scholarly journals The effects of exercise-induced heat stress on cognitive function in firefighters

2016 ◽  
Author(s):  
F. Michael Williams-Bell ◽  
Tom M McLellan ◽  
Bernadette A Murphy
Keyword(s):  
Heat Stress ◽  
Cognitive Function ◽  
Core Temperature ◽  
Visual Information ◽  
Situational Awareness ◽  
Spatial Working Memory ◽  
Task Complexity ◽  
Cognitive Tests ◽  
Active Cooling ◽  
Exercise Induced

Background. Firefighting requires tremendous cognitive demands including assessing emergency scenes, executing critical decisions, and situational awareness of their surroundings. The aim of this study was to determine the effects of differing rates of increasing core temperature on cognitive function during exercise-induced heat stress. Methods. Nineteen male firefighters were exposed to repeated cognitive assessments, randomized and counter-balanced, in 30°C and 35°C and 50% humidity. Participants performed treadmill walking (4.5 km.h-1 and 2.5% grade) with cognitive function assessed before exercise (PRE), after mounting the treadmill (Cog 1), at core temperatures of 37.8°C (Cog 2), 38.5°C (Cog 3), and 39.0°C (Cog 4), after dismounting the treadmill (POST), and following an active cooling recovery to a core temperature of 37.8°C (REC). The cognitive tests implemented at PRE and POST were spatial working memory (SWM), rapid visual information processing (RVP), and reaction time (RTI) while paired associates learning (PAL) and spatial span (SSP) were assessed at Cog 1, Cog 2, Cog 3, and Cog 4. All five cognitive tests were assessed at REC. Results. Planned contrasts revealed that SSP and PAL were impaired at Cog 3, with SSP also impaired at Cog 4 compared to Cog 1. REC revealed no difference compared to Cog 1, but increased errors compared to Cog 2 for PAL. Conclusions. The decrements in cognitive function observed at a core temperature of 38.5°C are likely attributed to the cognitive resources required to maintain performance being overloaded due to increasing task complexity and external stimuli from exercise-induced heat stress. The addition of an active cooling recovery restored cognitive function to initial levels.

scholarly journals The effects of exercise-induced heat stress on cognitive function in firefighters

2016 ◽  
Author(s):  
F. Michael Williams-Bell ◽  
Tom M McLellan ◽  
Bernadette A Murphy
Keyword(s):  
Heat Stress ◽  
Cognitive Function ◽  
Core Temperature ◽  
Visual Information ◽  
Situational Awareness ◽  
Spatial Working Memory ◽  
Task Complexity ◽  
Cognitive Tests ◽  
Active Cooling ◽  
Exercise Induced

Background. Firefighting requires tremendous cognitive demands including assessing emergency scenes, executing critical decisions, and situational awareness of their surroundings. The aim of this study was to determine the effects of differing rates of increasing core temperature on cognitive function during exercise-induced heat stress. Methods. Nineteen male firefighters were exposed to repeated cognitive assessments, randomized and counter-balanced, in 30°C and 35°C and 50% humidity. Participants performed treadmill walking (4.5 km.h-1 and 2.5% grade) with cognitive function assessed before exercise (PRE), after mounting the treadmill (Cog 1), at core temperatures of 37.8°C (Cog 2), 38.5°C (Cog 3), and 39.0°C (Cog 4), after dismounting the treadmill (POST), and following an active cooling recovery to a core temperature of 37.8°C (REC). The cognitive tests implemented at PRE and POST were spatial working memory (SWM), rapid visual information processing (RVP), and reaction time (RTI) while paired associates learning (PAL) and spatial span (SSP) were assessed at Cog 1, Cog 2, Cog 3, and Cog 4. All five cognitive tests were assessed at REC. Results. Planned contrasts revealed that SSP and PAL were impaired at Cog 3, with SSP also impaired at Cog 4 compared to Cog 1. REC revealed no difference compared to Cog 1, but increased errors compared to Cog 2 for PAL. Conclusions. The decrements in cognitive function observed at a core temperature of 38.5°C are likely attributed to the cognitive resources required to maintain performance being overloaded due to increasing task complexity and external stimuli from exercise-induced heat stress. The addition of an active cooling recovery restored cognitive function to initial levels.

The Effects of Exercise-Induced Heat Stress on Cognitive Function Assessed Using Serious Game Technology.

2016 ◽  
Vol 48 ◽  
pp. 630
Author(s):  
F. Michael Williams-Bell ◽  
Steven R. Passmore ◽  
Tom M. McLellan ◽  
Bernadette A. Murphy
Keyword(s):  
Heat Stress ◽  
Cognitive Function ◽  
Serious Game ◽  
Exercise Induced

scholarly journals Cognitive tests used in chronic adult human randomised controlled trial micronutrient and phytochemical intervention studies

2010 ◽  
Vol 23 (2) ◽  
pp. 200-229 ◽  
Author(s):  
Anna L. Macready ◽  
Laurie T. Butler ◽  
Orla B. Kennedy ◽  
Judi A. Ellis ◽  
Claire M. Williams ◽  
...  
Keyword(s):  
Randomised Controlled Trial ◽  
Statistical Power ◽  
Type I Error ◽  
Spatial Working Memory ◽  
Controlled Trial ◽  
Type I ◽  
Cognitive Tests ◽  
Cognitive Domains ◽  
Positive Effects ◽  
Randomised Controlled

In recent years there has been a rapid growth of interest in exploring the relationship between nutritional therapies and the maintenance of cognitive function in adulthood. Emerging evidence reveals an increasingly complex picture with respect to the benefits of various food constituents on learning, memory and psychomotor function in adults. However, to date, there has been little consensus in human studies on the range of cognitive domains to be tested or the particular tests to be employed. To illustrate the potential difficulties that this poses, we conducted a systematic review of existing human adult randomised controlled trial (RCT) studies that have investigated the effects of 24 d to 36 months of supplementation with flavonoids and micronutrients on cognitive performance. There were thirty-nine studies employing a total of 121 different cognitive tasks that met the criteria for inclusion. Results showed that less than half of these studies reported positive effects of treatment, with some important cognitive domains either under-represented or not explored at all. Although there was some evidence of sensitivity to nutritional supplementation in a number of domains (for example, executive function, spatial working memory), interpretation is currently difficult given the prevailing ‘scattergun approach’ for selecting cognitive tests. Specifically, the practice means that it is often difficult to distinguish between a boundary condition for a particular nutrient and a lack of task sensitivity. We argue that for significant future progress to be made, researchers need to pay much closer attention to existing human RCT and animal data, as well as to more basic issues surrounding task sensitivity, statistical power and type I error.

scholarly journals Acute Effects of a Polyphenol-Rich Leaf Extract of Mangifera indica L. (Zynamite) on Cognitive Function in Healthy Adults: A Double-Blind, Placebo-Controlled Crossover Study

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2194 ◽  
Author(s):  
Emma L. Wightman ◽  
Philippa A. Jackson ◽  
Joanne Forster ◽  
Julie Khan ◽  
Julia C. Wiebe ◽  
...  
Keyword(s):  
Single Dose ◽  
Cognitive Function ◽  
Visual Information ◽  
Leaf Extract ◽  
Mangifera Indica ◽  
Assessment System ◽  
Post Dose ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Healthy Humans

Extracts made from the leaves of the mango food plant (Mangifera indica L., Anacardiaceae) have a long history of medicinal usage, most likely due to particularly high levels of the polyphenol mangiferin. In rodent models, oral mangiferin protects cognitive function and brain tissue from a number of challenges and modulates cerebro-electrical activity. Recent evidence has confirmed the latter effect in healthy humans following a mangiferin-rich mango leaf extract using quantitative electroencephalography (EEG). The current study therefore investigated the effects of a single dose of mango leaf extract, standardised to contain >60% mangiferin (Zynamite®), on cognitive function and mood. This study adopted a double-blind, placebo-controlled cross-over design in which 70 healthy young adults (18 to 45 years) received 300 mg mango leaf extract and a matched placebo, on separate occasions, separated by at least 7 days. On each occasion, cognitive/mood assessments were undertaken pre-dose and at 30 min, 3 h and 5 h post-dose using the Computerised Mental Performance Assessment System (COMPASS) assessment battery and the Profile of Mood States (POMS). The results showed that a single dose of 300 mg mango leaf extract significantly improved performance accuracy across the tasks in the battery, with domain-specific effects seen in terms of enhanced performance on an ‘Accuracy of Attention’ factor and an ‘Episodic Memory’ factor. Performance was also improved across all three tasks (Rapid Visual Information Processing, Serial 3s and Serial 7s subtraction tasks) that make up the Cognitive Demand Battery sub-section of the assessment. All of these cognitive benefits were seen across the post-dose assessments (30 min, 3 h, 5 h). There were no interpretable treatment related effects on mood. These results provide the first demonstration of cognition enhancement following consumption of mango leaf extract and add to previous research showing that polyphenols and polyphenol rich extracts can improve brain function.

scholarly journals NCOG-10. RELATIONSHIP BETWEEN COGNITIVE FUNCTION, MOOD, AND FUNCTIONING IN GLIOMA SURVIVORS

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi160-vi161
Author(s):  
Kathleen Van Dyk ◽  
Brandon F Heimberg ◽  
Justin Choi ◽  
Catalina Raymond ◽  
Chencai Wang ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Processing Speed ◽  
Regression Models ◽  
Color Word ◽  
Work Productivity ◽  
Color Naming ◽  
Daily Activities ◽  
Daily Functioning ◽  
Depression Symptoms ◽  
Cognitive Tests

Abstract Ensuring optimal quality of life and functioning is a clinical priority in treating glioma survivors. Cognitive function and mood symptoms are prevalent in this population after treatment and it’s reasonable to consider these as significant contributors to patients’ functioning at work and in daily life. However, it’s unclear the degree to which these symptoms contribute to such outcomes. To address this question, we examined the relationships between cognitive tests (i.e., a neuropsychological battery) and mood measures (i.e., the Beck Depression Inventory-II, and the Beck Anxiety Inventory) and work and daily functioning (i.e., Work Productivity and Activity Impairment Questionnaire). Partial correlation of cognitive tests and regression models also included age and IQ (i.e., Test of Premorbid Functioning). Of the 11 participants who were currently working, worse work productivity was significantly associated with worse processing speed (Stroop color naming r=-.74,p=.03, Stroop color word r=-.78,p=.02). Similarly, worse ability in daily activities was also associated with worse processing speed and executive function (Stroop color naming, r=-.52,p=.04; Stroop color word, r=-.55,p=.03; Trails B, r=-.53,p=.03). Greater depression symptoms were strongly correlated with both worse work productivity (r=.83,p=.002), and worse ability in daily activities (r=.55,p=.01). Depression symptoms were generally uncorrelated with cognitive scores. In linear regression models that included both depression symptoms and cognitive scores, only depression emerged as a significant predictor of work productivity and ability to conduct daily activities. In sum, glioma survivors face multiple threats to work and daily functioning by way of tumor and treatment related symptoms. Our analyses suggest that both cognitive function and mood symptoms are important to consider in optimizing functioning, but depression appears to vastly outweigh cognitive function in this regard. These preliminary findings highlight the importance of careful attention to these symptoms in survivorship and point to future research directions elaborating on these relationships.

scholarly journals Trajectories of Cognitive Function Prior to Cancer Diagnosis: A Population-Based Study

2019 ◽  
Vol 112 (5) ◽  
pp. 480-488 ◽  
Author(s):  
Kimberly D van der Willik ◽  
Michael Hauptmann ◽  
Katarzyna Jóźwiak ◽  
Elisabeth J Vinke ◽  
Rikje Ruiter ◽  
...  
Keyword(s):  
Nervous System ◽  
Cognitive Function ◽  
Confidence Interval ◽  
Cancer Patients ◽  
Cancer Diagnosis ◽  
Population Based ◽  
Sensitivity Analyses ◽  
Cognitive Tests ◽  
Control Subjects ◽  
Nervous System Cancer

Abstract Background An emerging body of research suggests that noncentral nervous system cancer may negatively impact the brain apart from effects of cancer treatment. However, studies assessing cognitive function in newly diagnosed cancer patients cannot exclude selection bias and psychological effects of cancer diagnosis. To overcome these limitations, we investigated trajectories of cognitive function of patients before cancer diagnosis. Methods Between 1989 and 2013, a total of 2059 participants from the population-based Rotterdam Study were diagnosed with noncentral nervous system cancer. Cognitive assessments were performed every 3 to 5 years using a neuropsychological battery. The general cognitive factor was composed of individual cognitive tests to assess global cognition. Using linear mixed models, we compared change in cognitive function of cancer case patients before diagnosis with cognitive change of age-matched cancer-free control subjects (1:2). In addition, we performed sensitivity analyses by discarding assessments of control subjects 5 years before the end of follow-up to exclude effects from potential undiagnosed cancer. All statistical tests were two-sided. Results The Word Learning Test immediate recall declined faster among case patients than among control subjects (−0.05, 95% confidence interval = −0.09 to −0.01 vs 0.01, 95% confidence interval = −0.01 to 0.03; P for difference = .003). However, this difference was not statistically significant in sensitivity analyses. Furthermore, no statistically significant differences were observed in change of other individual cognitive tests and of the general cognitive factor. Conclusions In this study, we evaluated cognitive function in a large group of cancer patients prior to diagnosis, thereby excluding the psychological impact of cancer diagnosis and biased patient selection. In contrast to previous studies shortly after cancer diagnosis, we found no difference in change of cognitive function between cancer patients and control subjects.

Recovery from stunting and cognitive outcomes in young children: evidence from the South African Birth to Twenty Cohort Study

2015 ◽  
Vol 7 (2) ◽  
pp. 163-171 ◽  
Author(s):  
D. Casale ◽  
C. Desmond
Keyword(s):  
Cohort Study ◽  
Cognitive Function ◽  
Young Children ◽  
School Readiness ◽  
Economic Status ◽  
Cognitive Outcomes ◽  
Early Years ◽  
Cognitive Tests ◽  
Data Set ◽  
Urban South

In this study we analyse the implications for cognitive function of recovery from stunting in early childhood. More specifically, we test whether children who met the definition for stunted at age 2, but not at age 5, perform better in cognitive tests than children who remain stunted over this period. The sample is drawn from the Birth to Twenty Cohort Study, a prospective data set of children born in 1990 in urban South Africa. The measure of cognitive function that we use is based on the Revised Denver Prescreening Developmental Questionnaire implemented when the children were age 5. We employ multivariate regression in the analysis to control for child-specific characteristics, socio-economic status, the home environment and caregiver inputs. We find that recovery from stunting is not uncommon among young children in our sample. However, children who recover from stunting by age 5 still perform significantly worse on cognitive tests than children who do not experience early malnutrition, and almost as poorly as children who remain stunted. These findings suggest that the timing of nutritional inputs in the early years is key in a child’s cognitive development, with implications for school readiness and achievement.

Hyperhydration and Glycerol: Thermoregulatory Effects During Exercise in Hot Climates

2000 ◽  
Vol 25 (6) ◽  
pp. 536-545 ◽  
Author(s):  
William A. Latzka ◽  
Michael N. Sawka
Keyword(s):  
Heat Stress ◽  
Core Temperature ◽  
Body Water ◽  
Fluid Replacement ◽  
Whole Body ◽  
Threshold Temperature ◽  
Sweating Rate ◽  
Design Problems ◽  
Fluid Ingestion ◽  
Water Exercise

Hyperhydration or increasing body water content above normal (euhydration) level was thought to have some benefit during exercise heat-stress; however, attempts to overdrink have been minimized by a rapid diuretic response. The perception that hyperhydration might be beneficial for exercise performance and for thermoregulation arose from the adverse consequences of hypohydration. Many studies had examined the effects of hyperhydration on thermoregulation in the heat; however, most of them suffer from design problems that confound their results. The design problems included control conditions not representing euhydration but hypohydration, control conditions not adequately described, cold fluid ingestion that reduced core temperature, and/or changing heat acclimation status. Several investigators reported lower core temperatures during exercise after hyperhydration, while other studies do not. Some investigators reported higher sweating rates with hyperhydration, while other studies do not. Recent research that controlled for these confounding variables reported that hyperhydration (water or glycerol) did not alter core temperature, skin temperature, whole body sweating rate, local sweating rate, sweating threshold temperature, sweating sensitivity, or heart rate responces compared to euhydration trail. If euhydration is maintained during exercise-heat stress then hyperhydration appears to have no meaningful advantage. Key words: Hydration, fluid replacement, exercise heat-stress, total body water exercise

Sign in / Sign up

Export Citation Format

Share Document