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

Practice is the best of all instructors-Effects of enactment encoding and episodic future thinking on prospective memory performance in high-functioning adults with autism spectrum disorder

Prospective memory (PM) is the ability to remember to carry out intended actions in the future. The present study investigated the effects of episodic future thinking (EFT) and enactment encoding (EE) on PM performance in autistic adults (ASD). A total of 72 autistic individuals and 70 controls matched for age, gender, and cognitive abilities completed a computerized version of the Dresden breakfast Task, which required participants to prepare breakfast following a set of rules and time restrictions. A two (group: ASD vs. controls) by three (encoding condition: EFT vs. EE vs. standard) between-subjects design was applied. Participants were either instructed to engage in EFT or EE to prepare to the different tasks prior to performing the Dresden breakfast or received standard instructions. Analyses of variance were conducted. Autism-spectrum-disorders (ASD) participants did not differ from control participants in their PM performance, regardless of which strategy they used. Compared to the standard condition, EE but not EFT improved time-based PM performance in all participants. This is the first study to find spared time-based PM performance in autistic individuals. The results confirm earlier results of beneficial effects of EE on PM performance. Findings are discussed with regards to the methodology used, sample composition as well as autistic characteristics.

Communication-related aspects of prospective memory: an exploratory factor analysis of prospective memory questionnaires

PURPOSE

Prospective memory (PM) questionnaires are frequently used to evaluate perceptions of PM skills in daily life. This study aimed to systematically investigate communication-specific attributes using pre-existing PM self-rating questionnaires to inform clinicians and researchers about the role of PM in cognitive communicative evaluations.

METHODS

PM-related items from three questionnaires (i.e., Prospective Memory Questionnaire, Comprehensive Assessment of Prospective Memory, and Prospective and Retrospective Memory Questionnaire) were compiled and embedded in Google Forms and distributed to 70 Speech-Language Pathologists (SLPs) with expertise in Cognitive Communicative Disorders across India. Participants first identified items related to communication, and were then contacted to rate the communication-related PM items using a Likert scale for their degree of appropriateness. Responses from 40 SLPs were obtained and subjected to item-content validity index (i-CVI) and exploratory factor analysis (EFA).

RESULTS

Of the 114 PM items, 28 received ratings over 50% for their relevance to communication. Of the 28 items, 21 had an i-CVI score greater than 0.8. After the removal of overlapping content, 14 items were finalized and subjected to EFA, which resulted in four factors: PM failure due to loss of communicative content, PM failure due to loss of communicative intent, PM cost due to ongoing interference, and PM failure linked to the priority of communicative intent.

CONCLUSION

This study highlights communication-related aspects of PM that can be used as a framework for SLPs to assess and research PM skills.

The effects of combined cognitive training on prospective memory in older adults with mild cognitive impairment

This study aimed to assess the effects of combined cognitive training on prospective memory ability of older adults with mild cognitive impairment (MCI). A total of 113 participants were divided into a control group and three intervention groups. Over three months, the control group received only community education without any training, whereas for the first six weeks, an executive function training group received executive function training, a memory strategy training group received semantic encoding strategy training, and the combined cognitive training group received executive function training twice a week for the first six weeks, and semantic encoding strategy training twice a week for the next six weeks. The combined cognitive training group showed improvement on the objective neuropsychological testing (Montreal Cognitive Assessment scale). The memory strategy training group showed improvement on the self-evaluation scales (PRMQ-PM). Combined cognitive training improved the prospective memory and cognitive function of older adults with MCI.

How did individual differences in neurocognition and health literacy influence the initial uptake and use of health-related information about COVID-19?

Introduction: The rapid development of coronavirus disease 2019 (COVID-19) into a pandemic required people to quickly acquire, evaluate, and apply novel complex health-related information about the virus and transmission risks. This study examined the potentially unique and synergistic roles of individual differences in neurocognition and health literacy in the early uptake and use of COVID-19 public health information.Method: Data were collected between April 23 and 21 May 2020, a period during which 42 out of 50 states were under a stay-at-home order. Participants were 217 healthy adults who completed a telephone-based battery that included standard tests of neurocognition, health literacy, verbal IQ, personality, and anxiety. Participants also completed measures of COVID-19 information-seeking skills, knowledge, prevention intentions, and prevention behaviors.Results: A series of hierarchical multiple regressions with data-driven covariates showed that neurocognition (viz, episodic verbal memory and executive functions) was independently related to COVID-19 knowledge (e.g. symptoms, risks) at a medium effect size, but not to information-seeking skills, prevention intentions, or prevention behaviors. Health literacy was independently related to all measured aspects of COVID-19 health information and did not interact with neurocognition in any COVID-19 health domain.Conclusions: Individual differences in neurocognition and health literacy played independent and meaningful roles in the initial acquisition of knowledge related to COVID-19, which is a novel human health condition. Future studies might examine whether neurocognitive supports (e.g. spaced retrieval practice, elaboration) can improve COVID-19-related knowledge and health behaviors in vulnerable populations.

Effectiveness of a Visual Imagery Training Program to Improve Prospective Memory in Older Adults with and without Mild Cognitive Impairment: A Randomized Controlled Study

Prospective memory (PM) problems in aging and, to a greater extent, in mild cognitive impairment (MCI), compromise functional independence. This study examined the effectiveness of a cognitive training program based on visual imagery to improve PM among older adults with and without MCI. Participants were older adults, 24 with MCI and 24 cognitively healthy (HOA). Half of them (12 MCI and 12 HOA) were randomly assigned to the PM training program, the other half to the no-training control group. All participants also completed a pre- and post-test evaluation, including neuropsychological tests, questionnaires, and the Ecological Test of Prospective Memory (TEMP). There was no significant effect of the intervention on the TEMP total, event-based or time-based scores for either the MCI or HOA groups. However, the trained MCI group committed fewer false alarms (i.e., more efficient identification of prospective cues) in the event-based condition of the TEMP at post-test. On the other hand, all trained participants performed better than control participants on retrospective memory tests, which suggests that visual imagery-based training is more effective to improve retrospective memory than PM. Possible explanations for these results are explored.

Age Differences in the Subcomponents of Executive Functioning

OBJECTIVES

Across the life span, deficits in executive functioning (EF) are associated with poor behavioral control and failure to achieve goals. Though EF is often discussed as one broad construct, a prominent model of EF suggests that it is composed of three subdomains: inhibition, set shifting, and updating. These subdomains are seen in both younger (YA) and older adults (OA), with performance deficits across subdomains in OA. Therefore, our goal was to investigate whether subdomains of EF might be differentially affected by age, and how these differences may relate to broader global age differences in EF.

METHODS

To assess these age differences, we conducted a meta-analysis at multiple levels, including task level, subdomain level, and of global EF. Based on previous work, we hypothesized that there would be overall differences in EF in OA.

RESULTS

Using 1,268 effect sizes from 401 articles, we found overall differences in EF with age. Results suggested that differences in performance are not uniform, such that variability in age effects emerged at the task level, and updating was not as affected by age as other subdomains.

DISCUSSION

These findings advance our understanding of age differences in EF, and stand to inform early detection of EF decline.

Prospective Memory in Service Members with Mild Traumatic Brain Injury

INTRODUCTION

Prospective memory (PM) is the ability to remember the intention to perform an action in the future. Following mild traumatic brain injury (mTBI), the brain structures supporting such PM may be compromised. PM is essential for remembering activities specific to TBI survivors that promote recovery, such as following doctors' orders, taking necessary medications, completing physical rehabilitation exercises, and maintaining supportive social relationships. Since the year 2000, more than 315,897 US Service Members are reported to have sustained an mTBI1, yet little has been done to address possible PM concerns. Therefore, identifying impaired PM and interventions that may ameliorate such deficits is important. The primary aim of this study was to determine whether task encoding using implementation intentions leads to better PM performance than encoding using rote rehearsal in Service Members with mTBI (n = 35) or with bodily injuries but no TBI (n = 8) at baseline and 6 months later.

MATERIALS AND METHOD

Participants were randomized to one of the two encoding conditions. They were asked to remember to complete a series of four tasks over the course of a 2-hour event-related potential session and to contact a staff member during a specified 2-hour window later that day. PM performance was assessed based on completion of each task at the appropriate time. IRB approval was obtained from The Catholic University of America, Walter Reed National Military Medical Center, and Ft. Belvoir Community Hospital.

RESULTS

Service Members with mTBI using implementation intentions outperformed those using rote rehearsal. The effect of injury type and the interaction between encoding condition and injury type did not yield differences that were statistically significant.

CONCLUSIONS

The results suggest that implementation intentions may be a useful PM remediation strategy for those who have sustained mTBI. Future research should validate these findings in a larger sample.

Prospective memory assessment in acute mild traumatic brain injury

Objective: Prospective memory (PM) is the ability to remember to perform an intention at the appropriate time in the future. It is of primary importance for daily living, and its disruption may impact functional autonomy. To date, few studies have examined PM during the acute phase of mild traumatic brain injury (mTBI), despite the high prevalence of this neurological condition and its potential impact on cognition. Method: Twenty mTBI patients (time since injury ranged from 45 to 73 days) and 15 healthy control participants performed the Ecological Test of Prospective Memory (TEMP), a simulated errand task in which participants were required to execute 10 event-based (EB) and five time-based (TB) tasks. The TEMP separately evaluates PM phases as well as prospective and retrospective components in event- and time-based conditions. Participants also completed a neuropsychological test battery. Correlations were performed between cognitive composite scores and the TEMP. Results: mTBI patients experienced difficulty in learning the content of intentions, retrieving these intentions in the time-based condition (prospective component) and recalling the associated actions in the event- and time-based conditions (retrospective component). Retrospective memory composite score was correlated with the learning and retention phases of the TEMP, whereas attention/working memory and executive composite scores were correlated with the time-based condition and performance on the ongoing task. Conclusion: These results suggest the presence of global PM impairment during the acute phase of mTBI, as well as impairment of retrospective memory, attention/working memory, and executive functions, which are key components for PM performance.

Subjective and physiological stress measurement in a multiple sclerosis sample and the relation with executive functions performance

In multiple sclerosis (MS), hypothalamic-pituitary-adrenal (HPA) axis functioning may be dysregulated due to the high cortisol levels involved in the disease activity. HPA axis dysregulation can affect cognitive performance, including executive functions. This study aimed to evaluate hair cortisol concentration and perceived stress as well as verify the association with the performance of executive function in both individuals diagnosed with MS and control individuals. Hair cortisol concentration and perceived stress were evaluated and their association with the performance of healthy individuals (n = 33) and those with MS (n = 64), most of them with remitting-relapsing multiple sclerosis (RRMS) assessed using the Expanded Disability Status Scale (EDSS). Instruments that were employed to measure perceived stress and health aspects included the Behavioral Assessment Dysexecutive Syndrome, Wisconsin Card Sorting Test, Stroop Test, and Perceived Stress Scale. No significant statistical difference was found in the comparison of means among the groups; however, an association was found when using statistical correlation tests between cortisol and cognitive performance in the clinical group (r = 0.31, p = 0.10). Further, an absence of correlations with perceived stress measure was noted. It was possible to observe interaction between group factors and low level of cortisol and problem-solving/cognitive flexibility in the MS group. The results indicated that stress measures used in the present study seem to influence the performance of inhibitory control and problem-solving/cognitive flexibility, the latter with low levels of cortisol in individuals with MS. We suggest studies that examine different measures of physiological stress and characteristics of the disease such as more time of stress.

Impact of breast cancer on prospective memory functioning assessed by virtual reality and influence of sleep quality and hormonal therapy: PROSOM-K study

BACKGROUND

Breast cancer (BC) is the most frequent cancer in women with more than 70% of BC patients being treated with hormonal therapy (HT). Among these patients, some report difficulties in remembering what they are supposed to do at the right moment, referring to prospective memory (PM). PM is essential for autonomy and medical adherence of patients, and requires an ecological assessment. Virtual reality, that recreates naturalistic environment, seems to be a promising method to evaluate PM. Several BC patients also report sleep disturbances. Given the role of sleep on memory consolidation, it is imperative to explore the influence of sleep quality on PM in BC patients treated with HT. The purpose of PROSOM-K study is to assess PM functioning using virtual reality and sleep quality in BC treated or not with HT.

METHODS

PROSOM-K is a prospective study including post-menopausal BC patients ≤70 years old treated with radiotherapy (n = 25) or with radiotherapy and HT (n = 25), and healthy post-menopausal women (n = 25) matched for age and education. PM will be assessed using a virtual reality based task. Other cognitive functions and psychosocial factors will be assessed with validated questionnaires and neuropsychological tests. The study is divided in 3 sessions: a session of familiarisation with the virtual environment and the PM task: a day-time session during which participants learn intentions during the morning and recall them in the evening; and a night-time session during which participants learn intentions in the evening and recall them the following morning. Women will be monitored by wrist actigraphy; during the night-time session, objective sleep quality and quantity will be measured by polysomnography.

DISCUSSION

This is a novel study aiming to assess PM using virtual reality, coupled with the evaluation of other cognitive functions. Polysomnographic study of sleep will provide further information about architectural sleep disturbances in BC. Association between sleep architecture parameters and PM mechanism in BC women treated with HT will be described in detail. We expect our results will provide knowledge for patients and clinicians and further help to improve patient care and cognitive therapy.

TRIAL REGISTRATION

NCT03420105 , registered: January 10, 2018.

The interplay of intention maintenance and cue monitoring in younger and older adults' prospective memory

The retention phase of a prospective memory (PM) task poses different challenges, including demands to store or maintain an intended action and to realize the right moment for action execution. The interplay of these processes in younger and older adults has not been explored so far. In this study, the authors examined the impact of maintenance load and task focality on PM in 84 younger and in 83 older adults. Results indicated that PM performance and ongoing task response times were strongly affected by maintenance load and age. However, a focality effect only emerged when maintenance load was low but not when attentional resources were deployed for maintaining a more demanding intention. These findings suggest that maintenance and monitoring requirements compete for similar attentional resources. Furthermore, maintenance load may affect postretrieval processes through its impact on working-memory resources, which can restrain the typical advantage of focal over nonfocal PM tasks.

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.

Neuropsychology of traumatic brain injury: An expert overview

Traumatic brain injury (TBI) is a serious healthcare problem, and this report is a selective review of recent findings on the epidemiology, pathophysiology and neuropsychological impairments following TBI. Patients who survive moderate-to-severe TBI frequently suffer from a wide range of cognitive deficits and behavioral changes due to diffuse axonal injury. These deficits include slowed information-processing and impaired long-term memory, attention, working memory, executive function, social cognition and self-awareness. Mental fatigue is frequently also associated and can exacerbate the consequences of neuropsychological deficits. Personality and behavioral changes can include combinations of impulsivity and apathy. Even mild TBI raises specific problems: while most patients recover within a few weeks or months, a minority of patients may suffer from long-lasting symptoms (post-concussion syndrome). The pathophysiology of such persistent problems remains a subject of debate, but seems to be due to both injury-related and non-injury-related factors.

A meta-analysis of task-related influences in prospective memory in traumatic brain injury

Prospective memory is the ability to remember to do something in the future and it is essential to every-day functional independence. Traumatic brain injury is associated with frequent and persistent prospective memory deficits. This study presents a review and meta-analysis investigating the effects of task parameters on prospective memory performance of individuals with TBI. Individual studies using continuous behavioural measures of prospective memory with a sample of adults with TBI and matched controls were included. Consistent with previous research, a random effects meta-analysis indicated that TBI groups demonstrated lower prospective memory performance than control groups (d = 1.10, SE = 0.12, 95% CI = 0.86-1.34). In addition, we found that type of prospective memory cue, saliency of cues, and complexity of the ongoing task significantly moderated the difference in prospective memory performance between TBI and control groups. These findings suggest that prospective memory task parameters should be considered in the assessment of prospective memory in individuals with cognitive impairment. In addition, considering the influence of these task parameters would be useful to develop effective compensatory strategies to reduce prospective memory failures.

Regularity effect in prospective memory during aging

Background

Regularity effect can affect performance in prospective memory (PM), but little is known on the cognitive processes linked to this effect. Moreover, its impacts with regard to aging remain unknown. To our knowledge, this study is the first to examine regularity effect in PM in a lifespan perspective, with a sample of young, intermediate, and older adults.

Objective and design

Our study examined the regularity effect in PM in three groups of participants: 28 young adults (18–30), 16 intermediate adults (40–55), and 25 older adults (65–80). The task, adapted from the Virtual Week, was designed to manipulate the regularity of the various activities of daily life that were to be recalled (regular repeated activities vs. irregular non-repeated activities). We examine the role of several cognitive functions including certain dimensions of executive functions (planning, inhibition, shifting, and binding), short-term memory, and retrospective episodic memory to identify those involved in PM, according to regularity and age.

Results

A mixed-design ANOVA showed a main effect of task regularity and an interaction between age and regularity: an age-related difference in PM performances was found for irregular activities (older < young), but not for regular activities. All participants recalled more regular activities than irregular ones with no age effect. It appeared that recalling of regular activities only involved planning for both intermediate and older adults, while recalling of irregular ones were linked to planning, inhibition, short-term memory, binding, and retrospective episodic memory.

Conclusion

Taken together, our data suggest that planning capacities seem to play a major role in remembering to perform intended actions with advancing age. Furthermore, the age-PM-paradox may be attenuated when the experimental design is adapted by implementing a familiar context through the use of activities of daily living. The clinical implications of regularity effect are discussed.

Initial planning benefits complex prospective memory at a cost

The effect of initial planning on complex prospective memory was investigated using a virtual environment and a sample of healthy young adults (N = 34). Participants were assigned to either an initial planning or a control condition and were asked to complete a series of time- and event-based prospective memory tasks. The planning group completed the tasks more quickly and accurately than the control group. However, the total time spent, including both planning and task execution, was comparable for the two groups. Within the planning group, tasks that were planned were more likely to be completed than unplanned tasks, but inclusion of overly detailed information in the plans resulted in poorer performance. These results suggest that although initial planning can be beneficial to task completion, the complexity of a plan may contribute to decrements in performance.

Preserved Intention Maintenance and Impaired Execution of Prospective Memory Responses in Schizophrenia: Evidence from an Event-based Prospective Memory Study

Executive system dysfunction and impaired prospective memory (PM) are widely documented in schizophrenia. However, it is not yet clarified which components of PM function are impaired in this disorder. Two plausible target components are the maintenance of delayed intentions and the execution of PM responses. Furthermore, it is debated whether the impaired performance on frequently used executive tasks is associated with deficit in PM functions. The aim of our study was twofold. First, we aimed to investigate the specific processes involved in event-based PM function, mainly focusing on difference between maintenance of intention and execution of PM responses. Second, we aimed to unfold the possible connections between executive functions, clinical symptoms, and PM performance. An event-based PM paradigm was applied with three main conditions: baseline (with no expectation of PM stimuli, and without PM stimuli), expectation condition (participants were told that PM stimuli might occur, though none actually did), and execution condition (participants were told that PM stimuli might occur, and PM stimuli did occur). This procedure allowed us to separately investigate performances associated with intention maintenance and execution of PM responses. We assessed working memory and set-shifting executive functions by memory span tasks and by the Wisconsin Card Sorting Test (WCST), respectively. Twenty patients diagnosed with schizophrenia and 20 healthy control subjects (matched according to age and education) took part in the study. It was hypothesized that patients would manifest different levels of performance in the expectation and execution conditions of the PM task. Our results confirmed that the difference between baseline performance and performance in the execution condition (execution cost) was significantly larger for participants diagnosed with schizophrenia in comparison with matched healthy control group. However, this difference was not observed in the expectation condition. The PM performance in the execution condition was correlated with impaired executive functions in schizophrenia. Specifically, the size of execution cost positively correlated with percent of perseverative errors committed on WCST by the patient group. Our results suggest that maintenance of delayed intentions is unimpaired in schizophrenia, whereas the impairment in execution of PM responses is associated with set-shifting deficit.

Performance of Smokers with DSM-5 Tobacco Use Disorder in Time-Based Complex Prospective Memory

Studies that investigate time-based complex prospective memory (PM) functioning in participants with substance use disorders (SUD) in consideration of different PM-phases (planning, retention, initiation, execution) are lacking. This study was designed to investigate performance of young adults with DSM-5 tobacco use disorder (TUD) and healthy controls (HC) in different phases of complex PM. Community participants aged 18-35 (N=43) completed the modified Six Elements Test that includes the PM-phases planning, retention, initiation, and execution of a time-based complex PM-task (with delay phases and background activities). TUD participants were current daily smokers and fulfilled at least two DSM-5 TUD criteria. TUD did not differ significantly from HC in task planning errors and timely task initiation. No group differences showed in rule adherence and completeness during task conduction (execution). During execution, TUD showed significantly more deviations (Coef. 0.45; p=0.005) from their originally remembered plans than HC. Young adults with relatively mild TUD do not show general impairments in all phases of short-term, complex, and time-based PM. Future research may investigate whether a greater risk of deviation from originally remembered plans in TUD could play a role in the progression and cessation of smoking behavior.

Checking Behaviours, Prospective Memory and Executive Functions

Explanations implicating memory in the causes and severity of checking symptoms have focused primarily on retrospective memory, and relatively little attention has been paid to prospective memory. Limited research has examined the relationship between prospective memory and executive functions. We assessed whether impairments in prospective memory and executive function predict checking symptoms in a sample of 106 adults. Checking symptoms were assessed using the Padua Inventory Washington State University Revision (PI-WSUR). All participants completed the prospective memory questionnaire (PMQ) and four computerised executive function tasks from the CANTAB, measuring inhibition, planning, attention set-shifting and working memory. Prospective memory and inhibition predicted checking symptom severity. Importantly, there were no correlations between internally cued prospective memory and inhibition or between prospective memory aiding strategies and inhibition. These variables appear to have an independent role in checking. The current findings highlight prospective memory and inhibition as key contributors to the checking symptom profile and provide the first evidence that these cognitive processes may independently contribute to checking symptoms. These findings have implications for a model in which memory performance is thought to be secondary to impairments in executive functions.

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.

Future thinking improves prospective memory performance and plan enactment in older adults

Efficient intention formation might improve prospective memory by reducing the need for resource-demanding strategic processes during the delayed performance interval. The present study set out to test this assumption and provides the first empirical assessment of whether imagining a future action improves prospective memory performance equivalently at different stages of the adult lifespan. Thus, younger ( n = 40) and older ( n = 40) adults were asked to complete the Dresden Breakfast Task, which required them to prepare breakfast in accordance with a set of rules and time restrictions. All participants began by generating a plan for later enactment; however, after making this plan, half of the participants were required to imagine themselves completing the task in the future (future thinking condition), while the other half received standard instructions (control condition). As expected, overall younger adults outperformed older adults. Moreover, both older and younger adults benefited equally from future thinking instructions, as reflected in a higher proportion of prospective memory responses and more accurate plan execution. Thus, for both younger and older adults, imagining the specific visual–spatial context in which an intention will later be executed may serve as an easy-to-implement strategy that enhances prospective memory function in everyday life.

Cortical Excitability During Passive Action Observation in Hospitalized Adults With Subacute Moderate to Severe Traumatic Brain Injury: A Preliminary TMS Study

Studies indicate that motor functions in patients with traumatic brain injury (TBI) can be improved with action observation. It has been hypothesized that this clinical practice relies on modulation of motor cortical excitability elicited by passive action observation in patients with TBI, a phenomenon shown thus far only in normal controls. The purpose of this work was to test this hypothesis and characterize the modulation of motor cortex excitability during passive action observation in patients with subacute moderate to severe TBI. We measured motor evoked potentials induced by single-pulse transcranial magnetic stimulation to the left primary motor cortex and recorded from the contralateral first dorsal interosseus while 20 participants observed videos of static and moving right index finger. Results were compared with those of 20 age-and gender-matched healthy controls. As expected, greater excitability was elicited during moving than static stimuli in healthy subjects. However, this was not observed in patients with TBI. Modulation of motor excitability during action observation is impaired in patients with TBI depending on motor dysfunction, lesion site, and number of days postinjury. These preliminary results suggest a strategy to identify patients in whom action observation might be a valuable neurorehabilitative strategy.

Prospective memory in adults with high-functioning autism spectrum disorders: exploring effects of implementation intentions and retrospective memory load

This study examined, for the first time, the impact of implementation intentions on prospective memory (PM) performance in adults with autism spectrum disorders (ASD) and further explored the role of retrospective memory for PM in ASD. PM was assessed with Virtual Week, a computerized game simulating upcoming everyday-life tasks. Twenty-seven adults with ASD and 27 age- and ability-matched controls were included. Half of the participants were instructed to form implementation intentions (i.e., encoding PM tasks in form of if-then statements), while the rest received simple PM instructions. Results provide first tentative evidence for beneficial effects of implementation intentions and PM tasks with low demands on retrospective memory for adults with ASD's PM. Overall, results point to the importance of planning and retrospective memory for successful prospective remembering in ASD.

[Cognitive performance and frailty in older adults clients of a private health care plan]

OBJECTIVE

To investigate the association between frailty syndrome and cognitive performance in the older adults and the effect of schooling and age on this association.

METHODS

Data on frailty in older adults from Phase 1 of the FIBRA-RJ Study were analyzed, relating to 737 customers of a private health care provider, aged 65 and over, living in Rio de Janeiro, Southeastern Brazil, between January 2009 and January 2010. Data on socioeconomic and demographic characteristics, medical conditions and functional capacity were collected. Cognitive performance was assessed using the Mini-Mental State Examination (MMSE). Individuals who exhibited three or more of the following features were considered to be frail: unintentional weight loss (≥ 4.5 kg in the last year); feeling self-reported exhaustion, low grip strength, low physical activity level and slowness. The association between frailty and cognitive performance was evaluated using multivariate logistic regression, with adjustment for medical conditions, activities of daily living and socioeconomic variables. We evaluated the age and schooling as possible effect modifiers in this association.

RESULTS

The frail subjects had a higher prevalence of low cognitive performance, compared to not frail or pre-frail, in the three age groups studied (65-74; 75-84; ≥ 85 years), p < 0.001. After adjustment, the association between frailty and cognitive performance was found among older adults individuals aged 75 and older, with an OR(adj)= 2.78 (95%CI 1.23;6.27) for those aged 75 to 84 and OR(adj)= 15.62 (95%CI 2.20;110.99) for 85 and older. The age variable was an effect modifier in the association between frailty and cognitive performance, χ²(5) = 806.97, p < 0.0001; the same was not the case with schooling.

CONCLUSIONS

Frailty syndrome is associated with cognitive performance in the aging. Age proved to be an effect modifier in this association. The oldest patients showed a more significant association between the two phenomena.

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.

Everyday-like memory and its cognitive correlates in healthy older adults and in young patients with traumatic brain injury: a pilot study based on virtual reality

PURPOSE STATE: A pilot-study with a comparison approach between aging and traumatic brain injury (TBI) is proposed to investigate everyday object memory patterns using a virtual HOMES test.

METHODS

Sixteen young controls, 15 older adults and 15 TBI patients underwent the HOMES test and traditional tests.

RESULTS

Older adults and TBI patients exhibited similar HOMES performances: poor recall, a greater recognition benefit, high false recognitions, but intact clustering and proactive interference effects. The age-related differences for HOMES measures were mainly mediated by executive functioning, while the HOMES performances in the TBI group were correlated with memory measures.

CONCLUSION

The differential cognitive mediating effects for a similar everyday-like memory pattern are discussed by highlighting the need for more cautious interpretations of cognitive mechanisms behind similar behavioral patterns in different populations especially in clinical and rehabilitation settings.

Prospective memory impairment and executive dysfunction in prefrontal lobe damaged patients: is there a causal relationship?

BACKGROUND

The prospective memory (PM) construct is aimed at capturing cognitive operations involved in the successful accomplishment of delayed intentions. It is generally agreed that PM impairment occurs in patients with prefrontal lobes damage.

OBJECTIVE

To evaluate if there is a causal role of a deficit of executive abilities (failures of planning, set-shifting, selective attention, or working memory) over the PM impairment.

METHODS

We report a detailed investigation of PM and executive abilities in two patients with posttraumatic damage to prefrontal lobes who complained from a reduced compliance with appointments and daily routines.

RESULTS

Laboratory tests confirmed a difficulty in fulfilling delayed intentions in response to the occurrence of critical events and elapsed time. In one patient, PM impairment was associated with poor performance on tests investigating planning, working memory, and mental shifting. The other patient performed in the normal range on all executive tests.

CONCLUSIONS

Despite the frequent claim of a dependence of PM deficits from executive dysfunction, the reported cases demonstrate that this is not necessarily the case. The results are discussed in the light of current hypotheses relating PM impairment to other deficits that commonly occur as a result of damage to the prefrontal lobes.

Revisiting the age-prospective memory-paradox: the role of planning and task experience

The present study aimed at investigating age-related differences in prospective memory performance using a paradigm with high ecological validity and experimental control. Thirty old and 30 young adults completed the Dresden Breakfast task; a meal preparation task in the lab that comprises several subtasks including event- and time-based prospective memory tasks. Participants were required to plan how to perform the task. Results showed that young adults outperformed old adults: they completed more subtasks, showed better event- and time-based prospective memory performance and planning quality. In contrast, old adults adhered to their plans more closely than young adults. Further exploratory gender-specific analyses indicated that old women did not differ from young men in time-based prospective memory performance, general task performance and time monitoring in contrast to old men. Possibly, differences in experience in breakfast preparation might account for these differential findings.

A systematic review of assessments for identifying executive function impairment in adults with acquired brain injury

PURPOSE

To synthesize quantitative findings concerning measures of executive function (EF) in adults with acquired brain injury (ABI).

METHOD

Electronic databases were searched for studies of EF assessments in adults with ABI that reported any of 3 values: likelihood ratios (LRs), standardized group mean comparisons (ds), or correlations (rs) among EF tests. Forest plots were constructed for each value.

RESULTS

Searches yielded 1,417 unique citations. Full texts of 129 articles were reviewed; 34 reported at least 1 value of interest. Nineteen positive and negative LRs were calculated from 8 studies of 8 EF measures; some point estimates were in the clinically informative range, but all confidence intervals extended beyond it. From 24 studies of 14 measures, 114 d values were calculated; d values for only 11 measures had lower bounds > 0.80. From 8 studies involving 10 EF measures, 104 correlations were reported; in only 5 cases were r(2) values > .5.

CONCLUSIONS

Strong evidence concerning diagnostic accuracy and concurrent validity of EF measures for adults with ABI is lacking. Better specification of the construct of EF as well as research aimed at improving the quality of evidence concerning EF tests are needed.

Do adults with autism spectrum disorders compensate in naturalistic prospective memory tasks?

The present study is the first to directly compare event- and time-based prospective memory in Autism Spectrum Disorders (ASD) using a contextual task mirroring real life demands of prospective memory. Twenty-five individuals with ASD and 25 age- and ability-matched controls completed the Dresden Breakfast task which required participants to prepare breakfast following a set of rules and time restrictions. Overall, adults with ASD had less correct time- and event-based prospective memory responses in comparison to controls, which is consistent with previous research in children with ASD. Moreover, ASD participants completed fewer tasks, followed rules less closely, and monitored the elapsing time less closely than controls. Individuals with ASD seem not to be compensating in naturalistic prospective memory tasks.

Complex prospective memory in adults with attention deficit hyperactivity disorder

Objectives

Attention deficit hyperactivity disorder (ADHD) in adults has been associated with disturbances of attention and executive functions. Furthermore, impairments of verbal and figural retrospective memory were reported. However, little is known about the effects of ADHD on prospective memory, the execution of delayed intentions in the future.

Methods

The present study compared the performance of 45 adult patients with ADHD not treated with stimulant medication with the performance of 45 matched healthy individuals on a paradigm of complex prospective memory which measured task planning, plan recall, self-initiation and execution. Furthermore, the contribution of other cognitive functions to prospective memory functioning was assessed, including measures of attention, executive functions and memory.

Results

A large-scale impairment could be observed in task planning abilities in patients with ADHD. Only negligible to small effects were found for plan recall, self-initiation and execution. Inhibition was identified to contribute significantly to performance on task planning.

Conclusions

The present findings suggest that four cognitive components contribute to the performance of prospective memory. Impairments of prospective memory mainly emerged from deficient planning abilities in adults with ADHD. Implications on behavioral based intervention strategies are discussed.

Apathy and prospective memory in aging

BACKGROUND

Apathy is common in aging, but the processes underlying its different components are still unclear. The aim of this study was to examine the relationships between apathy and prospective memory (PM), a process involved in the execution of delayed intentions.

METHODS

Fifty elderly participants completed a PM task and a working memory task. Close relatives of the participants were given the Apathy Inventory, which assesses three dimensions of apathy (lack of initiative, lack of interest, emotional blunting), and a negative mood scale.

RESULTS

Correlation analyses showed strong relationships between PM and lack of initiative and interest. These relations remain significant even after controlling for global cognitive functioning, working memory, processing speed and negative mood.

CONCLUSION

This study sheds new light on the cognitive mechanisms associated with apathy in aging and opens up interesting prospects for psychological intervention.

Memory and Executive Screening (MES): a brief cognitive test for detecting mild cognitive impairment

Background

Mild cognitive impairment (MCI), defined as a transitional zone between normal cognition and dementia, requires a battery of formal neuropsychological tests administered by a trained rater for its diagnosis. The objective of this study was to develop a screening tool for MCI.

Methods

One hundred ninety seven cognitively normal controls (NC), one hundred sixteen patients with amnestic MCI –single domain (aMCI-sd), one hundred ninety five patients with amnestic MCI-multiple domain (aMCI-md), and two hundred twenty eight patients with mild Alzheimer’s disease (AD) were evaluated by comprehensive neuropsychological tests and by the Memory and Executive Screening (MES).

Results

Correlation analysis showed that the three indicators of the MES were significantly negatively related with age (P<0.05), yet not related with education (P>0.05). There was no ceiling or floor effect. Test completion averaged seven minutes (421.14±168.31 seconds). The receiver operating characteristics (ROC) analyses performed on the aMCI-sd group yielded 0.89 for the area under the curve (AUC) (95% CI, 0.85–0.92) for the MES-total score, with sensitivity of 0.795 and specificity of 0.828. There was 81% correct classification rate when the cut-off was set at less than 75. Meanwhile, the aMCI-md group yielded 0.95 for the AUC (95% CI, 0.93–0.97) for the MES-total score, with sensitivity of 0.87 and specificity of 0.91, and 90% correct classification rate when the cut-off was set at less than 72.

Conclusion

The MES, minimally time-consuming, may be a valid and easily administered cognitive screening tool with high sensitivity and specificity for aMCI, with single or multiple domain impairment.

Time-based prospective memory in severe traumatic brain injury patients: the involvement of executive functions and time perception

Prospective memory (PM) is the ability to remember to perform a future action at a specified later time, which is investigated through the use of event-based and time-based tasks. Prior investigations have found that PM is impaired following traumatic brain injury (TBI). However, there is limited information regarding the cognitive functions that mediate TBI and PM performance. Thus, this study investigated time-based PM in TBI patients, and the relationship among time-based PM, time perception, and executive functions. To accomplish this objective, 18 severe TBI patients and 18 healthy matched controls performed a time-based PM task, a time reproduction task, and two executive functions (Stroop and n-back) tasks. While both groups increased their monitoring frequency close to the target time, TBI patients monitored more and were less accurate than healthy controls at the target time confirming the time-based PM dysfunction in these patients. Importantly, executive functions, particularly inhibition and updating abilities, were strongly related to time-based PM performance; both time perception and executive functions are involved in time-based prospective memory in controls, whereas, only executive functions appear to be involved in TBI time-based prospective memory performance.

Prospective memory rehabilitation based on visual imagery techniques

Despite the frequency of prospective memory (PM) problems in the traumatic brain injury (TBI) population, there are only a few rehabilitation programmes that have been specifically designed to address this issue, other than those using external compensatory strategies. In the present study, a PM rehabilitation programme based on visual imagery techniques expected to strengthen the cue-action association was developed. Ten moderate to severe chronic TBI patients learned to create a mental image representing the association between a prospective cue and an intended action within progressively more complex and naturalistic PM tasks. We hypothesised that compared to TBI patients (n = 20) who received a short session of education (control condition), TBI patients in the rehabilitation group would exhibit a greater improvement on the event-based than on the time-based condition of a PM ecological task. Results revealed however that this programme was similarly beneficial for both conditions. TBI patients in the rehabilitation group and their relatives also reported less everyday PM failures following the programme, which suggests generalisation. The PM improvement appears to be specific since results on cognitive control tasks remained similar. Therefore, visual imagery techniques appear to improve PM functioning by strengthening the memory trace of the intentions and inducing an automatic recall of the intentions.

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.

Monetary incentive effects on event-based prospective memory three months after traumatic brain injury in children

Information regarding the remediation of event-based prospective memory (EB-PM) impairments following pediatric traumatic brain injury (TBI) is scarce. Addressing this, two levels of monetary incentives were used to improve EB-PM in children ages 7 to 16 years with orthopedic injuries (OI, n = 51), or moderate (n = 25) and severe (n = 39) TBI at approximately 3 months postinjury. The EB-PM task consisted of the child giving a specific verbal response to a verbal cue from the examiner while performing a battery of neuropsychological measures (ongoing task). Significant effects were found for age-at-test, motivation condition, period, and group. Within-group analyses indicated that OI and moderate TBI groups performed significantly better under the high- than under the low-incentive condition, but the severe TBI group demonstrated no significant improvement. These results indicate that EB-PM can be significantly improved at 3 months postinjury in children with moderate, but not severe, TBI.

Prospective memory after moderate-to-severe traumatic brain injury: a multinomial modeling approach

OBJECTIVE

Prospective memory (PM), which can be understood as the processes involved in realizing a delayed intention, is consistently found to be impaired after a traumatic brain injury (TBI). Although PM can be empirically dissociated from retrospective memory, it inherently involves both a prospective component (i.e., remembering that an action needs to be carried out) and retrospective components (i.e., remembering what action needs to be executed and when). This study utilized a multinomial processing tree model to disentangle the prospective (that) and retrospective recognition (when) components underlying PM after moderate-to-severe TBI.

METHOD

Seventeen participants with moderate to severe TBI and 17 age- and education-matched control participants completed an event-based PM task that was embedded within an ongoing computer-based color-matching task.

RESULTS

The multinomial processing tree modeling approach revealed a significant group difference in the prospective component, indicating that the control participants allocated greater preparatory attentional resources to the PM task compared to the TBI participants. Participants in the TBI group were also found to be significantly more impaired than controls in the when aspect of the retrospective component.

CONCLUSIONS

These findings indicated that the TBI participants had greater difficulty allocating the necessary preparatory attentional resources to the PM task and greater difficulty discriminating between PM targets and nontargets during task execution, despite demonstrating intact posttest recall and/or recognition of the PM tasks and targets.

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.