Anyone who's survived an all-nighter recognizes the haze—eyes wide open, but the mind adrift. A groundbreaking study reveals what's unfolding inside the skull during these alarming attention blackouts after sleep loss: the brain is sneaking in unauthorized mini-rest breaks, complete with sleep-like fluid surges, even as you fight to stay alert.
The Experiment: Rested vs. Exhausted in the Scanner
Researchers recruited 26 healthy young adults (average age 25.6) for two MRI sessions: one after a full night's sleep, the other after a supervised all-night wakeathon. Inside the scanner, participants tackled basic attention tasks—reacting to beeps or flashes—while scientists monitored brain activity, eye movements, pupil size, heart rate, breathing, and cerebrospinal fluid (CSF) flow, the brain's protective cushioning liquid.
The Lapse Sequence: A Predictable Cascade
Sleep deprivation triggered massive CSF waves during wakefulness, mirroring those in light non-REM sleep (stage N2). These weren't chaotic; they synced perfectly with attention failures.
Here's the step-by-step breakdown when a stimulus was missed:
1. **Attention drops**—participant fails to respond.
2. **Pupils constrict** (low alertness signal), within seconds.
3. **Brain waves shift**, heart rate slows, breathing decelerates.
4. **CSF flows outward** from the brain.
5. **Recovery phase**: Pupils dilate, brain activity ramps up, CSF reverses inward.
By classifying lapses (isolated vs. start/end of prolonged inattention), the team proved these changes weren't coincidental—they precisely tracked attention's decline and rebound. Outward flow marked the plunge; inward flow signaled recovery.
Pupils as a Brain Activity Spyglass
Even with eyes open and no actual dozing (confirmed by recordings), brief lapses unleashed sleep-intensity CSF pulsations—up 4.7 decibels from rested states, rivaling true stage 2 sleep. Brain waves and blood flow fluctuations also screamed "sleep intrusion."
Blood vessels likely orchestrate the fluid dance: dilation displaces CSF outward; constriction pulls it back. Pupil constriction preceded outward flow by ~4.75 seconds, a lag fitting vascular mediation. This link strengthened dramatically post-deprivation.
Pupils reflect the locus coeruleus, a norepinephrine hub for alertness that influences attention, vessels, and arousal. It's the likely conductor of syncing behavior and biology.
Why These Lapses Are Biologically Inevitable
These hijackings happened despite open eyes and effort. The brain forces sleep processes into wakefulness, prioritizing its needs over safety—like nodding off mid-drive.
Deprivation amplified lapses predictably, suggesting an irrepressible drive for micro-rests, not mere failure. One hypothesis: these episodes enable waste clearance, a key sleep function. Though unmeasured here, the synchronized symphony (attention, pupils, waves, flow, heart, breathing) screams purposeful biology, not glitch.
Rested folks showed milder versions during rare lapses, hinting at a baseline mechanism that sleep loss explodes into instability.
Rigorous Setup and Autonomic Clues
Participants were screened for sleep health, tracked via wrist monitors, and barred from caffeine/alcohol. Deprivation nights involved constant staff oversight—no eye closures over two seconds.
Cardiovascular dips (slower heart/breathing) involve the autonomic nervous system, underscoring these as whole-body arousal shifts, beyond "mental tiredness." Worse attention windows post-deprivation showed peak CSF power, even in wakeful stretches.
The Takeaway: Sleep Wins Every Time
Sleep loss destabilizes brain-state control, forcing wake-sleep oscillations despite consciousness. The brain won't be denied its restorative rituals indefinitely—it seizes them in stolen seconds.
Published in *Nature Neuroscience*, this explains those zoned-out stares or sudden driving jolts: your brain's covert cleanup crew at work. Sleep isn't negotiable; deprivation turns lapses from weakness into a biological takeover.
Insights like these could spark countermeasures for high-stakes jobs (medicine, transport, emergencies). Until then: heed your brain—it'll claim its rest, safety be damned.
While a softening labor market has affected pay gains for all Americans, those who are entering the workforce are the hardest hit. Annual income growth for those aged 25 to 29 slowed to 5.2% in September, according to the JPMorganChase Institute — one of the smallest gains since the Great Recession. Meanwhile, a pronounced slowdown in hiring has mooted the strategy of hopping jobs to boost wages. The onset of artificial intelligence, too, threatens to foreclose some entry-level options, meaning younger earners will likely wait longer to achieve goals like homeownership.
Federal Reserve Chair Jerome Powell drew a stark picture of a labor market that looks fine on the surface—4.3% unemployment, solid consumer spending—but is quietly losing momentum underneath. Once you adjust for statistical overcounting in the payroll data, he said during a press conference on Wednesday following the FOMC meeting, “job creation is pretty close to zero.”
He connected that slowdown, at least in part, to what CEOs are now openly telling investors: AI allows them to do more with fewer people.
He noted “a significant number of companies” have recently announced layoffs or hiring pauses, with many of them explicitly citing AI as the reason.
“Much of the time they’re talking about AI and what it can do,” Powell told reporters after the Fed’s rate-cut decision, warning large employers are signaling they won’t need to add headcount for years. “We’re watching that very carefully,” he added.
The comments come as the Fed cut interest rates by a quarter point to a range of 3.75%–4%, citing “downside risks to employment” even as inflation remains elevated. Powell said the U.S. economy is still expanding at a “moderate pace,” even as hiring slows. He described spending as one of the “big sources of growth in the economy,” driven by companies building data centers and other equipment tied to artificial intelligence.
Powell also pushed back on the idea that all that spending is amounting to another speculative bubble. He drew a clear line between today’s surge in capital expenditure and the dot-com era, noting “these companies actually have earnings.” Those projects, he said, aren’t especially sensitive to interest rates, though, since they reflect long-term bets on higher productivity.
At the same time, Powell emphasized the boom creates a policy dilemma for the Fed. AI and automation are boosting output, but they’re also allowing companies to do more with fewer workers, leaving the labor market softer, even while GDP stays positive.
“We have upside risks to inflation, downside risks to employment,” he said. “This is a very difficult thing for a central bank, because one of those calls for rates to be lower, one calls for rates to be higher.”
A bifurcated market
Recent corporate announcements illustrate Powell’s warning. Amazon announced this week it laid off 14,000 middle managers—about 4% of its white-collar workforce an effort to “remove organizational layers.” The layoffs come amid their rampant investments in AI. Target, Paramount, and other large firms followed with their own cuts.
According to a Challenger, Gray & Christmas report, U.S. employers have announced nearly 946,000 layoffs so far this year—the highest total since 2020—with more than 17,000 explicitly tied to AI and another 20,000 to automation.
“Job creation is very low, and the job-finding rate for people who are unemployed is very low,” Powell said.
The phenomenon is so widespread that some economists have coined a new term—the “Great Freeze”—to describe the dismal labor market conditions. With unemployment among recent college grads topping 5%—and AI threatening to automate entry-level office jobs—many Gen Z workers are turning to graduate school as a strategic timeout.
That awkward balance—strong investment but weak hiring— is now at the center of the Fed’s decision-making. Powell said the economy increasingly resembles a K-shape, with higher-income households and large corporations benefiting from strong stock markets and AI-fueled productivity gains, while lower-income consumers pull back under the weight of rising costs.
He pointed to anecdotal reports from major retailers and consumer companies describing a “bifurcated economy,” in which wealthier Americans continue to spend freely but those at the bottom are trading down to cheaper goods. “
“Consumers at the lower end are struggling and buying less and shifting to lower-cost products,” Powell said, noting the uneven effects of growth make the Fed’s balancing act even more complicated.
Treasury Secretary Scott Bessent said Thursday the U.S. and China have finalized an agreement on TikTok that would allow the popular social media platform to remain available in the U.S.
“In Kuala Lumpur, we finalized the TikTok agreement in terms of getting Chinese approval,” Bessent told Fox Business. “And I would expect that would go forward in the coming weeks and months, and we’ll finally see a resolution to that.”
President Trump approved the deal last month after receiving the “go-ahead” from Chinese President Xi Jinping. Under the agreement, TikTok will be spun off into a separate U.S. entity, majority owned by American investors such as Oracle and Silver Lake.
The deal seeks to limit the role of TikTok’s China-based parent company, ByteDance, to comply with a 2024 law requiring the firm to divest from TikTok or face a ban on U.S. networks and app stores.
The app’s future remained in limbo for nine months, as Trump repeatedly delayed enforcement of the divest-or-ban law in an effort to reach a deal to “save” TikTok, which he had promised to do during his 2024 campaign.
China, meanwhile, has continued to offer more tepid assessments of the status of the TikTok deal. A spokesperson for the Chinese Ministry of Commerce said Thursday that Beijing had agreed to work with the U.S. to resolve issues related to TikTok.
The latest development on the TikTok deal came as Trump and Xi met in South Korea. The highly anticipated meeting saw the two world leaders agree to ease recent trade tensions, with the U.S. scaling back tariffs and China delaying export controls on rare earth minerals and resuming some soybean purchases.