For quite some time it was assumed to be a micro expression indicating imagination. To the right was recollection I believe. While it’s not based in scientific fact the show ‘lie to me’ covers a lot of common ones. Fun watch even though the concept is a bit dodgy.

ADHD myself. Reading faces is a lot of information - and when you are trying to recall or focus you will look away to reduce stimulus. It’s similar to turning the car radio down when focusing or looking for something.