scholarly journals Caffeine may disrupt the impact of real-time drowsiness on cognitive performance: a double-blind, placebo-controlled small-sample study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. Aidman ◽  
M. Balin ◽  
K. Johnson ◽  
S. Jackson ◽  
G. M. Paech ◽  
...  

AbstractCaffeine is widely used to promote alertness and cognitive performance under challenging conditions, such as sleep loss. Non-digestive modes of delivery typically reduce variability of its effect. In a placebo-controlled, 50-h total sleep deprivation (TSD) protocol we administered four 200 mg doses of caffeine-infused chewing-gum during night-time circadian trough and monitored participants' drowsiness during task performance with infra-red oculography. In addition to the expected reduction of sleepiness, caffeine was found to disrupt its degrading impact on performance errors in tasks ranging from standard cognitive tests to simulated driving. Real-time drowsiness data showed that caffeine produced only a modest reduction in sleepiness (compared to our placebo group) but substantial performance gains in vigilance and procedural decisions, that were largely independent of the actual alertness dynamics achieved. The magnitude of this disrupting effect was greater for more complex cognitive tasks.

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sara Assecondi ◽  
Rong Hu ◽  
Gail Eskes ◽  
Michelle Read ◽  
Chris Griffiths ◽  
...  

Following publication of the original article [1], the authors flagged that the article had published with the Acknowledgements erroneously excluded from the declarations at the end of the article.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1310-1310
Author(s):  
Lu Hu ◽  
Chan Wang ◽  
Huilin Li ◽  
Margaret Curran ◽  
Collin J Popp ◽  
...  

Abstract Objectives We examined whether a diet personalized to reduce postprandial glycemic response (PPGR) to foods increases weight loss self-efficacy. Methods The Personal Diet Study is an ongoing clinical trial that aims to compare two weight loss diets: a one-size-fits-all, calorie-restricted, low-fat diet (Standardized) versus a diet having the same calorie restriction but utilizing a machine learning algorithm to predict and reduce PPGR (Personalized). Both groups receive the same behavioral counseling to enhance weight loss self-efficacy. Both groups self-monitor dietary intake using a mobile app, with Standardized receiving real-time feedback on calories and macronutrient distribution, and Personalized receiving real time feedback on calories, macronutrient distribution, and predicted PPGR. We examined changes in self-efficacy between baseline and 3 mos, using the 20-item Weight Efficacy Lifestyle questionnaire (WEL). Linear mixed models were used to analyze differences, adjusting for age, gender, and race. Results The analyses included the first 75 participants to complete 3-mos assessments (41 Personalized and 34 Standardized). The majority of the participants were white (69.3%), female (61.3%), with a mean age of 61.7 years (SD = 9.9) and BMI of 33.4 kg/m2 (SD = 4.8). At baseline, WEL scores were similar between the 2 groups [Standardized WEL: 118.8 (SD = 27.6); Personalized WEL: 124.9 (SD = 29.5), P = 0.47]. At 3 mos, the WEL score was significantly improved in both groups [16.0 (SD = 4.1) in the Standardized group (P < 0.001) and 7.4 (SD = 3.7) in the Personalized group (P = 0.048)], but the between group difference was not significant (P = 0.12). Conclusions Personalized feedback on predicted PPGRs does not appear to enhance weight loss self-efficacy at 3 mos. The lack of significance may be related to the short follow-up period in these preliminary analyses, the small sample accrued to date, or the fact that WEL is designed to assess confidence in various situations (e.g., depressed, anxious) that may not be impacted by personalization. These analyses will be replicated with a larger sample using data obtained through the 6-mos follow-up. New self-efficacy measures may be required to assess the impact of personalized dietary counseling. Funding Sources This research was supported by the American Heart Association.


2021 ◽  
Vol 15 ◽  
Author(s):  
Chin-Teng Lin ◽  
Jung-Tai King ◽  
Alka Rachel John ◽  
Kuan-Chih Huang ◽  
Zehong Cao ◽  
...  

Many studies have reported that exercise can influence cognitive performance. But advancing our understanding of the interrelations between psychology and physiology in sports neuroscience requires the study of real-time brain dynamics during exercise in the field. Electroencephalography (EEG) is one of the most powerful brain imaging technologies. However, the limited portability and long preparation time of traditional wet-sensor systems largely limits their use to laboratory settings. Wireless dry-sensor systems are emerging with much greater potential for practical application in sports. Hence, in this paper, we use the BR8 wireless dry-sensor EEG system to measure P300 brain dynamics while cycling at various intensities. The preparation time was mostly less than 2 min as BR8 system’s dry sensors were able to attain the required skin-sensor interface impedance, enabling its operation without any skin preparation or application of conductive gel. Ten participants performed four sessions of a 3 min rapid serial visual presentation (RSVP) task while resting and while cycling. These four sessions were pre-CE (RSVP only), low-CE (RSVP in 40–50% of max heart rate), vigorous-CE (RSVP in 71–85% of max heart rate) and post-CE (RSVP only). The recorded brain signals demonstrate that the P300 amplitudes, observed at the Pz channel, for the target and non-target responses were significantly different in all four sessions. The results also show decreased reaction times to the visual attention task during vigorous exercise, enriching our understanding of the ways in which exercise can enhance cognitive performance. Even though only a single channel was evaluated in this study, the quality and reliability of the measurement using these dry sensor-based EEG systems is clearly demonstrated by our results. Further, the smooth implementation of the experiment with a dry system and the success of the data analysis demonstrate that wireless dry EEG devices can open avenues for real-time measurement of cognitive functions in athletes outside the laboratory.


Author(s):  
Alan J. Kivitz ◽  
Oliver FitzGerald ◽  
Peter Nash ◽  
Shirley Pang ◽  
Valderilio F. Azevedo ◽  
...  

Abstract Objective Analyze tofacitinib efficacy and safety by background methotrexate (MTX) dose in patients with psoriatic arthritis (PsA). Methods This post hoc analysis pooled data from two phase III, double-blind trials (OPAL Broaden, NCT01877668; OPAL Beyond, NCT01882439) including patients receiving tofacitinib 5 or 10 mg twice daily (BID), or placebo, with stable MTX. Efficacy outcomes at month 3 stratified by MTX dose (≤ 15 month 3 stratified by MTX dose vs > 15 mg/week) were American College of Rheumatology (ACR)20/50/70, Health Assessment Questionnaire-Disability Index (HAQ-DI); Psoriasis Area and Severity Index (PASI)50/75; change from baseline in HAQ-DI; physician’s global assessment of PsA (PGA-PsA-visual analog scale [VAS]); patient’s global joint and skin assessment (PGJS-VAS), Leeds Enthesitis Index (LEI); and Dactylitis Severity Score (DSS). Safety assessments included adverse events and laboratory parameters. Results Five hundred fifty-six patients received tofacitinib 5 mg BID (n = 186), 10 mg BID (n = 178), or placebo (n = 192), plus MTX (≤ 15 mg/week, n = 371; > 15 mg/week, n = 185). At month 3, tofacitinib efficacy was generally greater than placebo. Patients receiving tofacitinib 5 mg BID demonstrated greater numerical improvements in efficacy outcomes at month 3 with MTX > 15 mg/week vs MTX ≤ 15 mg/week; patients receiving tofacitinib 10 mg BID displayed the opposite. The safety profile was generally consistent between groups; headache was associated with MTX > 15 mg/week; decreased hemoglobin levels were observed in patients receiving tofacitinib 10 mg BID and MTX ≤ 15 mg/week. Conclusion Efficacy of tofacitinib was generally numerically greater than placebo, regardless of MTX dose. Tofacitinib 5 mg BID was generally more efficacious with MTX > 15 mg/week vs ≤ 15 mg/week; the opposite was observed for tofacitinib 10 mg BID. Headache was more frequent with MTX > 15 mg/week. Trial registration ClinicalTrials.gov. Identifier: NCT01877668 (registration: June 14, 2013) and NCT01882439 (registration: June 20, 2013). Key Points• Methotrexate is widely used in the treatment of psoriatic arthritis; however, there are limited data on the impact of varying background methotrexate doses on the efficacy and safety of Janus kinase inhibitors in patients with psoriatic arthritis.• This post hoc analysis assessed the impact of background methotrexate dose (≤ 15 or > 15 mg/week) on tofacitinib efficacy and safety in patients with psoriatic arthritis.• Results indicated that tofacitinib efficacy was generally numerically greater than placebo, regardless of methotrexate dose. Tofacitinib 5 mg twice daily, in combination with a higher dose of background methotrexate, was more efficacious compared with a lower dose of background methotrexate; the opposite was observed for tofacitinib 10 mg twice daily.• Headache was more frequent with the higher methotrexate dose. Data should be interpreted with caution due to the small sample sizes.


2016 ◽  
Vol 41 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Wesley K. Lefferts ◽  
William E. Hughes ◽  
Corey N. White ◽  
Tom D. Brutsaert ◽  
Kevin S. Heffernan

The matching of oxygen supply to neural demand (i.e., neurovascular coupling (NVC)) is an important determinant of cognitive performance. The impact of hypoxia on NVC remains poorly characterized. NVC is partially modulated by nitric oxide (NO), which may initially decrease in hypoxia. This study investigated the effect of acute NO-donor (nitrate) supplementation on NVC and cognitive function in hypoxia. Twenty healthy men participated in this randomized, double-blind, crossover design study. Following normoxic cognitive/NVC testing, participants consumed either nitrate (NIT) or a NIT-depleted placebo (PLA). Participants then underwent 120 min of hypoxia (11.6% ± 0.1% O2) and all cognitive/NVC testing was repeated. NVC was assessed as change in middle cerebral artery (MCA) blood flow during a cognitive task (incongruent Stroop) using transcranial Doppler. Additional computerized cognitive testing was conducted separately to assess memory, executive function, attention, sensorimotor, and social cognition domains. Salivary nitrite significantly increased following supplementation in hypoxia for NIT (+2.6 ± 1.0 arbitrary units (AU)) compared with PLA (+0.2 ± 0.3 AU; p < 0.05). Memory performance (−6 ± 13 correct) significantly decreased (p < 0.05) in hypoxia while all other cognitive domains were unchanged in hypoxia for both PLA and NIT conditions (p > 0.05). MCA flow increased during Stroop similarly in normoxia (PLA +5 ± 6 cm·s−1, NIT +7 ± 7 cm·s−1) and hypoxia (PLA +5 ± 9 cm·s−1, NIT +6 ± 7 cm·s−1) (p < 0.05) and this increase was not altered by PLA or NIT (p > 0.05). In conclusion, acute hypoxia resulted in significant reductions in memory concomitant with preservation of executive function, attention, and sensorimotor function. Hypoxia had no effect on NVC. Acute NIT supplementation had no effect on NVC or cognitive performance in hypoxia.


2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A25-A25
Author(s):  
S Blunden ◽  
J Osborne

Abstract Background Behavioural sleep interventions to improve infant sleep disturbance commonly include extinction where an unwanted behaviour (night time crying) is periodically ignored. There have been conflicting findings regarding the impact of extinction methods on infant stress levels as measured with cortisol and as perceived by mothers and only one that measured cortisol at the time of the separation. This study aimed to compare a responsive method to extinction (controlled crying) and a control group evaluating subjective and objective stress for mother/infant dyads at the time of bedtime separation. Methods Mother/infant dyads were randomly allocated to behavioural sleep interventions (Responsive - n= 7, Controlled Crying - n=6 or Controls - n=4). Cortisol (two oral swabs on two nights at T2), maternal self-reported stress (Subjective Units of Distress - SUDS), and perceived infant distress (PIS) were compared over eight weeks. Correlations tested relationships between PIS, SUDS and infant cortisol levels. Mixed models analysis were used for cortisol analyses. Results There were no significant differences in cortisol levels between groups across time points but significant inter and intra-individual variability. Maternal stress was positively correlated with infant cortisol and PIS (p&lt;0.05) and mothers in the Responsive group were significantly less stressed (p=0.02). Conclusion In this small sample, infant cortisol during bedtime separation was variable, elevated in all sleep interventions and not significantly different. Mothers were less stressed in the Responsive group. Findings indicate responsive methods are comparable to extinction and less stressful for mothers offering a possible gentler choice at bedtime separation.


1995 ◽  
Vol 23 (3) ◽  
pp. 167-174
Author(s):  
M M-L Janssens ◽  
R L Lins

This randomized, double-blind, double-dummy, parallel-group trial was initiated to evaluate and compare the tolerability of once-daily astemizole-D capsules (10 mg astemizole/240 mg pseudoephedrine) and twice-daily loratadine-D tablets (5 mg loratadine/120 mg pseudoephedrine), with particular reference to the impact of treatment on quality of sleep. A total of 240 healthy volunteers participated in this study with a treatment duration of 3 days. Astemizole-D consistently produced less sleep impairment than loratadine-D with statistically significant differences in favour of astemizole-D reported for night-time waking on days 4 and 5 ( P = 0.004 and P = 0.006, respectively), as well as for night-time restlessness on day 4 and the total score for all sleep parameters on day 4 ( P < 0.05). Global evaluations of overall sleep quality at the end of the trial also revealed some statistically significant differences in favour of astemizole-D. Both drugs were well tolerated and there were no differences in the incidence and type of adverse events reported in the two treatment groups. Slight changes in heart rate and blood-pressure were observed in both treatment groups, but these were small and were not considered to be of clinical significance. In conclusion, once-daily astemizole-D is well tolerated and appears to cause less sleep impairment than twice-daily loratadine-D.


CJEM ◽  
2018 ◽  
Vol 20 (S1) ◽  
pp. S67-S67
Author(s):  
A. B. Dick ◽  
P. Olszynski ◽  
V. Behl

Introduction: Increasingly, hospitals are adopting electronic charting systems. Recent literature suggests that physicians are spending roughly 2:1 hours on charting as compared to actual patient care raising questions as to whether manual electronic charting is the best use of scarce physician resources. To counter these effects, some hospitals have introduced scribes into their departments. A medical scribe is a person, or paraprofessional, who specializes in charting physician-patient encounters in real time. In this pilot study, we assessed the impact of having a scribe on the mental and physical fatigue, patient and healthcare-team engagement, and overall work satisfaction of emergency physicians at an urban emergency department (St. Paul’s Hospital, Saskatoon). Methods: Three research participants (emergency physicians) were recruited to the study. Each participant completed a typing test to determine typing skills. The student researcher then provided scribe services for each participant for two shifts. The scribe charted physician-patient interactions in real time and also completed order sets, wrote orders, imaging requisitions, and prescriptions. Physicians completed surveys after each shift with the scribe as well as after 2 shifts without a scribe (for a total of 12 shifts in the study, 6 with the intervention). Physicians were asked to rate their mental and physical fatigue, enjoyment of work, and impact on patient/team engagement on a 10-point Likert scale. Results from the questionnaires were analyzed to determine individual and group mean responses. Given the small sample size, no further statistical calculations were completed. Results: Typing test results (in words per minute) were as follows: Scribe 93, Physician A 64, Physician B 40, Physician C 25. In terms of both mental and physical fatigue post shift, all 3 participants recorded being less fatigued after working shifts with a scribe. Mean group scores were as follows: mental fatigue decreased by 33%, physical fatigue decreased by 23%. Physicians work enjoyment improved by 10%. Team and patient interaction did not seem impacted by the intervention. Conclusion: It appears that regardless of typing skills, all physician participants noted a measurable benefit from having a scribe on shift. This suggests that off-loading documentation to the scribe has a positive effect on mental and physical endurance. These results warrant further investigations.


2017 ◽  
Author(s):  
E. Debellemaniere ◽  
S. Chambon ◽  
C. Pinaud ◽  
V. Thorey ◽  
D. Léger ◽  
...  

ABSTRACTObjectiveRecent research has shown that auditory closed-loop stimulations can enhance sleep slow oscillations (SO) to improve N3 sleep quality and cognition. Previous studies have been conducted in a lab environment and on a small sample size. The present study aimed at validating and assessing the performance of a novel ambulatory wireless dry-EEG device (WDD), for auditory closed-loop stimulations of SO during N3 sleep at home.Material and MethodsThe performance of the WDD to detect N3 sleep automatically and to send auditory closed-loop stimulations on SO were tested on 20 young healthy subjects who slept with both the WDD and a miniaturized polysomnography (part 1) in both stimulated and sham nights within a double blind, randomized and crossover design.The electrophysiological effects of auditory closed-loop stimulation on delta power increase were assessed after 1 and 10 nights of stimulations on an observational pilot study in the home environment including 90 middle-aged subjects (part 2).ResultsThe sensitivity and specificity of the WDD to automatically detect N3 sleep in real-time were 0.70 and 0.90, respectively. The stimulation accuracy of the SO ascending-phase targeting was 45±52°. The stimulation protocol induced an increase of 39.5 % of delta power after the stimulations. The increase of SO response to auditory stimulations remained at the same level after 10 consecutive nights.ConclusionThe WDD shows good performances to automatically detect in real-time N3 sleep and to send auditory closed-loop stimulations on SO accurately. These stimulations increased the SO amplitude during N3 sleep without any adaptation effect after 10 consecutive nights. This tool provides new perspectives to figure out novel sleep EEG biomarkers in longitudinal studies and can be interesting to conduct broad studies on the effects of auditory stimulations during sleep.


2007 ◽  
Vol 21 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Yunfeng Sun ◽  
Yinling Zhang ◽  
Ning He ◽  
Xufeng Liu ◽  
Danmin Miao

Abstract. Caffeine placebo expectation seems to improve vigilance and cognitive performance. This study investigated the effect of caffeine and placebo expectation on vigilance and cognitive performance during 28 h sleep deprivation. Ten healthy males volunteered to take part in the double-blind, cross-over study, which required participants to complete five treatment periods of 28 h separated by 1-week wash-out intervals. The treatments were no substance (Control); caffeine 200 mg at 00:00 (C200); placebo 200 mg at 00:00 (P200); twice caffeine 200 mg at 00:00 and 04:00 (C200-C200); caffeine 200 mg at 00:00 and placebo 200 mg at 04:00 (C200-P200). Participants were told that all capsules were caffeine and given information about the effects of caffeine to increase expectation. Vigilance was assessed by a three-letter cancellation test, cognitive functions by the continuous addition test and Stroop test, and cardiovascular regulation by heart rate and blood pressure. Tests were performed bihourly from 00:00 to 10:00 of the second day. Results indicated that C200-P200 and C200-C200 were more alert (p < .05) than Control and P200. Their cognitive functions were higher (p < .05) than Control and P200. Also, C200-P200 scored higher than C200 in the letter cancellation task (p < .05). No test showed any significant differences between C200-P200 and C200-C200. The results demonstrated that the combination of caffeine 200 mg and placebo 200 mg expectation exerted prolonged positive effects on vigilance and cognitive performance.


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