That's interesting albeit inconclusive. I guess being shifty eyed would be the real clincher. You look left to try to remember what your story was supposed to be, then you look right when you're asked a question which you weren't prepared for and have to use then creative side of your brain, then left again to try to come up with some logic to make sure that new part of your story fits into the picture.
It also makes a difference whether the subject is looking "up and to the left" or "down and to the left." Up is shiftier.