Simple Reaction Time Test Research Articles

Timed Up and Go Test With a Cognitive Task: Correlations With Neuropsychological Measures in People With Parkinson's Disease.

BackgroundThe Timed Up and Go (TUG) test is a simple and widely used clinical test for the assessment of lower extremity function, balance, mobility, and fall risk in various populations. The TUG has been found as a valid and reliable measure in people with Parkinson’s disease (PD). Besides, the addition of a cognitive task to the TUG (TUG-cognitive) enhances predictive validity related to fall risk in people with PD. However, further investigation is needed about the correlations of the TUG-cognitive test with neuropsychological measures in people with PD.MethodsThirty-three people with PD [modified Hoehn and Yahr scale, median (min-max)=2.5 (1.0-3.0)] participated in this cross-sectional study. The TUG was administered in the traditional way and with a cognitive task (counting backward by three from any number between 20 and 100). Neuropsychological measures included the Montreal Cognitive Assessment (MoCA), Trail Making Test (TMT), and the Simple Reaction Time (SRT) test for stepping. The self-reported number of falls in the last six months was also recorded.ResultsThe TUG-cognitive [13.1 (SD=8.5) seconds] was significantly longer than the TUG-traditional [12.2 (SD=8.1) seconds] (p<0.01). The TUG-cognitive significantly correlated with the MoCA [(rho=-0.712), TMT part A (TMT-A; rho=0.722), TMT part B (TMT-B; rho=0.694), SRT (rho=0.794), and number of falls (rho=0.960)] (p<0.01). The TUG-traditional also significantly correlated with the MoCA (rho=-0.682), TMT-A (rho=0.684), TMT-B (rho=0.746), SRT (rho=0.755), and number of falls (rho=0.702) (p<0.01).ConclusionBoth the TUG-cognitive and TUG-traditional strongly correlated with neuropsychological measures; while the correlations were slightly stronger for the TUG-cognitive, the difference was not significant. The TUG-cognitive can be used in the clinical practice as a simple and more informative alternative to the TUG-traditional in people with PD.

Pharmacokinetics and Safety of Intravenous, Intravesical, Rectal, Transdermal, and Vaginal Melatonin in Healthy Female Volunteers: A Cross-Over Study

Introduction: We aimed to investigate the pharmacokinetic properties and safety of melatonin administered by alternative routes of administration. Methods: This study employed a cross-over design in healthy female volunteers. Twenty-five milligrams of melatonin was administered intravenously, intravesically, rectally, transdermally, and vaginally. Blood samples were collected at specified time points up to 24 h following intravenous, intravesical, rectal, and vaginal administration, and up to 48 h following transdermal administration. Plasma melatonin concentrations were determined by radioimmunoassay. Sedation was evaluated by a simple reaction-time test, and sleepiness was assessed by the Karolinska Sleepiness Scale. Adverse events were registered for each route of administration. Results: Ten participants were included. We documented a mean (SD) time to maximal concentration of 51 (29) min for intravesical, 24 (20) min for rectal, 21 (8) h for transdermal, and 147 (56) min for vaginal administration. The mean (SD) elimination half-life was 47 (6) min for intravenous, 58 (7) min for intravesical, 60 (18) min for rectal, 14.6 (11.1) h for transdermal, and 129 (17) min for vaginal administration. The mean (SD) bioavailability was 3.6 (1.9)% for intravesical, 36.0 (28.6)% for rectal, 10.0 (5.7)% for transdermal, and 97.8 (31.7)% for vaginal administration. No significant changes in reaction times were observed following administration of melatonin by any of the administration routes. Increased tiredness was documented following transdermal administration only. No serious adverse effects were documented. Conclusion: Rectally and vaginally administered melatonin may serve as relevant alternatives to standard oral melatonin therapy. Transdermal delivery of melatonin displayed an extended absorption and can be applied if prolonged effects are intended. Intravesical administration displayed, as expected, a very limited bioavailability. Melatonin administered by these routes of administration was safe.

An evaluation of bicycle-specific agility and reaction times in mountain bikers and road cyclists.

Cycling is a popular recreational and competitive sport with many health benefits but also significant risks, with 85% of recreational cyclists reporting an injury each season. The most common mechanism of injury is through a loss of control of the bicycle, and collisions with other objects. Reaction time and agility in cyclists may contribute to the ability to control a bicycle. To evaluate bicycle-specific agility and reaction time in cyclists. The study was a cross-sectional observational study. Thirty-five cyclists (27 males, eight females) participated in this study. Participants attended a single testing session where they completed a bicycle-specific agility test, and online simple and choice reaction time testing while cycling at three different exercise intensities. There was a significant difference in agility between males and females (p=0.01). There was also a significant difference in choice reaction time between cycling at 'light' and 'very hard' intensities (p=0.004), and a significant positive relationship between agility and simple reaction time at a 'hard' intensity. Choice reaction time improved at 'very hard' cycling intensity, supporting the theory that increased exercise intensity improves cognitive arousal. This reaction time may be essential as a means to avoid collisions and falls from bicycles. Bicycle-specific agility appears to be related to simple reaction time, but there are no existing validated bicycle-specific agility tests available. The value of the tests undertaken by the authors needs to be assessed further. Choice reaction time was significantly decreased in high intensity cycling compared to cycling at low intensities. Further prospective studies are needed to establish links between reaction times and bicycle-specific agility.

Partial sleep deprivation affects endurance performance and psychophysiological responses during 12-minute self-paced running exercise

PurposeThis study aimed to investigate the effects of partial sleep deprivation (PSD) on physical performance and psychophysiological responses during 12-minute self-paced running exercise. MethodsTwenty runners (20.8±1.1 years, 70.6±4.9 kg, 175.1±3.9 cm) performed, in a randomized order, two running self-paced field exercises after a normal sleep night (CONT, bedtime from 22:30 h to 06:30 h) and one night of PSD (bedtime from 00:30 h to 04:30 h). Core temperature and motivation were recorded before exercise. Speed, covered distance, heart rate (HR), rating of perceived exertion (RPE) and respiratory parameters (i.e., minute ventilation (VE), oxygen uptake (VO2) and carbon dioxide production (VCO2)) were assessed during exercise. Blood lactate concentration [La] was assessed 2 min after exercise. Simple reaction time (SRT), mood and barrage test (BT) were assessed before and after exercise. ResultsHigher RPE (p=0.01, d=0.90) and lower physical performance (i.e., p=0.001, d=0.59 for running speed and p=0.01, d=0.7 and Δ (%)=-6% for covered distance), following PSD, were obtained compared to CONT. Similarly, PSD attenuated core temperature (p=0.01, d=0.84), HR (p=0.006, ɳp2=0.45), VE (p=0.001, ɳp2=0.73), VO2 (p=0.001, ɳp2=0.96), BT (p<0.0005, ɳp2=0.86), SRT (p=0.0009, ɳp2=0.44) and mood (p<0.0005). However, VCO2, [La] and motivation score were not affected by sleep conditions. ConclusionThe decrease of running performance and the increase of physical discomfort after PSD could be the origin of the lower cardio-respiratory responses to the 12-minute self-paced exercise. Effective strategies should be introduced to overcome the deterioration of physical performance and physiological responses after PSD.

White matter correlates of slowed information processing speed in unimpaired multiple sclerosis patients with young age onset

Slowed information processing speed is among the earliest markers of cognitive impairment in multiple sclerosis (MS) and has been associated with white matter (WM) structural integrity. Localization of WM tracts associated with slowing, but not significant impairment, on specific cognitive tasks in pediatric and young age onset MS can facilitate early and effective therapeutic intervention. Diffusion tensor imaging data were collected on 25 MS patients and 24 controls who also underwent the Symbol Digit Modalities Test (SDMT) and the computer-based Cogstate simple and choice reaction time tests. Fractional anisotropy (FA), mean (MD), radial (RD) and axial (AD) diffusivities were correlated voxel-wise with processing speed measures. All DTI metrics of several white matter tracts were significantly different between groups (p < 0.05). Notably, higher MD, RD, and AD, but not FA, in the corpus callosum correlated with lower scores on both SDMT and simple reaction time. Additionally, all diffusivity metrics in the left corticospinal tract correlated negatively with SDMT scores, whereas only MD in the right superior fronto-occipital fasciculus correlated with simple reaction time. In conclusion, subtle slowing of processing speed is correlated with WM damage in the visual-motor processing pathways in patients with young age of MS onset.

Effect of acute caffeine intake on hit accuracy and reaction time in professional e-sports players

Caffeine is considered a cognitive enhancer at low to moderate doses because it improves alertness, vigilance, attention, and reaction time. However, no previous investigation has assessed the effect of acute caffeine intake on e-sports-specific performance. The aim of this investigation was to determine the effect of the ingestion of 3 mg per kg of body mass on simple reaction time in a color test and on hit accuracy and reaction time during a first-person shooting game. Fifteen professional e-gamers (age= 22 ± 3 years) participated in a double-blind, cross-over, randomized experimental trial. In two trials 3 days apart, participants either ingested a placebo (cellulose) or 3 mg/kg of caffeine in an opaque and unidentifiable capsule. After a 45-min wait for substance absorption, participants performed 5 attempts at a simple reaction time test and completed a first-person shooting game that included 3 attempts at a 2-min game with 60 fixed targets (180 targets in total). Reaction times (in both tests) and accuracy in hitting the targets (only in the shooting game) were measured. In comparison to the placebo, caffeine decreased simple reaction time (0.20 ± 0.01 vs. 0.19 ± 0.01 s, P < 0.01), the mean time taken to hit the targets (0.92 ± 0.07 vs. 0.88 ± 0.07 s, P < 0.01) and enhanced hit accuracy (98.8 ± 0.92 vs. 99.8 ± 0.35% of targets hit, P < 0.01). In summary, the acute ingestion of 3 mg/kg of caffeine reduced the time taken to react to a simple stimulus, decreased the time taken to hit a fixed target and improved accuracy in hitting the target in a first-person shooting game in professional e-gamers. Thus, the caffeine ingestion (3 mg/kg) might be considered as an ergogenic aid for e-sports gamers based on its effect to enhance hit accuracy and time.

The Effect of Agility Training on Reaction Time in Fencers

The aim of this study was to investigate the effects of agility training on reaction time in fencers. Accordingly, 48 athletes (24 females and 24 males) actively involved in fencing participated in the study. Fencers were divided into two groups as 24 fencers in the Agility Training Group (ATG: 12F, 12M) (aged 11.95 years, sports age 2.54 years, height 159 cm, body weight 48.08 kg and body mass index 18.81 kg/m&amp;sup2;) and Conventional Training Group (CTG: 12F, 12M) (aged 12.12 years, sports age 2.20 years, height 156.54 cm, body weight 46.25 kg and body mass index 18.81 kg/m&amp;sup2;). There was a statistically significant difference between the pre-test and post-test values in agility, vertical jump, simple reaction time and multiple reaction time tests in the ATG (p&amp;lt;0.05). There was a statistically significant difference between the pre-test and post-test values in agility and vertical jump tests in the CTG (p&amp;lt;0.05). There was a statistically significant difference in the pre-tests between the groups in the simple reaction time test (p&amp;lt;0.05). There was a statistically significant difference in post-tests between the groups in the agility, simple reaction time and multiple reaction time test values (p&amp;lt;0.05). Based on the results of the study, it was found that simple and multiple reaction time could be positively affected by active-reactive agility training applications.

Психофизиологические и психологические особенности волейболисток-юниоров высокой квалификации

Objective: to analyze the psychological and psychophysiological features of effective volleyball play. Materials and methods: the study involved 19 female athlets with average age of 17±1 years. The study was conducted during the pre-competition period. Personality traits, sport motivation, coping strategies, emotional burnout, skills of mental training and visualization, were assessed by adapted Russian-language versions of questionnaires «Freiburg multi-factor personal questionnaire (FPI)», «Sport motivation scale (SMS)», «The Sport Imagery Questionnaire (SIQ)», «Strategic Approach to Coping Scale (SACS)», «Maslach burnout inventory». The levels of chronic and acute stress were assessed by «Acute and chronic stress scale». Attentional set-shifting, concentration of attention were examined by the Munsterberg test and the «Entangled lines» test. The speed and stability of sensorimotor functioning were assessed by Simple Reaction Time test and Choice Reaction Time test. Stress load was simulated by the game-biofeedback approach to examine the effectiveness of self-regulation. The obtained data were compared with the assessment of athletes’ gaming efficiency. Results: Revealed significant connection between game effectiveness and the reduced level of stress: high speed, reaction stability, internal motivation, decreased neuroticity, depressiveness, aggressiveness, emotional lability, developed skills of self-regulation, visualization and ideomotor training are discussed. Conclusions: Revealed psychological and psychophysiological features might be considered as components of the young female volleyball players’ model psychophysiological state.

Is the strong desire to void a source of diverted attention in healthy adult volunteers?

The strong desire to void (SDV) induces changes in both cognition and gait. This may be due to the sensation of urinary urge acting as a source of diverted attention. This exploratory study examined the influence of SDV and a standardized distracting task on the performance of two measures of cognition, a simple reaction time (SRT) test and the trail making B test (TMT-B). 18 volunteers, 8 male and 10 female, without lower urinary tract symptoms (LUTS) (mean age: 20.5, range: 20-47), performed a test of SRT and the TMT-B under three conditions; undistracted with an empty bladder, while experiencing SDV, and when performing a simultaneous distracting task, the auditory n back test. A statistically significant increase in SRT was found when experiencing SDV and when distracted compared with the undistracted, bladder empty condition. The time taken to compete the TMT-B significantly increased with distraction but was not affected by SDV. SDV induced a similar but smaller change in reaction time when compared with a distracting task, suggesting that SDV may act as a source of diverted attention in continent, healthy volunteers.

Relationships Between Reaction Time, Selective Attention, Physical Activity, and Physical Fitness in Children.

The objective of this study was to analyze the relationships between simple and complex reaction times (RTs) with the physical activity performed weekly, the physical fitness and selective attention in children of the third cycle of primary education. Participants were 119 children aged between 10 and 12 years (M = 10.71; SD = 0.77). The instruments used for data collection were the D2 attention test to analyze selective attention, various tests of the Eurofit and ALPHA-Fitness Battery to evaluate the physical condition, a bioimpedanciometer Tanita TBF 300 to evaluate the body composition, and the FITLIGHT Trainer to measure the simple and complex RTs. The group that carried out more weekly physical activity used less time in simple (p < 0.05, d = −0.68, 95% CI [−1.19, −0.17]) and complex RT tests (p < 0.05, d = −0.63, 95% CI [−1.14, −0.12]). Also, the results showed that the simple RT was related in a significant way with physical fitness, while the complex RT was related significantly to attentional capacity and physical fitness.

Is Utena's Brief Objective Measures (UBOM) useful in real‐world behavioral assessment of functioning? Validity and utility testing in patients with schizophrenia

Utena's Brief Objective Measures (UBOM) was developed to assess psychophysiological functions proximal to real-world functioning in individuals with psychiatric disorders, including schizophrenia (SCZ), to facilitate shared decision-making. However, the validity of UBOM has not been fully examined. We conducted a cross-sectional observational study to evaluate the validity of each of the three tests in UBOM: UBOM-Pulse, UBOM-Ruler, and UBOM-Random. We investigated associations: (i) between UBOM and existing cognitive- and autonomic-function tests; and (ii) between UBOM and daily social functioning. The participants included SCZ individuals and healthy controls. We evaluated the cognitive and autonomic function using UBOM, the heart rate variability test, the simple reaction time test, and the Brief Assessment of Cognition in Schizophrenia, Japanese version. We also assessed the daily social functioning using the WHO Disability Assessment Schedule 2.0 and the modified Global Assessment of Functioning, Japanese version. Thirty-one SCZ individuals and 35 healthy control individuals participated in this study. In the SCZ group, UBOM-Ruler was significantly associated with the Cognition and Getting Along domains of WHO Disability Assessment Schedule 2.0. UBOM-Random was significantly associated with the Brief Assessment of Cognition in Schizophrenia's Working Memory, Verbal Fluency and Attention domains, and the modified Global Assessment of Functioning in the SCZ group. The validity of the current version of UBOM is imperfect and further improvements will be necessary to attain the originally intended goal of developing a brief assessment tool for real-world functioning in SCZ.

GAD65 as a potential marker for cognitive performance in an adult population with prediabetes.

Diabetes mellitus (DM) is a well-known risk factor for cognitive dysfunction in aged populations. However, there are inconsistent reports about impaired fasting glucose or prediabetes as an independent risk factor for cognitive function. Glutamic acid decarboxylase 65 (GAD65) is the key enzyme responsible for γ-aminobutyric acid synthesis in the central nervous system. Antibodies against GAD65 (GAD65Abs) are not only detected in approximately 80% of early-onset type 1 DM, but also linked to several neurological disorders. This study aims to investigate the association between GAD65Ab titer levels and cognitive performance. In addition, we assessed the effect of GAD65Ab on cognitive function in adults with normal fasting glucose, prediabetes and DM. A total of 328 subjects aged 49.10 ± 5.72 years were enrolled from the Third Health and Nutrition Examination Survey dataset. Cognitive performance was assessed by three computerized neurobehavioral tests, including the serial digit learning test, simple reaction time test (SRTT) and symbol-digit substitution test (SDST). Subjects with higher GAD65Ab titers had significantly poorer cognitive function in the SRTT and SDST (P < 0.05). Additionally, GAD65Ab was associated with cognitive decline in non-diabetic adults after adjusting for a number of relevant variables (P < 0.05 in both SRTT and SDST). These results indicate that GAD65Ab may be a potential marker for cognitive impairment in non-diabetic adults.

Executive Functioning, Muscle Power and Reactive Balance Are Major Contributors to Gait Adaptability in People With Parkinson's Disease.

Background and Aim: The ability to adapt gait when negotiating unexpected hazards is crucial to maintain stability and avoid falling. This study investigated cognitive, physical and psychological factors associated with gait adaptability required for obstacle and stepping target negotiation in people with Parkinson’s disease (PD).Methods: Fifty-four people with PD were instructed to either: (a) avoid an obstacle at usual step distance; or (b) step onto a target at either a short or long step distance projected on a walkway two heel strikes ahead and then continue walking. Participants also completed clinical [Hoehn & Yahr rating scale; Movement Disorders Society version of the Unified Parkinson’s Disease Rating Scale motor section (MDS-UPDRS-III)], cognitive [simple reaction time, Trail Making and Stroop stepping (difference between incongruent and standard Choice Stepping Reaction Time, CSRT) tests], physical [hip abductor muscle power and reactive balance (pull test from the MDS-UPDRS-III)] and psychological (Fall Efficacy Scale–International) assessments.Results: Discriminant function analysis revealed Stroop stepping test (inhibitory control) performance was the best predictor of stepping errors across the Gait Adaptability Test (GAT) conditions. Poorer executive function [Trail Making Test (TMT)] and reactive balance predicted poorer stepping accuracy in the short target condition; poorer reactive balance predicted increased number of steps taken to approach the obstacle and the long target; and poorer executive function predicted obstacle avoidance. Weaker hip abductor muscle power, poorer reactive balance, slower reaction time, poorer executive function and higher concern about falling were significant predictors of shorter step length while negotiating the obstacle/targets.Conclusion: Superior executive function, effective reactive balance and good muscle power were associated with successful gait adaptability. Executive function and reactive balance appear particularly important for precise foot placements; and cognitive capacity for step length adjustments for avoiding obstacles. These findings suggest that impaired inhibitory control contributes to stepping errors and may increase fall risk in people with PD. These findings help elucidate mechanisms for why people with PD fall and may facilitate fall risk assessments and fall prevention strategies for this group.

Association between periodontitis and cognitive impairment: Analysis of national health and nutrition examination survey (NHANES) III.

Periodontitis has been hypothesized as being one of the most common potential risk factors for the development of dementia and cognitive impairment. In order to investigate the relationship between periodontitis and cognition impairment, the National Health and Nutrition Examination Survey (NHANES) database was analysed after adjusting for potential confounding factors, including age and other systemic co-morbidities. In total, 4,663 participants aged 20-59years who had received full-mouth periodontal examination and undergone the cognitive functional test were enrolled. The grade of periodontal disease was categorized into severe, moderate, and mild. Cognitive function examinations, including the simple reaction time test (SRTT), symbol digit substitution test (SDST), and serial digit learning test (SDLT), were adopted for the evaluation of cognitive impairment. The subjects with mild and moderate to severe periodontitis had higher SDLT and SDST scores, which indicated decreased cognitive function, compared with the healthy group. After adjusting for demographic factors, education, smoking, cardiovascular diseases, and laboratory data, periodontitis was significantly correlated with elevated SDST and SDLT scores (p values for trend=0.014 and 0.038, respectively) by generalized linear regression models. Our study highlighted that periodontal status was associated with cognitive impairment in a nationally representative sample of US adults.

Multiple-dose clinical pharmacology of ACT-541468, a novel dual orexin receptor antagonist, following repeated-dose morning and evening administration

ACT-541468 is a dual orexin receptor antagonist with sleep-promoting effects in humans. Following entry-into-humans, its pharmacokinetics (PK) including dose-proportionality and accumulation, pharmacodynamics (PD), safety, and tolerability following multiple-ascending oral dose (MAD) administration in the morning, and next-day residual effects after repeated evening administration were investigated in a double-blind, placebo-controlled, randomized study. 31 healthy male and female subjects in 3 dose-groups (10, 25, and 75 mg) received study drug in the morning for 5 days (MAD part), and 20 healthy subjects received 25 mg in the evening for 1 week (evening part). PK, PD (saccadic peak velocity (SPV), adaptive tracking, body sway, Bond and Lader visual analogue scales (VAS), Karolinska Sleepiness Scale (KSS), VAS Bowdle for assessment of psychedelic effects), Digit Symbol Substitution Test (DSST), and Simple Reaction Time Test (SRTT), safety, and tolerability were assessed. ACT-541468 was absorbed with a median tmax of 1.0–2.0 h across the 3 dose groups. The geometric mean elimination half-life (t½) on Day 5 was between 5.6 and 8.5 h, and the exposure (area under the curve (AUC)) showed dose proportionality. No accumulation and no influence of sex on the multiple-dose PK parameters of ACT-541468 was observed. No effects were observed at 10 mg. Administration of 25 and 75 mg during the day showed clear dose-dependent effects on the PD parameters, while next-day effects were absent after evening administration of 25 mg. The drug was safe and well tolerated. In conclusion, multiple-dose PK/PD of ACT-541468 were compatible with a drug designated to treat insomnia.

Psychomotor Abilities of Professional Handball Players.

The main purpose of the paper was to evaluate selected psychomotor abilities of handball players depending on the competition class (league), position on the court, training seniority and the dominant hand. The study covered a group of 40 handball players (age: 24.02 ± 3.99), while 50 non-training men (age: 22.90 ± 1.13) formed the control group. Studies were performed using Test2Drive computer tests. The following four tests were used for measuring psychomotor fitness: simple reaction time test, choice reaction time test, hand-eye coordination test and spatial anticipation test. An analysis revealed that handball players had better reaction times and movement times than the control group. The league, position on the court, training seniority and the dominant upper limb were analysed for their impact on the reaction time and movement time in handball players. An analysis of psychomotor abilities of handball players with regard to the league revealed that in the majority of tests the Superliga players had a shorter reaction time than players in lower leagues.

Neurobehavioral Effects of Organic Solvents Exposure Among Wood Furniture Makers in Ile-Ife, Osun State, Southwestern Nigeria.

Furniture making industries are small scale businesses that commonly use organic solvents. There has been minimal focus on the health effects of this chemical hazard on the nervous system among furniture makers in Nigeria. The present study aimed to assess the association between organic solvents exposure and neurobehavioral status of furniture makers, using electronic technicians as a comparison group. A comparative cross-sectional study design was employed. A sample size of 108 was calculated for each group. A semi-structured interviewer-administered questionnaire was used to obtain data on the socio-demographic variables and use of personal protective equipment (PPE). A proforma was developed to collect neurobehavioral assessment data. A checklist was used to assess the furniture makers' workshops. Air was sampled from all of the workshops in both the study and comparison groups to determine the concentration of total volatile organic compounds (TVOCs). The use of PPE was poor in both the study and comparison groups, with no significant difference between them (34.4% and 37.7% respectively). Total volatile organic compound and formaldehyde (HCHO) concentrations were significantly higher at the furniture makers' workshops compared with electronic technicians (p<0.001) for both chemicals. The 8-hour time-weighted average of TVOC was also higher in the furniture makers' workshops (4.4±0.6 mg/m3) compared with the control group (0.3±0.3 mg/m3). The neurobehavioral symptoms score was significantly higher among the study group relative to the comparison group (p<0.001). There was a significant difference in the outcome of the auditory verbal learning test, total recall (p=0.005), and delayed recall (p=0.003). There was no significant association between solvent exposure index and findings from the simple reaction time test. Poor compliance with the use of PPE among furniture makers may increase their exposure to organic solvents. There were more neurobehavioral changes in the furniture makers with a higher exposure index. Measures are needed to educate artisans about workrelated chemical hazards and ensure compliance with basic occupational safety and hygiene standards. Obtained. Ethics approval was obtained from the Health Research and Ethics Committee of the Institute of Public Health, Obafemi Awolowo University (IPH/OAU/12/1049). The authors declare no competing financial interests.

Thyroid hormones and neurobehavioral functions among adolescents chronically exposed to groundwater with geogenic arsenic in Bangladesh

Groundwater, the major source of drinking water in Bengal Delta Plain, is contaminated with geogenic arsenic (As) enrichment affecting millions of people. Children exposed to tubewell water containing As may be associated with thyroid dysfunction, which in turn may impact neurodevelopmental outcomes. However, data to support such relationship is sparse. The purpose of this study was to examine if chronic water As (WAs) from Holocene alluvial aquifers in this region was associated with serum thyroid hormone (TH) and if TH biomarkers were related to neurobehavioral (NB) performance in a group of adolescents. A sample of 32 healthy adolescents were randomly drawn from a child cohort in the Health Effects of Arsenic Longitudinal Study (HEALS) in Araihazar, Bangladesh. Half of these participants were consistently exposed to low WAs (<10 μg/L) and the remaining half had high WAs exposure (≥10 μg/L) since birth. Measurements included serum total triiodothyronine (tT3), free thyroxine (fT4), thyrotropin (TSH) and thyroperoxidase antibodies (TPOAb); concurrent WAs and urinary arsenic (UAs); and adolescents' NB performance. WAs and UAs were positively and significantly correlated with TPOAb but were not correlated with TSH, tT3 and fT4. After accounting for covariates, both WAs and UAs demonstrated positive but non-significant relationships with TSH and TPOAb and negative but non-significant relationships with tT3 and fT4. TPOAb was significantly associated with reduced NB performance indicated by positive associations with latencies in simple reaction time (b = 82.58; p < 0.001) and symbol digit (b = 276.85; p = 0.005) tests. TSH was significantly and negatively associated with match-to-sample correct count (b = −0.95; p = 0.05). Overall, we did not observe significant associations between arsenic exposure and TH biomarkers although the relationships were in the expected directions. We observed TH biomarkers to be related to reduced NB performance as hypothesized. Our study indicated a possible mechanism of As-induced neurotoxicity, which requires further investigations for confirmatory findings.

Resting Cerebral Blood Flow Immediately Post Concussion is correlated to Cognitive Performance

Sports related concussion is estimated to affect more than 3.8 million Americans a year. Despite the large number of concussions, our understanding of the mechanisms underlying concussion are limited. We also lack an accurate diagnostic tool to provide an indication of concussion severity. Currently, most concussion assessments use cognitive testing to assess severity. Our lab has been examining use of Doppler ultrasound in the field as a possible novel objective measures of concussion severity. We recruited players from recreational rugby tournaments. Players who were seen at the medical tent and determined not to need further treatment were offered the opportunity to participate. A control group of players who had played a rugby match but did not receive a head hit were also recruited. During the tournaments, we used a portable tent based lab to obtain measures of internal carotid cerebral blood flow by imaging the artery to obtain diameter and velocity. Additionally, we measured both beat‐by‐beat blood pressure (Finometer) as well as end tidal CO2 using a nasal cannula during rest, both in the seated and supine position. In a subgroup of 47 players (28 controls, 19 concussed, Mean age= 30, range= 19–66 yrs) out of our large study (125 players, 49 concussed), we had players perform a Simple Reaction Time Test (SRTT), Trails A &amp; B, Digit Symbol Substitution Test (DSST), Paced Auditory Serial Addition Test (PASAT) with 3 sec and 2 sec delay and a Digit Span Memory Test. Concussed players had significantly higher SCAT total number of symptoms (15 ± 11 vs 5 ± 7, P=0.029) as well as Symptom Severity Score (33 ± 18 vs 7 ± 9, P=0.002). Concussed players only performed significantly worse on the SRTT (353 ± 128 ms vs 278 ± 44 ms, P=0.046) while trending on DSST (54 ± 15 ms vs 63± 4 ms, P=0.085). Concussed players demonstrated significantly greater cerebral blood flow when seated (646 ± 180 mL/min vs 415 ± 85 mL/min, P=0.001). Cerebral blood flow was also significantly correlated to performance on SRTT (r=0.84, P=0.035), Trails B Time (r=0.94, P=0.006), DSST (r=−0.88, P=0.021) and Digit Span (r=−0.89, P=0.019). Surprisingly increased seated cerebral blood flow was found in the concussed players and associated with worse cognitive performance. This initial study suggests that cerebral blood flow immediately post‐concussion may be an objective indicator of severity. Future work is needed to examine how immediate measures of cerebral blood flow are predictive of cognitive recovery and post‐concussive symptoms.Support or Funding InformationThis work was supported by Dept. of Pharmacology, Physiology, and Neuroscience, Rutgers and the War Related Illness and Injury Study Center.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Children with autism spectrum disorder show increased sensitivity to time-based predictability

Objectives: We studied timed-based expectancy as well as general perceptual-motor speed in children with autism spectrum disorder (ASD).Methods: In Experiment 1, 11 children with ASD and 11 typically developing children (TD) (6–13 years) completed a binary choice response task in which foreperiod duration predicted the response target’s location with a probability of 0.8. In Experiment 2, we compared performance between 10 children with ASD (6–11 years) and 10 TD children by using a simple reaction time test.Results: Employing a binary forced choice task where the duration of a pre-target interval (800 or 1400 ms) probabilistically predicted the target, we found that children with ASD were sensitive to the temporal regularity, whereas TD children were not. Children with ASD were faster for expected combinations of interval and target location but they were also less accurate for those combinations. Results from an additional simple reaction time test indicate that the development of general perceptual-motor processes was delayed in children with ASD. However, the ability for children with ASD to form time-based expectancies was not correlated with their performance in the simple reaction time test.Conclusion: Children with ASD show significantly greater sensitivity towards time-based predictability than TD children. However, the development of general perceptual-motor processes was impaired in children with ASD.