BattleMoose wrote:I missed that part, where did that happen?
Well, in the summary sentence for starters -
"Unlike physical exercise, mental workouts probably do not demand significantly more energy than usual. Believing we have drained our brains, however, may be enough to induce weariness"
Second paragraph -
"What the latest science reveals, however, is that the popular notion of mental exhaustion is too simplistic. The brain continuously slurps up huge amounts of energy for an organ of its size, regardless of whether we are tackling integral calculus or clicking through the week's top 10 LOLcats. Although firing neurons summon extra blood, oxygen and glucose, any local increases in energy consumption are tiny compared with the brain's gluttonous baseline intake. So, in most cases, short periods of additional mental effort require a little more brainpower than usual, but not much more."
Little later -
"Although quite a few studies have confirmed these predictions, the evidence as a whole is mixed and most of the changes in glucose levels range from the miniscule to the small."
And particularly damning to the claim that thinking hard burns more glucose -
"Authors of other review papers have reached similar conclusions. Robert Kurzban of the University of Pennsylvania points to studies showing that moderate exercise improves people's ability to focus. In one study, for example, children who walked for 20 minutes on a treadmill performed better on an academic achievement test than children who read quietly before the exam. If mental effort and ability were a simple matter of available glucose, then the children who exercised—and burnt up more energy—should have performed worse than their quiescent peers."
Basically, the brain isn't a muscle, and using it 'harder' isn't burning glucose. It's certainly stressful, and this may certainly affect your glucose use, but it's not like a bench press.
BattleMoose wrote:Right. The stress is not a consequence of consuming more glucose. Doesn't mean, more glucose wasn't consumed.
Well, right, but that's an important disThe data suggests that thinking hard increases stress, and this can cause people to eat more, and that stress can cause fluctuations in blood glucose (note: fluctuations != always reductions). The article does NOT suggest that thinking hard results in more glucose being consumed.
BattleMoose wrote:Its not thermodynamically possible to have a higher heart rate, and not use more energy.
Sure. But again, the brain isn't a muscle. 'Thinking hard' or 'doing math' or thinking '+infinity! -infinity!' over and over isn't like bench pressing.
BattleMoose wrote:Calculus tutorials/lectures, are just about the most mentally demanding environments, commonly (for some definition of common) many humans are subjected to. I have read for hours on end to, its not demanding at all in my opinion.
Eh - I could argue that being a drone operator is more mentally demanding than calculus. That being a 911 operator is more mentally demanding. But yes, I find reading very relaxing personally too.
morriswalters wrote:Certainly. But when was the last time you spent say 8 hours doing so? That is my average time for a book. I'm not making a relative value statement about the intellectual worth of any given media. I'm simply saying that books require time to acquire and ingest than a movie. Even if they required exactly the same energy per unit time to acquire, books would take more energy than movies because of the time involved in ingesting them.
You read 8 hours straight? Or do you mean it takes 8 hours to read a book?
But, sure - I was on vacation the month of April, and during this time I watched a number of tv shows and movies. For example, I powered through season 2 of Daredevil in maybe 2 sittings. I wager sitting on the couch watching that show was exactly as intellectually demanding as when I later read Mother of Storms.
If you're talking about 'unit of time per thing' then that's not a good comparison - I'm sure many of us have spent a lot of time reading, just like many of us have spent a lot of time watching TV or playing videogames. Getting a movie in 2 hours vs getting a book in 8 doesn't change the fact that both represent the same sort of activity - passively consuming information.
... with gigantic melancholies and gigantic mirth, to tread the jeweled thrones of the Earth under his sandalled feet.