Predictors of prospective memory in adults with traumatic brain injury

Further clarification of cognitive processes of prospective memory in schizophrenia by comparing eye-tracking and ecologically-valid measurements

The aim of this study is to compare ecologically-valid measure (the Cambridge Prospective Memory Test, CAMPROMPT) and laboratory measure (eye-tracking paradigm) in assessing prospective memory (PM) in individuals with schizophrenia spectrum disorders (SSDs). In addition, eye-tracking indices are used to examine the relationship between PM and other cognitive domains in SSDs patients. Initially, the study sample was formed by 32 SSDs patients and 32 healthy control subjects (HCs) who were matched in sociodemographic profile and the performance on CAMPROMPT. An eye-tracking paradigm was employed to examine the differences in PM accuracy and key cognitive processes (e.g., cue monitoring) between the two groups. Additional 31 patients were then recruited to investigate the relationship between PM cue monitoring, other cognitive functions, and the severity of clinical symptoms within the SSDs group. The monitoring of PM cue was reflected in total fixation time and total fixation counts for distractor words. Cognitive functions were assessed using the Chinese version of the MATRICS Consensus Cognitive Battery (MCCB). The Positive and Negative Syndrome Scale (PANSS) was applied to assess psychopathology. SSDs patients exhibited fewer total fixation counts for distractor words and lower PM accuracy compared to HCs, even though they were priori matched on CAMPROMPT. Correlation analysis within the SSDs group (63 cases) indicated a negative correlation between PM accuracy and PANSS total score, and a positive correlation with working memory and attention/vigilance. Regression analysis within the SSDs group revealed that higher visual learning and lower PANSS total scores independently predicted more total fixation counts on distractor words. Impairment in cue monitoring is a critical factor in the PM deficits in SSDs. The eye-tracking laboratory paradigm has advantages over the ecologically-valid measurement in identifying the failure of cue detection, making it a more sensitive tool for PM deficits in patients with SSDs.

Prospective memory in early and established psychosis: An Indian perspective

Individuals affected by psychosis often have deficits in several neurocognitive functions. Prospective memory (PM), the ability to remember to do things, is crucial for activities of daily living, social and occupational functioning, but very few studies have attempted to examine this domain of functioning in people with psychosis, particularly in India. A total of 71 patients with psychosis, (both early and established psychosis), and 140 age, gender and education-matched healthy controls were assessed using the Positive and Negative Symptom Scale, Hospital Anxiety and Depression scale, and Addenbrooke's Cognitive Examination. PM was assessed using the Cambridge Prospective Memory Test and the Prospective and Retrospective Memory Questionnaire (PRMQ). Group differences were evaluated using Mann-Whitney U-tests. Significantly greater cognitive deficits, higher anxiety and depression were evident in the psychosis group compared with controls. The psychosis group performed significantly poorer on both time- and event-based tests in CAMPROMPT than controls. These differences remained when controlling for age, education, general cognitive functioning and mood. The subjective measure of PM (PRMQ) did not differentiate the two groups. The PM performance of early and established psychosis patients was similar. Comparisons with cross-cultural data (PRMQ UK norms and CAMPROMPT and PRMQ Chinese data) revealed important differences in PM performance. Individuals with psychosis have significant deficits in both time- and event-based PM. CAMPROMPT emerged as a more sensitive PM measure compared with PRMQ. Results from cross-cultural comparisons underscore the need for cultural contextualization of assessments.

Improving self-awareness of prospective memory function after TBI using experiential feedback on a board game activity: An observational study

This study investigated whether experiential and video feedback on performance of prospective memory (PM) tasks embedded within a board game activity improved self-awareness of PM function in adults with moderate-severe traumatic brain injury. An observational pre-post study design with 26 participants from a larger trial of a 6-session PM rehabilitation programme. Sessions 3 and 4 included a board game activity with embedded time-, event-, and activity-based PM tasks. Verbal feedback was provided by therapists during the game and video feedback afterwards. Self-ratings of performance were used to divide the sample into under-estimators (n = 7), accurate estimators (n = 9) and over-estimators (n = 10) of actual PM performance. The discrepancy between self- and therapist ratings of PM performance was measured before and after the game, and following video feedback, and compared between timepoints using non-parametric statistics. Post-task self-evaluations were more accurate than pre-task self-evaluations for the under- and over-estimator groups. Under-estimators showed significant improvement in accuracy of ratings for activity-based PM. Over-estimators showed improvement for event-based PM. Further improvements after video feedback were not significant. The board game activity provided a vehicle for experiential feedback and a means of engaging both those with impaired self-awareness and heightened self-awareness of PM in cognitive rehabilitation.

Cognitive performance in older adults at three months following mild traumatic brain injury

Introduction: In the context of limited research assessing outcomes following mild traumatic brain injury (mTBI) in older adults, this study evaluated cognitive outcomes through prospective memory, and expected that performance of an older mTBI group (≥65 years) would be lower compared to orthopedic and community controls. The study also explored whether cognitive resources (retrospective memory, executive function) moderated any association between presenting Glasgow Coma Scale (GCS) and prospective memory.Method: At three-months post-injury, a mTBI group (n = 39), an orthopedic control group (n = 63), and a community control group (n = 46) completed a neuropsychological assessment, including (i) prospective memory, using a standardized paper-and-pencil task (Cambridge Prospective Memory Test), an augmented reality task and a naturalistic task, and (ii) standardized measures of retrospective memory (Hopkins Verbal Learning Test) and executive function (Trail Making Test). Group performances were compared, and bootstrapped moderation analyses evaluated the role of cognitive resources in the relationship between GCS and prospective memory outcome.Results: The mTBI group, as compared to community controls, performed significantly lower on the augmented reality task (d = -0.64 to d = -0.79), and there was a small-moderate but non-significant effect (d = -0.45) on the naturalistic task. There were no differences between the mTBI group and orthopedic controls. Retrospective memory was a unique predictor of the augmented reality task (B = 1.83) and moderated the relationship between presenting GCS and the naturalistic task (B = -5.60). Executive function moderated the association between presenting GCS and augmented reality (B = -1.13) and naturalistic task (B = -1.57).Conclusions: At three-months post-mTBI, older adults are at risk of poor cognitive performance; and the relationship between GCS and prospective memory can be moderated by cognitive resources. Further follow-up is indicated to determine whether impairments resolve or persist over time.

Prospective memory impairment in neurological disorders: implications and management

Prospective memory is a core neurocognitive ability that refers to memory for future intentions, such as remembering to take medications and to switch off appliances. Any breakdown in prospective memory, therefore, has serious implications for the ability to function independently in everyday life. In many neurological disorders, including Parkinson disease and dementia, prospective memory deficits are common even in the earliest stages and typically become more severe with disease progression. Consequently, clinical assessment of prospective memory is of critical importance. This article provides an overview of the various manifestations and neural bases of prospective memory deficits. To facilitate clinical decision-making, validated measures of this construct are identified and their suitability for clinical practice is discussed, focusing in particular on clinical sensitivity and psychometric properties. The article concludes by reviewing the approaches that can be used to rehabilitate different types of prospective memory impairment, and algorithms to guide the evaluation and treatment of these impairments are provided.

Prospective memory and spontaneous compensatory mnemonic strategy use in the laboratory and daily life in HIV-associated neurocognitive disorders

INTRODUCTION

Older adults with HIV-associated neurocognitive disorders (HAND) are at high risk for deficits in the resource-demanding, strategic aspects of prospective memory (PM) that can adversely affect health outcomes. This study examined the frequency and correlates of spontaneous compensatory strategy use during a laboratory-based PM task and its associations with the use of mnemonic strategies in daily life.

METHOD

Participants included 53 older adults with HAND, 89 older persons with HIV without HAND, and 62 seronegatives who completed the Cambridge Prospective Memory Test (CAMPROMPT), on which the type, frequency, and quality of their compensatory strategy use was quantified. Participants also completed self-report measures of PM symptoms and the frequency of mnemonic compensatory strategy use in daily life.

RESULT

There were no significant group-level effects on strategy use during the CAMPROMPT. Persons with HAND had moderately lower time-, but not event-based PM scores. Higher compensatory strategy use was strongly associated with better PM, particularly for time-based cues. Moreover, higher compensatory strategy use on the CAMPROMPT was associated with more frequent general mnemonic strategy use in daily life, and specifically with more frequent use of internal PM strategies (e.g., visualization) for medication adherence.

CONCLUSION

Spontaneous compensatory mnemonic strategy use can support PM performance among older adults with HAND in the laboratory. Strategy use in the laboratory may be a marker for the extent to which older adults with HAND use other compensatory strategies to support memory in their daily life. Future studies may examine whether compensatory mnemonic strategies can be taught and used to support PM in the daily lives of older persons with HIV disease.

The Assessment and Prediction of Prospective Memory after Stroke

OBJECTIVE

Prospective memory (PM) is the memory used when intentions are to be carried out in the future. Little research has been conducted examining PM after stroke. This study aimed to determine if PM is impaired after stroke through comparison of individuals with stroke to healthy controls. Additionally, it aimed to explore the predictors of PM performance post-stroke.

METHOD

Twenty-eight individuals with stroke and 27 neurologically healthy controls completed the Cambridge Prospective Memory Test (CAMPROMPT), 2 self-report PM questionnaires, and multiple cognitive measures.

RESULTS

Individuals with stroke performed significantly lower on both event- and time-based PM than controls on the CAMPROMPT, indicating PM impairment. Event-based PM after stroke was significantly predicted by age, retrospective memory (RM), and global cognitive function, whereas time-based PM was only predicted by the metacognitive skill of note-taking. Age and note-taking predicted time-based PM for controls, whereas only age predicted event-based PM for control participants.

CONCLUSIONS

The findings of this study have helped to confirm that PM impairment does exist after stroke, particularly when using a standardised PM measure. Furthermore, PM impairment may be predicted by variables, such as age, strategy use, RM, and cognitive ability.

Comparing different tests to detect early manifestation of prospective memory decline in aging

Objective: Prospective memory (PM) is the ability to remember to perform future intentions. Previous studies have demonstrated that, compared to a younger cohort, healthy older adults have impairments in PM. Considering the importance of early detection of age-related PM decline, the present study aims to compare the performance of healthy older adults using three well-known PM tests commonly used in clinical settings.Method: In the present study, we tested 70 older adults (65-95 years old) using the Cambridge Prospective Memory Test (CAMPROMPT), the Memory for Intentions Screening Test (MIST) and the Royal Prince Alfred Prospective Memory Test (RPA-ProMem). In order to compare performance across tests and the interaction between age and cues, we performed a linear mixed model with random intercept and random slopes. Moreover, additional mixed models with random intercept were run for analyzing the additional information provided by MIST and RPA-ProMem regarding delay responses, response modality effects and type of errors committed.Results: Our data showed a drop in PM performance as age increased detected by all three tests. Furthermore, CAMPROMPT was the most sensitive test to identify differences in PM for event-and time-based cues, at least for participants with 65-77 years old. When data were analyzed in term of delay responses, participants were more accurate for 2 min delay (MIST) and 30 in delay (RPA-ProMem). Participants were less accurate when response modality was "verbal" compared to "action" (MIST) and made more PM errors as age increased.Conclusions: Overall, the study provides important information regarding age-related PM decline and can help researchers as well as clinicians in deciding the preferred test to evaluate PM performance.

Predicting Remembering: Judgments of Prospective Memory After Traumatic Brain Injury

PURPOSE

Adults with traumatic brain injuries (TBIs) often struggle with prospective memory (PM), the ability to remember to complete tasks in the future, such as taking medicines on a schedule. Metamemory judgments (or how well we think we will do at remembering) are linked to strategy use and are critical for managing demands of daily living. The current project used an Internet-based virtual reality tool to assess metamemory judgments of PM following TBI.

METHOD

Eighteen adults with moderate to severe TBI and 20 healthy controls (HCs) played Tying the String, a virtual reality game with PM items embedded across the course of a virtual work week. Participants studied PM items and made two judgments of learning about the likelihood of recognizing the CUE, that is, when the task should be done, and of recalling the TASK, that is, what needed to be done.

RESULTS

Participants with TBI adjusted their metamemory expectations downward, but not enough to account for poorer recall performance. Absolute difference scores of metamemory accuracy showed that healthy adults were underconfident across PM components, whereas adults with TBI were markedly overconfident about their ability to recall TASKs.

CONCLUSIONS

Adults with TBI appear to have a general knowledge that PM tasks will be difficult but are poor monitors of actual levels of success. Because metamemory monitoring is linked to strategy use, future work should examine using this link to direct PM intervention approaches.

A review of prospective memory in individuals with acquired brain injury

OBJECTIVE

Prospective memory (PM) deficits have emerged as an important predictor of difficulty in daily life for individuals with acquired brain injury (BI). This review examines the variables that have been found to influence PM performance in this population. In addition, current methods of assessment are reviewed with a focus on clinical measures. Finally, cognitive rehabilitation therapies are reviewed, including compensatory, restorative and metacognitive approaches.

METHOD

Preferred reporting items for systematic reviews and meta-analyses guidelines were used to identify studies. Studies were added that were identified from the reference lists of these.

RESULTS

Research has begun to elucidate the contributing variables to PM deficits after BI, such as attention, executive function and retrospective memory components. Imaging studies have identified prefrontal deficits, especially in the region of BA10 as contributing to these deficits. There are now several clinical measures available with good psychometric properties. Rehabilitation techniques have mostly focused on compensatory strategies, but, in addition, some restorative and metacognitive approaches have shown preliminary promise.

CONCLUSIONS

PM deficits are a common and important deficit after BI. Clinical evaluation is recommended and further understanding of rehabilitation techniques is needed.

Ecologically Valid Assessment of Prospective Memory for Task Planning and Execution by Adults With Acquired Brain Injury

PURPOSE

Individuals with acquired brain injury (ABI) often struggle due to inadequate planning and execution skills for completing nonroutine tasks. This study's purpose was to pilot ecologically valid procedures to assess planning for and execution of prospective daily activities.

METHOD

Participants included 9 adults with histories of severe ABI and 9 controls. Data collection included both prospective task planning and execution. First, participants created a plan for later execution of daily tasks in accordance with preestablished rules. Over the subsequent 10 days, participants independently attempted task completion. Differences within and between participant groups regarding planning and task performance were evaluated statistically and through examiner observation.

RESULTS

Participants with ABI implemented minimal planning strategies. They demonstrated highly variable performance and displayed substantially greater difficulty initiating and successfully executing tasks in adherence to rules than participants without ABI.

CONCLUSIONS

Evaluating planning strategies and execution of novel prospective tasks is a crucial but often neglected aspect of assessment following ABI. Implementing ecologically valid procedures to evaluate this aspect of functioning can reveal individual strengths and challenges and provide guidance for developing effective intervention programs. Examining potential roles played by planning and strategy execution provides critical assessment information relating to independent living.

The efficacy of prospective memory rehabilitation plus metacognitive skills training for adults with traumatic brain injury: study protocol for a randomized controlled trial

BACKGROUND

Impairment of prospective memory (PM) is common following traumatic brain injury (TBI) and negatively impacts on independent living. Compensatory approaches to PM rehabilitation have been found to minimize the impact of PM impairment in adults with TBI; however, poor self-awareness after TBI poses a major barrier to the generalization of compensatory strategies in daily life. Metacognitive skills training (MST) is a cognitive rehabilitation approach that aims to facilitate the development of self-awareness in adults with TBI. This paper describes the protocol of a study that aims to evaluate the efficacy of a MST approach to compensatory PM rehabilitation for improving everyday PM performance and psychosocial outcomes after TBI.

METHODS/DESIGN

This randomized controlled trial has three treatment groups: compensatory training plus metacognitive skills training (COMP-MST), compensatory training only (COMP), and waitlist control. Participants in the COMP-MST and COMP groups will complete a 6-week intervention consisting of six 2-h weekly training sessions. Each 1.5-h session will involve compensatory strategy training and 0.5 h will incorporate either MST (COMP-MST group) or filler activity as an active control (COMP group). Participants in the waitlist group receive care as usual for 6 weeks, followed by the COMP-MST intervention. Based on the sample size estimate, 90 participants with moderate to severe TBI will be randomized into the three groups using a stratified sampling approach. The primary outcomes include measures of PM performance in everyday life and level of psychosocial reintegration. Secondary outcomes include measures of PM function on psychometric testing, strategy use, self-awareness, and level of support needs following TBI. Blinded assessments will be conducted pre and post intervention, and at 3-month and 6-month follow-ups.

DISCUSSION

This study seeks to determine the efficacy of COMP-MST for improving and maintaining everyday PM performance and level of psychosocial integration in adults with moderate to severe TBI. The findings will advance theoretical understanding of the role of self-awareness in compensatory PM rehabilitation and skills generalization. COMP-MST has the potential to reduce the cost of rehabilitation and lifestyle support following TBI because the intervention could enhance generalization success and lifelong application of PM compensatory strategies.

TRIAL REGISTRATION

New Zealand Clinical Trials Registry, ACTRN12615000996561 . Registered on 23 September 2015; retrospectively registered 2 months after commencement.

Duration of post-traumatic amnesia as a predictor of functional outcome in school-age children: a systematic review

AIM

In adults, duration of post-traumatic amnesia (PTA) is a powerful early predictor of functional outcomes in traumatic brain injury. The aim of this work was to assess the predictive validity of PTA duration for outcomes in children (6-18y).

METHOD

PsycINFO, MEDLINE, Web of Science, and Embase were searched for papers published to January 2014. Ten studies met inclusion criteria: they used standardized instruments to assess PTA and functional outcomes, and examined relationships between the two. Outcomes were classified according to (1) the International Classification of Functioning, Disability and Health (ICF) core sets for neurological conditions for post-acute care and (2) global functioning and quality of life. Methodological quality was rated for each study.

RESULTS

The search identified 10 studies of moderate mean quality (M=11.8 out of 18). Longer PTA duration related to worse functional outcomes: global functioning and in the two ICF categories ('body function', 'activities and participation'). Relationships between PTA duration and quality of life and the ICF category of 'body structure' were not examined. PTA duration was, in 46 out of 60 (76.67%) instances, a stronger predictor of outcomes than other indices of injury severity.

CONCLUSION

Longer PTA duration is a valid predictor of worse outcomes in school-age children. Thus, PTA should be routinely assessed in children after traumatic brain injury.

Prospective memory performance in traumatic brain injury patients: a study of implementation intentions

Traumatic brain injury (TBI) patients often present with prospective memory (PM) dysfunction. Forgetting to complete tasks may result in a loss of independence, limited employment prospects and anxiety, therefore, it is important to develop programs to improve PM performance in TBI patients. A strategy which may improve PM performance is implementation intentions. It involves making explicit plans specifying when, where and how one will perform a task in the future. In the present study, a group of 36 TBI patients and a group of 34 controls performed Virtual Week using either implementation intentions or no strategy. The results showed that the PM performance of TBI patients was less accurate than controls, in particular when the PM cue was time-based. No effect of implementation intentions was observed for TBI patients, however, controls improved their PM performance when the task was time-based. The findings suggest that strategies to improve PM in this clinical group are likely to be more complex than those that benefit healthy adults and may involve targeting phases of the PM process other than, or in addition to, the intention formation phase.

Rule monitoring ability predicts event-based prospective memory performance in individuals with TBI

Numerous studies have demonstrated that prospective memory (PM) abilities are impaired following traumatic brain injury (TBI). PM refers to the ability to remember to complete a planned action following a delay. PM post-TBI has been shown to be related to performance on neuropsychological tests of executive functioning and retrospective episodic memory (RM). However, the relative influence of impairments in RM versus executive functioning on PM performance post-TBI remains uninvestigated. In the current study, PM and neuropsychological test performance were examined in 45 persons with a history of moderate to severe TBI at least 1 year before enrollment. Regression analyses examined the relative contributions of RM and executive functioning in the prediction of PM performance on the Rivermead Behavioral Memory Test (RBMT). Results indicated that scores on tests of delayed RM and rule monitoring (i.e., ability to avoid making errors on executive measures) were the strongest predictors of PM. When the interaction between RM impairment and rule monitoring was examined, a positive relationship between PM and rule monitoring was found only in TBI participants with impaired RM. Results suggest that PM performance is dependent upon rule monitoring abilities only when RM is impaired following TBI.

Mild traumatic brain injury in older adults: early cognitive outcome

Severe traumatic brain injury (TBI) in older age is associated with high rates of mortality. However, little is known about outcome following mild TBI (mTBI) in older age. We report on a prospective cohort study investigating 3 month outcome in older age patients admitted to hospital-based trauma services. First, 50 mTBI older age patients and 58 orthopedic controls were compared to 123 community control participants to evaluate predisposition and general trauma effects on cognition. Specific brain injury effects were subsequently evaluated by comparing the orthopedic control and mTBI groups. Both trauma groups had significantly lower performances than the community group on prospective memory (d=0.82 to 1.18), attention set-shifting (d=-0.61 to -0.69), and physical quality of life measures (d=0.67 to 0.84). However, there was only a small to moderate but non-significant difference in the orthopedic control and mTBI group performances on the most demanding task of prospective memory (d=0.37). These findings indicate that, at 3 months following mTBI, older adults are at risk of poor cognitive performance but this is substantially accounted for by predisposition to injury or general multi-system trauma.

Assessment of prospective memory in schizophrenia using the Chinese version of the Cambridge Prospective Memory Test: a controlled study

INTRODUCTION

Data on the psychometric assessment of prospective memory (PM) are limited. The Cambridge Prospective Memory Test (CAMPROMPT) and its Chinese version (CAMPROMPT-C) have been applied to a variety of clinical conditions except for chronic schizophrenia. This controlled study explored the clinical utility of the CAMPROMPT-C in patients with schizophrenia by comparing their PM performance with that of normal controls.

METHODS

Forty-four schizophrenia patients and 44 normal controls formed the study sample. Sociodemographic characteristics, PM, retrospective memory, and intelligence were measured in all subjects. Patients' psychopathology was rated with a standardized instrument.

RESULTS

Patients performed worse than normal controls on both the sum and subscale scores of the CAMPROMPT-C. Patients had comparable performances in PM subtypes. Bivariate analyses revealed that education level, intelligence, and retrospective memory were associated with PM functions.

DISCUSSION

The study supports the clinical utility of the CAMPROMPT-C in chronic schizophrenia and corroborated the significant relationship between PM and education, intelligence, and retrospective memory.

Evaluation of a virtual reality prospective memory task for use with individuals with severe traumatic brain injury

The current study aimed to evaluate the sensitivity, convergent validity and ecological validity of a newly developed virtual reality prospective memory (PM) task (i.e., the Virtual Reality Shopping Task; VRST) for use with individuals with traumatic brain injury (TBI). Thirty individuals with severe TBI and 24 uninjured adults matched on age, gender and education level were administered the VRST, a lexical decision PM task (LDPMT), an index of task-friendliness and a cognitive assessment battery. Significant others rated disruptions in the TBI participants' occupational activities, interpersonal relationships and independent living skills. The performance of the TBI group was significantly poorer than that of controls on event-based PM as measured by the LDPMT, and on time- and event-based PM as measured by the VRST. Performance on the VRST significantly predicted significant others' ratings of patients' occupational activities and independent living skills. The VRST was rated as significantly more reflective of an everyday activity, interesting and was afforded a higher recommendation than the LDPMT. For the TBI group, event and total PM performance on the VRST significantly correlated with performance on measures of mental flexibility and verbal fluency, and total PM performance correlated with verbal memory. These results provide preliminary but promising evidence of the sensitivity, as well as the convergent and ecological validity of the VRST.

Spanish Version of the Prospective and Retrospective Memory Questionnaire (PRMQ-S)

The concept of prospective memory is relatively recent. Thus, it is necessary to have instruments to assess it, in interaction with retrospective memory. The Prospective and Retrospective Memory Questionnaire (PRMQ; Smith et al., 2000) is an instrument that has been effectively used for assessment in several languages. Nevertheless, there is still no Spanish adaptation. The aim of this study was to translate the PRMQ and obtain information about its psychometric properties. A back translation process was applied to the PRMQ. The resulting PRMQ-S was self-administered to 520 subjects after applying the pilot test. Confirmatory factor analysis (CFA) was used to test competing models of its latent structure. Internal consistency was evaluated using Cronbach's alpha. The results showed an adequate internal consistency of the total scale and the Prospective and Retrospective scales were: .89, .84 and .76, respectively. The factor structure was compared with the original study. Our results suggested a disagreement with the tripartite model defended by the authors of the PRMQ. Since there is a high correlation between two factors in the bi-factor model, and the tripartite model showed non-significant loadings to the two specific factors, we recommend that the PRMQ-S be used as one general memory score. We demonstrated adequate psychometric properties of the PRMQ-S if it is used as unique measurement of memory failures. These results are relevant due to the need for a short and accurate instrument in our language that explores memory failures, which has a major impact on the activities of daily living.

Time discrimination in traumatic brain injury patients

Time management skills are required for most daily activities. Traumatic brain injury (TBI) patients often present with cognitive dysfunction, but few studies have investigated temporal impairment. The aim of the present study was to assess temporal abilities in TBI patients using a time discrimination task. Twenty-seven TBI patients (ages = 18-60 years) and 27 controls (ages = 20-60 years) were asked to discriminate between two time intervals presented sequentially. The standard intervals were 500 ms or 1,300 ms long followed by a comparison stimulus that was 25% shorter or longer than the standard one. Participants were also asked to perform two tasks to assess attention, speed-of-processing (the Stroop task), and working memory (the n-back task) abilities. The TBI patients were less accurate than the controls on the time discrimination task and showed greater time-order error effects. In fact, TBI patients pressed the "short" key more times when the standard time interval was 500 ms and the "long" key more times when the standard interval was 1,300 ms. Significant correlations were found between time discrimination, working memory, and speed of processing in both TBI and controls when the standard time interval was 1,300 ms. Attention appeared to be involved in different ways in the two groups. Working memory and speed of processing were involved in time processing only in TBI patients when the standard time interval was 500 ms. These data lend additional support to the notion that two different systems are responsible for elaborating time durations shorter or longer than a second.

Improving memory in outpatients with neurological disorders using a group-based training program

Memory problems are common in patients with a range of neurological conditions, but there have been few attempts to provide and evaluate the usefulness of memory training for groups of neurological outpatients. We used a waitlist-controlled trial design to assess the effectiveness of a newly created, 6-session intervention, which involved training in the use of compensatory strategies as well as education regarding memory function, neurological damage, sleep and lifestyle factors that have an impact on memory. Fifty-six patients with neurological conditions (e.g., stroke, epilepsy) and memory complaints completed the training and assessments. Outcomes were evaluated in terms of reported strategy use as well as objective and subjective measures of anterograde and prospective memory. Training resulted in significant improvements on number of strategies used, scores on the Rey Auditory Verbal Learning Test (total learning and delayed recall) and self-report on the Comprehensive Assessment of Prospective Memory. Improvements were stable at 3-month follow-up. Better individual outcomes were related to lower baseline memory scores, fewer symptoms of depression and greater self-awareness of memory function. Overall the study provides encouraging results to indicate that patients with neurological conditions such as stroke and epilepsy can show improvements in memory after a relatively short group-based intervention.

Cannabis-related deficits in real-world memory

BACKGROUND

Research shows that cannabis users exhibit deficits in prospective memory (PM) and executive function, which persist beyond acute intoxication. However, many studies rely on self-reports of memory failures or use laboratory-based measures that may not mimic functional deficits in the real world. The present study aimed to assess real-world memory functioning.

METHOD

Twenty cannabis-only users and 20 non-illicit drug users were recruited. Participants completed a substance use inventory and a mood scale, followed by a non-immersive virtual reality task assessing PM and executive functioning. The task involved the participant playing the role of an office worker for the day and performing routine office duties. A number of subscales were used to assess facets of executive function (planning, adaptive thinking, creative thinking, selection, prioritisation) and PM (time-based, event-based and action-based PM).

RESULTS

Multivariate analysis of variance revealed cannabis users performed worse overall on the task, with poor performance on the planning, time-based PM and event-based PM subscales. In addition, indices of cannabis (length, dose, frequency, total use) were correlated with performance on these three subscales.

CONCLUSIONS

The present study expands on previously established research, providing support for the cannabis-related deficits in PM and executive functioning, and the role of different aspects of cannabis use in these deficits.

Clinical measures of prospective memory in amnestic mild cognitive impairment

Recent research has established that individuals with amnestic mild cognitive impairment (aMCI) have impaired prospective memory (PM); however, findings regarding differential deficits on time-based versus event-based PM have been less clear. Furthermore, the diagnostic utility of PM measures has received scant attention. Healthy older adults (n = 84) and individuals with aMCI (n = 84) were compared on the Cambridge Prospective Memory Test (CAMPROMPT) and two single-trial event-based PM tasks. The aMCI participants showed global impairment on all PM measures. Measures of retrospective memory and complex attention predicted both time and event PM performance for the aMCI group. Each of the PM measures was useful for discriminating aMCI from healthy older adults and the time- and event-based scales of the CAMPROMPT were equivalent in their discriminative ability. Surprisingly, the brief PM tasks were as good as more comprehensive measures of PM (CAMPROMPT) at predicting aMCI. Results indicate that single-trial PM measures, easily integrated into clinical practice, may be useful screening tools for identifying aMCI. As PM requires retrospective memory skills along with complex attention and executive skills, the interaction between these skills may explain the global PM deficits in aMCI and the good discriminative ability of PM for diagnosing aMCI.

Everyday Memory for Everyday Tasks: Prospective Memory as an Outcome Measure Following TBI in Older Adults

Traumatic brain injury in older adults is an increasing problem in our aging community. Traditional functional outcome measures, such as return to work or academic achievement, as used with younger samples following traumatic brain injury are of limited use for older people. Although challenging to assess reliably, evaluation of prospective memory is gradually being included in outcome assessments following traumatic brain injury in younger samples and may be a useful index of cognitive competence in everyday life when assessing older adults following traumatic brain injury.

Traumatic Brain Injury and Prospective Memory in a Virtual Shopping Trip Task: Does It Matter Who Generates the Prospective Memory Target?

The current study aimed to investigate prospective memory in traumatic brain injury by using a laboratory-based but naturalistic style assessment task. The objective was to determine if performance differed when the prospective memory targets were self-generated or experimenter-generated (a generation effect). Sixteen people who had sustained a traumatic brain injury and had received rehabilitation were compared to 16 healthy age-matched control participants on a naturalistic virtual measure of shopping and prospective memory. Results demonstrated that the traumatic brain group was less accurate in overall prospective remembering performance than the control group but there was a lack of difference between the self- and experimenter-generated prospective memory targets for both participant groups. Both retrospective memory and executive attention of working memory were associated with prospective memory performance in the naturalistic task. The findings of the study suggest that the generation effect commonly observed in retrospective memory performance may not impact performance in prospective memory.

Memory for Intentions Screening Test: Psychometric Properties and Clinical Evidence

As the field of prospective memory (ProM) research has expanded, recognition of the need to make a clinical diagnosis of ProM difficulties has also increased. In addition, there is increasing interest in understanding in more detail the ways in which ProM deficits differ in populations with different underlying neurological dysfunctions. While questionnaires, naturalistic studies and laboratory studies have all been invaluable in furthering our understanding of ProM, until recently there has not been a standardised clinical measure. The Memory for Intentions Screening Test (MIST) was designed to be a relatively brief clinical measure of ProM in clinical populations. The MIST allows for comparisons of performance with event-based and time-based cues. The MIST also has some items with a short (2-minute) and some with a long (15-minute) delay period. Finally, the MIST contains items that require a verbal response as well as items that require an action response. The MIST has now been used in studies of normal ageing as well as a range of clinical populations, including individuals with traumatic brain injury, individuals with HIV infection and individuals with schizophrenia. The psychometric properties of the MIST have been found to be acceptable. Data from each of the clinical populations that have been administered the MIST demonstrate good specificity and sensitivity of the measure as well as the ability to begin to make comparisons about different patterns of performance between disease types.

Memory impairment induced by amphetamine derivatives in laboratory animals and in humans: a review

The 20th century brought with it the so-called club drugs (the most notorious being amphetamine derivatives), which are used by young adults at all-night dance parties. Methamphet­amine and 3,4-methylenedioxymethamphetamine (MDMA or ecstasy) are synthetic drugs with stimulant and psychoactive properties that belong to the amphetamine family. Here, we have reviewed the literature about the cognitive impairment induced by these two amphetamine derivatives and the preclinical and clinical outcomes. Although there is controversial evidence about the effect of methamphetamine and MDMA on learning and memory in laboratory animals, results from published papers demonstrate that amphetamines cause long-term impairment of cognitive functions. A large number of pharmacological receptors have been studied and screened as targets of amphetamine-induced cognitive dysfunction, and extensive research efforts have been invested to provide evidence about the molecular mechanisms behind these cognitive deficits. In humans, there is a considerable body of evidence indicating that methamphetamine and MDMA seriously disrupt memory and learning processes. Although an association between the impairments of memory performance and a history of recreational amphetamine ingestion has also been corroborated, a number of methodological difficulties continue to hamper research in this field, the most important being the concomitant use of other illicit drugs.

Effect of type of cue, type of response, time delay and two different ongoing tasks on prospective memory functioning after acquired brain injury

Failures of prospective memory (PM) are one of the most frequent, and least studied, sequelae of brain injury. PM, also referred to as memory for intentions, is the ability to remember to carry out a future task. Successful completion of a PM task requires the ability to monitor time, keep the action to be performed periodically in awareness, remember the task to be performed, and initiate the action. Although PM has been shown to be a common difficulty after brain injury, it remains unknown which aspects of performance are impaired. In this study, the performance of 25 individuals with brain injury and that of 25 healthy participants were measured separately on the following variables: time until completion of the task, difficulty of the ongoing task being performed while waiting, whether the task to be performed is an action or is verbal, and whether the cue to perform the task is the passing of a particular amount of time (e.g., 10 minutes) or is an external cue (e.g., an alarm sounding). Individuals with brain injury demonstrated impairment compared to healthy adults on virtually all variables. PM performance was also compared to a battery of standard neuropsychological measures of attention, memory, and executive functions, and to self-report measures of PM functioning, in order to determine the underlying cognitive deficits responsible for poor PM performance, if any. PM performance was correlated with measures of executive functioning but not to self-report measures of PM functioning. Implications are discussed in terms of cognitive rehabilitation recommendations.

Prospective memory functioning among ecstasy/polydrug users: evidence from the Cambridge Prospective Memory Test (CAMPROMPT)

RATIONALE

Prospective memory (PM) deficits in recreational drug users have been documented in recent years. However, the assessment of PM has largely been restricted to self-reported measures that fail to capture the distinction between event-based and time-based PM. The aim of the present study is to address this limitation.

OBJECTIVES

Extending our previous research, we augmented the range laboratory measures of PM by employing the CAMPROMPT test battery to investigate the impact of illicit drug use on prospective remembering in a sample of cannabis only, ecstasy/polydrug and non-users of illicit drugs, separating event and time-based PM performance. We also administered measures of executive function and retrospective memory in order to establish whether ecstasy/polydrug deficits in PM were mediated by group differences in these processes.

RESULTS

Ecstasy/polydrug users performed significantly worse on both event and time-based prospective memory tasks in comparison to both cannabis only and non-user groups. Furthermore, it was found that across the whole sample, better retrospective memory and executive functioning was associated with superior PM performance. Nevertheless, this association did not mediate the drug-related effects that were observed. Consistent with our previous study, recreational use of cocaine was linked to PM deficits.

CONCLUSIONS

PM deficits have again been found among ecstasy/polydrug users, which appear to be unrelated to group differences in executive function and retrospective memory. However, the possibility that these are attributable to cocaine use cannot be excluded.

Event-based prospective memory in children with sickle cell disease: effect of cue distinctiveness

Event-based prospective memory (EB-PM) is the formation of an intention and remembering to perform it in response to a specific event. Currently, EB-PM performance in children with sickle cell disease (SCD) is unknown. In this study, we designed a computer-based task of EB-PM; No-Stroke, Silent-Infarct, and Overt-Stroke groups performed significantly below the demographically similar control group without SCD. Cue distinctiveness was varied to determine if EB-PM could be improved. All groups, with the exception of the Overt-Stroke group, performed significantly better with a perceptually distinctive cue. Overall, these results suggest that EB-PM can be improved significantly in many children with SCD.