I have this problem, every time i talk to someone, face of NPC become black from time to time, like there was no texture. Then the camera changes angle and everything is ok. It's quite annoying, because the game runs good on ultra high settings and lowering them doesn't seem to solve anything. I have nvidia gtx 850

I would like an answer to this problem, as well.

disable the waterreflection and you get rid of the problem.