







Summary Sleep loss, which affects about one‐third of the US population, can severely impair physical and neurobehavioural performance. Although caffeine, the most widely used stimulant in the world, can mitigate these effects, currently there are no tools to guide the timing and amount of caffeine consumption to optimize its benefits. In this work, we provide an optimization algorithm, suited for mobile computing platforms, to determine when and how much caffeine to consume, so as to safely maximize neurobehavioural performance at the desired time of the day, under any sleep‐loss condition. The algorithm is based on our previously validated Unified Model of Performance, which predicts the effect of caffeine consumption on a psychomotor vigilance task. We assessed the algorithm by comparing the caffeine‐dosing strategies (timing and amount) it identified with the dosing strategies used in four experimental studies, involving total and partial sleep loss. Through computer simulations, we showed that the algorithm yielded caffeine‐dosing strategies that enhanced performance of the predicted psychomotor vigilance task by up to 64% while using the same total amount of caffeine as in the original studies. In addition, the algorithm identified strategies that resulted in equivalent performance to that in the experimental studies while reducing caffeine consumption by up to 65%. Our work provides the first quantitative caffeine optimization tool for designing effective strategies to maximize neurobehavioural performance and to avoid excessive caffeine consumption during any arbitrary sleep‐loss condition.
Nicolas Mattia – Keep your Mac awake with caffeinate
This explains how to keep a Mac from going to sleep using a simple command


Sleep Deficit: The Performance Killer
Reprint: R0610B Companies today glorify the executive who logs 100-hour workweeks, the road warrior who lives out of a suitcase in multiple time zones, and the negotiator who takes a red-eye to make an 8 AM meeting. But to Dr. Charles A. Czeisler, the Baldino Professor of Sleep Medicine at Harvard Medical School, this kind of corporate behavior is the antithesis of high performance. In fact, he says, it endangers employees and puts their companies at risk. In this interview, Czeisler describes four neurobiological functions that affect sleep duration and quality as well as individual performance. When these functions fall out of alignment because of sleep deprivation, people operate at a far lower level of performance than they would if they were well rested. Czeisler goes on to observe that corporations have all kinds of policies designed to protect employees—rules against smoking, sexual harassment, and so on—but they push people to the brink of self-destruction by expecting them to work too hard, too long, and with too little sleep. The negative effects on cognitive performance, Czeisler says, can be similar to those that occur after drinking too much alcohol: “We now know that 24 hours without sleep or a week of sleeping four or five hours a night induces an impairment equivalent to a blood alcohol level of .1%. We would never say, ‘This person is a great worker! He’s drunk all the time!’ yet we continue to celebrate people who sacrifice sleep for work.” Czeisler recommends that companies institute corporate sleep policies that discourage scheduled work beyond 16 consecutive hours as well as working or driving immediately after late-night or overnight flights. A sidebar to this article summarizes the latest developments in sleep research.
Sleep as a Competitive Advantage
Too many of us live by the myth that one less hour of sleep gives us one more hour of productivity, Tony Schwartz writes in the Life@Work column. In reality, lost sleep not only leaves us more fatigued, but also takes a toll on our cognitive capacity.

Sleep as a Competitive Advantage
Too many of us live by the myth that one less hour of sleep gives us one more hour of productivity, Tony Schwartz writes in the Life@Work column. In reality, lost sleep not only leaves us more fatigued, but also takes a toll on our cognitive capacity.

Sleep: Educational Impact and Habit Formation
In a field experiment among US university students, incentives for sleep increase both sleep and academic performance. Our primary intervention pairs bedtime reminders with morning feedback and immediate rewards for sleeping at least 7 hours on weeknights. The intervention raises the share of weeknights with 7+ hours of sleep by 26% and average sleep by 19 minutes during a 4-week treatment period, with posttreatment effects of 8 minutes. Immediate incentives outperform both delayed incentives and reminders/feedback alone during treatment but have no distinguishable impacts posttreatment. The primary intervention improves average semester course performance by 0.075–0.089 grade points, a 0.10–0.11 standard deviation increase. Our results demonstrate that incentives targeting sleep can be a cost-effective approach to improve educational outcomes.
Methods to fall asleep quickly/instantly?
36 votes, 40 comments. Any tips on falling asleep INSTANTLY? For years I have been staying up until 1 AM (usually) and my body has adapted to it. Now…
How Caffeine Can Cramp Creativity
Caffeine prevents our focus from becoming too diffuse; it instead hones our attention in a hyper-vigilant fashion.

Caffeine could limit damage of chronic stress
A cup of joe wards off depression following chronic stress.

Sleep deprivation is not a badge of honor
Forgoing sleep is like borrowing from a loan shark. Sure you get those extra hours right now to cover for your overly-optimistic estimation, but at what price? The shark will be back, and if you ca…
Opinion | Rethinking Sleep (Published 2012)
It’s not the quantity of sleep that restores and refreshes, but the quality.

<em>Journal of Sleep Research</em> | ESRS Journal | Wiley Online Library
Napping is a cross-cultural phenomenon which occurs across the lifespan. People vary widely in the frequency with which they nap as well as the improvements in alertness and well-being experienced. T...

Enhancing Human Cognition with Cocoa Flavonoids
Enhancing cognitive abilities has become a fascinating scientific challenge, recently driven by the interest in preventing age-related cognitive decline and sustaining normal cognitive performance in response to cognitively demanding environments. In recent years cocoa and cocoa-derived products, as a rich source of flavonoids, mainly the flavanols sub-class, have been clearly shown to exert cardiovascular benefits. More recently, neuromodulation and neuroprotective actions have been also suggested. Here, we discuss human studies specifically aimed at investigating the effects of acute and chronic administration of cocoa flavanols on different cognitive domains, such as executive functions, attention and memory. Through a variety of direct and indirect biological actions, in part still speculative, cocoa and cocoa-derived food have been suggested to possess the potential to counteract cognitive decline and sustain cognitive abilities, particularly among patients at risk. Although still at a preliminary stage, research investigating the relations between cocoa and cognition shows dose-dependent improvements in general cognition, attention, processing speed and working memory. Moreover, cocoa flavanols administration could also enhance normal cognitive functioning and exert a protective role on cognitive performance and cardiovascular function specifically impaired by sleep loss, in healthy subjects. Together, these findings converge at pointing to cocoa as a new interesting nutraceutical tool to protect human cognition and counteract different types of cognitive decline, thus encouraging further investigations. Future research should include complex experimental designs combining neuroimaging techniques with physiological and behavioral measures to better elucidate cocoa neuromodulatory properties and directly compare immediate versus long-lasting cognitive effects.

How to Fall Asleep in 2 Minutes or Less | The Art of Manliness
With our archives now 3,500+ articles deep, we’ve decided to republish a classic piece each Friday to help our newer readers discover some of the best, evergreen gems from the past. This article was originally published in March 2018. Have you ever unexpectedly found yourself with a snatch of time in which to steal a […]

How to Fall Asleep in 120 Seconds
Trouble sleeping? Here's a military-tested trick for guaranteed slumber
Are two halves better than one whole? A comparison of the amount and quality of sleep obtained by healthy adult males living on split and consolidated sleep-wake schedules
The aim of this study was to compare the quantity/quality of sleep obtained by people living on split and consolidated sleep-wake schedules. The study had a between-groups design, with 13 participants in a consolidated condition (all males, mean age of 22.5yr) and 16 participants in a split condition (all males, mean age of 22.6yr). Both conditions employed forced desynchrony protocols with the activity:rest ratio set at 2:1, but the consolidated condition had one sleep-wake cycle every 28h (9.33+18.67), while the split condition had one sleep-wake cycle every 14h (4.67+9.33). Sleep was assessed using polysomnography. Participants in the split and consolidated conditions obtained 4.0h of sleep per 14h and 7.6h of sleep per 28h, respectively. Some differences between the groups indicated that sleep quality was lower in the split condition than the consolidated condition: the split sleeps had longer sleep onset latency (9.7 vs. 4.3min), more arousals (7.4 vs. 5.7 per hour in bed), and a greater percentage of stage 1 sleep (4.1% vs. 3.1%), than the consolidated sleeps. Other differences between the groups indicated that sleep quality was higher in the split condition than the consolidated condition: the split sleeps had a lower percentage of wake after sleep onset sleep (11.7% vs. 17.6%), and a greater percentage of slow wave sleep (30.2% vs. 23.8%), than the consolidated sleeps. These results indicate that the split schedule was not particularly harmful, and may have actually been beneficial, to sleep. Split work-rest schedules can be socially disruptive, but their use may be warranted in work settings where shiftworkers are separated from their normal family/social lives (e.g., fly-in fly-out mining) or where the need for family/social time is secondary to the task (e.g., emergency response to natural disasters).