I don't think the research does an adequate job differentiating intellectual activity from agency. Is the learning and exploring their substitute for addiction

I don't think the research does an adequate job differentiating intellectual activity from agency. Is the learning and exploring their substitute for addiction? Or is it the linking of action and effort to reward? I'd be interested in comparing the inert mice to mice that are rewarded sporadically for a physically demanding but intellectually effortless task, such as running on a mouse wheel. I'd guess the results would be similar.