Browsing by Author "Stephens, Jaclyn, committee member"
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Item Open Access A smart-device based motor function battery(Colorado State University. Libraries, 2018) Monaghan, Patrick G., author; Tracy, Brian L., advisor; Fling, Brett W., committee member; Stephens, Jaclyn, committee memberGrowth in the older population will increase the overall impact of age-related neurological disorders. Aging and neurological conditions share features such as impaired motor function and physical dysfunction including reduced muscle strength and power, slowness of movement, increased movement variability and balance dysfunction. Successful performance of daily activities and maintenance of mobility is key to independence and quality of life. Therefore, tracking changes in physical function is critical in gauging quality of life. However truly quantitative measures of physical capacity often require the use of expensive, lab-based equipment. Smart devices contain sensitive tri-axial accelerometers and gyroscopes that measure acceleration and rotation and offer a more cost-effective, portable yet still quantitative means of physical assessment. The purpose is to describe an iPod Touch-instrumented test battery designed to assess features of physical and motor function often shared by normal aging and age-related movement disorders. We have been assessing the correlation between measures taken from expensive lab devices and the iPod Touch smart device for a variety of movements. We developed and tested a multi-item smart device-based battery of motor tasks that addresses motor variability, slowness and postural instability across a range of young, healthy college students. By changing the location of the device we can assess upper and lower limb movement speed and power, hand tremor, or postural control. We have also used previously validated lab devices concurrently with the smart device, which allows us to correlate the results between devices to assess the extent of the association between devices. Outcomes such as peak acceleration and variability of movements can be obtained. Generally, the smart device demonstrated strong correlations with the lab grade sensors for all motor tasks. Furthermore, the smart device was also correlated with the accelerometer across a large range of speed and variability. Strong correlations were seen in ballistic arm and leg tasks, tremor, and postural control assessments. This finding suggests that the smart device can sufficiently assess a broad range of functional capacity. This battery can then be used to study populations exhibiting motor impairment, ranging from older adults, to neurological patients. Using the sensors on the smart device, this testing can be administered remotely and inexpensively by non-experts, providing cost-effective, mobile, user- and patient-friendly physical function testing. More importantly, accessibility of testing is increased while retaining quantitative precision. This should aid in quantifying disease progression and response to pharmacological or exercise/rehabilitative intervention, with the goal of improved function and quality of life in those with impairment.Item Open Access Assessing the impact of a music therapy program on attention in children with autism using behavioral and neurophysiological measures(Colorado State University. Libraries, 2021) Coates, Carolyn, author; Davies, Patricia L., advisor; Merz, Emily, committee member; Stephens, Jaclyn, committee member; LaGasse, Blythe, committee memberChildren with Autism Spectrum Disorders (ASD) are known to have difficulty with auditory sensory processing. Music therapy is a common intervention approach for children with autism to address numerous behavioral and sensory challenges using auditory stimuli. Auditory processing capabilities have also been linked with attention skills and with attentional challenges often observed in children with ASD. This study seeks to understand the differences between children with ASD and their typically developing peers in auditory processing and attention. An additional study goal is to evaluate impacts of a music therapy protocol on those constructs. Baseline measurements were collected for 10 children with ASD using the Test of Everyday Attention in Children (TEA-Ch) and EEG under a sensory registration paradigm. These data were compared to those of age- and sex-matched typically developing peers (n = 10). The children with ASD participated in biweekly music therapy over 5 weeks for a total of 10 sessions and then completed the same assessments during a post-test. The sensory registration paradigm measured passive responses to four auditory tones at two different intensities (50 and 70 dB) and two different frequencies (1 and 3 kHz). The resultant event related potentials (ERPs) were averaged into a waveform for each child at each tone and amplitudes and latencies were calculated for N1, P2, N2 and P3 components. The TEA-Ch resulted in an overall attention score and a score for each of three subdomains of attention: sustained, selective and switching. Results indicated that children with ASD performed more poorly on the TEA-Ch with significantly poorer scores in overall attention, selective attention, and sustained attention. A series of independent sample t-tests on ERP components revealed few significant differences but a trend of increased latency at N1, P2, and N2 in children with ASD for each of the four tones. Children with ASD had lower amplitude of N1 components and greater amplitude P2 components compared with the typically developing children. Following the music therapy intervention, children with ASD improved significantly in selective attention and showed a trend of improvement in switching and total attention compared to pre-testing scores. The music therapy did not result in statistically significant changes in EEG results, but a trend of increased latency was noted for N1, P2, and N2. Amplitude of the P3 component decreased following the music therapy intervention in response to the high and loud tone when age was used as a covariate. Some significant associations were found between the latency of N1, P2, and N2 and sustained and selective attention in response to the 1kHz 70dB tone across all participants at baseline (TD children and children with ASD before music therapy). In conclusion, this study shows that children with ASD have different neural processing of simple auditory tones and reduced performance in multiple domains of attention. The music therapy intervention is a promising approach to improving attention skills. The intervention did not appear to alter neural processing in the expected way of children with ASD performing more like their typically developing peers. Further research at this foundational level of neural processing may help clarify the differences in processing between children with ASD and their typically developing peers and may provide a way of monitoring interventions which seek to alter neural processing to target attentional skills and behaviors.Item Open Access Assessing usability of full-body immersion in an interactive virtual reality environment(Colorado State University. Libraries, 2020) Raikwar, Aditya R., author; Ortega, Francisco R., advisor; Beveridge, Ross, committee member; Stephens, Jaclyn, committee member; Smith, Charles, committee memberImproving immersion and playability has a direct impact on the effectiveness of certain Virtual Reality applications. This project looks at understanding how to develop an immersive soccer application with the intention to measure skills, particularly for the use of assessment and health promotion. This project will show the requirements to create a top-down immersive experience with commodity devices. The particular system serves the simulation of a soccer training environment to evade opponents, pass to teammates, and score goals with the objective of measuring the difficulty of single, double, and triple tasks. It is expected that the performance will go down as the level of tasks increases. This hypothesis is extremely relevant as it provides a system that could serve as an assessment tool for people with concussions to return to play (with an OK by a physician) or to promote exercise to non-athletes. This thesis provides all the necessary steps to explain the high-level details of highly immersive applications while providing a future-path for human-subject experiments.Item Open Access Evaluating central mechanisms for age-related force control deficits of the legs(Colorado State University. Libraries, 2019) Hanson, Moriah R., author; Fling, Brett W., advisor; Broussard, Josiane, committee member; Stephens, Jaclyn, committee memberAdvancing age is accompanied by several motor control impairments, including increased movement and force variability. Specifically, older adults display more variable and less accurate submaximal forces than young adults, which have been associated with fall risk in the aged population. These motor control changes take place in muscles in both the upper and lower limbs, and the mechanisms of these alterations are multifactorial, including sources in the peripheral and central nervous systems. Furthermore, inhibitory signaling in the motor cortex is related to force variability in small hand muscles, as well as to coordination of the legs during walking. It is unknown, however, whether inhibition is associated with force variability in the legs. Therefore, the purpose of this study was to assess the relationship between motor cortex inhibition and force variability in the quadriceps muscles of young and old adults. We measured quadriceps force variability and accuracy during a 2-minute force matching task and inhibition via the cortical silent period in 14 young and 15 old adults. Older adults produced more variable and less accurate forces than the young adults, though these differences were not significant. Additionally, older adults displayed less inhibition in their right cortical hemisphere than young adults, as well as interhemispheric inhibitory differences. Specifically, the left hemisphere displayed more inhibition than the right hemisphere in old adults. Furthermore, young adults with more inhibition generally produced more variable and less accurate forces than young adults with less inhibition, while older adults with more inhibition displayed less variable and more accurate forces. The between- and within-group differences in inhibition may point to age-related decline in right hemispheric function. Moreover, between-group differences in inhibition and force variability associations indicate a shift in the inhibitory control of movement, which is a similar finding to previous work on inhibition and lower limb coordination.Item Open Access Examining sensory gating and processing speed in adults with autism using EEG(Colorado State University. Libraries, 2018) Jacoby, Erica C., author; Davies, Patricia, advisor; Stephens, Jaclyn, committee member; LaGasse, Blythe, committee memberObjectives. Most individuals with Autism Spectrum Disorder (ASD) experience sensory deficits in their auditory processing (Tomchek & Dunn, 2007). These deficits can further impact their ability to participate in their physical and social environments. One way to increase understanding of these deficits is through use of electroencephalography (EEG), which measures brain activity in real-time and is able to distinguish brain processes such as sensory processing and the deficits that might be occurring during this process (Davies & Gavin, 2007). This study's purpose is to understand how processing speed and ability to filter out irrelevant stimuli impacts adults with ASD compared to their neurotypical (NT) peers through measurements of latency of prominent brain activity following presentation of an auditory stimulus and sensory gating. This study also analyzed how active and passive attention states impact sensory gating and latency. Methods. 24 adults with autism (M = 23.3 years, SD = 3.8) and 24 neurotypical adults (M = 23.7 years, SD = 3.5) participated in this study. They completed a sensory gating paradigm in both an active and a passive listening condition. In the active condition they were asked to press a button when they heard a single click, and in the passive condition they simply stared at a static image on a screen while the auditory stimuli were presented to them. Results. The results showed that there are no significantly different sensory gating responses between the ASD and NT groups. Individuals with ASD had delayed processing speed as measured through latency as early as 100 milliseconds following an auditory stimulus. Both groups experienced slower processing in the passive condition starting at approximately 200 milliseconds post-stimulus onset. As expected, more gating was observed for both groups in the passive condition at early components, where-as the active condition - which required attention to the stimulus that is usually suppressed in this task - resulted in less gating. In the latest component analyzed, approximately 200 milliseconds post-stimulus, both groups showed more gating in the active attention state, which was the opposite of the expected results, and the possible reason for this unexpected result needs further exploration. Conclusions. These findings suggest that individuals with autism do not have deficits in the ability to filter out irrelevant stimuli, however, they are likely more impacted by delayed processing speeds. Implications for practice include allowing more time to process auditory information for individuals with autism, and using compensatory strategies to influence neural processing speeds and amount of gating in response to auditory stimuli through the use of activity demands to create either passive or active attention states.Item Open Access Measuring executive function after yoga for adults with acquired brain injury: a pilot study(Colorado State University. Libraries, 2022) Grieb, Emily, author; Schmid, Arlene, advisor; Stephens, Jaclyn, committee member; Riggs, Nathaniel, committee memberBackground: Acquired brain injury (ABI) may result in cognitive impairments, particularly deficits in executive function (EF), which may impact engagement in everyday activities. Yoga has been shown to improve various health outcomes for individuals with ABI. This study aims to explore the impact of group yoga on EF for individuals with ABI. Methods and Materials: This was a single-arm pilot study that involved eight weeks of therapeutic group yoga led by a registered yoga teacher. Nine participants attended hour-long, in-person yoga classes once a week. Sessions included seated, standing, and floor postures combined with breathwork and meditation. EF was assessed pre- and post-intervention using the Behavior Rating Inventory of Executive Function for Adults (BRIEF-A) self-report form. Results: The behavioral regulation index improved significantly pre to post yoga. No significant improvements were found on the EF scales, metacognition index, or global executive composite. However, measurable improvements (>5%) were found in the following EF scales: Emotional Control, Plan/Organize, and Organization of Materials. Conclusion: Group-based yoga may improve behavioral regulation for adults with chronic ABI, however further research is needed.Item Embargo Neuromuscular electrical stimulation: getting amped up to prevent exercise resistance(Colorado State University. Libraries, 2024) Bomar, Matthew Charles, author; Bell, Christopher, advisor; Perry, Richard, committee member; Stephens, Jaclyn, committee memberPurpose: Exercise resistance (ER) is characterized by the absence of exercise induced improvements in fat metabolism following a meal. The prolonged sedentary behavior between successive workouts is what contributes to this lack of health improvements typically associated with exercise. The suggested energy expenditure (EE) threshold for avoiding ER is the equivalent of walking ~8,500 steps/day. Population data indicate that the typical adult walks 5,000 steps/day. Neuromuscular Electrical Stimulation (NMES) evokes skeletal muscle contractions and increases EE. This study aims to determine the feasibility of using NMES to increase total daily EE by the equivalent of 3,500 steps, thereby meeting the theoretical threshold sufficient to prevent ER. Methods: Fourteen recreationally active males and females (7/7) underwent measures of resting EE, with and without NMES, and EE while walking 8,500 steps on a treadmill. The duration of NMES sufficient to increase EE to match 3,500 steps was calculated, and then verified with measures of EE while walking 5,000 steps after a bout of NMES. Results: Bland–Altman statistics of agreement were used to assess concordance between the EE associated with walking 8,500 steps (286 ± 64 kcal; mean ± SD), and the EE associated with walking 5,000 steps after NMES (293 ± 65 kcal). The mean difference between the EE values was 7 kcal, and the 95% limits of agreement were -39 to 53 kcal. Implications: These preliminary data suggest NMES can be used to increase total daily EE by the equivalent of 3,500 steps, thereby meeting the theoretical threshold to prevent ER.Item Open Access Parents' tolerance of risk in play and parents' country of birth predict children's abilities to assess risk: a pilot study with implications for occupational therapists(Colorado State University. Libraries, 2019) VanSkiver, Alison K., author; Bundy, Anita, advisor; Stephens, Jaclyn, committee member; Gloeckner, Gene, committee memberImportance: Many parents do not allow their children to engage in risky play despite its many benefits on health and development. Objective: We investigated to what extent parents' tolerance of risky play predicts children's abilities to assess risk in a virtual street-crossing task. Other factors that were examined include age, sex, motor coordination, mothers' education level, and parents' country of birth. Design: Correlational, cross-sectional pilot study. Participants: Nineteen children (11 boys, 8 girls; M age = 8 years) and their parents (9 immigrant; 10 native to U.S. or Canada). Outcome and Measures: Tolerance of Risk in Play Scale (TRiPS); Motor Assessment Battery for Children (MABC-2); and virtual street-crossing task where we evaluated frequency of hits and close calls from virtual cars. Results: Parents' tolerance of risky play significantly predicted hits and close calls on the virtual street-crossing task (R2=.29, F(1,16)=6.52, p<.05). When all variables were forced into the regression analysis, parents' country of birth was the only significant predictor of hits and close calls (R2=.304, F(1,16)=6.99, p<.05). There was a strong correlation between parents' tolerance of risky play and parents' country of birth (r=.704, p<.01). Conclusions and Relevance: There was a co-occurrence for both parents' tolerance of risky play and country of birth as significant predictors of hits and close calls. This suggests that children whose parents have a higher tolerance for risky play are more likely to demonstrate safe pedestrian behavior. Additionally, children whose parents are immigrants, especially from Mexico, may be less likely to tolerate risky play, which may have a negative effect on children's abilities to cross the road safely. What This Article Adds: Occupational therapists can use these findings to encourage risky play opportunities through parent education to enhance children's abilities to assess risk and reduce chance of pedestrian injuries.Item Open Access Sensation seeking, impulsivity, and Big Five personality factors as predictors of risky behavior following concussion(Colorado State University. Libraries, 2020) Gardner, Megan M., author; Conner, Bradley T., advisor; Seger, Carol, committee member; Stephens, Jaclyn, committee memberSports-related concussion is a growing public health concern. With 30-50% of concussions remaining undiagnosed for a variety of reasons, it is crucial to identify risk factors and establish appropriate prevention and harm reduction strategies to prevent the risk of multiple concussions. Few studies have investigated personality factors as predictors of concussion and continued participation following an initial injury. However, research has concluded that personality likely plays a role in symptom reporting and post-injury behaviors that may put one at risk of additional injury and premature return to play. Most research on personality and health risk behaviors has focused on substance use, gambling, and criminal behavior, with little research done on personality, risky sports, and injury. The limited work in this area has concluded that the personality construct of sensation seeking is predictive of engagement in sports that have an increased risk for injury, while other constructs like impulsivity, are more predictive of injury once already participating in risky sports. The Big Five factors of personality differentially predict injury during sport such that openness to experience and extraversion predict risk-taking overall, while low levels of neuroticism and low levels of conscientiousness predict risky behavior during sport to different degrees depending on the sport studied. The current study found that sensation seeking dimensions, experience seeking and risk seeking, were positively associated with returning to play more quickly than others in the sample. Further, both of these dimensions were negatively predictive of use of protective behavioral strategies against incurring sports-related concussion. Risk seeking, attentional impulsivity, motor impulsivity, and non-planning impulsivity were found to be positively predictive of likelihood of reporting repeat sports-related concussions. Regarding the Big Five, conscientiousness was associated with taking longer to return to play, more protective behavioral strategy use, and a lower likelihood of reporting more than 1 sports-related concussion. These findings may be used in implementing individualized targeted prevention and intervention efforts for athletes. Future work should investigate the mechanisms underlying these relations, as well as include additional sports-related concussion risk factors.Item Open Access The effects of footwear cushioning on walking performance in females with multiple sclerosis(Colorado State University. Libraries, 2018) Monaghan, Andrew S., author; Fling, Brett W., advisor; Li, Kaigang, committee member; Stephens, Jaclyn, committee memberMultiple sclerosis is a chronic and progressive neurodegenerative disease which incurs a multitude of walking impairments. Protective strategies targeted at maintaining postural stability during walking include increasing stance and double support time with reciprocal decreases in swing and single support time, however these adaptions inadvertently increase fall risk. The midsole construct of footwear has demonstrated the ability to mediate these deficits in running but has not been explored in a neurologic population with known fall risk. The purpose of this study was to investigate the effects of two different midsole conditions on the spatiotemporal parameters of gait in females with multiple sclerosis (MS). Gait testing was conducted while 18 females with MS performed two-minute walk tests in 1) a high-cushion and 2) a standard-cushion midsole shoe. Spatiotemporal gait parameters were assessed using wireless inertial sensors. Participants spent less time in double support and stance phase with concomitantly more time in single support and swing phase in the high-cushion midsole shoe as compared to the standard-cushion. The high-cushion shoe may decrease fall risk by improving gait parameters associated with increased risk of falls.Item Open Access The impact of time-restricted eating on circulating factors, insulin sensitivity and circadian rhythms(Colorado State University. Libraries, 2020) Kennedy, Devin, author; Broussard, Josiane, advisor; Braun, Barry, committee member; Stephens, Jaclyn, committee memberPurpose: Obesity has been steadily increasing over several decades. In 2008, prevalence rates of obesity were reported at over 300 million people, defined as a body mass index of >30kg/m2. For years, scientists have tried to find "solutions" to obesity. While obesity prevention measures taken in childhood might result in decreased adulthood obesity, childhood prevention measures are not common, and obesity is often a health issue in adulthood. Negative energy balance and caloric restriction is most effective for reducing body weight, and studies have reported beneficial effects such as reduced fasting glucose and insulin, reductions in body weight [1], significantly higher insulin sensitivity, significantly lower BMI [2], reduced β-cell sensitivity [3], and reduced fasting glycemia and fasting insulinemia [4]; however, long-term adherence to caloric restriction is low. Certain fasting practices are emerging as promising possible solutions to help combat obesity. Fasting practices have resulted in improvements in cardiometabolic health including but not limited to protection from obesity [5], improved LDL and HDL cholesterol, reduced HbA1c and c-reactive proteins, [6], cell proliferation, and body weight [7]. Intermittent fasting is one method by which an individual can reduce body weight but also improve numerous cardiometabolic factors. However, research exploring intermittent fasting (IF), specifically time-restricted eating (TRE), as a method of improving cardiometabolic health is limited. Circadian rhythms might be the reason that aligning feeding windows to earlier in the day is showing these benefits. Currently, a gap in the knowledge exists as to whether circadian rhythms play a role in contributing to the metabolic benefits that are conferred by TRE, or if the timing of the food intake/duration is what results in the benefits. Therefore, our objective was to examine the effects of TRE on 24-hour glucose homeostasis and nighttime patterns of circulating factors (glucose, insulin, free fatty acids, triglycerides, and glycerol) as well as insulin sensitivity and the central circadian clock. Methods and results: This study employed a consecutive design. Eight healthy adults (6F; 27±4 y; 22.6±2.1 kg/m2; mean ± SD) completed a 2-week protocol. During Week 1 participants were instructed to consume their daily calories over a 13h period (control condition). In Week 2, participants were instructed to consume their daily calories over an 8h period (TRE condition). Specified mealtimes were pre-determined based on the habitual sleep and wake time for each individual participant. At the end of each week, participants were admitted to the Sleep and Metabolism Laboratory for an overnight stay that involved hourly blood samples. Plasma samples were analyzed for glucose, insulin, free fatty acids (FFA), lactate, triglycerides, and glycerol. The plasma analyses indicated that TRE decreased glucose variability during sleep (p=0.03), reduced nighttime insulin concentrations (p=0.005), increased nighttime FFA levels (p=0.04), increased nighttime triglycerides (p=0.006) and increased nighttime glycerol (p=0.02). TRE did not impact glucose variability during wakefulness (p = 0.49), nighttime glucose (p = 0.39), insulin sensitivity (MATSUDA-ISI, p = 0.38), or central circadian rhythms. Conclusion: The observed changes in nighttime glucose variability and insulin levels could represent mechanisms by which TRE can improve metabolic homeostasis in healthy lean individuals. Future studies are warranted to determine whether TRE can improve metabolic homeostasis in people at risk for diabetes such as people with overweight and obesity, and impaired glucose tolerance.Item Open Access Validating a points-based effort expenditure for rewards task(Colorado State University. Libraries, 2024) Sturm, Emily T., author; Thomas, Michael L., advisor; Seger, Carol, committee member; Stephens, Jaclyn, committee member; Tompkins, Sara Anne, committee memberInvalid performance on neurocognitive tests due to lack of effort expenditure is a concern for researchers and clinicians. Performance validity tests determine when adequate effort has been expended, but they fail to differentiate between subcomponents of effort that may be responsible for poor performance. The Effort Expenditure for Reward Task (EEfRT) is a task that provides separate measurements of reward processing and valuation constructs which could be informative as performance validity indicators. However, previous versions of the EEfRT use monetary performance-based rewards to investigate the expected value of effort, which can be problematic due to the influence of socio-economic factors and potential to systematically disadvantage participants with neurocognitive disorders. This study first aimed to examine the construct validity, specifically, the construct representation of a points-based version of the EEfRT online and in-person. The second aim of this study, which is exploratory, is to characterize patterns in embedded performance validity test performance obtained for separate neurocognitive measures as well as the EEfRT, thereby informing nomothetic span, or patterns of significant relations across measures of effort. This aim assessed whether the scores from the EEfRT indicate performance validity in other domains. Online participants (n = 342) from Prolific.com for the online sample and in-person participants (n = 27) were recruited via advertisements. Participants completed a battery including the EEfRT along with three working memory tasks, two executive functioning tasks, and one reward learning task. Results of regression analyses showed that, as hypothesized, both online and in-person participants chose hard tasks significantly more often at higher reward levels and at higher probability levels. However, contrary to expectations, a significant interaction between reward and group showed that points were more motivating in the online setting compared to in-person. Exploratory latent profile analysis revealed no clear pattern in embedded performance validity tests within the EEfRT or across other tasks. The results of this study suggest that a points-based version of the EEfRT is potentially valid for measuring effort-based decision making, but more research is needed before it can be called an objective measure of effort in the context of validating performance on cognitive tests.