Effects of Caffeine Intake on Cognitive Performance Related to Total Sleep Deprivation and Time on Task: A Randomized Cross-Over Double-Blind Study

Abstract

Introduction It is widely admitted that both total sleep deprivation (TSD) and extended task engagement (Time-On-Task, TOT) induce a cognitive fatigue state in healthy subjects. Even if EEG theta activity and adenosine both increase with cognitive fatigue, it remains unclear if these modifications are common mechanisms for both sustained attention and executive processes. Methods We performed a double-blind counter-balanced (placebo (PCBO) and caffeine (CAF) - 2×2.5 mg/kg/24 h)) study on 24 healthy subjects (33.7 ± 5.9 y). Subjects participated in an experimental protocol including an habituation/training day followed by a baseline day (D0 and D1) and a total sleep deprivation (TSD) day beginning on D1 at 23:00 until D2 at 21:00. Subjects performed the psychomotor vigilance test (PVT) assessing sustained attention, followed by the executive Go-NoGo inhibition task and the 2-NBack working memory task at 09:15 on D1 and D2. Results We showed differential contributions of TSD and TOT on deficits in sustained attention and both executive processes. An alleviating effect of caffeine intake is only observed on sustained attention deficits related to TSD and not at all on TOT effect. The caffeine dose slows down the triggering of sustained attention deficits related to TOT effect. Discussion These results suggest that sustained attention deficits induced by TSD rely on the adenosinergic mechanism whereas TOT effect observed for both sustained attention and executive would not.

Relationship between Habitual Caffeine Consumption, Attentional Performance, and Individual Alpha Frequency during Total Sleep Deprivation

“…The electrophysiological correlates of acute caffeine intake have also been widely described with a consensus on its global decreasing effects on EEG powers during cognitive tasks in sleep-deprived and non-sleep-deprived subjects [ 6 , 7 , 8 ] or in resting states with the eyes closed [ 16 ]. In agreement with the literature, we found significant main treatment (caffeine/placebo) effects on theta, alpha, and beta power bands which were reflected by decreasing powers with acute caffeine intake.…”

“…In experimental protocols on total sleep deprivation, vigilant attention, assessed by the psychomotor vigilance task (PVT), is the most affected cognitive capability [ 4 , 5 ]. Changes in the individual EEG alpha and theta power after prolonged wakefulness were also found to be related to subjective sleepiness and PVT performance [ 6 , 7 , 8 ].…”

“…Caffeine is a non-selective antagonist of adenosine receptors (mainly A1 and A2A) which modulates glutamatergic, cholinergic, dopaminergic, serotoninergic, and noradrenergic neurotransmission [ 10 ]. In laboratory studies on sleep deprivation, acute caffeine administration helped to restore cognitive function, often by preventing a decrease in sustained attention, with doses ranging from 200 to 600 mg [ 7 , 8 , 11 , 12 , 13 ]. The acute intake of caffeine reduced sleepiness and EEG theta activity during wakefulness [ 6 , 7 , 14 ].…”

“…In laboratory studies on sleep deprivation, acute caffeine administration helped to restore cognitive function, often by preventing a decrease in sustained attention, with doses ranging from 200 to 600 mg [ 7 , 8 , 11 , 12 , 13 ]. The acute intake of caffeine reduced sleepiness and EEG theta activity during wakefulness [ 6 , 7 , 14 ]. Under non-deprived sleep conditions, the acute intake of 200 mg of caffeine caused a significant reduction in total EEG power at the frontal, central, and parieto-occipital electrode positions of both hemispheres when the subjects kept their eyes open, and the absolute power of the slow and fast alpha and slow beta activities was diminished in various regions of the brain [ 15 ].…”

Effects of Chronic Administration of Green Tea Ethanol Extract on Sleep Architecture in Mice: A Comparative Study with a Representative Stimulant Caffeine

“…Moreover, consumption of caffeine can lead to improved wakefulness and decreased fatigue [ 8 ]. Various studies related to the arousal effects of caffeine in humans and animals have reported prolonged sleep latency and a state of wakefulness [ 9 , 10 , 11 , 12 ]. A recent study reported that coffee is the main source of caffeine, accounting for approximately 80% of total intake of caffeine in adults [ 13 ].…”