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

Memory and Traumatic Brain Injury: Assessment and Management Practices of Speech-Language Pathologists

PURPOSE

Memory impairments are among the most commonly reported deficits and among the most frequent rehabilitation targets for individuals with traumatic brain injury (TBI). Memory and learning are also critical for rehabilitation success and broader long-term outcomes. Speech-language pathologists (SLPs) play a central role in memory management for individuals with TBI across the continuum of care. Yet, little is known about the current practice patterns of SLPs for post-TBI memory disorders. This study aims to examine the clinical management of memory disorders in adults with TBI by SLPs and identify opportunities to improve post-TBI memory outcomes.

METHOD

SLPs from across the continuum of care were recruited to complete an online survey. The survey assessed key practice areas specific to memory and memory disorders post-TBI, including education and training, knowledge and confidence, and assessment and treatment patterns.

RESULTS

Surveys from 155 SLPs were analyzed. Results revealed that TBI-specific training remains low in the field. Respondents varied in their practice patterns in assessing and treating memory disorders. Most SLPs do not appear to have access to appropriate standardized assessments to measure unique forms of memory. Respondents also reported a range of barriers and opportunities to advance memory outcomes following TBI and provided suggestions of areas in which they would like to see more basic and clinical research.

CONCLUSIONS

These findings establish a baseline of the current practices for clinical management of memory impairment in adults with TBI by SLPs. Improved opportunities for clinician training, the development of a single tool to assess multiple forms of memory, better access to existing memory assessments, and implementation of evidence-based interventions promise to lead to improved memory outcomes for individuals with TBI.

The effects of implementation intentions on prospective memory in young and older adults

Prospective memory (PM) is the ability to perform a planned action at a future time, while carrying on with other unrelated tasks. Implementation Intentions (II) is a promising metacognitive strategy for improving PM in older adults, though its generalization and longer-term effects are not well-understood. We examined the effects of II on PM in 48 community-dwelling older adults (77% female, M_age = 71.52) and 59 young adults (75% female, M_age = 19.86). Participants were randomly allocated to a conventional instruction or II group and administered a laboratory-based PM task in the first session. In the second session, participants returned to complete a similar but new laboratory-based PM task and an ecological PM task without prompts to use a strategy. We found strong age effects on PM performance whereby older adults performed worse than young adults across all PM tasks. While the overall facilitation effect of II was not statistically significant, there was a trend that this strategy facilitated PM performance on the laboratory-based PM task in the first session for older adults with a medium sized effect (d = 0.37). The generalization and longer-term effect of II were not significant for either the similar laboratory-based or the ecological PM task. These results suggest that a single-session II intervention may not be sufficient to elicit transfer to other similar new PM tasks in healthy populations.

The impact of using implementation intentions as task instructions on prospective memory performance after stroke

Prospective Memory (PM), the ability to remember to carry out intentions in the future, is often impaired after stroke. Little is known about rehabilitation of PM post-stroke with literature limited by small sample sizes and reliance on self-reported memory performance. Implementation intentions may make prospective remembering more automatic and follow a simple if-then structure (if X occurs, then I will do Y), focusing on the cue rather than the task. We aimed to investigate the effect of implementation intentions on PM post-stroke. Twenty-eight individuals with stroke and 27 controls were randomly allocated to a standard instruction or implementation intention condition and completed an assessment battery over two sessions. Implementation intention instructions were provided for PM tasks on the Delayed Message Task, Lexical Decision Prospective Memory Task (LDPMT), and the Virtual Reality Prospective Memory Shopping Task. The implementation intention groups performed better on all PM tasks compared to the standard instruction group, but no results reached statistical significance, likely due to the small sample size. In addition, the implementation intentions group monitored the time significantly more on the LDPMT than those in the standard instruction group.

Rodent models used in preclinical studies of deep brain stimulation to rescue memory deficits

Deep brain stimulation paradigms might be used to treat memory disorders in patients with stroke or traumatic brain injury. However, proof of concept studies in animal models are needed before clinical translation. We propose here a comprehensive review of rodent models for Traumatic Brain Injury and Stroke. We systematically review the histological, behavioral and electrophysiological features of each model and identify those that are the most relevant for translational research.

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 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.

The relationship between episodic future thinking and prospective memory in middle childhood: Mechanisms depend on task type

Episodic future thinking (EFT), the ability to imagine experiencing a future event, and prospective memory (PM), the ability to remember and carry out a planned action, are core aspects of future-oriented cognition that have individually been the focus of research attention in the developmental literature. However, the relationship between EFT and PM, including the extent to which it varies with PM task type, remains poorly delineated, particularly in middle childhood. The current study tested this relationship in 62 typically developing children aged 8-12 years. Results indicated that EFT ability was significantly related to performance on three types of PM tasks (regular and irregular event based and regular time based). Age was not found to moderate the relationship. Children's performance on the retrospective memory component of the PM tasks mediated the relationship between EFT ability and their performance on three types of PM tasks. For irregular event-based tasks, however, EFT made an additional significant contribution. This study adds to the limited empirical literature supporting a relationship between EFT and PM in this age band and supports theoretical models arguing that EFT ability may support PM performance by strengthening the encoding of PM task details in retrospective memory. However, additional mechanisms were also indicated for irregular event-based PM tasks, possibly involving strengthening of cue-context associations. These data show for the first time that the contribution of EFT to children's PM performance varies across task types. This study provides an important and novel contribution to current understanding of the processes that underlie PM development.

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.

Encoding strategy training and self-reported everyday prospective memory in people with Parkinson disease: a randomized-controlled trial

Objective To compare the effects of laboratory-based training in implementation intentions (II; experimental strategy) and verbal rehearsal (VR; control strategy) on self-reported everyday prospective memory among people with Parkinson disease (PD) and to investigate potential correlates of change in self-reported everyday prospective memory in response to this training. Method This was a randomized-controlled trial. Participants with mild to moderate PD without dementia underwent one session of training in either II (n = 25) or VR (n = 27). Then they were instructed to use their strategy as much as possible in their everyday lives to help them remember to do things. The Prospective and Retrospective Memory Questionnaire Prospective Scale (PRMQ-Pro) administered at baseline and one month after training assessed training-related change in self-reported everyday prospective memory. Baseline depressive symptoms, perceptions of the strategy (credibility, expectancy), prospective memory-related awareness, global cognition, and disease severity were correlated to PRMQ-Pro Change scores (post minus pre) to determine their association with response to training. Results The VR group's PRMQ-Pro scores declined from pre to post training, while the II group's remained stable (p = .03). This effect was driven by change in self-cued everyday prospective memory tasks. Higher baseline depressive symptoms, treatment expectancy, and global cognition related to better response to training in the II group (rs ≤ -.40, ps ≤ .05). Conclusions II training may prevent everyday prospective memory decline among people with PD. In addition, people with higher depression, stronger expectations of improvement from strategy training, or better global cognition may benefit the most from II training.

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.

Goal intention reminding in traumatic brain injury: A feasibility study using implementation intentions and text messaging

OBJECTIVE

To examine feasibility of participant-created implementation intentions, delivered as text message reminders, to enhance goal-related activity in persons with chronic, moderate/severe traumatic brain injury (TBI).

DESIGN

Pilot randomized controlled trial on effects of 8 weeks receiving goal-related implementation intentions (GI) compared to control condition, educational review regarding goals (GR).

PARTICIPANTS

Eight persons with moderate/severe TBI nearing discharge from intensive outpatient brain injury treatment.

MEASURES

Neuropsychological tests to characterize cognitive status; Participation with Recombined Tools-Objective (PART-O) assessing community activity, social relations and productivity; Brief Symptom Inventory-18 (BSI-18) assessing depression, anxiety and overall distress; Goal Attainment Scales (GAS). PART-O, BSI-18 and GAS were completed at baseline and 8 weeks; significant others provided ratings on PART-O and GAS.

RESULTS

Participants replied to SMS messages at high rates. Statistically significant group × time interactions with medium-to-large effect sizes favouring the GI group were observed on PART-O community activity and social relations. Neither BSI-18 nor GAS revealed differences or trends by group. Qualitative results suggested overall acceptance and success of SMS reminders.

CONCLUSIONS

Given positive preliminary findings, implementation intentions delivered by text holds promise as a simple, low-cost intervention to help people with moderate/severe TBI to implement goal-relevant behaviours.