> The student is asking his or her brain to expend lots of energy (from a biological perspective, studying for an orgo exam is an expensive thing to do). I hav

> The student is asking his or her brain to expend lots of energy (from a biological perspective, studying for an orgo exam is an expensive thing to do). I have wondered for some time: is there research that can put a number on how much caloric energy the brain (just the brain) uses when it's being worked/stressed (as the article suggests, studying for an organic chemistry exam) compared to when it's relatively relaxed or even asleep? Some cursory searching hasn't gotten me past "the brain uses about 20-25% of consumed energy a day," but that doesn't really answer my question. I acknowledge it is difficult to define when the brain is "relaxed," because it's always doing something, but I suppose what I'd like to know is if there is a truly significant difference in energy expenditure due to intense activity or if comparatively it's just background noise because the brain is always working hard. To take it to an extreme/absurd point, could thinking hard help you lose weight? p.s. thanks for posting the article due to the 503