Trainee Schedule

Friday, May 7, 2021: 11:30 AM - 12:30 PDT
Break Out Room #1: Cognitive and Brain Health
Name Time Title and Abstract
11:30 – 11:35 AM Opening Remarks
Katrina Rbeiz 11:35 – 11:43 AM

Sensitivity of the Memory Binding Test in Preclinical Alzheimer's Disease

Introduction: The Memory Binding Test (MBT) was developed to detect early memory changes in those at risk for Alzheimer’s disease (AD) dementia, but this has primarily been tested in the mild cognitive impairment stage. The current study investigated the utility of the MBT in the preclinical stage among cognitively unimpaired older adults who were imaged to detect brain amyloid deposition. Methods: 140 cognitively unimpaired adults completed the MBT and amyloid PET imaging. Participants were separated into two groups: amyloid negative (n = 90) and amyloid positive (n = 50). Age was covaried in all analyses. Partial spearman rank correlations were conducted between amyloid burden and the MBT scores. A nonparametric ANVOCA was used to assess between-groups differences in MBT scores. The ability of the four MBT variables to discriminate between groups was assessed using area under the receiver operating characteristic curves. Results: Higher amyloid burden was associated with worse immediate paired recall (rho = -0.23, p = .007) and delayed paired recall (rho = -0.24, p = .004) on the MBT. The amyloid positive group performed significantly worse than the amyloid negative group on all four MBT variables, with large effect sizes (2 values: 0.132 - 0.142, p’s < .001). AUC values were > 0.73 for all four MBT variables. Discussion: MBT scores, particularly measures of associative learning, are associated with brain amyloid burden even among cognitively unimpaired individuals. The MBT demonstrated moderate discriminative validity, suggesting that it detects subtle cognitive deficits in otherwise cognitively normal adults with preclinical AD.

Weiran Yuchi 11:43 – 11:51 AM

Road proximity, air pollution, noise, green space and neurologic disease incidence: a population-based cohort study

Background: Emerging evidence links road proximity and air pollution with cognitive impairment. Joint effects of noise and greenness have not been evaluated. We investigated associations between road proximity and exposures to air pollution, and joint effects of noise and greenness, on non-Alzheimer’s dementia, Parkinson’s and Alzheimer’s disease and multiple sclerosis within a population-based cohort. Methods: We assembled administrative health database cohorts of 45–84 year old residents (N ~ 678,000) of Metro Vancouver, Canada. Cox proportional hazards models were built to assess associations between exposures and non-Alzheimer’s dementia and Parkinson’s disease. Given reduced case numbers, associations with Alzheimer’s disease and multiple sclerosis were evaluated in nested case-control analyses by conditional logistic regression. Results: Road proximity was associated with all outcomes (e.g. non-Alzheimer’s dementia hazard ratio: 1.14, [95% confidence interval: 1.07–1.20], for living < 50 m from a major road or < 150 m from a highway). Air pollutants were associated with incidence of Parkinson’s disease and non-Alzheimer’s dementia (e.g. Parkinson’s disease hazard ratios of 1.09 [1.02–1.16], 1.03 [0.97–1.08], 1.12 [1.05–1.20] per interquartile increase in fine particulate matter, Black Carbon, and nitrogen dioxide) but not Alzheimer’s disease or multiple sclerosis. Noise was not associated with any outcomes while associations with greenness suggested protective effects for Parkinson’s disease and non-Alzheimer’s dementia. Conclusions: Road proximity was associated with incidence of non-Alzheimer’s dementia, Parkinson’s disease, Alzheimer’s disease and multiple sclerosis. This association may be partially mediated by air pollution, whereas noise exposure did not affect associations. There was some evidence of protective effects of greenness.

Narlon Cassio Boa Sorte Silva 11:51 AM – 11:59 PM

Gait variability and myelin integrity in older adults with vascular cognitive impairment: A preliminary analysis

Introduction: In individuals with vascular cognitive impairment (VCI), myelin loss may contribute to mobility impairment. Using myelin water fraction (MWF), we investigated whether myelin content is associated with gait parameters in older adults with VCI. Methods: We analyzed cross-sectional data from fifty-one subjects with MRI-evidence of VCI (mean [SD], age = 74.8 [5.2], MoCA = 22.5 [2.5], 66.6% female). We used T1-weighted MRI data for structural analysis, and gradient and spin echo (GRASE) contrast for acquisition of MWF data. Gait parameters were measured using an electronic walkway (GAITRite). Using the FSL package, MWF was computed for fifteen specific white matter structures. T1-weighted images were processed with FreeSurfer to estimate intracranial volume (ICV) and cortical thickness. Hierarchical regression models adjusting for ICV, cortical thickness, age, MoCA, and sex were conducted to determine whether poorer gait parameters were independently associated with lower MWF. Results: In models adjusting for ICV, cortical thickness, and age, higher gait variability was associated with lower average MWF in all white matter structures combined (p = 0.022). In models also accounting for MoCA, higher gait variability was associated with lower MWF in the anterior corona radiata (p = 0.037), body of the corpus callosum (p = 0.046), and superior longitudinal fasciculus (p = 0.047). In fully adjusted models, accounting for sex, higher gait variability was associated with lower MWF in the genu of the corpus callosum (p = 0.035) and cingulum (p = 0.01). Discussion: Myelin loss may underlie the effects of VCI on mobility by increasing gait variability, which could lead to higher falls risk

Agnes Belkacem 11:59 – 12:07 PM

Longitudinal Study on Hippocampal Volume and Verbal Memory in Patients with First-Episode Psychosis: Effects of Dopaminergic and Anticholinergic Burden of Antipsychotics

Antipsychotics help reduce positive symptoms of psychosis, but have limited impact on cognitive deficits and negative symptoms and have been associated with structural changes in the brain. Studies have shown that antipsychotic dosage can be associated with hippocampal volume, with reduced volumes in areas with dense dopamine receptors, such as in the dentate gyrus subfield. In addition, the literature also suggests considering anticholinergic burden of antipsychotics as it is associated with deficits in verbal memory in First-Episode Psychosis (FEP). As part of a longitudinal study over an 18-month period with 4 time points, our objectives were to examine changes in verbal memory performance and hippocampal subfield volumes in patients versus controls over time and to determine the extent to which antipsychotic treatment may partly account for changes over time. (1) We hypothesized that patients would have poorer verbal memory performance and reduced hippocampal subfield volumes over time relative to controls. (2) a. We expected that dopaminergic burden would be negatively associated with subfields with denser dopaminergic receptors. (2) b. We expect anticholinergic burden to be negatively associated with cognition, especially verbal memory performance in FEP patients. FEP patients, followed by the PEPP-Montreal clinic (N = 74), and non-clinical controls (N = 53) completed a 3T MRI scan and a neurocognitive evaluation (CogState) at 3, 9, 12 and 18 months after admission. (1) Generalized Estimating Equations (GEE) analysis revealed a significant timepoint by group interaction for verbal memory performance and for the right CA1, left CA4/dentate gyrus subfield. (2) a. Significant negative correlations were found between dopaminergic burden and left CA1, left CA4/dentage gyrus, left fimbria and left hippocampus subfields volumes change over time. (2) b. A significant negative correlation was found between anticholinergic burden and verbal memory performance over time. Knowledge of a significant reduction in hippocampal volume at the onset in FEP shows that it is crucial to provide treatment at the onset of the first psychotic symptoms, which may not only reduce cognitive deficits but also eventually restore damaged neuronal pathways. In addition, the associations found between medications, brain volume, and cognitive performance provide evidence in favor in prescribing lower doses of antipsychotics.

Ali Mirza 12:07 – 12:15 PM

Functional survey of the pediatric multiple sclerosis microbiome

Introduction: Metagenomic sequencing reveals the functional potential of the Multiple Sclerosis (MS) gut microbiome. We examined the gut microbiome functional potential by metagenomic analysis of stool samples from pediatric MS cases and controls. Methods: Persons ≤21 years old enrolled in the Canadian Pediatric Demyelinating Disease Network who provided a stool sample were included for study. Twenty MS cases were matched to 20 non-affected controls by sex, age (± 3 years), stool consistency (Bristol Stool Scale, BSS) and, when possible, by race. Shotgun metagenomic reads were generated using the Illumina NextSeq platform and assembled using MEGAHIT. Metabolic pathway analysis was used to compare the gut microbiome between cases and controls, as well as cases by DMD status. Gene ontology classifications were used to assess α-diversity and differential abundance analyses (based on the negative binomial distribution). Results: The MS cases were aged 13.6 mean years at symptom onset. On average, MS cases and controls were 16.1 and 15.4 years old at the time of stool collection and 80% of each group were girls. Eight MS cases were DMD naïve. Richness of gene ontology classifications did not differ by disease status or DMD status (all p>0.4). However, differential analysis of metabolic pathways indicated that the relative abundance of tryptophan degradation (via the kynurenine pathway; LFC 13; 95%CI: 8–19; p<0.0005) and cresol degradation (LFC 19; 95%CI: 13–25; p<0.0001) pathways were enriched for MS cases vs controls. Differences by DMD status were also observed, e.g., choline biosynthesis was enriched in DMD exposed vs naïve MS cases (LFC 21; 95%CI: 12–29; p<0.0001). Discussion: We observed differences in the functional potential of the gut microbiome of young individuals with MS relative to controls at various metabolic pathways, including enrichment of pathways related to tryptophan and metabolism of industrial chemicals. DMD exposure affected findings, with enrichment of pathways involved in promoting CNS remyelination (e.g., choline).

12:25 – 12:30 PM Closing Remarks
Break Out Room #2: Interventions
Name Time Title and Abstract
11:30 – 11:35 AM Opening Remarks
Ryan Stein 11:35 – 11:43 AM

The Effect of Computerized Cognitive Training, With and Without Physical Activity, on the Brain

Introduction: Evidence shows that cognitive training and exercise can improve cognitive outcomes in older adults. We previously showed that computerized cognitive training, with or without exercise, improved executive functions in community-dwelling older adults. We now aim to examine the neural correlates associated with improved executive functions. Methods: A secondary analysis of structural MRI data acquired from an 8-week, 3-arm proof of concept randomized control trial. Participants were randomly assigned to: 1) computerized cognitive training delivered by the Fitbrains program (FBT) 2) exercise and FBT (Ex-FBT); or 3) balance and tone (i.e., active control, BAT). A subset of participants (n=55; FBT = 16, Ex-FBT = 18, and BAT = 21) underwent MRI scanning at baseline and trial completion (i.e., 8 weeks). Areas of interest include: the anterior cingulate cortex and fronto-parietal lobe. Between-group differences in these regional brain volumes will be compared using analysis of covariance. Pearson correlation coefficients will be calculated to assess the association between change in regional brain volumes and change in executive function. Results: To be completed; feedback is welcomed. Discussion: The results will provide insight to the underlying neural changes that accompany cognitive changes secondary to computerized cognitive training, and whether these changes vary with the addition of exercise.

Ofir Yakobi 11:43 – 11:51 AM

The Effects of Mindfulness Meditation on Cognition in Healthy Adults: A Meta-analysis of Randomized Controlled Trials

Introduction: Mindfulness based interventions (MBI) are becoming increasingly popular. Given their nature (i.e., training of focused attention and cognitive control), efforts have been made to study their potential benefits to different aspects of cognition, resulting in mixed results. In light of the inconsistent findings, concerns regarding the methodological quality of such studies, and recent surge in randomized controlled trials of mindfulness interventions, we conducted a meta-analysis focused on MBIs effects on attention, working-memory and executive control in healthy adults. Methods: We limited the included studies to randomized controlled trials of mindfulness-based interventions in healthy adults, resulting in 27 included studies (N=1632). Results: We found an overall effect of g=0.2, with significant effects on attention (g=0.18) and executive control (g=0.18), but not on working-memory. Moderation analyses showed that the type of control group included in the study or the dosage (total hours of intervention) did not modulate these effects, but the number of in-class sessions did: the more sessions, the stronger the effect. Conclusions: MBIs have limited positive effects on attention and executive control in healthy adults. More studies are needed to address how participants' motivation may account for this effect, and clarify whether the smaller effects we found are due to our focus on healthy adults, or due to overestimation of effect sizes in previous meta-analyses.

Patricia Hewston 11:51 AM – 11:59 PM

Effects of GERAS DANCE on cognitive function in older adults with and without cognitive impairment

Introduction: Mild cognitive impairment (MCI) is one of the first cognitive expressions of Alzheimer's Disease and other dementias. Dance activates many brain regions to integrate complex movement patterns with musical and emotional expression and may lower the risk of dementia over time. We investigated the effect of 12-weeks of GERAS DANcing for Cognition and Exercise (DANCE) on cognitive function in older adults (aged 60+) with and without cognitive impairment. Methods: GERAS DANCE is a specialised program tailored for older adults with early memory or mobility problems. It was offered across 12 YMCAs in Southern Ontario, Canada with in-person classes 2x weekly (1-hour each) and homework (10-minutes daily) for a period of 12 weeks. Cognitive function was assessed with the Montreal Cognitive Assessment [MOCA]. Changes in cognitive function from baseline to 12 weeks were evaluated using ANOVA [2 (Time: pre- post-intervention) x 2 (Group: cognitive impairment, no cognitive impairment)]. Results: 106 older adults participated in the analysis (mean age = 76.12±7.03, range 61-93 years, 81% female). Overall GERAS DANCE improved cognitive function [F(1,105) = 4.928, p = 0.029]. In older adults with cognitive impairment, the mean difference of MOCA total scores improved by 1.04 points (pre = 21.71 ± 3.34, post = 22.74 ± 4,12). Discussion: GERAS DANCE has the potential to improve or maintain cognitive function in older adults with and without dementia. Next steps include testing for efficacy of GERAS DANCE as a part of an overall approach for cognitive health and inform clinical practice guidelines.

Daniel Gan 11:59 – 12:07 PM

Playfulness for Brain Health in Community Settings: Preliminary Analysis from a Systematic Scoping Review to Support Non-Pharmacological Interventions

Introduction: Brain health – defined as stroke, dementia, and their protective factors – becomes more important as lifespan increases. Recent reviews of non-pharmacological interventions in the community suggest that new theory-based approaches may be required. We conduct a systematic scoping review on playfulness as a construct and preliminary study (US NIH Stage 0) that may support the development of novel non-pharmacological interventions to prevent decline in brain health. Using Deweyan person-place integration (Cutchin, 2004), we define playfulness as an open, attentive, and fun-loving disposition that may be inhibited or facilitated by one’s environment. We aim to (1) develop a theoretical framework, (2) evaluate the evidence base, and (3) recommend directions and methodologies for future research. Methods: We conduct a systematic search on an interdisciplinary database that spans the health, social, and environmental sciences. Search strategies included articles with a focus on “brain health” AND “playful” AND “environmental stimuli” or related terms. Documents were screened in stages by two independent reviewers for relevant peer-reviewed journal articles. Titles on adolescents, athletes, autism, gaming behavior, physical rehabilitation, psychological experiments (e.g., Ultimatum Game) and psychosis were excluded. Results: Systematic search yielded 370 documents. 59 titles/abstracts were short-listed for full-text review. Preliminary analysis reveals potentially relevant articles from as many as 52 journals ranging from Aging and Mental Health to Technology and Disability, and grew exponentially since 1975. Discussion: Playfulness is an important interdisciplinary construct for non-pharmacological prevention of cognitive decline. Inputs of persons living with dementia will be solicited from the VCH Community Engagement Advisory Network.

Taylor Willi 12:07 – 12:15 PM

A Brief Breathing Intervention for Anxiety

Introduction: Self-regulation of breathing is a simple and accessible intervention that has been hypothesized to decrease symptoms of anxiety. Brief breathing exercises have become popularized despite little empirical research on the efficacy of a consistent practice. Here, we investigate the effect of a brief, one-minute breathing exercise on self-reported trait anxiety in a randomized two-group comparison of a controlled breathing exercise and a counting exercise. Methods: Recruited from undergraduate Psychology classes at Simon Fraser University, 65 participants were enrolled into the study and randomized to learning either a one-minute breathing exercise or a one-minute counting exercise. Participants downloaded a mobile application to their smart device to complete the exercise twice a day for the study duration. Self-reported trait anxiety, with somatic and cognitive subscales, was measured with the STICSA at three time-points over eight weeks. Results: Outcome variables meeting the assumptions of normality were analyzed with a repeated measures ANCOVA, controlling for the frequency the exercise was performed. The analysis showed a significant effect of Group by Time, such that participants who performed the breathing exercise reported a greater change in anxiety over the course of eight weeks than participants who performed the counting exercise in measures of Total trait anxiety and the Cognitive subscale (p<0.05). Discussion:The results indicate that the brief breathing exercise investigated in this study is more efficacious at lowering self-report trait anxiety than a comparable counting exercise, when performed over a period of two-months. Further investigation into the optimal parameters for controlled breathing are warranted.

12:25 – 12:30 PM Closing Remarks
Break Out Room #3: Health Behaviours
Name Time Title and Abstract
11:30 – 11:35 AM Opening Remarks
Kyle Gooderham 11:35 – 11:43 AM

Subjective Experiences of Cognition in Young Adults: The association between health behaviours and self-reported cognitive function

Introduction: Engagement in physical activity (PA) is associated with enhanced cognitive performance and greater self-reported psychological wellbeing. Research has consistently demonstrated positive psychological effects of PA in developing and aging populations; however, there remains a lack of consensus regarding cognitive benefits in young adults. Specifically, it is not well understood why, following PA, young adults report increased wellbeing but show inconsistent improvement in objective cognitive performance. The aim of the present study was to investigate whether self-reported assessments of one's own cognitive performance may be sensitive to PA interventions and provide the interface between wellbeing and cognitive functioning. We hypothesized that greater cumulative PA would be associated with higher subjective ratings of cognitive performance. Methods: Across two studies, 2057 young adults (M age = 20.7) completed self-report measures of PA, and the covariates of stress, sleep, and diet, in addition to questionnaires measuring executive control, attention, and memory function. Results: Analysis revealed that PA was not consistently associated with subjective cognitive function. However, stress and sleep habits were significantly predictive of executive function, attention, and memory performance, while diet was linked to executive control and some aspects of memory performance. Discussion: These findings provide novel evidence that engagement in health behaviours for young adults is positively associated with self-reported perceptions of cognitive functioning and suggests that subjective experiences of cognition are susceptible to interventions targeting health behaviours. PA is yet to be proven a significant mediator or moderator of the observed relationships and is an avenue for future research.

Tyler Kruger 11:43 – 11:51 AM

Healthy Living as Correlates of Attentional Engagement in Everyday Life

Introduction: Focusing our attention on the task-at-hand and avoiding moments of inattention are important for the successful completion of many everyday task. Sometimes people experience moments of deep and effortless concentration while performing a task (often referred to as “flow”); other times people experience lapses in attention, moments of absent-mindedness and mind-wandering. To identify correlates of daily attentional engagement, we examined how three different components of healthy living—physical activity, sleepiness, and dietary habits—relate to self-reported inattention (i.e., attention lapses, cognitive errors, and mind-wandering) and deep, effortless concentration (i.e., flow) in everyday life. Methods: 193 participants were recruited through Amazon Mechanical Turk in exchange for $2 USD. Results: In general, our results indicated there was a negative relation between healthy living and inattention, such that greater healthy living was associated with fewer failures of attention, fewer cognitive errors, and less mind-wandering. In addition, we observed a positive relation between healthy living and deep effortless concentration, such that healthier living was associated with more frequent self-reported experiences of flow. Discussion: Although the present findings are only correlational in nature, they present the tantalizing possibility that improving the healthiness of one’s lifestyle may positively influence one’s attentional engagement in everyday activities.

Timothy Morris 11:51 AM – 11:59 PM

Brain-based metrics are better predictors of adherence to exercise interventions than psychosocial and behavioral measures and provide mechanistic insights

Introduction: To date, approaches to develop efficacious exercise interventions that lead to sustained behavior change have not been developed. We hypothesize that brain-based measures will better predict adherence to exercise interventions than behavioral measures. And, at the same time, uncover mechanistic correlates of adherence that can be leveraged to develop novel interventions that lead to sustained behavior change. Methods: Using a data-driven machine learning approach we predicted adherence to the intervention sessions (3/week) of a 6-month randomized controlled trial of exercise in 201 low-active older adults using baseline psychosocial, demographic, accelerometry and physical function, cognitive and brain structural measures (cortical thickness, surface area, diffusion tractography). Data partitioning (test/train approach) and two regularized machine learning algorithms (Lasso and Elastic Net), which provide both feature selection and penalization to reduce model overfitting were used. Results: We found that the model trained with cortical thickness data was better at predicting adherence in the unseen dataset (Lasso R2 = 0.13, Elastic Net R2 = 0.12), than the behavioral models (psychosocial R2 = 0.04, demographic R2 = 0.05, accelerometry R2 = 0.07, cognitive R2 = 0.04). Through post-selection inference methods, we found cortical thickness in the left caudal anterior cingulate, cuneus, post central gyrus, the right isthmus cingulate and middle temporal gyrus were consistently selected by both models as informative predictors. In comparison, sex, education, cardiorespiratory fitness and week-day self-reported sitting time were consistent behavioral predictors. Discussion: Brain-based structural measures provide mechanistic predictions of adherence to an exercise intervention. 

Miranda Bahng 11:59 – 12:07 PM

Physical Activity and Cognitive Function: Preliminary Evidence for Public Health Messaging in Young Adults

Studies have shown the lifestyle factors of physical activity and sleep are critical when it comes to cognitive functioning (i.e. attention, memory, processing) and long-term health benefits. However, the immediate effects of these lifestyle factors in real-life situations, such as on scholastic achievement, are still unclear. Thus, the goal of this study was to investigate the immediate effects of the following lifestyle factors, physical activity, sleep quality, sleep duration, and study duration, on a common situation measuring scholastic achievement in young adults' lives, a final examination. A survey was administered to young-adult students after the completion of a university final exam. The brief survey assessed their levels of physical activity, the duration and quality of their sleep, and the quantity of studying done a day prior to their respective final exams. Exam performance, as obtained from the course instructors, was analyzed as a function of their lifestyle behaviors. Sleep duration and quality, along with hours spent studying were found to positively predict exam performance. Exploratory analyses were also conducted alluding to a mediating relationship between physical activity and exam performance. These findings support the need to promote lifestyle behaviors in young adults based not on its longer-term consequences for improved physical and mental health, but on its more immediate effects (i.e. scholastic achievement).

Ryan Falck 12:07 – 12:15 PM

There Are No Age and Sex Differences in the Relationship between Cardiometabolic Risk and Cognitive Function: A cross-sectional analysis of the Canadian Longitudinal Study on Aging

Background: It is unclear if cardiometabolic risk moderates age-associated differences in cognition, and whether this relationship is sex-dependent. Methods: We conducted cross-sectional analyses using baseline data from the Canadian Longitudinal Study on Aging (2010-2015) to examine whether 1) peripheral blood-based cardiometabolic risk factors (i.e., hemoglobin A1c, C-reactive protein, plasma triglycerides, and high-density and low-density cholesterol) moderate age-related variation in cognition; and 2) these moderation effects are sex-dependent. We modeled age-associated cognitive performance for cognitively health participants from the Comprehensive cohort (n= 25,830; 45-86 years) using restricted cubic splines for age and each cardiometabolic risk factor, as well as their interactive effects. Sex was included as a separate predictor, as well as all 2- and 3-way interactions with age and cardiometabolic risk. Wald chi-square statistics were used to determine importance of age, cardiometabolic risk factors, and their interactive effects on cognitive performance; we then examined the importance of 3-way interactions of age, cardiometabolic risk and sex. Results: Age was the most important variable in each model, accounting for 34-48% of χ2; cardiometabolic risk factors were the fifth or sixth most important predictors, depending on the factor (1-3% of χ2). The interaction between peripheral blood-based cardiometabolic risk factors and age were the sixth or seventh most important predictors (1-2% of χ2); 3-way interactions between age, cardiometabolic risk, and sex were unimportant predictors (≤1% of χ2). Conclusions: Differences in cardiometabolic risk factors do not meaningfully account for age-associated differences in cognition, and these relationships (or lack thereof) do not seem to be sex-dependent.

12:25 – 12:30 PM Closing Remarks
Friday, May 28, 2021: 11:30 AM - 12:30 PDT
Break Out Room #1: Sleep
Name Time Title and Abstract
11:30 – 11:35 AM Opening Remarks
Tara Kuhn 11:35 – 11:43 AM

Can fitness protect older adult's memory from poor sleep?

Introduction: Sleep is a vital process associated with cognitive decline and Alzheimer’s disease. It is critical to find interventions that improve sleep and promote healthy cognitive aging. Physical activity is a promising modifiable lifestyle factor which improves an individual’s cognitive functioning and sleep. However, there has been little investigation into the relationship between physical activity, sleep, and cognition together, which the present study sought to explore. Methods: In this cross-sectional study, 26 older adults completed the Rockport 1-mile walk test to measure cardiorespiratory fitness, and wore an actigraph for one week to measure habitual sleep. Participants returned for a second visit to assess hippocampal dependent memory, using the Mnemonic Similarities Test. We performed a moderation analyses to examine how fitness may impact the relationship between sleep and memory. Results: An interaction was found between sleep quality and cardiorespiratory fitness (p = .021), in that sleep enhanced memory for low fit older adults (p = .047) but not for high fit older adults (p = .19). Discussion: Overall, these results suggest that cardiorespiratory fitness may act as a protective buffer for memory in older adults who sleep poorly. The protective effects of cardiorespiratory fitness may be age specific, as these effects were not found in young adults. Future research should further investigate the underlying mechanism for the relationship between sleep, cardiorespiratory fitness, and cognition.

Leqi Sun 11:43 – 11:51 AM

Effects of early hormone deprivation via bilateral salpingo-oophorectomy on sleep disturbance and hippocampal volume

Introduction: Early (<45 years) ovarian hormone deprivation via surgical menopause is associated with greater Alzheimer’s disease (AD) risk (Rocca et al., 2007). As sleep disturbance and hippocampus atrophy are implicated in both AD pathogenesis (Lim et al., 2013; Wisse et al., 2014) and menopause (Cho et al., 2019; Goto et al., 2011), the present study investigated whether middle-aged women with early bilateral oophorectomy (BSO) who are not taking hormone therapy show greater risks for AD in terms of sleep disturbance and reduced hippocampal volume. Methods: Women with early BSO that were either taking estradiol-based hormone therapy (BSO+ET, n = 25) or not taking ET (BSO, n = 18) were recruited to the study, and were compared to age-matched premenopausal controls (AMC, n = 21) as well as spontaneous post menopausal women (SM, age = , n = 23). Autonomic sleep staging data was generated with Z3score (Neurobit Technologies) based on one night of polysomnography recorded on a portable device (Vitaport-5/REMbo-234, Temec Technologies), and high-resolution T2-weighted scans acquired with a Siemens 3T Prisma scanner was used towards the manual segmentation (Olsen et al., 2017) of three hippocampus subfields (CA1, Subiculum, DGCA23) in FSLView. Results: No group differences were found in objective sleep, but the BSO group demonstrated reduced volume in anterior CA1 (left anterior: p = 0.00, d = 0.00; right anterior: p=0.01, d = 1.06), as well as smaller left anterior DGCA23 (p = 0.00, d=1.30) than AMC. A significant negative correlation between REM percentage and DGCA23 volume was found in women with early BSO. Discussion: The findings suggest elevated AD risk in women with early BSO, as well as a potential use for atrophy in specific hippocampal subfields as clinical markers for detecting early AD pathology in this population.

Arslan Salikhov 11:51 AM – 11:59 PM

Evaluation of a Novel Accelerometry-Based Logistic Regression Sleep Detection Algorithm.

Introduction: Sleep quality and quantity is important to brain health and the risk of neurodegenerative disease. Wearable biosensors are used to detect and monitor sleep in everyday life. Current methods to detect sleep periods are typically dependent on two thresholds from wrist-worn accelerometer data: absence of movement and duration of inactivity. Absolute thresholds and single wear locations limit the efficacy of these methods. The objective of this study is to evaluate a novel machine learning approach to improve sleep detection in free-living scenarios. Methods: Data was collected from 39 individuals with neurodegenerative disease through the Ontario Neurodegenerative Disease Research Initiative who wore 5 biosensors continuously over 7-days. The logistic regression algorithm was trained on three features: 1) arm angle, 2) temperature from the ankle, and 3) body posture (from leg orientation). Outputs from the algorithm were compared to visually detected sleep, determined by an expert observer, using skin temperature and accelerometer data. Results: The algorithm correctly predicted 88% of 15-second sleep windows over a 7-day collection period, with an average confidence of 83%. Moreover, the average loss from the log loss function (or sum of the errors) in validation set of the model was 0.32. Discussion: Compared to threshold-dependent algorithms, which produce a binary sleep/wake output, the current approach provides a probability output, which may allow improved accuracy and performance testing of the model. The next steps will include inclusion of heart rate and testing generalizability using different accelerometers. The proposed approach will help clinicians and researchers assess sleep behaviour with greater accuracy.

Daria Tai 11:59 – 12:07 PM

Exercise Training Can Promote Sleep and Reduce Fatigue in Chronic Stroke: A Systematic Review

Introduction: Poor sleep is common in people with chronic stroke, contributing to post-stroke fatigue and impacting stroke outcome and risk of recurrent stroke. Based on limited published evidence in individuals without stroke, exercise training is a promising non-pharmacological strategy to promote sleep quality in adults with chronic stroke. Thus, we conducted a systematic review to assess the effects of exercise on sleep and fatigue among adults with chronic stroke. Methods: We examined peer-reviewed literature using the search engines: EMBASE, MEDLINE, AgeLine, the Cochrane Database of Systematic Reviews, CINAHL, as well as reference lists of relevant reviews for articles meeting the inclusion criteria. We extracted study characteristics (design, intervention, sample, and stroke characteristics) and outcome measures. We then assessed quality of reporting and risk of bias using the CONSORT criteria and Cochrane risk-of-bias tool, respectively. Search results were limited to adults ≥18 years, randomized controlled trials, quasi-experimental, and pre-post studies.Results: Four studies were included that examined the effects of exercise on sleep (n=2) and fatigue (n=2). Sleep was measured both objectively (n=1) and subjectively (n=2). All four studies reported positive effects of exercise on sleep and fatigue, suggesting exercise promotes and reduces fatigue in people with chronic stroke. Discussion: However, significant limitations included the lack of randomization and control groups, small sample sizes, and the lack of sample size justification; none of the studies were powered apriori for sleep as an outcome. Future rigorous randomized controlled trials are needed to assess the effect of exercise on sleep in adults with chronic stroke.

Rebecca Kenny 12:07 – 12:15 PM

Sleep disturbances after repetitive subconcussive impacts in female collegiate soccer athletes

Introduction: Sleep is an important factor that contributes to optimal athletic performance (1). Sleep disturbances often are common post-concussion (2).  There is little research investigating sleep disturbances after repetitive sub-concussive events. Soccer is a unique sport where players use their unprotected heads to manipulate the ball in both practice and game scenarios (3). The purpose of this study is to investigate the potential sleep disturbances after a season of repetitive subconcussive impacts in female collegiate soccer players. Methods: Ten female collegiate soccer players were recruited.  Two sleep questionnaires were administered pre- and post-season.  Video was collected throughout the season to quantify the number of head impacts and categorize players based on the number of headers. The sleep questionnaires included the Pittsburgh Sleep Quality Index (PSQI) and Sleep Condition Indicator (SCI) (4,5). Results: Video analysis revealed three threshold categories for head impacts experienced over the course of the 2019 soccer season. Players were divided into high, medium, and low heading groups based on the average number of headers experienced per on-field activity. Those in the high heading group reported, on average, worse sleep at the end of the season, reporting a 72% change in PSQI and a 25% change in SCI. Discussion: This is the first study to evaluate changes in sleep over the course of one season of soccer.  Our pilot data suggests that there is an association between number of headers and sleep quality and behaviour. Data collection and analysis is ongoing and further analyses will be conducted to better understand this relationship.

12:25 – 12:30 PM Closing Remarks
Break Out Room #2: Interventions
Name Time Title and Abstract
11:30 – 11:35 AM Opening Remarks
Munira Sultana 11:35 – 11:43 AM

Virtual Reality Exposure Therapy Reducing Responsive Behaviors in Nursing Home Residents with Dementia: A Case Series

OBJECTIVE: People with advanced dementia often exhibit responsive behaviors such as apathy, depression, agitation, aggression, sleep disorders, and psychosis causing physical and emotional harm to the individual and their caregivers. Non-pharmacological approaches are now a first-line strategy to manage responsive behaviours in clinical practice because of potential risks associated with the use of antipsychotic medications. The objective of this study is to evaluate whether virtual reality exposure therapy a feasible non-pharmacological approach to reduce responsive behaviors in nursing home residents with advanced dementia. METHODS: We conducted a single site case series with a convenience sample (N=24; age=85.8 ±8.6 years; Cognitive Performance Scale score=3.4 ± 0.6). Our intervention was 30 minutes of customized immersive three-dimensional virtual reality delivered using remote-controlled projectors for five days a week for two weeks. Primary outcome was feasibility and secondary outcome was change in responsive behaviours pre-and-post-intervention. RESULTS: The intervention was feasible with 0% attrition. The average length of each session was 22 minutes. Eighteen out of 24 of participants were able to complete 8/10 of the sessions. No related adverse events were registered. A clinically significant change in depression (ES= 0.4, p≤0.05) and in agitation (ES= 0.2, p<0.06) was observed with Cornell Scale for Depression in Dementia and Cohen-Mansfield Agitation Inventory. CONCLUSION: Virtual reality exposure therapy is a safe and feasible non-pharmacological approach. Our intervention is remote-controlled, does not need a headset, and is compatible with COVID-19 infection prevention policies; promising a novel approach to reduce responsive behaviors. A future RCT can confirm our results.

Sudeshna Chatterjee 11:43 – 11:51 AM

Retention of practice effects on a complex walking task is enhanced by a single session of prefrontal brain stimulation in older adults

Introduction: Older adults often have poor walking skills which may increase fall risk. Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulatory adjuvant shown to enhance motor skills through long-term potentiation-like plasticity. We tested the hypothesis that a single session of prefrontal tDCS during complex walking practice would facilitate greater locomotor learning and retention of practice-related gains in walking in older adults, compared to sham and no-tDCS conditions. Methods: Fifty older adults aged 65 to 92 years were randomized to receive either active (20 minutes at 2mA intensity), sham (30 seconds at 2mA) or no-tDCS. For the learning session, tDCS was administered bilaterally to the prefrontal cortex during ten trials of walking practice on a 10-meter complex obstacle course. Retention of walking gains was assessed one week later. Obstacle walking speeds were normalized as a percentage of the participants 10-meter fastest unobstructed walking speed Results: At the learning session, the active group significantly increased their obstacle walking speed from 37% to 44% of fastest unobstructed speed (p<0.01). Similarly, the learning effects were also significant for sham (35% to 50%) and no-tDCS (42% to 50%) groups. At the retention session, only the active group exhibited significant offline gains and continued improvement in obstacle walking speed (44% to 48%, p=0.004). Retention effects were not significant for sham (50% to 52%) and no-tDCS (50% to 48%) groups. Discussion: Prefrontal tDCS may facilitate the offline consolidation of practice effects to enhance the retention of walking gains between-sessions. Sham tDCS may have a placebo effect that enhanced within-session learning.

Deborah Jehu 11:51 AM – 11:59 PM

The effect of exercise on falls in older adults living with dementia: A systematic review

Introduction: Whether exercise reduces falls in people living with dementia (PWD) is not clear. We conducted a systematic review of randomized controlled trials (RCTs) examining the efficacy of exercise to reduce falls and injurious falls relative to usual care among PWD. Methods: We included peer-reviewed RCTs evaluating any mode of exercise on falls and injurious falls among PWD. We excluded studies if they did not solely involve PWD and if they were not the key publication of the RCT with falls as an outcome. We searched AgeLine (1978-Present), the ALOIS (i.e., Cochrane Dementia and Cognitive Improvement Group’s Specialized Register), and grey literature on August 19, 2020. We removed duplicates, and screened titles, abstracts, and full-texts. We evaluated the risk of bias using the Cochrane Risk of Bias Tool and study quality using the Consolidated Standards of Reporting Trials. Results: Ten studies were included (n=1713; age: 80.7±7.0 years; female: 58.1%; Mini-Mental State Examination: 19.8±4.2points; intervention duration: 27±17.8 weeks; adherence: 73.0±15.4%; attrition: 22.1±12.5%). Exercise reduced falls in 1/10 studies (incident rate ratio=0.44 [0.32,0.56]); all other studies reported null findings. No studies (0/4 studies) found an effect for injurious falls. All studies had risk of bias, notably: 1) they were not powered for falls (10 studies, 100%); 2) the assessors became unblinded (2 studies, 20%); and 3) they had short intervention durations (≤4 months; 5 studies, 50%). The quality of reporting was good (79.5±10.8%). Discussion: Exercise does not appear to prevent falls or injurious falls in PWD; higher quality research is needed.

Matthew Noseworthy 11:59 – 12:07 PM

Comparing the effects of outdoor versus indoor walking on cognitive and physical function in older adults with mild cognitive impairment

INTRODUCTION: Aerobic exercise (AE) is a promising strategy to mitigate cognitive and physical decline in older adults with mild cognitive impairment (MCI). Evidence suggests that outdoor, natural environments, as compared to indoor or built environments, may augment the health benefits of AE. However, the potential utility of green exercise among older adults requires further investigation. Objectives:• Primary: To compare the cognitive effects of 12 weeks of moderate-intensity outdoor forest walking (OUT) versus indoor treadmill walking (IN) among older adults with MCI. • Proof-of-Concept: To demonstrate recruitment rate, withdrawal rate, adherence, adverse events, and acceptability. METHODS: Study Design: A 12-week, single-blinded, 2-arm, proof-of-concept RCT: OUT and IN (1:1). Measurement will occur at baseline and at trial completion. Participants: 68 community-dwelling adults aged 65-80 years old with MCI. Interventional Arms: Both OUT and IN will involve three supervised, group-based training sessions per week for 12 weeks. Each session will comprise 10 min warm-up, 40 min moderate-intensity AE (progressing from 45% to 75% of heart rate reserve), and 10 min cool-down. AE will involve walking or jogging outdoors in an urban forest (OUT) or indoors on treadmills (IN). Outcomes: • Primary: Working memory (National Institutes of Health Toolbox (NIHTB) List Sorting Test; Verbal Digits Forward and Backward Test). • Secondary: Cognitive function (NIHTB; Digit Symbol Substitution Test); motor function (Short Physical Performance Battery; Timed Up and Go Test); affective outcomes (anxiety; depression; affective responses to exercise); blood pressure; physical activity level; sleep quality; and quality of life. DISCUSSION: We welcome suggestions for improving trial design.

Melissa Woodward 12:07 – 12:15 PM

Medial Temporal Lobe Cortical Changes In Response To Exercise Interventions In Women With Early Psychosis: A Randomized Controlled Trial

Objective: Exercise has been shown to induce changes in hippocampal volume in individuals with psychosis, but its ability to impact cortical regions remains equivocal. Psychosis patients are observed to have neuroanatomical deficits in the prefrontal-limbic network, associated with greater positive symptom severity and cognitive impairment. Despite the fact that women have greater potential to benefit from exercise interventions due to greater exercise-induced upregulation of brain growth factors, women with psychosis have been under-represented in exercise intervention studies. We hypothesized that women with early psychosis who complete an aerobic exercise intervention would demonstrate significant increases in prefrontal-limbic cortical regions and these neuroplastic changes would be associated with reduced symptom severity. Methods: In a cohort of 51 women with early psychosis from Hong Kong, we investigated the effects of a twelve-week exercise intervention (yoga, aerobic or waitlist group) on cortical grey matter. Clinical assessments and structural MRI were completed at the beginning and end of the intervention. Results: Increases in cortical volume and thickness were observed in the medial temporal cortical regions, primarily in the entorhinal and fusiform temporal gyrus for participants who completed the aerobic intervention. For the aerobic group only, increases in the entorhinal and fusiform temporal gyri were associated with decreasing psychosis symptom severity, particularly for the general psychopathology subscale. Conclusions: Neuroplastic increases in cortical grey matter were observed in women with early psychosis and these exercise-induced changes were associated with improvements in psychosis symptom severity. Psychosis patients may benefit from aerobic exercise interventions as a safe, adjunct treatment.

12:25 – 12:30 PM Closing Remarks
Break Out Room #3: Physical Activity and Exercise
Name Time Title and Abstract
11:30 – 11:35 AM Opening Remarks
Matthew Miller 11:35 – 11:43 AM

Physical activity in older adults who are cognitively impaired without dementia: what happens vs. what is possible

Introduction: Physical inactivity may increase risk of progression to dementia in people with cognitive impairment that is not severe enough to meet criteria for dementia (Cognitive Impairment, No Dementia: CIND), but little is known about the factors associated with physical inactivity in this group. Methods: We studied 1875 community dwelling adults (over age 65) with CIND in the Health and Retirement Study. Unadjusted and adjusted associations of physical inactivity (moderate vigorous physical activity [MVPA] ≤1x/week) with sociodemographic, health, and physical function variables were assessed using chi-square and modified Poisson regression adjusted for age, sex, and race/ethnicity. In participants who were physically inactive, we also determined whether they were capable of greater MVPA. Results: Mean participant age was 77 and 58% were women. The prevalence of physical inactivity was 56%. The largest adjusted risk ratios (aRR [95% CI]) for physical inactivity were self-rated health as poor (77%; aRR: 2.28[1.58–3.30]) and fair (63%; aRR: 1.88[1.29-2.74]) versus excellent (34%), and difficulty walking across the room (87%; aRR: 2.10[1.88–2.34]) and one block (79%; aRR: 1.91[1.68-2.18]) versus no difficulty (41%). Physical inactivity was also associated with older age, women, lower total assets, lower education, specific health conditions, depression, higher BMI, current smoking, not drinking alcohol, and significant pain. Sixty-one percent of physically inactive participants were capable of greater MVPA. Discussion: More than half of older adults with CIND are physically inactive, yet most are capable of greater MVPA. Study findings suggest a need for physical activity interventions for older adults with CIND.

Benjamin Tari 11:43 – 11:51 AM

An investigation of the relationship between hemodynamics and executive function across a continuum of exercise intensities

Executive functions are high-level cognitive processes that encompass response inhibition, task-updating and set-shifting. Importantly, a single bout of aerobic exercise has been shown to provide a transient executive benefit related to an increase in cerebral blood flow (CBF). However, whether increases in CBF are responsible for an executive improvement across a continuum of intensities is unknown. Here, participants completed four experimental sessions: a V̇O2peak test to determine cardiorespiratory fitness and lactate threshold (LT); and separate 10-min sessions of light- (i.e., 25 W), moderate- (i.e., 80% estimated LT), and heavy- (i.e., 15% of the difference between LT and V̇O2peak) intensity exercise. An estimate of CBF was achieved via transcranial Doppler ultrasound and near-infrared spectroscopy that monitored blood velocity (BV) and deoxygenated hemoglobin (HHb), respectively. Executive function was assessed before and after each session via the antisaccade task. Antisaccades are goal-directed eye-movements mirror-symmetrical to a presented target, and are mediated via executive networks that demonstrate task-dependent modulation following acute and chronic aerobic exercise. Prosaccades (i.e., non-executive saccade to veridical target location) were also included to determine whether exercise-induced increases in CBF were specific to executive-related oculomotor control. Results showed that BV increased according to exercise intensity, whereas HHb decreased by a comparable magnitude across conditions. In terms of oculomotor performance, postexercise antisaccade, but not prosaccade reaction times were reliably shortened by a similar magnitude across the continuum of intensities used here. Accordingly, our results indicate the presence of a threshold after which increased CBF becomes superfluous to a postexercise executive benefit.

Guilherme Balbim 11:51 AM – 11:59 PM

Association of Physical Activity Levels and Brain White Matter in Older Latino Adults

Background: Healthy brain white matter (WM) is pivotal to cognitive health in older adults. Greater levels of physical activity (PA) is associated with healthier WM. However, older Latinos engage in less PA than non-Latino whites.  Objective: Investigate the associations between self-reported PA and WM health (i.e., volume, integrity, and hyperintensities) in older Latinos. Methods: Participants were 34 cognitively healthy older Latinos from two cohorts who self-reported demographic information and PA levels (CHAMPS), and performed MRI. High-resolution three-dimensional T1- and T2-FLAIR weighted images and diffusion tensor imaging were acquired. We performed separate hierarchical linear regression models with the addition of relevant covariates. P-values were adjusted with Benjamini-Hochberg's false discovery rate procedure. Results: Controlling for intracranial volume, higher levels of leisure-time moderate-to-vigorous PA were associated with higher WM volume of the posterior cingulate (β = 0.220, SE = 0.125, 95% CI 0.009-0.431, p = 0.047) and isthmus cingulate (β = 0.212, SE = 0.110, 95% CI 0.001-0.443, p = 0.044). Higher levels of total PA were associated with higher overall WM volume of the posterior cingulate (β = 0.220, SE = 0.125, CI 0.024-0.421, p = 0.046) and isthmus cingulate (β = 0.220, SE = 0.125, 95% CI 0.003-0.393; p = 0.040). Significant p-values did not withstand adjustments. PA was not associated with WM integrity or hyperintensities. Conclusion: In older Latinos, higher levels of PA might be associated with greater WM volume in select regions key to brain network integration of physical and cognitive functioning. Further studies are needed to confirm associations.

Rachel Crockett 11:59 AM – 12:07 PM

Sweat the Fall Stuff: Physical Activity Moderates the Association of White Matter Hyperintensities with Falls Risk in Older Adults

Background: Falls in older adults are a major public health problem. White matter hyperintensities (WMHs) are highly prevalent in older adults and are a risk factor for falls. Physical activity (PA) is a promising countermeasure to reduce both WMHs and falls risk. However, no study has yet investigated whether PA attenuates the association of WMHs with falls risk. We hypothesised that PA moderates the association between WMHs and falls risk. Methods: Seventy-six older adults (70-80 years old) were included in this cross-sectional study. We indexed PA using the Physical Activity Score for the Elderly (PASE) Questionnaire. Falls risk was assessed using the Physiological Profile Assessment (PPA), and WMH volume (mm3) was determined from T2-weighted and PD-weighted MRI scans. We examined the independent associations of WMH volume and PASE score with PPA. Subsequently, we examined whether PASE moderated the relationship between WMH volume and PPA. We plotted simple slopes to interpret the interaction effects. Age, sex, and Montreal Cognitive Assessment (MoCA) score were included as covariates in all models. Results: Both PASE (β= -0.26 ± 0.11; p= 0.022) and WMH volume (β= 0.23 ± 0.11; p= 0.043) were each independently associated with PPA score. The interaction model indicated that PASE score moderated the association between WMH volume and PPA (β= -0.27 ± 0.12; p= 0.030), whereby higher PASE score attenuated the association between WMHs and falls risk. Conclusion: PA is an important moderator of falls risk. Importantly, older adults with WMH can reduce their risk of falls by increasing their PA.

Maryam Marashi 12:07 – 12:15 PM

Exploring the relationship between estimated cardiorespiratory fitness and mental health in thesis-based graduate students impacted by COVID-19

The COVID-19 lockdown has significantly impacted graduate student’s mental health. Physical activity is a promising strategy to mitigate the effects of COVID-19 on mental health by increasing cardiorespiratory fitness (CRF), a physiological adaptation to routine physical activity. Heart rate variability (HRV) is the beat-to-beat variability of the heart measured over a wide range and has been established as an index of favorable neurovisceral integration in response to environmental stress. CRF is positively linked with favorable resting HRV and HRV recovery following environmental stress. It is possible then that HRV might partially mediate the relationship between CRF and mental health. The present study will examine the relationship between mental health, CRF, and HRV in graduate students experiencing academic set backs due to the COVID-19 lockdowns. Using a cross-sectional approach, graduate students with varying fitness levels (as determined by the 6-minute walk test) will report on various aspects of their mental health (anxiety, depression, and COVID-related stress). Resting HRV will be captured using a validated smartphone app. We predict that higher CRF will correlate with better mental health, and that higher resting HRV will account for significant variance between the two. Results from this study will provide insight into the relationship between physical activity and mental health to help graduate students better cope with the stress of the pandemic.

Adam Vert 12:15 – 12:23 PM

A novel non-wear algorithm using to improve accuracy of activity estimates from accelerometry

Introduction: Accelerometry is commonly used to quantify physical activity and sedentary behaviour. Accurate detection of sensor removal is important to ensure non-wear periods are not misrepresented as sedentary behaviour or sleep. Current non-wear algorithms assess parameters including bout duration and temperature that lead to undetected non-wear periods and overestimated sedentary time. This work aimed to improve the accuracy of existing non-wear algorithms. Methods Data were collected from 39 participants through the Ontario Neurodegenerative Disease Research Initiative who wore a wrist biosensor continuously for 7-days as part of a multi-sensor collection. Absolute and rate-of-change of near-body temperature, and standard deviation of the acceleration signal were used to train a decision tree classifier (depth 3, cross-validation 10) on 10 participants to detect non-wear start and stop times (5-minute minimum duration). Algorithm performance was compared to two commonly reported algorithms (1, 2) on the remaining data (n = 29) using a ‘gold standard’ visually-inspected dataset. The algorithm was evaluated using precision, recall, accuracy and F1-score. Results: The current algorithm exceeded performance metrics of both comparator algorithms: Precision Recall F1-score  Accuracy Current 0.77 0.92 0.84 0.99 Zhou (1) 0.52 0.83 0.64 0.97 Van Hees (2) 0.58 0.61 0.59 0.97 Discussion: The addition of a temperature rate-of-change threshold and focus on start and stop times improved non-wear detection. Performance outcomes existed for 5–minute minimum bout durations, which also has important implications for accurately detecting real-life non-wear events and improving activity estimates.

Jasmyn Skinner 12:23 – 12:30 PM

Individual differences in lifestyle factors and the effects of an acute exercise intervention on executive functioning in children and youth with ADHD

Attention-Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder among children and youth. Individuals with ADHD typically experience executive functioning deficits that negatively impact their working memory, inhibitory control, and task-switching. Exercise interventions have been identified as a potential supplemental treatment to help ameliorate ADHD symptomology. Research has demonstrated that exercise interventions can enhance executive functioning among children and youth with ADHD. However, little to no research has investigated how individual differences in lifestyle factors may impact a child's reactivity to acute exercise interventions. The current study focused on the role of three individual difference factors (medication status, physical fitness level, physical activity behaviours), and how they impact the relationship between acute exercise and executive functioning in children and youth with ADHD. Participants diagnosed with ADHD between the ages of 10-14 engaged in two sessions, an exercise session and a control session. During the exercise condition, participants completed a 10-minute bout of moderate-intensity stationary biking in addition to a pre-post battery of executive functioning assessments. The control condition consisted of 10-minutes of silent reading. Following a 10-minute bout of exercise, we found that regardless of medication status, physical fitness level, or physical activity behaviours, all individuals performed similarly well on each measure of executive functioning. Despite similar performance across groups, the pattern of data suggests that physical fitness level may impact the relationship between acute exercise and executive functioning among children and youth with ADHD. However, further research with a greater sample size is needed to fully unravel this issue.

12:25 – 12:30 PM Closing Remarks

First Nations land acknowledegement

The UBC Point Grey campus is situated on the traditional, ancestral, and unceded territory of the xʷməθkʷəy̓əm.

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