Why Do We Sleep?

History is full of scientists' attempts to explain why we sleep, but some researchers think zebrafish could be the key.

By Henry Nicholls
Jan 3, 2019 2:48 PMNov 12, 2019 4:45 AM
Sandman.jpg
Bill Diodato/Getty Images; background mist by Soloma/Shutterstock

Newsletter

Sign up for our email newsletter for the latest science news
 

Hans Berger could do nothing as the huge field gun rolled toward him.

In 1892, the 19-year-old German had enlisted for military service. One spring morning, while pulling heavy artillery for a training session, Berger’s horse suddenly threw him to the ground. He watched, helpless and terrified, as the rolling artillery came toward him, only to stop at the very last minute.

At precisely the same moment, Berger’s sister — far away in his hometown of Coburg — was struck by a premonition, an overwhelming sense that something tragic had befallen her brother. She begged her father to send him a telegram to make sure he was OK. Berger was stunned by the coincidence. “It was a case of spontaneous telepathy,” he later wrote of the incident.

Determined to make sense of the event and what he called “psychic energy,” Berger began to study the brain and the electrical signals it gave off during wakefulness. In a sense, he succeeded. His efforts to record the small electrical signals that escape from the brain and ripple across the scalp have given us one of the key tools for studying sleep, the electroencephalogram (EEG), or, as Berger described it, “a kind of brain mirror.”

In 1929, Berger published his discovery. As others looked to replicate Berger’s work, they realized the EEG revealed electrical activity during sleep, too. Based on the EEG signature, researchers could show there were several different stages of sleep, and the sequence and timing of them underpins the diagnosis of many sleep disorders. But in the first few decades of using the EEG, there was one stage of sleep nobody noticed.

0 free articles left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

0 free articlesSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!

Subscribe

Already a subscriber?

Register or Log In

Stay Curious

Sign up for our weekly newsletter and unlock one more article for free.

 

View our Privacy Policy


Want more?
Keep reading for as low as $1.99!


Log In or Register

Already a subscriber?
Find my Subscription

More From Discover
Recommendations From Our Store
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2024 Kalmbach Media Co.