Where can one find good research on the human psychology around these patterns? They're fascinating (ideally more towards gaming, not the casino side of it though I understand the crossing between both)
Not exactly on the "casino" nose, but "100 things every designer should know about humans" by Weinschenk has a lot of these principles outlined (backed up with academic references).
Sutherland is seductive, but essentially just a Marketing Executive with after-dinner speaking skills. For something a bit more robust, I'd recommend the consumer culture exposition in Adam Curtis''The Century of the Self'; particularly the segment where Edward Bernays used psychoanalysis to market cigarettes to women as feminist "torches of freedom".
Curtis' summary at the conclusion of the series works just as well as a chilling indictment of Gacha Gaming and the self-imposed Skinnerbox of the microtransaction era - "Although we feel we are free, in reality, we - like the politicians - have become the slaves of our own desires."