The Brain Takes Forever to Wake Up and There's Nothing We Can Do About It

The 22nd most surprising thing we learned about humans this year.


The night is dark and full of terrors, but for most of us the true terror begins each morning when the alarm clock goes off. This year, scientists at the University of California Berkeley discovered a key reason why so many of us spend precious mornings groping for reality in a sleep-induced fog. “Sleep inertia” is real, they said, and it’s really, really hard to get rid of.

In September, Raphael Vallat, Ph.D., a postdoctoral fellow at Berkeley’s Walker Lab, published a paper in NeuroImage describing why it takes the brain 30 long and painful minutes to transition from a sleep state to an awake state. Even more importantly, his study, based on fMRI imaging on 34 participants, illuminated why it’s so challenging.

This is #22 on Inverse‘s list of the 25 Most Surprising Human Discoveries of the year.

When Inverse first reported this story, Vallat explained that the brain fluidly switches between a “task active mode” (used during reading or solving problems) and a “task negative mode” (used during daydreaming). When we’re using one mode, we tend to not see very much activity in the other, and Vallat calls this division “functional segregation.”

During the day, our brain has no trouble switching between active and negative, but right when we wake up, the brain seems to really struggle with functional segregation. What ends up happening is that the two modes end up working simultaneously, which causes the sensation of “sleep inertia.”

In 2018, we learned that it can take 30 minutes for the brain to fully wake up each morning 


Vallat demonstrated this by making his 34 participants do math problems right after they woke up from 45-minute naps. He also took fMRI images of their brains while they completed the problems. Perhaps unsurprisingly, his participants performed worse on the math tests upon awaking, largely, Vallat believes, because their brains were caught between these two modes.

When asked whether there was any way to speed up this waking-up process — maybe a quick caffeine dose in the morning — Vallat didn’t have good news. Though caffeine can improve functional segregation, he explained, it probably won’t kick in fast enough to help out during those crucial first 30 minutes of the morning.

“The best thing to do is certainly to wait for a few minutes before making any important decisions or hitting the road, especially if you feel that you have just woken up from a deep slumber,” Vallat said.

It seems like the only wise thing to do is wait for the cognitive fog to clear before we make any important decisions. At least, from now on, we’ll know exactly how long we have to wait.

As 2018 winds down, Inverse is highlighting the year’s 25 Most Surprising Human Discoveries. These stories told us weird stuff about our bodies and brains, uncovered insights into our social lives, and illuminated why we’re such complicated, wonderful, and weird animals. This story was #22. Read the original story here.

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