Ashley E. Shortz

Standing Up for Learning: A Pilot Investigation on the Neurocognitive Benefits of Stand-Biased School Desks

Standing desks have proven to be effective and viable solutions to combat sedentary behavior among children during the school day in studies around the world. However, little is known regarding the potential of such interventions on cognitive outcomes in children over time. The purpose of this pilot study was to determine the neurocognitive benefits, i.e., improvements in executive functioning and working memory, of stand-biased desks and explore any associated changes in frontal brain function. 34 freshman high school students were recruited for neurocognitive testing at two time points during the school year: (1) in the fall semester and (2) in the spring semester (after 27.57 (1.63) weeks of continued exposure). Executive function and working memory was evaluated using a computerized neurocognitive test battery, and brain activation patterns of the prefrontal cortex were obtained using functional near infrared spectroscopy. Continued utilization of the stand-biased desks was associated with significant improvements in executive function and working memory capabilities. Changes in corresponding brain activation patterns were also observed. These findings provide the first preliminary evidence on the neurocognitive benefits of standing desks, which to date have focused largely on energy expenditure. Findings obtained here can drive future research with larger samples and multiple schools, with comparison groups that may in turn implicate the importance of stand-biased desks, as simple environmental changes in classrooms, on enhancing children’s cognitive functioning that drive their cognitive development and impact educational outcomes.

Cognitive challenges, aging, and neuromuscular fatigue

Cognitive challenges, such as concurrent cognitive demands or prior cognitive fatigue, have shown to adversely impact neuromuscular fatigue, specifically in younger adults. Whether these relationships are similar for the aging population remains unclear. The aim of this study was to investigate the effects of different cognitive challenges on handgrip fatigue with aging. Ten younger (24.10 (1.79) years) and ten older (75.90 (7.80) years) females attended three experimental conditions (control, i.e., exercise only, cognitive fatigue prior to exercise, and concurrent mental arithmetic during exercise) on different days. The exercise required them to grip intermittently at 30% maximum handgrip strength until voluntary exhaustion. Endurance time, strength loss, force steadiness, muscle activity, cardiovascular responses, perceptions of cognitive fatigue, mental demand, and discomfort were obtained. While endurance time was similar across age groups and conditions, older adults demonstrated ~35% reduced endurance than younger adults (46.96 (13.08) min.), but this was observed only in the concurrent cognitive demand condition. This was also accompanied with a decrease in force steadiness. No endurance differences between age groups were found during the control and cognitive fatigue condition. The findings indicate that the relationship between cognitive challenges and neuromuscular fatigue depends on age, the type of cognitive challenge imposed, and the type of exercise performed.

Evaluation of Offshore Shiftwork using Heart Rate Variability

The high fatality rate in oil and gas extraction (OGE) is a growing concern within the industry. OGE workers are exposed to long work hours, intense mental and physical workload, coupled with changing shift patterns, which can lead to elevated fatigue levels. The aim of this study was to explore the effect of shiftwork on heart rate variability indicators of workload and fatigue using wearable monitors in offshore operations. Ten male operators (age: 31.3 (6.1) years; stature: 1.72 (0.1) m; weight: 85.24 (9.8) kg) were monitored throughout their daily shifts for six days on an offshore drillship using physiological sensors. Heart rate variability (HRV) was measured in the frequency (ratio of low to high frequency; LF/HF) and temporal (root mean square of successive differences; RMSSD) domains. Six of the ten operators underwent swing shifts in the middle of the data collection period. There was a main effect of shift time on HRV parameters (i.e., operators on night shift were in a more fatigued state), and a main effect of swing shift on LF/HF (i.e., when swing shift occurred, those operators were more fatigued). Findings suggest that physiological profiles differ based on shift time and swing shifts, and that swing shifts for night shift workers adversely affect heart rate variability responses.

Fatigue indicators of 12-hour day and night shifts in simulated offshore well control scenarios

Fatigue plays a critical role in determining operator performance, safety, and productivity and is ranked among the top 5 human factors issues (Lerman et al., 2012). Additionally, it is one of the most prevalent symptoms in the work force affecting 54% of individuals (Son, 2012). Specifically fatigue in oil and gas extraction (OGE) can have detrimental and catastrophic effects and may contribute to the elevated fatality rate within this sector. Workers are exposed to high levels of physical and cognitive workload, long work periods, coupled with rigorous shift work, which contribute to high levels of fatigue. In offshore operations, fatigue can be predominantly attributed to sleep and shift-related factors as operations are typically running 24 hours a day. Shift work has been shown to impair performance in both lab-based tests and work-related tasks such as basic cognitive function and vigilance (Jansen, van Amelsvoort, Kristensen, van den Brandt, & Kant, 2003). By rotating between different shifts, there is disruption in the natural circadian rhythm potentially causing deteriorated performance (Åkerstedt & Wright, 2009; Eldevik, Flo, Moen, Pallesen, & Bjorvatn, 2013). In addition, adaptation to the shift may take several days (Eldevik et al., 2013). This is a critical concern in OGE shiftwork; often workers are rotated midway during their offshore deployment to “swing” shifts (shifting from a day to night shift, with 18-24 hours’ rest period to adapt (Harris et al., 2010). Not only are sleep and shift-related factors a concern, workers are exposed to high levels of cognitive workload. Drillers play a critical role in maintaining and improving offshore rig safety and productivity. They ensure that the drill plan, which is a complex and dynamic set of tasks is followed properly (Skogdalen, Utne, & Vinnem, 2011). Because offshore drilling is a 24/7 operation, it is imperative to determine how a driller’s cognitive capabilities to perform safety critical tasks change over shift types and swing shifts. However, there is limited empirical evidence that captures this interplay (shiftwork and cognitive load) on fatigue. Due to the multidimensional nature of fatigue, it becomes a challenge to properly assess, considering the complex OGE working environment. Non-intrusive objective performance assessments could potentially be a safe and sustainable solution for assessing fatigue in high-risk environments, but have not been explored as a viable tool for practice. Several performance tests have been used to quantify fatigue, particularly in assessing sleep-related fatigue. These include the Iowa Gambling Test (IGT), Psychomotor Vigilance Task (PVT), Balloon Analog Risk Task (BART), and the Purdue Pegboard Test (PPB) to objective assessment of fatigue. The aim of this exploratory study was to quantify fatigue levels of offshore drillers in high-fidelity simulated offshore well control scenarios using a performance assessment test battery and physiological monitoring over the course of two 12-hour work shifts (i.e. day shift and a night shift). It was hypothesized that drillers will be more fatigued at the end of the shift (post) compared to the beginning of shift (pre) and will be most pronounced during the night shift.

Addendum: Mehta et al. Standing Up for Learning: A Pilot Investigation on the Neurocognitive Benefits of Stand-Biased School Desks. Int. J. Environ. Res. Public Health 2016, 13(1), 59; doi:10.3390/ijerph13010059

The authors wish to update the Introduction in their paper published in the International Journal of Environmental Research and Public Health (IJERPH)[...]

Functional and Biomechanical Assessments of A Matter of Balance/Volunteer Lay Leader Model A Pilot Investigation

The purpose of this pilot study was to evaluate the effectiveness of A Matter of Balance/Volunteer Lay Leader model (AMOB/VLL), an evidence-based falls prevention program, on improving balance and mobility. Twenty-eight community-dwelling older adults completed an eight-week AMOB/VLL program. Pre/post assessments of biomechanical and functional outcomes of balance during single and dual-task trials, as well as perceptions of fear of falling, were compared using pairwise t-tests and Wilcoxon signed rank tests. Our findings suggest that while improvements in functional indicators of mobility and perception regarding fear of falling were observed, biomechanical and functional assessments specific to balance during the single-task trials remained unaffected by the intervention. Interestingly, the group exhibited improvements in biomechanical measures during the dual-task trials. Since AMOB/VLL primarily focuses on restructuring participants’ perceptions about falls and only includes generalized exercises, including balance-specific training within the program can potentially improve balance outcomes among older adults.

The Impact of Cognitive Fatigue on Age-related Differences in Neuromuscular Function A Neuroergonomic Approach

Fatigue is a multifactorial phenomenon including both cognitive and physical components. While age-related changes in neuromuscular function due to physical fatigue are well investigated, the effects of cognitive fatigue on neuromuscular function in older adults are unclear. The purpose of this study is to describe the methodology to examine the influence of cognitive fatigue on age-related changes in neuromuscular function and associated prefrontal cortex (PFC) activity. 4 younger and 1 older females underwent a 60-minute quiet session (control) and 60-minute cognitive fatigue session prior to a moderate intensity fatiguing handgrip exercise. An integrated neuroergonomic approach for collecting brain and muscle activity, cardiovascular responses and fatigue-related self-reports are described. Expected outcomes from this neuroergonomic investigation will provide the rationale for developing training and rehabilitative interventions for promoting both brain and body health to improve physical competencies in older adults.