This is one of the most important studies in sleep science.
Van Dongen et al. ran the experiment that changed how we understand chronic sleep restriction. They had subjects sleep 4h, 6h, or 8h nightly for 14 days, testing cognitive performance every 2 hours.
The 6h group’s reaction time deficits by day 14 matched subjects who had been awake for 24 hours straight. The 4h group? They performed like someone awake 48 hours.
But here’s what makes this study terrifying.
The Stanford Sleepiness Scale ratings in Panel B plateau after day 3-4. Subjects stopped feeling more tired even as their cognitive performance continued deteriorating through day 14. Your subjective experience of fatigue is a lagging indicator that eventually just… stops updating.
This explains why chronic undersleeping feels sustainable. You’ve adapted to feeling tired. Your prefrontal cortex hasn’t adapted to being impaired.
The PVT (Psychomotor Vigilance Task) in Panel A measures lapses in attention. These are the moments where you’re staring at a screen and your brain simply checks out for 500ms. Every additional day of 6h sleep adds more lapses. The curve never flattens.
Panel C and D show working memory and processing speed. Same pattern: continuous degradation with no subjective awareness.
The practical implications:
If you’re sleeping 6h and think you’re functioning fine, you’ve lost the internal calibration to know you’re not. The subjects in this study would have told you they felt “okay” while performing like they’d pulled an all-nighter.
For anyone doing cognitively demanding work, this means you cannot trust how you feel. You need to track objective markers: error rates, decision latency, problem-solving throughput.
Sleep need is biological, not negotiable. Most adults require 7-9 hours, and the research shows no population-level adaptation to chronic restriction. “I only need 6 hours” is almost always “I’ve forgotten what baseline cognition feels like.“
Bon je poste jamais ici et personne ne me suit mais on sait jamais : j'ai sorti un projet hier, le lien est en bio. Je suis aux prods, au mix, au master, et bien sûr à la voix
Pour l'occasion j'ai aussi sorti mon 1er clip : https://t.co/gFQfSmjceu
Si y en a qui passent par là 👀
I'm speechless.
Not peer-reviewed yet but a submitted paper.
The 'presented images' were shown to a group of humans. The 'reconstructed images' were the result of an fMRI output to Stable Diffusion.
In other words, #stablediffusion literally read people's minds.
Source 👇
« Mettre à contribution les pauvres qui s’appauvrissent, tout en épargnant les riches qui s’enrichissent : voilà les conséquences factuelles de la réforme des retraites. »
Et si tout était la faute... des milliardaires ? Ma chronique, pour @franceinfo.
Hey @GothamChess, despite all our disputes, I thought it was important to thank you for all the work you do for chess, we share above all the same passion, and I believe that your work contributes greatly to the propagation of this discipline internationally. Keep up good work 🌹
@AOC1978 Madame la Ministre, vous proposez d’interdire les matchs à 21h pour des raisons écologiques.
Pourquoi ne pas avoir joué le Trophée des Champions en France, ce qui aurait évité les émissions équivalentes à l’éclairage de 165 saisons complètes de Ligue 1?
#PSGFCN ⬇️