15
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Caffeine improves reaction time, vigilance and logical reasoning during extended periods with restricted opportunities for sleep

      research-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Rationale

          Various occupational groups are required to maintain optimal physical and cognitive function during overnight periods of wakefulness, often with less than optimal sleep. Strategies are required to help mitigate the impairments in cognitive function to help sustain workplace safety and productivity.

          Objectives

          To test the effectiveness of repeated 200 mg doses of caffeine on cognitive function and live-fire marksmanship with soldiers during three successive nights of sustained wakefulness followed by 4-h afternoon sleep periods.

          Methods

          Twenty Special Forces personnel (28.6 ± 4.7 years, 177.6 ± 7.5 cm and 81.2 ± 8.0 kg) were randomly assigned to receive four 200-mg doses of caffeine ( n = 10) or placebo ( n = 10) during the late evening and early morning hours during three successive days. An afternoon 4-h sleep period followed. The psychomotor (PVT) and field (FVT) vigilance, logical reasoning (LRT) tests and a vigilance monitor assessed cognitive function throughout the study. Live-fire marksmanship requiring friend–foe discrimination was assessed.

          Results

          Caffeine maintained speed on the PVT ( p < 0.02), improved detection of events during FVT ( p < 0.001), increased number of correct responses to stimuli as assessed by the vigilance monitor ( p < 0.001) and increased response speed during the LRT ( p < 0.001) throughout the three overnight testing periods. Live-fire marksmanship was not altered by caffeine.

          Conclusions

          A total daily dose of 800 mg caffeine during successive overnight periods of wakefulness is an effective strategy to maintain cognitive function when optimal sleep periods during the day are not available.

          Related collections

          Most cited references60

          • Record: found
          • Abstract: not found
          • Article: not found

          Patterns of performance degradation and restoration during sleep restriction and subsequent recovery: a sleep dose-response study

            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            Neural basis of alertness and cognitive performance impairments during sleepiness. I. Effects of 24 h of sleep deprivation on waking human regional brain activity

              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features.

              Although reports of caffeine withdrawal in the medical literature date back more than 170 years, the most rigorous experimental investigations of the phenomenon have been conducted only recently. The purpose of this paper is to provide a comprehensive review and analysis of the literature regarding human caffeine withdrawal to empirically validate specific symptoms and signs, and to appraise important features of the syndrome. A literature search identified 57 experimental and 9 survey studies on caffeine withdrawal that met inclusion criteria. The methodological features of each study were examined to assess the validity of the effects. Of 49 symptom categories identified, the following 10 fulfilled validity criteria: headache, fatigue, decreased energy/activeness, decreased alertness, drowsiness, decreased contentedness, depressed mood, difficulty concentrating, irritability, and foggy/not clearheaded. In addition, flu-like symptoms, nausea/vomiting, and muscle pain/stiffness were judged likely to represent valid symptom categories. In experimental studies, the incidence of headache was 50% and the incidence of clinically significant distress or functional impairment was 13%. Typically, onset of symptoms occurred 12-24 h after abstinence, with peak intensity at 20-51 h, and for a duration of 2-9 days. In general, the incidence or severity of symptoms increased with increases in daily dose; abstinence from doses as low as 100 mg/day produced symptoms. Research is reviewed indicating that expectancies are not a prime determinant of caffeine withdrawal and that avoidance of withdrawal symptoms plays a central role in habitual caffeine consumption. The caffeine-withdrawal syndrome has been well characterized and there is sufficient empirical evidence to warrant inclusion of caffeine withdrawal as a disorder in the DSM and revision of diagnostic criteria in the ICD.
                Bookmark

                Author and article information

                Contributors
                +1-905-6420659 , DrTom.McLellan@gmail.com
                Journal
                Psychopharmacology (Berl)
                Psychopharmacology (Berl.)
                Psychopharmacology
                Springer Berlin Heidelberg (Berlin/Heidelberg )
                0033-3158
                1432-2072
                21 December 2014
                21 December 2014
                2015
                : 232
                : 12
                : 2031-2042
                Affiliations
                [ ]Behavioral Biology Branch, Center for Psychiatry and Neuroscience, Walter Reed Army Institute of Research, BLD 503, Silver Spring, MD 20910 USA
                [ ]DRDC Toronto, 1133 Sheppard Avenue West, Toronto, ON M3M 3B9 Canada
                [ ]New Zealand Defence Force, Auckland, New Zealand
                [ ]Military Nutrition Division, US Army Research Institute of Environmental Medicine (USARIEM), Natick, MA 01760-5007 USA
                [ ]TM McLellan Research Inc., 25 Dorman Drive, Stouffville, ON L4A8A7 Canada
                Article
                3834
                10.1007/s00213-014-3834-5
                4432086
                25527035
                a0d1ed14-2cac-4c9d-8874-56728ac13cf0
                © The Author(s) 2014

                Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.

                History
                : 24 September 2014
                : 26 November 2014
                Categories
                Original Investigation
                Custom metadata
                © Springer-Verlag Berlin Heidelberg 2015

                Pharmacology & Pharmaceutical medicine
                sleep loss,sustained operations,afternoon sleep,cognitive function,marksmanship

                Comments

                Comment on this article