI) compared to healthy controls. Using an emotional version of the Virtual Week paradigm, we examined how positive, negative, and neutral emotional content influenced both event-based and time-based PM tasks. Thirty-one participants with TBI and 31 matched healthy controls completed the computerised PM measure over three simulated days, and a recognition task to assess the retrospective component of PM. Participants with TBI performed less accurately than controls across all conditions. For event-based tasks, positive emotional content enhanced PM performance in both groups. Time-based tasks showed a different pattern, with neutral content leading to better performance. Analysis of the retrospective component revealed a significant group by valence interaction: participants with TBI showed enhanced recognition of negative stimuli in time-based tasks, while healthy controls maintained high recognition accuracy across all valence conditions. These findings suggest a complex interaction between emotional valence, task type, and PM components in TBI, with implications for cognitive rehabilitation strategies.

Cognitive correlates of prospective memory in dystonia

ABSTRACTWe examined prospective memory (PM) function in children with attention deficit hyperactivity disorder (ADHD). A group of 28 children with ADHD and 28 typically developing children completed event-, time- and activity-based PM tasks and attention tests. ADHD children had impaired attention but intact PM performance. Both groups performed best in activity-based PM tasks, followed by event-based PM tasks, and performed worst in time-based PM tasks. ADHD children had lower ongoing task performance in the event-based PM task. The findings indicate that children with ADHD may have an intact PM, but this may be at the cost of ongoing task performance.

This study investigates prospective memory (PM) deficits as well as the interplay between performance in executive functions (EFs), speed of processing, episodic memory and PM in traumatic brain injury (TBI), differentiating between time based and event based tasks. The Memory for Intentions Screening Test was administrated to a sample of 19 participants with TBI and 50 healthy controls. Tasks probing different EFs (i.e., shifting, updating/working memory, inhibition, and access to long term memory), speed of processing, and episodic memory were also administrated to the TBI group. PM deficits were found in participants with TBI compared to controls. In the role of EFs in PM, only tasks probing updating/working memory and access to the long-term memory showed to play a specific role in PM performance in TBI. However, while updating/working memory was related to both time and event based PM, access to the long term memory was associated to performance on time based PM task only. Speed of processing and retrospective memory abilities do not seem to play a specific role in PM deficit in TBI. Our results provide a better understanding of the PM deficit in TBI, which may contribute to improve existing rehabilitation programs for individuals with TBI.

ObjectiveTime-based prospective memory (PM), remembering to do something at a particular moment in the future, is considered to depend upon self-initiated strategic monitoring, involving a retrieval mode (sustained maintenance of the intention) plus target checking (intermittent time checks). The present experiment was designed to explore what brain regions and brain activity are associated with these components of strategic monitoring in time-based PM tasks.Method24 participants were asked to reset a clock every four minutes, while performing a foreground ongoing word categorisation task. EEG activity was recorded and data were decomposed into source-resolved activity using Independent Component Analysis. Common brain regions across participants, associated with retrieval mode and target checking, were found using Measure Projection Analysis.ResultsParticipants decreased their performance on the ongoing task when concurrently performed with the time-based PM task, reflecting an active retrieval mode that relied on withdrawal of limited resources from the ongoing task. Brain activity, with its source in or near the anterior cingulate cortex (ACC), showed changes associated with an active retrieval mode including greater negative ERP deflections, decreased theta synchronization, and increased alpha suppression for events locked to the ongoing task while maintaining a time-based intention. Activity in the ACC was also associated with time-checks and found consistently across participants; however, we did not find an association with time perception processing per se.ConclusionThe involvement of the ACC in both aspects of time-based PM monitoring may be related to different functions that have been attributed to it: strategic control of attention during the retrieval mode (distributing attentional resources between the ongoing task and the time-based task) and anticipatory/decision making processing associated with clock-checks.

The present study investigated time-based prospective memory (PM) during the transition from kindergarten/preschool to school age and applied mediation models to test the impact of executive functions (working memory, inhibitory control) and time monitoring on time-based PM development. Twenty-five preschool (age: M = 5.75, SD = 0.28) and 22 primary school children (age: M = 7.83, SD = 0.39) participated. To examine time-based PM, children had to play a computer-based driving game requiring them to drive a car on a road without hitting others cars (ongoing task) and to refill the car regularly according to a fuel gauge, which serves as clock equivalent (PM task). The level of gas that was still left in the fuel gauge was not displayed on the screen and children had to monitor it via a button press (time monitoring). Results revealed a developmental increase in time-based PM performance from preschool to school age. Applying the mediation models, only working memory was revealed to influence PM development. Neither inhibitory control alone nor the mediation paths leading from both executive functions to time monitoring could explain the link between age and time-based PM. Thus, results of the present study suggest that working memory may be one key cognitive process driving the developmental growth of time-based PM during the transition from preschool to school age.

Prospective memory and quality of life in older and younger autistic adults.