Call of Duty... hmm... how does that somehow train to shut down my brain? Is it like when you get shot in-game and you just feel like wanting to shut down the game, sleep, and get revenge on those players that killed you?
"Shut off your brain" as in, hyper focused on the task at hand. In COD, your objectives are mostly reflex-based. Map-knowledge and strats are all valid but they need substantial skills to back up, which is your aiming, tracking and flicking.
What I mean by this is that COD is a game reliant on moment-to-moment gameplay, propped up with lightning fast decisions and short-term predictions of enemy placement and movements.
Idk about you but for me, games like COD or those similar to it got me used to focusing on the task at hand and make a conscious sit-down analysis on my performance later. Where I do so in gameplay, I apply it so on my reading, in which turn my brain to a mode where I focus on the words itself and properly digesting it when I put it down. I simply invest 100% of my energy into the book and then speedread that shit.
It burns you out fast (for me, at least) but that's how it worked for me. I only question after the reading. For now, the task is to recieve new information and ONLY that. Everything else comes later. I never attempt to multi-task as I listen/read. I make my analysis after, so as to not ruin the experience.