I can shut off emotional expression if I want to, mostly because when I express emotion it's either wildly uninhibited or something I have to remember to do. For me, deciding not to express emotions is like deciding not to talk, and about as easy.
But I really suck at deceiving people, so I'm not a really good poker player. The only thing I can do is just send no signals at all. I guess that could go up to "passable" if I learned to keep track of how likely the cards were to be in certain places. But I don't see the point. I'd have to spend so much time on something that wouldn't really be very rewarding.
I mean, what would be the point? I could win pennies off my friends, but if I wanted to make any money off it, I'd have to go play poker someplace noisy and bright and generally chaotic. No thanks. I'd much rather work at a supermarket than go to a casino, and that's pretty far down on my list of tolerable occupations. Plus, it wouldn't be guaranteed income; you could lose everything just on a run of bad luck, and if you made any more than a small amount they'd kick you out. Uh-uh, SO not for me. That'd just be torture.
I'll happily solve abstract statistical problems involving poker hands, but that's different. That, I can do sitting at home in my nice comfortable chair with my favorite calculator and my cat trying to chase the end of the pen.