Zoning out? Study blames fluid flowing from the brain

It's never a great look. The morning meeting is in full swing but, thanks to a late night, your brain switches off as a question comes your way.

- Ian Sample Science editor

The feeling may be familiar, but exactly what happens in the brain during these lapses has long proved hard to pin down. Now scientists have found that the loss of focus coincides with a wave of fluid flowing briefly out of the brain.

"The moment somebody's attention fails is the moment this wave of fluid starts to pulse," said Dr Laura Lewis, a senior author on the study at the Massachusetts Institute of Technology in Boston. "It's not just that your neurons aren't paying attention to the world, there's this big change in fluid in the brain at the same time."