That’s a lot of caffeine, and from my own experiences with caffeine use and withdrawal, I question how much of the negative results are related to sleep patterns caused by intake and withdrawal.
I also question the methodology of only re-testing on the tenth day, I’d think testing every day would lead to better results and the study would be able to show a gradual decrease in cognitive performance.
Very curious about the long term implications. I drink a lot of coffee to keep up with work and powerlifting. I’ve started cutting back because of said sleep pattern issues.