Scans shed light on changes in brain when we zone out while tired

Volunteers took turns to wear an EEG cap while lying in an fMRI scanner for the study. Photograph: Ian Allenden/Alamy

It’s never a great look. The morning meeting is in full swing but thanks to a late night out your brain switches off at the precise moment a question comes your way.

Such momentary lapses in attention are a common problem for the sleep deprived, but what happens in the brain in these spells of mental shutdown has proved hard to pin down.