tongue in the right angle?

[ZeTeX]

first I seen my dad putting his tongue in the right angle when doing something tricky, then I saw dave, and other youtubers
where did it started and why ? 

[Gyro]

Yes there is a psychological/physiological reason for it, I saw it on a documentary recently, I'm pretty sure it was 'The Brain with David Eagleman'...

http://www.bbc.co.uk/programmes/b06y8hyr

It struck a chord because I do it and so did my Dad. I think it has the effect of somehow blocking sub-vocalization to allow greater concentration on a spacial task, but can't remember the exact detail.

EDIT: Ah, nearly right:

http://www.sciencefocus.com/qa/why-do-i-stick-out-my-tongue-when-i-concentrate

http://www.thenakedscientists.com/forum/index.php?topic=25239.10;wap2

[calexanian]

Tongue angle is also affected by the brand and model of the tool being used for adjustment. Very critical.