Development of a tailored concussion education program for athletes: a pragmatic multimethods design and integrated knowledge translation approach from needs assessment to design.

OBJECTIVES: To understand Canadian university athletic programme concussion management needs, and to describe development and content of a tailored online concussion education tool for Canadian university/college athletes. DESIGN: An integrated knowledge translation multiphased, multimethods approach was used. Phases included a needs assessment survey with university representatives and athletes, content selection, mapping behavioural goals to evidenced-based behaviour change techniques, script/storyboard development, engagement interviews with university athletes and tool development using user-centred design techniques. SETTING: Canadian U SPORTS universities (n=56). PARTICIPANTS: Overall, 64 university representatives (eg, administrators, clinicians) and 27 varsity athletes (52% male, 48% female) completed the needs assessment survey. Five athletes participated in engagement interviews. OUTCOME MEASURES: Surveys assessed previous athlete concussion education, recommendations for concussion topics and tool design, concussion management challenges and interest in implementing a new course. RESULTS: Institutions used a median (Med) of two (range 1-5) approaches when educating athletes about concussion. Common approaches were classroom-style education (50%), online training (41%) and informational handouts (39%). University representatives rated most important topics as: (1) what is a concussion, (2) how to recognise a concussion and (3) how to report a concussion (Medall=4.8/5). Athletes felt symptom recognition (96%) and effects on the brain (85%) were most important. The majority of athletes preferred learning via computer (81%) and preferred to learn alone (48%) versus group learning (7%). The final resource was designed to influence four behaviours: (1) report symptoms, (2) seek care, (3) encourage teammates to report symptoms and (4) support teammates through concussion recovery. Examples of behaviour change techniques included: knowledge/skills, problem-solving scenarios, verbal persuasion and social comparison. Athletes are guided through different interactions (eg, videos, flip cards, scenarios, testimonials) to maximise engagement (material review takes ~30 min). CONCLUSIONS: The Concussion Awareness Training Tool for athletes is the first Canadian education tool designed to address the needs of Canadian university/college athletes.

Electrophysiological variability during tests of executive functioning: A comparison of athletes with and without concussion and sedentary control participants.

OBJECTIVE: Sport participation may benefit executive functioning (EF), but EF can also be adversely affected by concussion, which can occur during sport participation. Neural variability is an emerging proxy of brain health that indexes the brain's range of possible responses to incoming stimuli (i.e., dynamic range) and interconnectedness, but has yet to be characterized following concussion among athletes. This study examined whether neural variability was enhanced by athletic participation and attenuated by concussion. METHOD: Seventy-seven participants (18-25 years-old) were classified as sedentary controls (n = 33), athletes with positive concussion history (n = 21), or athletes without concussion (n = 23). Participants completed tests of attention switching, response inhibition, and updating working memory while undergoing electroencephalography recordings to index neural variability. RESULTS: Compared to sedentary controls and athletes without concussion, athletes with concussion exhibited a restricted whole-brain dynamic range of neural variability when completing a test of inhibitory control. There were no group differences observed for either the switching or working memory tasks. CONCLUSIONS: A history of concussion was related to reduced dynamic range of neural activity during a task of response inhibition in young adult athletes. Neural variability may have value for evaluating brain health following concussion.

Functional near infrared spectroscopy activation during an executive function task differs between healthy older and younger adults.

Background: Healthy aging can include declines in processing speed and executive function. Further research is needed to characterize the neurobiological underpinnings of these cognitive changes in older adulthood. The current study used functional near infrared spectroscopy (fNIRS), an optical neuroimaging technique, to examine differences in cerebral oxygenation between healthy older adults (OA) and younger adults (YA) during a measure of cognitive interference. Methods: Thirty-four participants were sampled from two age groups: YA (mean age = 28.1 years, SD = 2.8, F = 9) and OA (mean age = 70.9 years, SD = 5.4, F = 9). Participants completed the Multi-Source Interference Task (MSIT), a measure of executive function with high and low-demand conditions, while undergoing fNIRS recordings using a TechEn CW6 system with 34-source-detector channels, situated over the prefrontal cortex. Functional activation patterns, accuracy, and reaction time were compared between and within groups for each condition. Results: Behaviourally, during the control condition, OA and YA had comparable accuracy, although OA had significantly slower reaction times than YA. During the interference condition, OA had significantly lower accuracy and slower reaction times than YA. Results demonstrated a significant difference between groups with an age-related increase in HbO for OA in both conditions (p < 0.05). Within groups, OA showed greater activation during the control condition, while YA demonstrated greater activation during the interference condition. Conclusions: The findings suggest that OA recruit additional neural resources to achieve similar behavioural performance during low-level cognitive interference, but that compensation in OA may be insufficient to support behavioural performance at higher levels of interference.

Intraindividual variability in executive and motor control tasks in children with attention deficit hyperactivity disorder.

OBJECTIVE: Emerging evidence highlights intraindividual variability (IIV) during executive function (EF) tasks as a reliable endophenotype of Attention Deficit/Hyperactivity Disorder (ADHD) and as contributing to motor dysregulation and hyperactive-impulsive behaviors. This study examined the relationship between EF and motor control in children with and without ADHD. METHOD: Ninety-seven children (6-13 years) completed standardized and experimental tasks of executive and motor control. Primary caregivers completed a semi-structured interview, and behavioral rating forms for ADHD symptoms and EF. RESULTS: Children with ADHD demonstrated lower performance on motor dexterity and sequencing tasks, and greater IIV during EF tasks with lower cognitive demand. IIV accounted for ADHD symptoms of hyperactivity, beyond age and motor dexterity. IIV from EF measures with lower cognitive demand was also sensitive to ADHD symptoms. CONCLUSION: IIV metrics may tap into the motor regulation challenges associated with ADHD, as well as attentional lapsing at lower levels of cognitive demand.

A socially-engaged lifestyle moderates the association between gait velocity and cognitive impairment.

Objective: Cognitive status has been linked to impaired gait velocity, and diminished social and physical engagement. To date, the potential moderating influence of lifestyle engagement on gait-cognitive status associations has not been systematically explored. The present investigation examines whether a socially- or physically-engaged lifestyle moderates the association between diminished gait velocity and likelihood of amnestic mild cognitive impairment (a-MCI) classification.Methods: Participants (aged 65+, Mage=73 years) were classified as either healthy controls (n = 30) or a-MCI (n = 24), using neuropsychological test scores and clinical judgement. Gait velocity was indexed using a GAITRite computerized walkway, engaged lifestyle (social and physical subdomains) were measured using a well-validated self-report measure, the revised Activity Lifestyle Questionnaire.Results: Logistic regression, evaluating likelihood of a-MCI classification, yielded a significant interaction between a socially-engaged lifestyle and gait velocity (b=.01, SE=.003, p=.015). Follow-up simple effects were derived for two levels (+/-1SD) of social engagement; for individuals 1 SD below the mean, the association between gait velocity and increased likelihood of a-MCI classification was exacerbated (probability of a-MCI classification for those with slower gait velocity was 60% higher for individuals 1 SD below vs 1 SD above the mean of social engagement). Physically-engaged lifestyle did not significantly moderate the gait-cognitive status association.Conclusions: The significant moderating influence of social engagement has several implications, including the likelihood that distinct mechanisms underlie the relationships of social engagement and gait velocity to cognitive function, the value of social variables for well-being, and the potential utility of socially-based interventions that may prevent/delay a-MCI onset.

White Matter Integrity Is Associated With Intraindividual Variability in Neuropsychological Test Performance in Healthy Older Adults.

Inconsistency of performance across neuropsychological testing instruments (dispersion) shows sensitivity to acquired injury and neurodegenerative pathology in older adults. The underlying neural correlates have remained speculative however, in spite of known white matter degradation seen in conjunction with elevated inconsistency in related operationalizations of intraindividual variability. Consistently, these operationalizations have controlled for artifactual age-related variance to increase measurement sensitivity of CNS dysfunction. In this study, dispersion was examined alongside composite scores of memory and executive functioning from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Forty-four healthy older adults (M = 72.0, SD = 6.4) underwent Diffusion Tensor Imaging (DTI) and neuropsychological testing spanning a range of cognitive domains. The results replicated previous findings, demonstrating reduced microstructural integrity with advanced age and increased integrity in high memory and executive functioning performers, across all major white matter tracts. With age first regressed from the composite scores, significant associations remained between greater executive functioning scores and greater microstructural integrity in the genu of the corpus callosum, right anterior corona radiata, anterior, posterior and rentrolenticular parts of right internal capsule, as well as right posterior thalamic radiation. With age regressed from the dispersion scores, greater values were primarily associated with decreased white matter integrity in the body and genu of corpus callosum, anterior corona radiata bilaterally and left superior longitudinal fasciculus. Dispersion is easily computed across speeded and accuracy-based measures and shows promise in detecting white matter damage, beyond that seen in the typical aging process. This appears to be the first investigation of neural correlates associated with increased dispersion.

Adaptation of the Mullen Scales of Early Learning for use among infants aged 5- to 24-months in rural Gambia.

Infants in low-resource settings are at heightened risk for compromised cognitive development due to a multitude of environmental insults in their surroundings. However, the onset of adverse outcomes and trajectory of cognitive development in these settings is not well understood. The aims of the present study were to adapt the Mullen Scales of Early Learning (MSEL) for use with infants in a rural area of The Gambia, to examine cognitive development in the first 24-months of life and to assess the association between cognitive performance and physical growth. In Phase 1 of this study, the adapted MSEL was tested on 52 infants aged 9- to 24-months (some of whom were tested longitudinally at two time points). Further optimization and training were undertaken and Phase 2 of the study was conducted, where the original measures were administered to 119 newly recruited infants aged 5- to 24-months. Infant length, weight and head circumference were measured concurrently in both phases. Participants from both phases were split into age categories of 5-9 m (N = 32), 10-14 m (N = 92), 15-19 m (N = 53) and 20-24 m (N = 43) and performance was compared across age groups. From the ages of 10-14 m, Gambian infants obtained lower MSEL scores than US norms. Performance decreased with age and was lowest in the 20-24 m old group. Differential onsets of reduced performance were observed in the individual MSEL domains, with declines in visual perception and motor performance detected as early as at 10-14 months, while reduced language scores became evident after 15-19 months of age. Performance on the MSEL was significantly associated with measures of growth.

A Comprehensive Comparison of Quantifications of Intraindividual Variability in Response Times: A Measurement Burst Approach.

OBJECTIVES: To formally identify and contrast the most commonly-employed quantifications of response time inconsistency (RTI) and elucidate their utility for understanding within-person (WP) and between-person (BP) variation in cognitive function with increasing age. METHOD: Using two measurement burst studies of cognitive aging, we systematically identified and computed five RTI quantifications from select disciplines to examine: (a) correlations among RTI quantifications; (b) the distribution of BP and WP variation in RTI; and (c) the comparability of RTI quantifications for predicting attention switching. RESULTS: Comparable patterns were observed across studies. There was significant variation in RTI BP as well as WP across sessions and bursts. Correlations among RTI quantifications were generally strong and positive both WP and BP, except for the coefficient of variation. Independent prediction models indicated that slower mean response time (RT) and greater RTI were associated with slower attention switching both WP and BP. For selecting simultaneous prediction models, collinearity resulted in inflated standard errors and unstable model estimates. DISCUSSION: RTI reflects a novel dimension of performance that is a robust and theoretically informative predictor of BP and WP variation in cognitive function. Among the plenitude of RTI quantifications, not all are interchangeable, nor of comparable predictive utility.

Comparing executive function, evoked hemodynamic response, and gait as predictors of variations in mobility for older adults.

OBJECTIVE: Falls represent a major concern for older adults and may serve as clinically salient index events for those presenting in the prodromal stages of mild cognitive impairment. Declines in executive function performance and in gait consistency have shown promise in predicting fall risk; however, associated neurophysiological underpinnings have received less attention. In this study, we used a multimodal approach to assess fall risk in a group of older adults with and without a previous fall history. METHOD: Processing speed, inductive reasoning, verbal fluency, crystallized ability, episodic memory, and executive functioning were assessed using standardized neuropsychological tests. Cognitive interference was assessed using the Multi-Source Interference Task. Spatiotemporal gait parameters were assessed with and without cognitive load using a 6.4-m instrumented walkway. Hemodynamic responses were measured using functional near-infrared spectroscopy. RESULTS: Whereas no group differences were observed in cognitive behavioral performance, during a cognitive interference task fallers displayed more oxygenated hemoglobin across the prefrontal cortex than nonfallers, suggesting that engaging in the cognitive task was more effortful for them overall, therefore eliciting greater cortical activation. Between-group differences in spatial as well as temporal gait parameters were also observed. CONCLUSIONS: These results are in keeping with assertions that diminished executive control is related to fall risk. Notably, the group differences observed in prefrontal cortical activation and in gait parameters may ultimately precede those observed in cognitive behavioral performance, with implications for measurement sensitivity and early identification.

Mean and variability in functional brain activations differentially predict executive function in older adults: an investigation employing functional near-infrared spectroscopy.

OBJECTIVE: although the preponderance of research on functional brain activity investigates mean group differences, mounting evidence suggests that variability in neural activity is beneficial for optimal central nervous system (CNS) function. Independent of mean signal estimates, recent findings have shown that neural variability diminishes with age and is positively associated with cognitive performance, underscoring its adaptive nature. The present investigation sought to employ functional near infrared spectroscopy (fNIRS) to derive two operationalizations of cerebral oxygenation, representing mean and variability [using standard deviation (SD)] in neural activity, and to specifically contrast these mean- and SD-oxyhemoglobin (HbO) estimates as predictors of cognitive function. METHOD: a total of 25 older adults (71 to 81 years of age) completed a test of cognitive interference (Multisource Interference Task) while undergoing fNIRS recording using a multichannel continuous-wave optical imaging system (TechEn CW6) over bilateral prefrontal cortex (PFC). Time-varying covariation models were employed to simultaneously estimate the within- and between-person effects of cerebral oxygenation on behavioral performance fluctuations. RESULTS: mean effects were predominantly observed at the between-person level and suggest that greater concentrations of HbO are associated with slower and less accurate performance. Greater HbO variability at the between-person level was associated with slower performance, but was associated with faster performance at the within-person level. CONCLUSIONS: these findings are in keeping with assertions that mean and variability confer complementary (as opposed to redundant) sources of information regarding the effective functioning of a neural system and suggest that fNIRS is a viable methodology for capturing meaningful variance in the hemodynamic response that is characteristic of adaptive CNS function.

Intraindividual Variability across Neuropsychological Tests: Dispersion and Disengaged Lifestyle Increase Risk for Alzheimer's Disease.

Objective: Increased intraindividual variability (IIV) in function has been linked to various age-related outcomes including cognitive decline and dementia. Most studies have operationalized IIV as fluctuations across trials (e.g., response latencies) for a single task, with comparatively few studies examining variability across multiple tasks for a given individual. In the present study, we derive a multivariable operationalization of dispersion across a broad profile of neuropsychological measures and use this index along with degree of engaged lifestyle to predict risk of cognitive impairment. Participants and Methods: Participants (n = 60) were community-dwelling older adults aged 65+ years (M = 74.1, SD = 6.5) participating in a cross-sectional investigation of risk factors for amnestic mild cognitive impairment (a-MCI) and probable Alzheimer's Disease (AD). Participants were classified into three subgroups based on test performance and clinical judgement. Healthy controls (n = 30) scored better than -1 SD relative to existing norms on all classification measures, in the absence of memory complaints or functional impairments. The a-MCI group (n = 23) had self- or informant-reported memory complaints and scored 1 SD or more below the mean for at least one memory task while scoring better than 1 SD below the mean for all other cognitive domains, in the absence of functional impairments. The AD group (n = 7) scored at least 2 SD below the mean for two cognitive domains (including memory) with impairments in functioning. Measures spanned a range of cognitive domains (episodic memory, executive function, language), with the derived dispersion estimates reflecting variability across an individual's neuropsychological profile relative to the group average. Further, an Activities Lifestyle Questionnaire, indexing social, cognitive, and physical behaviors, was administered to assess the protective benefits of engaged lifestyle. Results: Multinomial logistic regression models examined the risk of being classified as a-MCI or AD as a function of increased dispersion, (dis)engaged lifestyle, and their interaction. Greater dispersion was associated with an increased likelihood of being classified with AD, with protective engaged-lifestyle benefits apparent for a-MCI individuals only. Conclusion: As a measure of IIV, dispersion across neuropsychological profiles holds promise for the detection of cognitive impairment.

Concurrent Indicators of Gait Velocity and Variability Are Associated with 25-Year Cognitive Change: A Retrospective Longitudinal Investigation.

Background/Objectives: Physical function indicators, including gait velocity, stride time and step length, are linked to neural and cognitive function, morbidity and mortality. Whereas cross-sectional associations are well documented, far less is known about long-term patterns of cognitive change as related to objective indicators of mobility-related physical function. Methods: Using data from the Victoria Longitudinal Study, a long-term investigation of biological and health aspects of aging and cognition, we examined three aspects of cognition-physical function linkages in 121 older adults. First, we examined a simple marker of physical function (3 m timed-walk) as a predictor of cross-sectional differences and up to 25-year change for four indicators of cognitive function. Second, we tested associations between two markers of gait function derived from the GAITRite system (velocity and stride-time variability) and differences and change in cognition. Finally, we evaluated how increasing cognitive load during GAITRite assessment influenced the associations between gait and cognition. Results: The simple timed-walk measure, commonly used in clinical and research settings, was a minor predictor of change in cognitive function. In contrast, the objectively measured indicator of walking speed significantly moderated long-term cognitive change. Under increasing cognitive load, the moderating influence of velocity on cognitive change increased, with increasing variability in stride time also emerging as a predictor of age-related cognitive decline. Conclusion: These findings: (a) underscore the utility of gait as a proxy for biological vitality and for indexing long-term cognitive change; and (b) inform potential mechanisms underlying age-related linkages in physical and cognitive function.

Cognitively-Impaired-Not-Demented Status Moderates the Time-Varying Association between Finger Tapping Inconsistency and Executive Performance.

OBJECTIVE: Response time inconsistency (RTI) in cognitive performance predicts deleterious health outcomes in late-life; however, RTI estimates are often confounded by additional influences (e.g., individual differences in learning). Finger tapping is a basic sensorimotor measure largely independent of higher-order cognition that may circumvent such confounds of RTI estimates. We examined the within-person coupling of finger-tapping mean and RTI on working memory, and the moderation of these associations by cognitive status. METHOD: A total of 262 older adults were recruited and classified as controls, cognitively-impaired-not-demented (CIND) unstable or CIND stable. Participants completed finger-tapping and working-memory tasks during multiple weekly assessments, repeated annually for 4 years. RESULTS: Within-person coupling estimates from multilevel models indicated that on occasions when RTI was greater, working-memory response latency was slower for the CIND-stable, but not for the CIND-unstable or control individuals. CONCLUSIONS: The finger-tapping task shows potential for minimizing confounds on RTI estimates, and for yielding RTI estimates sensitive to central nervous system function and cognitive status.

A reciprocal model of face recognition and autistic traits: evidence from an individual differences perspective.

Although not a core symptom of the disorder, individuals with autism often exhibit selective impairments in their face processing abilities. Importantly, the reciprocal connection between autistic traits and face perception has rarely been examined within the typically developing population. In this study, university participants from the social sciences, physical sciences, and humanities completed a battery of measures that assessed face, object and emotion recognition abilities, general perceptual-cognitive style, and sub-clinical autistic traits (the Autism Quotient (AQ)). We employed separate hierarchical multiple regression analyses to evaluate which factors could predict face recognition scores and AQ scores. Gender, object recognition performance, and AQ scores predicted face recognition behaviour. Specifically, males, individuals with more autistic traits, and those with lower object recognition scores performed more poorly on the face recognition test. Conversely, university major, gender and face recognition performance reliably predicted AQ scores. Science majors, males, and individuals with poor face recognition skills showed more autistic-like traits. These results suggest that the broader autism phenotype is associated with lower face recognition abilities, even among typically developing individuals.