It's said about brain that, "use it or lose it" — now, question being, do you think if person plays brainless gambling games such as slots, dice for major part of his/her daily routine, will it make him/her dull?
Edit: "brainless" as in playing gambling games that does not require using brain, I thought it was clear especially given examples.
To be fair, in most of the casino games one can find out there, there is a minimum mental effort to be done. There are just a few games which require us to have enough attention to make choices, like blackjack (since one needs to pay attention on whether to continue to take cards or stop) and also crash (since one needs to decide when exactly ro cash out).
Anyways, I would not say slots make one brainless or numb, but I personally believe slots could make one to become insensitive, because there is not much to think about and those games mess much with out dopamine receptors in our brains, that is common knowledge.
One of the reasons I am not particularly fan of slots and prefer card games.