Does your brain stay cooler when you think less?

Personal testimony: I am way less productive when I’m hot. I am loathe to start any not-absolutely-necessary task, regardless of how hard it actually is. This even extends to tasks that are purely mental.

For example, I have been ‘trapped’ in a non-AC house over this past heat wave, and I’m being astonishingly inert. Now, I understand why I don’t feel like scrubbing the kitchen floor, given that it’s 94 degrees F and a zillion per cent humidity. The activity would generate more heat in my body and that’s the last thing I have need of.

But I also have found it very hard to make myself do simple, non challenging tasks that require little more than sitting in front of a computer. I’m talking here about opening a few spreadsheets, entering the previous month’s data, and then backing the results up to off-site storage. I’ve had the paperwork sitting on my desk since Saturday and have yet to open the first spreadsheet. :frowning:

Not that I haven’t spent, er, wasted plenty of time sitting in front of that computer. Over the same time period I’ve watched several episodes of Longmire, Nailed It!, and youtube videos beyond count.

That I can do. Enter bill amounts? Nope.

I know your brain is supposed to use a big chunk of all the energy you burn, I think I’ve heard 20%, but does is matter what your brain is actually doing? And I staying a few degrees cooler internally because it takes less energy to veg out in front of a video of a hawk stealing a rabit from a fox versus typing some numbers into a spreadsheet?

Is there any scientific justification for my actions or is it pure sloth?

I’ve seen studies showing that your brain works faster in the cold, it also works more recklessly though. I assume it’s an evolutionary thing where sitting around pondering things in the winter will probably waste energy.

The vast majority of the brain’s energy use is based on keeping your body going, modelling the world around you and lots of subconscious stuff, thinking hard might up the workload and bit but not that much.

Heat is just tiring, regulating temperature is hard work…that’s why siestas exist

I heard it’s a disease thing: your body and brain work better at colder temperatures, but infectious microbes work much much better at colder temperature (no citation. maybe it was Lincoln or FDR)

Anyway, regarding headline question: I think the brain gets warmer when you think more: doesn’t all that MRI stuff show increased blood flow in areas of the brain that are active?

I’ve wondered the same thing: does intense calculation, say, generate more heat in the brain in the same way it does in a CPU? It seems that you would have to expend energy to derive a solution, but does it work that way in the brain, or is it always running to the same level anyway?

I cannot do mathematics when it is this hot. There is a calculation I just have to do and cannot bring myself to do. Tomorrow when the heat spell breaks. But I don’t think it has much to do with the temperature in the brain; just a general feeling of lassitude.

I definitely have that feeling of lassitude.

Also major “who gives a damn?” I’m going away over the weekend, and some of the clothes I’d like to take are dirty. On the other hand, I have plenty of other (not as favorite) clothes that I could wear…

Many current studies on brain activity use blood flow as a proxy for metabolic activity, which again is a proxy for neural activity. I’m sure they’ve checked that this correlates with actual neural activity through comparisons with EEGs and such.

So thinking means more metabolic activity, which means more heat.

:smiley: This is one of the funniest things I’ve read on the Dope in years.

I once had to take a test in math grad school in the full heat of the summer in a building without air conditioning. I couldn’t do it. Luckily I was a good enough student that I could tell the teacher that it was impossible for me to work in the heat and I was able to do it the next day in the building with his office.

As it turned out, I was woefully underprepared for the kinds of questions on the test, and I would have a lot of use out of the time I had to study those kinds of problems before I had to complete the exam. This sort of thing, where the problems on the exam were not particularly related to anything that we had actually gone over in class, made me start questioning my true aptitude for mathematics. Later on I realized that I was effectively incapable of doing the kinds of independent research expected of a professional mathematician - I was good at learning how to solve various classes of problems from others, but not at figuring out how to solve them in the first place. So I became an accountant, where most of the work was applying all the rules, not figuring out what the rules should be.