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1.
Effects of 90 Days of Resveratrol Supplementation on Cognitive Function in Elders: A Pilot Study.
Anton, SD, Ebner, N, Dzierzewski, JM, Zlatar, ZZ, Gurka, MJ, Dotson, VM, Kirton, J, Mankowski, RT, Marsiske, M, Manini, TM
Journal of alternative and complementary medicine (New York, N.Y.). 2018;(7):725-732
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Abstract
OBJECTIVE The purpose of this trial was to study the effects of chronic resveratrol use on cognitive function in humans. DESIGN The authors conducted a double-blind, Phase IIa randomized, placebo-controlled trial to obtain preliminary estimates of the effects of resveratrol supplementation on cognitive function over a 90-day period in older adults. LOCATION University of Florida in Gainesville, FL. SUBJECTS Sedentary, overweight older adults (N = 32; age range: 65-93 years, M age = 73.34 years, SD age = 7.02 years). INTERVENTION Participants were randomized to one of three treatment groups (placebo, 300 mg/day resveratrol, 1000 mg/day resveratrol) for 90 days. OUTCOME MEASURES Cognitive function was assessed before and after treatment using a well-characterized test battery: Trail Making, Digits Forward and Backward, Erikson-Flanker, Controlled Oral Word Association, Hopkins Verbal Learning Test-Revised, and Task Switching. RESULTS Psychomotor speed improved on the Trail Making Test part A in participants taking 1000 mg/day of resveratrol compared with participants in both the 300 mg/day condition and the placebo condition (p = 0.02). CONCLUSION This pilot study suggests that 90 days of resveratrol supplementation at a dose of 1000/mg per day selectively improves psychomotor speed but does not significantly affect other domains of cognitive function in older adults. These findings provide modest support to further study the effects of resveratrol on cognitive function in older adults.
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Neurobehavioral Outcomes 11 Years After Neonatal Caffeine Therapy for Apnea of Prematurity.
Mürner-Lavanchy, IM, Doyle, LW, Schmidt, B, Roberts, RS, Asztalos, EV, Costantini, L, Davis, PG, Dewey, D, D'Ilario, J, Grunau, RE, et al
Pediatrics. 2018;(5)
Abstract
BACKGROUND AND OBJECTIVES Caffeine is effective in the treatment of apnea of prematurity. Although caffeine therapy has a benefit on gross motor skills in school-aged children, effects on neurobehavioral outcomes are not fully understood. We aimed to investigate effects of neonatal caffeine therapy in very low birth weight (500-1250 g) infants on neurobehavioral outcomes in 11-year-old participants of the Caffeine for Apnea of Prematurity trial. METHODS Thirteen academic hospitals in Canada, Australia, Great Britain, and Sweden participated in this part of the 11-year follow-up of the double-blind, randomized, placebo-controlled trial. Measures of general intelligence, attention, executive function, visuomotor integration and perception, and behavior were obtained in up to 870 children. The effects of caffeine therapy were assessed by using regression models. RESULTS Neurobehavioral outcomes were generally similar for both the caffeine and placebo group. The caffeine group performed better than the placebo group in fine motor coordination (mean difference [MD] = 2.9; 95% confidence interval [CI]: 0.7 to 5.1; P = .01), visuomotor integration (MD = 1.8; 95% CI: 0.0 to 3.7; P < .05), visual perception (MD = 2.0; 95% CI: 0.3 to 3.8; P = .02), and visuospatial organization (MD = 1.2; 95% CI: 0.4 to 2.0; P = .003). CONCLUSIONS Neonatal caffeine therapy for apnea of prematurity improved visuomotor, visuoperceptual, and visuospatial abilities at age 11 years. General intelligence, attention, and behavior were not adversely affected by caffeine, which highlights the long-term safety of caffeine therapy for apnea of prematurity in very low birth weight neonates.
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Impact of a purported nootropic supplementation on measures of mood, stress, and marksmanship performance in U.S. active duty soldiers.
Barringer, N, Crombie, A, Kotwal, R
Journal of the International Society of Sports Nutrition. 2018;(1):26
Abstract
BACKGROUND The purpose of this study was to determine the impact of a commercially available purported nootropic supplement on mood, stress, and rifle marksmanship accuracy and engagement time via an Engagement Skills Trainer. METHODS In this double-blind, placebo-controlled trial, 43 U.S. active duty Soldiers participating in a professional military course were assigned to treatment (n = 20; 16 males and 4 females) or placebo (n = 23; 15 males and 8 females) based on initial marksmanship score. The study period was 31 days (testing performed on days 1 and 31, supplementation days 2 through 30). Participants were instructed to consume 2 pills at breakfast and 1 pill at dinner for a total of 3 pills per day (1925 mg) of either the Alpha Brain® nootropic supplement or a placebo. Height, weight, cortisol (in a hair sample), body composition using multi-frequency tetrapolar bioelectrical impedance (InBody 720), and marksmanship (Engagement Skills Trainer 2000). Marksmanship was assessed in the prone position with zeroed M-4 rifles with a twenty target protocol with targets presenting and remaining for 3 s at set intervals. Participants' performance were assessed with hits versus misses, distance of hit from target center mass (DCM), and target engagement speed. Statistical analysis via SPSS Statistics 21 (IBM) was conducted using a repeated measures ANOVA with significance set at P < 0.5. RESULTS There was no statistically significant difference between Treatment and Placebo for hits (TreatmentPre 18.5 ± 1.5, TreatmentPost 19.4 ± 0.8, PlaceboPre18.2 ± 2.9, PlaceboPost19.4 ± 1.3), initial reaction time in seconds (TreatmentPre 1.65 ± 0.28, TreatmentPost 1.43 ± 0.28, PlaceboPre1.59 ± 0.29, PlaceboPost1.41 ± 0.21), mean reaction time in seconds (TreatmentPre 1.60 ± 0.20, TreatmentPost 1.41 ± 0.16, PlaceboPre1.61 ± 0.51, PlaceboPost1.46 ± 0.56), or distance from center mass in centimeters (TreatmentPre 11.28 ± 4.28, TreatmentPost 11.92 ± 4.23, PlaceboPre10.52 ± 5.29, PlaceboPost10.94 ± 4.64). A significant time effect (P < 0.5) was found for both groups on all variables except distance from center mass. Reaction time values were adjusted to give percent decrease for initial reaction and mean reaction for the Treatment group (- 12.3% ± 16, - 15.2% ± 21.6) compared to the Placebo group (- 8.3% ± 21.8, - 12.5% ± 23.5), but no significant difference was found. CONCLUSION The Alpha Brain® nootropic supplement did not have any statistically significant effects on marksmanship performance in this study. Given the rising popularity of nootropic supplements, future research on their potential impact on cognitively demanding soldier tasks, such as target discrimination scenarios, are recommended.
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Effect of alternating postures on cognitive performance for healthy people performing sedentary work.
Schwartz, B, Kapellusch, JM, Schrempf, A, Probst, K, Haller, M, Baca, A
Ergonomics. 2018;(6):778-795
Abstract
Prolonged sitting is a risk factor for several diseases and the prevalence of worksite-based interventions such as sit-to-stand workstations is increasing. Although their impact on sedentary behaviour has been regularly investigated, the effect of working in alternating body postures on cognitive performance is unclear. To address this uncertainty, 45 students participated in a two-arm, randomised controlled cross-over trial under laboratory conditions. Subjects executed validated cognitive tests (working speed, reaction time, concentration performance) either in sitting or alternating working postures on two separate days (ClinicalTrials.gov Identifier: NCT02863731). MANOVA results showed no significant difference in cognitive performance between trials executed in alternating, standing or sitting postures. Perceived workload did not differ between sitting and alternating days. Repeated measures ANOVA revealed significant learning effects regarding concentration performance and working speed for both days. These results suggest that working posture did not affect cognitive performance in the short term. Practitioner Summary: Prior reports indicated health-related benefits based on alternated (sit/stand) body postures. Nevertheless, their effect on cognitive performance is unknown. This randomised controlled trial showed that working in alternating body postures did not influence reaction time, concentration performance, working speed or workload perception in the short term.
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Do perturbation-evoked responses result in higher reaction time costs depending on the direction and magnitude of perturbation?
Inkol, KA, Huntley, AH, Vallis, LA
Experimental brain research. 2018;(6):1689-1698
Abstract
To date, little work has focused on whether cognitive-task interference during postural response execution is influenced by the direction and/or magnitude of the perturbation applied. Hypothetically, the increased difficulty associated with a backward loss of balance could necessitate increased allocation of cognitive resources to counteract destabilizing forces. The current study investigated these relationships using a paradigm in which individuals performed a cognitive task (auditory Stroop task during quiet stance; baseline condition). In certain trials, a translation of the support surface was concurrently evoked (magnitude: small or large; direction: forward or backward) which required a postural response to maintain balance. Ten healthy young adults completed four blocks of these experimental trials (26 randomized trials/block). Postural stability during balance recovery was evaluated using the margin of stability (MoS), while Stroop task performance was based on reaction time cost (RTC) and differences between experimental conditions. Results showed no effect of perturbation direction on RTC, but there was an observed MoS increase at peak extrapolated center of mass excursion following a small perturbation evoked concurrently with the cognitive task. No effect of cognitive-task performance was detected for MoS during stepping strategies (followed large perturbations). Instead, increased RTC were observed relative to the fixed base of support responses. In general, young adults adopted a "posture-first" strategy, regardless of perturbation direction, reinforcing the importance of cognition in the maintenance of upright balance.
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The ipsilateral corticospinal responses to cross-education are dependent upon the motor-training intervention.
Leung, M, Rantalainen, T, Teo, WP, Kidgell, D
Experimental brain research. 2018;(5):1331-1346
Abstract
This study aimed to identify the ipsilateral corticospinal responses of the contralateral limb following different types of unilateral motor-training. Three groups performing unilateral slow-paced strength training (SPST), non-paced strength training (NPST) or visuomotor skill training (VT) were compared to a control group. It was hypothesised that 4 weeks of unilateral SPST and VT, but not NPST, would increase ipsilateral corticospinal excitability (CSE) and reduce short-interval cortical inhibition (SICI), resulting in greater performance gains of the untrained limb. Tracking error of the untrained limb reduced by 29 and 41% following 2 and 4 weeks of VT. Strength of the untrained limb increased by 8 and 16% following 2 and 4 weeks of SPST and by 6 and 13% following NPST. There was no difference in cross-education of strength or tracking error. For the trained limb, SPST and NPST increased strength (28 and 26%), and VT improved by 47 and 58%. SPST and VT increased ipsilateral CSE by 89 and 71% at 2 weeks. Ipsilateral CSE increased 105 and 81% at 4 weeks following SPST and VT. The NPST group and control group showed no changes at 2 and 4 weeks. SPST and VT reduced ipsilateral SICI by 45 and 47% at 2 weeks; at 4 weeks, SPST and VT reduced SICI by 48 and 38%. The ipsilateral corticospinal responses are determined by the type of motor-training. There were no differences in motor performance between SPST, NPST and VT. The data suggests that the corticospinal responses to cross-education are different and determined by the type of motor-training.
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Repeated Administration Effects on Psychomotor Vigilance Test Performance.
Basner, M, Hermosillo, E, Nasrini, J, McGuire, S, Saxena, S, Moore, TM, Gur, RC, Dinges, DF
Sleep. 2018;(1)
Abstract
STUDY OBJECTIVES The Psychomotor Vigilance Test (PVT) is reported to be free of practice effects that can otherwise confound the effects of sleep loss and circadian misalignment on performance. This differentiates the PVT from more complex cognitive tests. To the best of our knowledge, no study has systematically investigated practice effects on the PVT across multiple outcome domains, depending on administration interval, and in ecologically more valid settings. METHODS We administered a validated 3-minute PVT (PVT-B) 16 times in 45 participants (23 male, mean ± SD age 32.6 ± 7.3 years, range 25-54 years) with administration intervals of ≥10 days, ≤5 days, or 4 times per day. We investigated linear and logarithmic trends across repeated administrations in 10 PVT-B outcome variables. RESULTS The fastest 10% of response times (RT; plin = .0002), minimum RT (plog = .0010), and the slowest 10% of reciprocal RT (plog = .0124) increased while false starts (plog = 0.0050) decreased with repeated administration, collectively decreasing RT variability (plog = .0010) across administrations. However, the observed absolute changes were small (e.g., -0.03 false starts per administration, linear fit) and are probably irrelevant in practice. Test administration interval did not modify the effects of repeated administration on PVT-B performance (all p > .13 for interaction). Importantly, mean and median RT, response speed, and lapses, which are among the most frequently used PVT outcomes, did not change systematically with repeated administration. CONCLUSIONS PVT-B showed stable performance across repeated administrations. Combined with its high sensitivity, this corroborates the status of the PVT as the de facto gold standard measure of the neurobehavioral effects of sleep loss and circadian misalignment.
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On the effects of tyrosine supplementation on interference control in a randomized, double-blind placebo-control trial.
Stock, AK, Colzato, L, Beste, C
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology. 2018;(8):933-944
Abstract
Exerting cognitive control is an effortful endeavor that is strongly modulated by the availability of dopamine (DA) and norepinephrine (NE), which are both synthesized from the amino acid precursor tyrosine. Supplementing tyrosine may increase the synthesis of both catecholamines. This has been suggested to improve executive functioning and potentially even counteract depletion effects in this domain. Yet, it has remained unclear whether tyrosine also improves interference control and whether subliminally and consciously triggered response conflicts are subject to the same modulation. We investigated this question in a double-blind intra-individual study design. N = 26 young healthy subjects performed two consecutive cognitive control tasks that triggered automatic incorrect response tendencies; once with tyrosine supplementation and once with a placebo. The results show that tyrosine decreased the size of consciously perceived conflicts in a Simon Task, but not a Flanker task, thus suggesting that stimulus-response conflicts might be modulated differently from stimulus-stimulus conflicts. At the same time, tyrosine supplementation increased the size of subliminally triggered conflicts whenever a different, consciously perceived conflict was also present. This suggests that control-related DA and NE release may increase visuo-motor priming, especially when no conflict-specific top-down control may be triggered to counteract subliminal priming effects. Also, these subliminal conflicts might be aggravated by concurrent control investments in other kinds of conflict. Taken together, our data suggest that beneficial effects of tyrosine supplementation do not require depletion effects, but may be limited to situations where we consciously perceive a conflict and the associated need for conflict-specific control.
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Effectiveness of Psycho-Physiological Portable Devices to Analyse Effect of Ergogenic Aids in Military Population.
Diaz-Manzano, M, Robles-Pérez, JJ, Herrera-Mendoza, K, Herrera-Tapias, B, Fernández-Lucas, J, Aznar-Lain, S, Clemente-Suárez, VJ
Journal of medical systems. 2018;(5):84
Abstract
Caffeine is one of the ergogenic substances most used by warfighters in current operation areas, but the effect on the organic response and operational performed is already poor knowledge. This research aimed to study the acute effect of 400 mg of caffeine monohydrate on the psycho-physiological response and rifle marksmanship of warfighters during a close quarter combat simulation. We analysed parameter of heart rate, blood lactate, cortical arousal, state anxiety and marksmanship of 20 Spanish Army veteran warfighters before and after a close quarter combat simulation in a double-blind procedure, also a correlation analysis was conducted between all the study variables. Marksmanship of warfighters did not improve with the caffeine ingestion, but it produced an increase in blood lactate concentration (caffeine: 1.9 ± 0.5 vs. 9.2 ± 1.1 mmol.l-1; placebo: 1.8 ± 0.7 vs. 6.9 ± 2.2 mmol.l-1), cortical arousal (% of change: caffeine: 2.51; placebo: -1.96) and heart rate (caffeine: 80.0 ± 7.2 vs. 172.9 ± 28.2 bpm; placebo: 79.3 ± 6.4 vs. 154.0 ± 26.8 bpm). In addition, higher heart rate values correlated negatively with marksmanship in close quarter combat. We concluded that caffeine intake did not improve the warfighters rifle marksmanship in close quarter combat possibly due to the increase in the physiological response.
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Two-day fasting evokes stress, but does not affect mood, brain activity, cognitive, psychomotor, and motor performance in overweight women.
Solianik, R, Sujeta, A
Behavioural brain research. 2018;:166-172
Abstract
The physiological, cognitive state, and motor behavior changes that occur during acute fasting are not completely understood. Thus, the aim of this study was to estimate the effect of 2-day total fasting on evoked stress, mood, brain activity, and cognitive, psychomotor, and motor function in overweight women. Eleven overweight women (body mass index above 25kg/m2) aged 20-30 years were tested under two conditions allocated randomly: 2-day zero-calorie diet with water provided ad libitum and 2-day usual diet. One week before the experiment, aerobic fitness was evaluated. Subjective stress ratings in relation to the diet, autonomic function, prefrontal cortex activity, cognitive performance, psychomotor coordination, and grip strength were evaluated before and after each diet. The study demonstrated that fasting decreased log-transformed high-frequency (HF) power, without affecting heart rate. The relative maximum oxygen uptake was negatively correlated with subjective stress rating and changes in log-transformed HF. Fasting did not affect mood, brain activity, and cognitive, motor, and psychomotor performance. Thus, 2-day total fasting evoked moderate stress with a shift of the autonomic nervous system balance toward sympathetic activity in overweight women. Better aerobic endurance is likely to facilitate the capacity for dealing with acute fasting. Regardless of the evoked stress, cognitive state and motor behavior remained intact.