Psychopharmacology

, Volume 200, Issue 2, pp 255–260 | Cite as

Effects of caffeine on alertness as measured by infrared reflectance oculography

  • Natalie Michael
  • Murray Johns
  • Caroline Owen
  • John Patterson
Original Investigation

Abstract

Rationale

Caffeine is a well-known stimulant that can be used to increase alertness and performance especially in low arousal situations such as monotonous highway driving or after sleep deprivation. The effects of caffeine in rested, alert, participants are less clear, and this may be attributable to difficulties in objectively assessing small changes in alertness.

Objectives

The present study examined the effects of caffeine in non-sleep-deprived participants with methods that have previously been shown to be sensitive to changes in alertness. In order to avoid confounding results, low, or non-users of caffeine, were sought as participants.

Materials and methods

Twelve subjects participated in a within-subjects double-blind placebo-controlled design study and were administered either a capsule containing 200 mg of caffeine or placebo on two separate days. Ten-minute long tests of vigilance were performed at baseline and then at 30, 60, 120, 180, and 240 min after swallowing the capsule. During vigilance tests, eye blink variables were measured using infrared reflectance oculography and converted into a drowsiness score, Johns Drowsiness Scale (JDS).

Results

Caffeine significantly reduced JDS scores (drowsiness) and reaction times, and these changes persisted for 3 to 4 h. Self reports of sleepiness were not as sensitive, with Karolinska Sleepiness Scale scores only being significantly lower in the caffeine compared to placebo condition at 30 min post capsule administration.

Conclusions

The results demonstrated that despite being well rested, administration of caffeine significantly increased alertness and enhanced performance, and these changes were able to be detected with the JDS.

Keywords

Alertness Blinks Caffeine Vigilance Drowsiness scale Infrared reflectance 

References

  1. Abernethy DR, Todd EL (1985) Impairment of caffeine clearance by chronic use of low-dose oestrogen-containing oral contraceptives. Eur J Clin Pharmacol 28:425–428PubMedCrossRefGoogle Scholar
  2. Akerstedt T, Gilberg M (1990) Subjective and objective sleepiness in the active individual. Int J Neurosci 52:29–37PubMedCrossRefGoogle Scholar
  3. Arnaud MJ (1987) The pharmacology of caffeine. Prog Drug Res 31:273–313PubMedGoogle Scholar
  4. Beaumont M, Batejat D, Pierard C, Coste O, Doireau P, Van Beers P, Chauffard F, Chassard D, Enslen M, Denis JB, Lagarde D (2001) Slow release caffeine and prolonged (64-h) continuous wakefulness: effects on vigilance and cognitive performance. J Sleep Res 10:265–276PubMedCrossRefGoogle Scholar
  5. Bocca ML, Denise P (2006) Total sleep deprivation effect on disengagement of spatial attention as assessed by saccadic eye movements. Clin Neurophysiol 117:894–9PubMedCrossRefGoogle Scholar
  6. Bonnet MH, Balkin TJ, Dinges DF, Roehrs T, Rogers N, Wesensten NJ (2005) The use of stimulants to modify performance during sleep loss: a review by the sleep deprivation and stimulant task force of the American Academy of Sleep Medicine. Sleep 28:1163–1187PubMedGoogle Scholar
  7. Caffier PP, Erdman U, Ullsperger P (2003) Experimental evaluation of eye-blink parameters as a drowsiness measure. Eur J Appl Physiol 89:319–325PubMedCrossRefGoogle Scholar
  8. Food Standards Australia New Zealand (2006) CaffeineGoogle Scholar
  9. Fredholm BB (1995) Astra award lecture: adenosine, adenosine receptors and the actions of caffeine. Pharmacol Toxicol 76:93–101PubMedCrossRefGoogle Scholar
  10. Fredholm BB, Battig K, Holmen J, Nehlig A, Zvartau EE (1999) Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacol Rev 51:83–133PubMedGoogle Scholar
  11. Heitmann A, Guttkuhn R, Aguirre A, Trutschel U, Moore-Ede M (2001) Technologies for the monitoring and prevention of driver fatigue. In: Proceedings of the First International Driving Symposium on Human Factors in Driver Assessment, Training and Vehicle Design. Aspen, CO, USA, pp 81–86Google Scholar
  12. Horne JA, Reyner LA (1996) Counteracting driver sleepiness: effects of napping, caffeine, and placebo. Psychophysiology 33:306–309PubMedCrossRefGoogle Scholar
  13. James JE, Rogers PJ (2005) Effects of caffeine on performance and mood: withdrawal reversal is the most plausible explanation. Psychopharmacology 182:1–8PubMedCrossRefGoogle Scholar
  14. Johns M (1991) A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep 14:540–545PubMedGoogle Scholar
  15. Johns M (2003) Eyelid closure, visual suppression and hypovigilance in the drowsy state: lapses in performance with eyes open or closed. Sleep 26(Suppl):A52Google Scholar
  16. Johns M, Tucker A, Chapman R, Michael N, Beale C (2006) A new scale of drowsiness based on multiple characteristics of blinks: the Johns drowsiness scale. Sleep 29(suppl):A365Google Scholar
  17. Johns M, Tucker A, Chapman R, Crowley K, Michael N (2007) Monitoring eye and eyelid movements by infrared reflectance oculography to measure drowsiness in drivers. Somnologie 11:234–242CrossRefGoogle Scholar
  18. Liguori A, Hughes JR, Grass JA (1997) Absorption and subjective effects of caffeine from coffee, cola and capsules. Pharmacol Biochem Behav 58:721–726PubMedCrossRefGoogle Scholar
  19. Lorist MM, Snel J, Kok A, Mulder G (1994) Influence of caffeine on selective attention in well-rested and fatigued subjects. Psychophysiology 31:525–534PubMedCrossRefGoogle Scholar
  20. Morris TL, Miller JC (1996) Electrooculographic and performance indices of fatigue during simulated flight. Biol Psychol 42:343–360PubMedCrossRefGoogle Scholar
  21. Minzhong Y, Russo M, Johnson D, Kamimori G (2004) Oculomotor measures over 30-hours of continuous wake with and without caffeine. Sleep 27(Suppl):A138Google Scholar
  22. Parsons WD, Neims AH (1978) Effect of smoking on caffeine clearance. Clin Pharmacol Ther 24:40–45PubMedGoogle Scholar
  23. Patat A, Rosenzweig P, Enslen M, Trocherie S, Miget N, Bozon MC, Allain H, Gandon JM (2000) Effects of a new slow release formulation of caffeine on EEG, psychomotor and cognitive functions in sleep-deprived subjects. Hum Psychopharmacol 15:153–170PubMedCrossRefGoogle Scholar
  24. Smith A, Brice C, Nash J, Nutt DJ (2003) Caffeine and central noradrenaline: effects on mood, cognitive performance, eye movements and cardiovascular function. J Psychopharmacol (Oxf) 17:283–292CrossRefGoogle Scholar
  25. Smith A, Sutherland D, Christopher G (2005) Effects of repeated doses of caffeine on mood and performance of alert and fatigued volunteers. J Psychopharmacol 19:620–626PubMedCrossRefGoogle Scholar
  26. Stern JA, Walrath LC, Goldstein R (1984) The endogenous eye blink. Psychophysiology 21:23–33CrossRefGoogle Scholar
  27. Van Deventer G, Kamemoto E, Kuznicki JT, Heckert DC, Schulte MC (1992) Lower esophageal sphincter pressure, acid secretion, and blood gastrin after coffee consumption. Dig Dis Sci 37:558–569PubMedCrossRefGoogle Scholar
  28. Van Orden KF, Jung T-P, Makeig S (2000) Combined eye activity measures accurately estimate changes in sustained visual task performance. Biol Psychol 52:221–240PubMedCrossRefGoogle Scholar
  29. Vanderveen JE, Armstrong LE, Butterfield GE, Chenoweth WL, Dwyer JT, Fernstrom JD, Kanarek RB, Levander OA, Sternberg EM (2001) Caffeine for the sustainment of mental task performance: formulations for military operations. National Academy, Washington, DCGoogle Scholar
  30. Wesensten NJ, Killgore WDS, Balkin TJ (2005) Performance and alertness effects of caffeine, dextroamphetamine, and modafinil during sleep deprivation. J Sleep Res 14:255–266PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Natalie Michael
    • 1
  • Murray Johns
    • 2
  • Caroline Owen
    • 3
  • John Patterson
    • 1
  1. 1.Sensory Neuroscience Laboratory, Faculty of Life and Social SciencesSwinburne University of TechnologyMelbourneAustralia
  2. 2.Sleep Diagnostics Pty LtdMelbourneAustralia
  3. 3.Peter MacCallum Cancer Center Research DivisionMelbourneAustralia

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