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.“
To make progress in improving America in a real macro way, the people who need to lose wealth so that everyone else can thrive aren’t “billionaires,” it’s actually “people who have their wealth in the value of their home.”
And that’s actually a much much more powerful interest group.
@Rusting_Iron@MavwreckTweet@JMackSupreme@SethBurn I don’t believe Trump ordered a new census, and I’m not sure he could, given that the constitution is clear about the census being once every 10 years. He just told Texas lawmakers to redraw the map, without a new census.
Sigh Epstein is literally one rich guy who had a lot of connections and an obsession with young girls, but there are a lot bigger trafficking rings exposed/prosecuted regularly. It’s fine to want answers but a lot of the people pushing this keep ignoring any answers they don’t like.
The GOP used to offer energetic, low-cost tax reform bills to simplify the tax code & encourage competitiveness. Now its lazy tax carve-outs for allies.
And they've also basically given up fixing SocSec, Medicare, health care, passing approps bills, spending cuts, trade, etc.
I HATE having to address transgender issues, but the bad-faith ignorance is astounding.🧵
My feed has been filled with conservatives attacking transgenderism as a mental illness with no legit biological basis. Which is medically, demonstrably FALSE. Yes, transgender women are obviously not biologically identical to cis women. However, most also are not biologically identical to cis men either.
Countless, broadly accepted medical studies have found that most transgender individuals have brain anatomy and functioning – and often hormonal, chromosomal, and genetic traits – that more closely match their experienced gender. My Substack post in my pinned tweet links to dozens of these medical studies.
The conservatives yelling “that’s impossible because male and female brains are fully identical in design and function" are not only clearly, biologically, wrong, but also hypocritical. The longstanding conservative belief in “gender essentialism” centers around such brain differences as the basis for male masculine vs. female feminine personalities – as they remind us every time a liberal mom tries to raise her baby boy with barbie dolls to reject masculinity. If conservatives suddenly believe that the brain is genderless, then they are endorsing the more radical leftist idea that male masculinity and female femininity are entirely social constructs that can be erased anytime. Any takers on that theory? I didn’t think so.
Typical male and female brains contain subtle but real differences. And because our genes contain a full blueprint for both male and female development, it is possible even for some people with XX or XY genes to experience chemical changes in the womb that alter some of the gender development signals, particularly to the brain.
This all relates to the assertion that transgender people “live under the delusion that they can change their sex.” No, we don’t. The point is that most transgender people were already born with biological differences relative to cisgender people. They aren’t trying to “change their sex” because, biologically, they never completely developed as the other sex to begin with.
As a trans person, I did not wake up and decide to “change my sex.” I knew from age 4 that something was off with my gender, and later participated in several gender medical studies that confirmed a more female brain chemistry/architecture/functioning, hormone levels, and other biological characteristics. Most people who transition are merely aligning the rest of their body with other observable biological gender aspects (mostly in the brain) that emerged before birth.
So, no, a trans woman is not the same as a cis woman. But she is probably not biologically identical to a cis male either. While the scientific discoveries continue to evolve (particularly in identifying the key genes), it has been firmly, medically established that transgenderism does indeed have an observable, biological basis. So it would be nice if more of the conservatives (and some liberals) who pride themselves on “standing up for truth and basic gender science” actually bothered to read and understand the scientific research.
And if you are too invested in hating trans people to accept that gender science is more complicated than the simplified model you learned in 10th grade biology, well, as conservatives love to remind everyone else, “facts don’t care about your feelings.”
Bill Clinton in 1994:
"Thanks to the Ukrainian parliament, you are removing the threat of nuclear power and laying the groundwork for an era of peace with your neighbours. I salute the courage you have shown. America will stand with you to support your independence, your territorial integrity, and your reforms. We are bound together by dedication to peace."
@WizardBenjamin@DamonLinker@jessesingal They’re not being sent back to their country of origin though. And they’re deporting people who were here legally and broke no laws.