Very slow brain waves, long considered an artifact of brain scanning techniques, may be more important than anyone had realized, reports the Washington University School of Medicine in St. Louis.

If you keep a close eye on an MRI scan of the brain, you’ll see a wave pass through the entire brain like a heartbeat once every few seconds. This ultra-slow rhythm was recognized decades ago, but no one quite knew what to make of it. MRI data are inherently noisy, so most researchers simply ignored the ultra-slow waves.

But by studying electrical activity in mouse brains, researchers at Washington University School of Medicine in St. Louis have found that the ultra-slow waves are anything but noise.

Get the full story at the Washington University School of Medicine in St. Louis.