Nourishing the brain on deep space missions: nutritional psychiatry in promoting resilience.

The grueling psychological demands of a journey into deep space coupled with ever-increasing distances away from home pose a unique problem: how can we best take advantage of the benefits of fresh foods in a place that has none? Here, we consider the biggest challenges associated with our current spaceflight food system, highlight the importance of supporting optimal brain health on missions into deep space, and discuss evidence about food components that impact brain health. We propose a future food system that leverages the gut microbiota that can be individually tailored to best support the brain and mental health of crews on deep space long-duration missions. Working toward this goal, we will also be making investments in sustainable means to nourish the crew that remains here on spaceship Earth.

Safety Review and Perspectives of Transcranial Focused Ultrasound Brain Stimulation.

Ultrasound is an important theragnostic modality in modern medicine. Technical advancement of both acoustic focusing and transcranial delivery have enabled administration of ultrasound waves to localized brain areas with few millimeters of spatial specificity and penetration depth sufficient to reach the thalamus. Transcranial focused ultrasound (tFUS) given at a low acoustic intensity has been shown to increase or suppress the excitability of region-specific brain areas. The neuromodulatory effects can outlast the sonication, suggesting the possibility of inducing neural plasticity needed for neurorehabilitation. Increasing numbers of studies have shown the efficacy and excellent safety profile of the technique, yet comparisons among the safety-related parameters have not been compiled. This review aims to provide safety information and perspectives of tFUS brain stimulation. First, the acoustic parameters most relevant to thermal/mechanical tissue damage are discussed along with regulated parameters for existing ultrasound therapies/diagnostic imaging. Subsequently, the parameters used in studies of large animals, non-human primates, and humans are surveyed and summarized in terms of the acoustic intensity and the mechanical index. The pulse-mode operation and the use of low ultrasound frequency for tFUS-mediated brain stimulation warrant the establishment of new safety guidelines/recommendations for the use of the technique among healthy volunteers, with additional cautionary requirements for its clinical translation.

Operationally Relevant Behavior Assessment Using the Robotic On-Board Trainer for Research (ROBoT-r).

INTRODUCTION: Spaceflight can strain astronaut physical, physiological, and mental well-being, whereas maintaining astronaut operational performance remains an essential goal. Although various cognitive tests have been used for spaceflight assessment, these have been challenged on their lack of operational relevance.METHODS: To address this gap, we developed and characterized the Robotic On-Board Trainer for Research (ROBoT-r) system, based on the Robotic On-Board Trainer (ROBoT) currently used for astronaut training on Canadarm2 track-and-capture activities. The task requires use of dual hand-controllers (6 degrees of freedom) to grapple an incoming vehicle in free-drift in a time-limited setting. After developing a platform for conducting research studies, characterization testing of ROBoT-r was completed by 14 astronaut-like volunteers (35 ± 11 yr; N = 5 women) over 16 sessions each.RESULTS: We describe the design and capabilities of the ROBoT-r system for conducting operationally relevant research on human performance. Version 6.2 of the system supports H-II Transfer Vehicle track-and-capture operations within a multimillion component, physics-enabled 3D model using NASA's DOUG graphics platform. It has configurable task initialization and auto-run capabilities, saves 38 variables continuously at 20 Hz throughout each run, provides the user quantitative feedback after each run, and provides summaries after each session. Detailed performance characterization data is reported for future experimental planning purposes.DISCUSSION: ROBoT-r's range of performance variables enables detailed and quantitative performance assessment. Its use in spaceflight will help provide insight into operational performance, as well as allowing investigators to compare these results with more traditional cognitive tests to help better understand the interaction between individual cognitive abilities and operational performance.Ivkovic V, Sommers B, Cefaratti DA, Newman G, Thomas DW, Alexander DG, Strangman GE. Operationally relevant behavior assessment using the Robotic On-Board Trainer for Research (ROBoT-r). Aerosp Med Hum Perform. 2019; 90(9):819-825.

Technology Development for Simultaneous Wearable Monitoring of Cerebral Hemodynamics and Blood Pressure.

For many cerebrovascular diseases both blood pressure (BP) and hemodynamic changes are important clinical variables. In this paper, we describe the development of a novel approach to noninvasively and simultaneously monitor cerebral hemodynamics, BP, and other important parameters at high temporal resolution (250 Hz sampling rate). In this approach, cerebral hemodynamics are acquired using near infrared spectroscopy based sensors and algorithms, whereas continuous BP is acquired by superficial temporal artery tonometry with pulse transit time based drift correction. The sensors, monitoring system, and data analysis algorithms used in the prototype for this approach are reported in detail in this paper. Preliminary performance tests demonstrated that we were able to simultaneously and noninvasively record and reveal cerebral hemodynamics and BP during people's daily activity. As examples, we report dynamic cerebral hemodynamic and BP fluctuations during postural changes and micturition. These preliminary results demonstrate the feasibility of our approach, and its unique power in catching hemodynamics and BP fluctuations during transient symptoms (such as syncope) and revealing the dynamic features of related events.

Wearable brain imaging with multimodal physiological monitoring.

The brain is a central component of cognitive and physical human performance. Measures, including functional brain activation, cerebral perfusion, cerebral oxygenation, evoked electrical responses, and resting hemodynamic and electrical activity are all related to, or can predict, health status or performance decrements. However, measuring brain physiology typically requires large, stationary machines that are not suitable for mobile or self-monitoring. Moreover, when individuals are ambulatory, systemic physiological fluctuations-e.g., in heart rate, blood pressure, skin perfusion, and more-can interfere with noninvasive brain measurements. In efforts to address the physiological monitoring and performance assessment needs for astronauts during spaceflight, we have developed easy-to-use, wearable prototypes, such as NINscan, for near-infrared scanning, which can collect synchronized multimodal physiology data, including hemodynamic deep-tissue imaging (including brain and muscles), electroencephalography, electrocardiography, electromyography, electrooculography, accelerometry, gyroscopy, pressure, respiration, and temperature measurements. Given their self-contained and portable nature, these devices can be deployed in a much broader range of settings-including austere environments-thereby, enabling a wider range of novel medical and research physiology applications. We review these, including high-altitude assessments, self-deployable multimodal e.g., (polysomnographic) recordings in remote or low-resource environments, fluid shifts in variable-gravity, or spaceflight analog environments, intracranial brain motion during high-impact sports, and long-duration monitoring for clinical symptom-capture in various clinical conditions. In addition to further enhancing sensitivity and miniaturization, advanced computational algorithms could help support real-time feedback and alerts regarding performance and health.

Increased cerebral blood volume pulsatility during head-down tilt with elevated carbon dioxide: the SPACECOT Study.

Astronauts aboard the International Space Station (ISS) have exhibited hyperopic shifts, posterior eye globe flattening, dilated optic nerve sheaths, and even optic disk swelling from spaceflight. Elevated intracranial pressure (ICP) consequent to cephalad fluid shifts is commonly hypothesized as contributing to these ocular changes. Head-down tilt (HDT) is frequently utilized as an Earth-based analog to study similar fluid shifts. Sealed environments like the ISS also exhibit elevated CO2, a potent arteriolar vasodilator that could further affect cerebral blood volume (CBV) and cerebral blood flow, intracranial compliance, and ICP. A collaborative pilot study between the National Space Biomedical Research Institute and the German Aerospace Center tested the hypotheses that 1) HDT and elevated CO2 physiologically interact and 2) cerebrovascular pulsatility is related to HDT and/or elevated CO2 In a double-blind crossover study (n = 6), we measured CBV pulsatility via near-infrared spectroscopy, alongside noninvasive ICP and intraocular pressure (IOP) during 28-h -12° HDT at both nominal (0.04%) and elevated (0.5%) ambient CO2 In our cohort, CBV pulsatility increased significantly over time at cardiac frequencies (0.031 ± 0.009 µM/h increase in total hemoglobin concentration pulsatility amplitude) and Mayer wave frequencies (0.019 ± 0.005 µM/h increase). The HDT-CO2 interaction on pulsatility was not robust but rather driven by one individual. Significant differences between atmospheres were not detected in ICP or IOP. Further work is needed to determine whether individual differences in pulsatility responses to CO2 relate to visual changes in space.NEW & NOTEWORTHY Cerebral blood volume (CBV) pulsatility-as measured by near-infrared spectroscopy-increases over time during -12° head-down tilt at both cardiac and Mayer wave frequencies. CBV pulsatility appeared to increase more under elevated (0.5%) CO2 at Mayer wave frequencies in some individuals. If similar dynamic pulsatility increases occur in astronauts, there is the potential to initiate vascular and possibly other remodeling processes that lead to symptoms associated with sustained increases in intracranial pressure.

Acute Mountain Sickness Symptoms Depend on Normobaric versus Hypobaric Hypoxia.

Acute mountain sickness (AMS), characterized by headache, nausea, fatigue, and dizziness when unacclimatized individuals rapidly ascend to high altitude, is exacerbated by exercise and can be disabling. Although AMS is observed in both normobaric (NH) and hypobaric hypoxia (HH), recent evidence suggests that NH and HH produce different physiological responses. We evaluated whether AMS symptoms were different in NH and HH during the initial stages of exposure and if the assessment tool mattered. Seventy-two 8 h exposures to normobaric normoxia (NN), NH, or HH were experienced by 36 subjects. The Environmental Symptoms Questionnaire (ESQ) and Lake Louise Self-report (LLS) were administered, resulting in a total of 360 assessments, with each subject answering the questionnaire 5 times during each of their 2 exposure days. Classification tree analysis indicated that symptoms contributing most to AMS were different in NH (namely, feeling sick and shortness of breath) compared to HH (characterized most by feeling faint, appetite loss, light headedness, and dim vision). However, the differences were not detected using the LLS. These results suggest that during the initial hours of exposure (1) AMS in HH may be a qualitatively different experience than in NH and (2) NH and HH may not be interchangeable environments.

Ambulatory diffuse optical tomography and multimodality physiological monitoring system for muscle and exercise applications.

Ambulatory diffuse optical tomography (aDOT) is based on near-infrared spectroscopy (NIRS) and enables three-dimensional imaging of regional hemodynamics and oxygen consumption during a person's normal activities. Although NIRS has been previously used for muscle assessment, it has been notably limited in terms of the number of channels measured, the extent to which subjects can be ambulatory, and/or the ability to simultaneously acquire synchronized auxiliary data such as electromyography (EMG) or electrocardiography (ECG). We describe the development of a prototype aDOT system, called NINscan-M, capable of ambulatory tomographic imaging as well as simultaneous auxiliary multimodal physiological monitoring. Powered by four AA size batteries and weighing 577 g, the NINscan-M prototype can synchronously record 64-channel NIRS imaging data, eight channels of EMG, ECG, or other analog signals, plus force, acceleration, rotation, and temperature for 24+ h at up to 250 Hz. We describe the system's design, characterization, and performance characteristics. We also describe examples of isometric, cycle ergometer, and free-running ambulatory exercise to demonstrate tomographic imaging at 25 Hz. NINscan-M represents a multiuse tool for muscle physiology studies as well as clinical muscle assessment.

Evidence for cerebral edema, cerebral perfusion, and intracranial pressure elevations in acute mountain sickness.

INTRODUCTION: We hypothesized that cerebral alterations in edema, perfusion, and/or intracranial pressure (ICP) are related to the development of acute mountain sickness (AMS). METHODS: To vary AMS, we manipulated ambient oxygen, barometric pressure, and exercise duration. Thirty-six subjects were tested before, during and after 8 h exposures in (1) normobaric normoxia (NN; 300 m elevation equivalent); (2) normobaric hypoxia (NH; 4400 m equivalent); and (3) hypobaric hypoxia (HH; 4400 m equivalent). After a passive 15 min ascent, each subject participated in either 10 or 60 min of cycling exercise at 50% of heart rate reserve. We measured tissue absorption and scattering via radio-frequency near-infrared spectroscopy (NIRS), optic nerve sheath diameter (ONSD) via ultrasound, and AMS symptoms before, during, and after environmental exposures. RESULTS: We observed significant increases in NIRS tissue scattering of 0.35 ± 0.11 cm(-1) (P = 0.001) in subjects with AMS (i.e., AMS+), consistent with mildly increased cerebral edema. We also noted a small, but significant increase in total hemoglobin concentrations with AMS+, 3.2 ± 0.8 µmolL(-1) (P < 0.0005), consistent with increased cerebral perfusion. No effect of exercise duration was found, nor did we detect differences between NH and HH. ONSD assays documented a small but significant increase in ONSD (0.11 ± 0.02 mm; P < 0.0005) with AMS+, suggesting mildly elevated ICP, as well as further increased ONSD with longer exercise duration (P = 0.005). CONCLUSION: In AMS+, we found evidence of cerebral edema, elevated cerebral perfusion, and elevated ICP. The observed changes were small but consistent with the reversible nature of AMS.

Hypoxia, Hypobaria, and Exercise Duration Affect Acute Mountain Sickness.

INTRODUCTION: This study simultaneously quantified the effects of normobaric hypoxia (NH), hypobaric hypoxia (HH), exercise duration, and exposure time on acute mountain sickness severity (AMS-C). METHODS: Thirty-six subjects (27.7 ± 7.8 yr) participated in a partial repeated measures study, completing two of six conditions: normobaric normoxia (NN: 300 m/984 ft equivalent), NH or HH (Po2 = 91 mmHg; 4400 m/14,436 ft equivalent), combined with moderate intensity cycling for 10 or 60 min. Subjects completed the Environmental Symptoms Questionnaire and oxygen saturation (Spo2) was measured before, 1.5 h, 4 h, and 6.5 h into an 8-h exposure, and 1.5 h post-exposure. We fit multiple linear regression models with cluster adjusted standard errors on the exposure times using NH, HH, and long exercise as indicator variables, and AMS-C as the outcome variable. The Spo2and pre-exposure AMS-C score were used as covariates. RESULTS: NH and HH led to substantial and progressively increasing AMS-C, but NN did not. The effect of HH on AMS-C was significantly different from NH, with AMS-C in HH being 1.6 times higher than in NH. HH led to significantly increasing AMS-C, regardless of the exercise duration, while NH only did so in combination with longer exercise. DISCUSSION: Increases in AMS-C were each independently related to NH, HH, and long duration exercise, with HH affecting AMS-C more severely. This suggests that hypobaria may affect AMS development above the level induced by hypoxia alone. This further suggests that NH and HH may not be interchangeable for studying AMS and that exercise duration may impact physiological responses.

Human cognitive performance in spaceflight and analogue environments.

Maintaining intact cognitive performance is a high priority for space exploration. This review seeks to summarize the cumulative results of existing studies of cognitive performance in spaceflight and analogue environments. We focused on long-duration (>21 d) studies for which no review has previously been conducted. There were 11 published studies identified for long-duration spaceflight (N = 42 subjects) as well as 21 shorter spaceflight studies (N = 70 subjects). Overall, spaceflight cognitive studies ranged from 6-438 d in duration. Some 55 spaceflight analogue studies were also identified, ranging from 6 to 520 d. The diverse nature of experimental procedures and protocols precluded formal meta-analysis. In general, the available evidence fails to strongly support or refute the existence of specific cognitive deficits in low Earth orbit during long-duration spaceflight, which may be due in large part to small numbers of subjects. The studies consistently suggest that novel environments (spaceflight or other) induce variable alterations in cognitive performance across individuals, consistent with known astronaut experiences. This highlights the need to better quantify the magnitude and scope of this interindividual variability, and understand its underlying factors, when predicting in-flight cognitive functioning for extended periods.

Twenty-four-hour ambulatory recording of cerebral hemodynamics, systemic hemodynamics, electrocardiography, and actigraphy during people's daily activities.

The feasibility and utility of wearable 24-h multimodality neuromonitoring during daily activities are demonstrated. We have developed a fourth-generation ambulatory near infrared spectroscopy device, namely NINscan 4. NINscan 4 enables recording of brain function (via cerebral hemodynamics), systemic hemodynamics, electrocardiography, and actigraphy simultaneously and continuously for up to 24 h at 250-Hz sampling rate, during (and with minor restriction to) daily activities. We present initial 24-h human subject test results, with example analysis including (1) comparison of cerebral perfusion and oxygenation changes during wakefulness and sleep over a 24-h period and (2) capturing of hemodynamic changes prior, during and after sudden waken up in the night during sleep. These results demonstrate the first ambulatory 24-h cerebral and systemic hemodynamics monitoring, and its unique advantages including long-term data collection and analysis capability, ability to catch unpredictable transient events during activities of daily living, as well as coregistered multimodality analysis capabilities. These results also demonstrate that NINscan 4's motion artifact at 1-g head movement is smaller than physiological hemodynamic fluctuations during motionless sleep. The broader potential of this technology is also discussed.

Scalp and skull influence on near infrared photon propagation in the Colin27 brain template.

Near-infrared neuromonitoring (NIN) is based on near-infrared spectroscopy (NIRS) measurements performed through the intact scalp and skull. Despite the important effects of overlying tissue layers on the measurement of brain hemodynamics, the influence of scalp and skull on NIN sensitivity are not well characterized. Using 3555 Monte Carlo simulations, we estimated the sensitivity of individual continuous-wave NIRS measurements to brain activity over the entire adult human head by introducing a small absorption perturbation to brain gray matter and quantifying the influence of scalp and skull thickness on this sensitivity. After segmenting the Colin27 template into five tissue types (scalp, skull, cerebrospinal fluid, gray matter and white matter), the average scalp thickness was 6.9 ± 3.6 mm (range: 3.6-11.2mm), while the average skull thickness was 6.0 ± 1.9 mm (range: 2.5-10.5mm). Mean NIN sensitivity - defined as the partial path length through gray matter divided by the total photon path length - ranged from 0.06 (i.e., 6% of total path length) at a 20mm source-detector separation, to over 0.19 at 50mm separations. NIN sensitivity varied substantially around the head, with occipital pole exhibiting the highest NIRS sensitivity to gray matter, whereas inferior frontal regions had the lowest sensitivity. Increased scalp and skull thickness were strongly associated with decreased sensitivity to brain tissue. Scalp thickness always exhibited a slightly larger effect on sensitivity than skull thickness, but the effect of both varied with SD separation. We quantitatively characterize sensitivity around the head as well as the effects of scalp and skull, which can be used to interpret NIN brain activation studies as well as guide the design, development and optimization of NIRS devices and sensors.

Depth sensitivity and source-detector separations for near infrared spectroscopy based on the Colin27 brain template.

Understanding the spatial and depth sensitivity of non-invasive near-infrared spectroscopy (NIRS) measurements to brain tissue-i.e., near-infrared neuromonitoring (NIN) - is essential for designing experiments as well as interpreting research findings. However, a thorough characterization of such sensitivity in realistic head models has remained unavailable. In this study, we conducted 3,555 Monte Carlo (MC) simulations to densely cover the scalp of a well-characterized, adult male template brain (Colin27). We sought to evaluate: (i) the spatial sensitivity profile of NIRS to brain tissue as a function of source-detector separation, (ii) the NIRS sensitivity to brain tissue as a function of depth in this realistic and complex head model, and (iii) the effect of NIRS instrument sensitivity on detecting brain activation. We found that increasing the source-detector (SD) separation from 20 to 65 mm provides monotonic increases in sensitivity to brain tissue. For every 10 mm increase in SD separation (up to ~45 mm), sensitivity to gray matter increased an additional 4%. Our analyses also demonstrate that sensitivity in depth (S) decreases exponentially, with a "rule-of-thumb" formula S=0.75*0.85(depth). Thus, while the depth sensitivity of NIRS is not strictly limited, NIN signals in adult humans are strongly biased towards the outermost 10-15 mm of intracranial space. These general results, along with the detailed quantitation of sensitivity estimates around the head, can provide detailed guidance for interpreting the likely sources of NIRS signals, as well as help NIRS investigators design and plan better NIRS experiments, head probes and instruments.

Fractional anisotropy helps predicts memory rehabilitation outcome after traumatic brain injury.

Traumatic brain injury (TBI) commonly results in residual memory difficulties. Such deficits are amenable to cognitive rehabilitation, but optimal selection of rehabilitation interventions remains a challenge. We hypothesized that diffusion tensor imaging (DTI) could be used to predict which individuals were likely to benefit from a specific memory rehabilitation intervention. Thirty-seven individuals with TBI, of all severities, first underwent DTI scanning, along with 18 matched controls. Participants with TBI then attended a 12-session memory intervention emphasizing internal memory strategies (I-MEMS). Primary outcome measures (HVLT, RBMT) were collected at the time of DTI scanning, and both immediately and one month post-therapy. In contrast to typical neuroimaging analysis, fractional anisotropy (FA) was used to predict long-term outcome scores, adjusting for typical predictors (injury severity, age, education, time since injury, pretest score). FA of the parahippocampal white matter was a significant negative predictor of HVLT, while the anterior corpus callosum, left anterior internal capsule, and right anterior corona radiata were negative predictors of RBMT outcome. The importance of these predictors rivaled those of pretest scores. Thus, FA measures may provide substantial predictive value for other cognitive interventions as well. The reason why higher FA was associated with less successful response to cognitive intervention remains unclear and will require further study.

Test-re-test reliability of the Hopkins Verbal Learning Test-Revised in individuals with traumatic brain injury.

PRIMARY OBJECTIVE: To determine test-re-test reliability of the Hopkins Verbal Learning Test-Revised (HVLT-R) in a group of individuals with traumatic brain injury (TBI). RESEARCH DESIGN: Single-group repeated measures design. METHODS AND PROCEDURES: Seventy-five individuals with TBI were administered the HVLT-R twice, with 6-8 weeks between the two test sessions. MAIN OUTCOMES AND RESULTS: Test-re-test reliability on HVLT-R scoring parameters ranged from 0.537-0.818, with seven of the eight scoring parameters exhibiting r > 0.6. At re-test, scores did not significantly change on any of the eight HVLT-R scoring parameters. CONCLUSIONS: HVLT-R use with individuals with TBI is supported. Test-re-test reliability of total recall and delayed recall sub-scores was particularly high.

Development of motion resistant instrumentation for ambulatory near-infrared spectroscopy.

Ambulatory near-infrared spectroscopy (aNIRS) enables recording of systemic or tissue-specific hemodynamics and oxygenation during a person's normal activities. It has particular potential for the diagnosis and management of health problems with unpredictable and transient hemodynamic symptoms, or medical conditions requiring continuous, long-duration monitoring. aNIRS is also needed in conditions where regular monitoring or imaging cannot be applied, including remote environments such as during spaceflight or at high altitude. One key to the successful application of aNIRS is reducing the impact of motion artifacts in aNIRS recordings. In this paper, we describe the development of a novel prototype aNIRS monitor, called NINscan, and our efforts to reduce motion artifacts in aNIRS monitoring. Powered by 2 AA size batteries and weighting 350 g, NINscan records NIRS, ECG, respiration, and acceleration for up to 14 h at a 250 Hz sampling rate. The system's performance and resistance to motion is demonstrated by long term quantitative phantom tests, Valsalva maneuver tests, and multiparameter monitoring during parabolic flight and high altitude hiking. To the best of our knowledge, this is the first report of multiparameter aNIRS monitoring and its application in parabolic flight.

Regional brain morphometry predicts memory rehabilitation outcome after traumatic brain injury.

Cognitive deficits following traumatic brain injury (TBI) commonly include difficulties with memory, attention, and executive dysfunction. These deficits are amenable to cognitive rehabilitation, but optimally selecting rehabilitation programs for individual patients remains a challenge. Recent methods for quantifying regional brain morphometry allow for automated quantification of tissue volumes in numerous distinct brain structures. We hypothesized that such quantitative structural information could help identify individuals more or less likely to benefit from memory rehabilitation. Fifty individuals with TBI of all severities who reported having memory difficulties first underwent structural MRI scanning. They then participated in a 12 session memory rehabilitation program emphasizing internal memory strategies (I-MEMS). Primary outcome measures (HVLT, RBMT) were collected at the time of the MRI scan, immediately following therapy, and again at 1-month post-therapy. Regional brain volumes were used to predict outcome, adjusting for standard predictors (e.g., injury severity, age, education, pretest scores). We identified several brain regions that provided significant predictions of rehabilitation outcome, including the volume of the hippocampus, the lateral prefrontal cortex, the thalamus, and several subregions of the cingulate cortex. The prediction range of regional brain volumes were in some cases nearly equal in magnitude to prediction ranges provided by pretest scores on the outcome variable. We conclude that specific cerebral networks including these regions may contribute to learning during I-MEMS rehabilitation, and suggest that morphometric measures may provide substantial predictive value for rehabilitation outcome in other cognitive interventions as well.

Test-re-test reliability of the virtual planning test in individuals with traumatic brain injury.

PRIMARY OBJECTIVE: To determine test-re-test reliability of the VIrtual Planning Test (VIP) in a group of individuals with traumatic brain injury (TBI). RESEARCH DESIGN: Single-group repeated measures design. METHODS AND PROCEDURES: Seventy-five individuals with TBI were administered the VIP, with 6-8 weeks between the two test sessions. MAIN OUTCOMES AND RESULTS: Test-re-test reliability on VIP scoring parameters--as measured by Pearson correlation coefficients--ranged from 0.341-0.855, with five of the seven scoring parameters exhibiting r > 0.6. CONCLUSIONS: Based on the findings of the current study, the VIP has overall moderate test-re-test reliability when administered to individuals with TBI. Some VIP scoring parameters, i.e. Total correct/accuracy and Total absence, demonstrated high test-re-test reliability. Others, i.e. Planning time and Total wrong order, demonstrated low test-re-test reliability.

A controlled treatment study of internal memory strategies (I-MEMS) following traumatic brain injury.

OBJECTIVE: To evaluate the effects of participation in a memory group intervention focusing on internal strategy use on persons with traumatic brain injury-related memory impairment. PARTICIPANTS: Ninety-four adults with traumatic brain injury (54 in the experimental group and 40 controls) and resulting memory impairment, with severities ranging from mild to severe. All participants were at least 18 years of age at the time of injury and at least 1 year post injury at the time of study. DESIGN: Non randomized pre/posttest group comparison design. MAIN OUTCOME MEASURES: Hopkins Verbal Learning Test-Revised and Rivermead Behavioral Memory Test II. RESULTS: Participation in the memory group intervention was associated with improved memory performance immediately postintervention, and improvements were maintained 1 month postintervention. Severe injury was associated with less improvement in memory outcomes than mild and moderate injuries. Age and preinjury education were not related to outcome. CONCLUSIONS: Individuals with traumatic brain injury may benefit from memory group intervention focusing on internal strategy use. Study hypotheses should be retested using a randomized, controlled design, and further research is needed to better delineate influences on intervention candidacy and outcomes.