I had the opportunity to watch people work in the past few days (as I am wont to do), and noticed that a number of them like to stick out their tongue while working. Not stick out their tongue to make a silly face, but just keeping the tip of their tongue between their lips.
I'm really curious why people do that. I'm pretty sure it's unconscious, but there should be a biological/neurological reason for people to do so.
Of course, my own focusing habits are nothing to be proud of: I often drool when I'm concentrating really hard on something. I think it's because I'm so focused that my jaw muscles become slack, and saliva builds up to overflow.
Eheheh, I probably shouldn't have told you that.