Self-monitoring cognitive performance during sleep deprivation: effects of modafinil, d-amphetamine and placebo.
Self-monitoring refers to the ability to assess accurately one's own performance in a specific environment. The present study investigated the effects of the stimulating drugs modafinil (300 mg) and d-amphetamine (20 mg) on the ability to self-monitor cognitive performance during 64 h of sleep deprivation (SD) and sustained mental work. Two cognitive tasks were investigated: a visual (perceptual) judgement task and a complex mental addition task. Subjects in the placebo condition displayed marked circadian and SD effects on cognitive task performance but their self-monitoring was substantively undisturbed by SD. Subjects performing under the influence of d-amphetamine likewise displayed highly proficient self-monitoring throughout the SD period. In contrast, modafinil had a disruptive effect on self-monitoring, inducing a reliable 'overconfidence' effect (i.e. an overestimation of actual cognitive performance), which was particularly marked 2-4 h post-dose. Although modafinil has proven to be a safe and effective countermeasure to the effects of extensive SD on cognitive task performance, we encourage a more comprehensive understanding of the relation between its subjective and performance enhancing effects before the drug is recommended as a viable fatigue countermeasure.
Baranski
J V
JV
Information Processing Sector, Defence and Civil Institute of Environmental Medicine, North York, Ontario, Canada. joe.baranski@dciem.dnd.ca
Pigeau
R A
RA
D000328:Adult; D001559:Benzhydryl Compounds / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D000077408:Modafinil; D010919:Placebos; D012892:Sleep Deprivation
D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D010919:Placebos; D000077408:Modafinil; D003913:Dextroamphetamine