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.
It's possible. but only if someone gambles for hours every day, without engaging in other activities, but if someone gambles responsibly and manages their daily playing time, it won't affect their cognitive health. moreover, as one gets older, a person's cognitive health will also decrease, even without gambling, so if they want to hone their thinking skills, they can train themselves by reading or engaging in activities that require logic and concentration such as chess, etc., so that their cognitive health can be maintained longer, and help slow down the decline in brain function as they age.