I’m sure I’m going to flub this up somehow but hopefully you’ll get the gist.
My question stems from the idea that a compressed spring weighs more than one that is not.
So would it be fair to say an educated brain weighs more than one that is not?
First of all, while a compressed spring does, technically, weigh more than an uncompressed one, due to its stored energy, the difference is entirely negligible and beyond the capacity of even our most sensitive measuring instruments. It’s likely that compressing the spring causes some tiny flecks of the metal to break off, or the like, which would have a much greater effect on its mass.
Second, even that’s at least a matter of energy. The relevant difference between an educated brain and an uneducated one is a matter of information, not energy. While some very deep physics does imply some sort of connection between the two, we’re now at a much higher order of negligible (i.e., we’re taking one number that’s negligibly small times another number that’s negligibly small).
Third, of course, we’re talking about living tissue, and living tissue routinely changes its matter content to a far greater degree than a spring does, continually and as a matter of course. It’s not out of the question that a brain might increase its matter content (i.e., grow) in response to being used a lot (not much, because it’s constrained by the skull, but probably some). And even short of that, you definitely have to consider things like blood flow and cellular respiration.
If only! Instead of standardized tests, final exams, etc., we could just weigh a student’s brain before and after taking a class.
This sounds a little like the question of whether a hard drive, thumb drive, etc. weighs more when there’s a lot of information on it.
Well let’s start with how brains change in response to learning. Part of it is forming new connections between neurons. Part of it, increasingly so after early childhood, is pruning connections. And part of it is increased myelination - the sheaths around what can be considered the wires that transmit information place to place that allow transmission to happen more quickly. Myelin is mostly sphingolipids and relatively low density. Blood flow increases with brain activity as well. But I don’t think blood volume does.
If I had to add that all up I’d completely WAG that the lesser density of myelin is the bigger factor and that brain mass decreases with learning. Ever so slightly.
If you write your name on a sand dune using a stick, the weight of the sand dune doesn’t change. It’s doubtful that educating a brain - rewiring the connections among extant neurons - would change its weight.
However, I will speculate that there might be a still be a correlation.
Compared to an uneducated person, an educated person is more likely to have had greater access to resources during their formative years. Education is one of those resources, but another one is nutrition. Poor nutrition during childhood is likely to affect brain development. It ends up being a snowball effect: poor kids are more likely to have underdeveloped brains because of poor nutrition - and if you’re poor and your brain isn’t up to the task, it’s doubly hard to access opportunities for education later in life.
Which it actually does, albeit by a tiny amount, according to the colleagues over at Physics Stackexchange. The idea is that a drive with data on it has a higher energetic state, which, as per E = mc[sup]2[/sup], translates into higher mass.
Well in terms of lead exposure and even increased absorption of lead (hungry for calcium and iron with lead getting sucked up in the wake), maybe. But moderately poor nutrition, be it amount or quality, that lower SES Americans experience, tends to spare brain. Body fat, then muscle, then slowed height, then other organs, and only when those are all pretty much tapped out, brain growth. That’s way below the poor nutrition of low SES Americans, which is more often a quality issue than caloric sufficiency.
Neuroplasticity allows the brain to change physically through use. Whether or not it gets heavier seems unclear. If a brain does get heavier through mental activity, and depending on what ‘education’ means, a brain might get heavier as a result of an education. I think in terms of this question we should look at greater mental activity instead of education since we are learning something whenever we use our brains. There’s no reason to believe any formal field of study would have more effect on a brain than simply observing life going by.
That’s clearly untrue. Passive observation of life going by is not the same impact on brain development than active engagement with challenging cognitive activities including problem solving, anymore than sitting around passively is of the same muscle effects as active exercise is. FWIW for both a balance of stress and recovery is likely optimal.
Educated is a bit squishy of a term. You can open an encyclopedia to each page for five minutes in front of someone for months and years on end until you’ve gone through the whole thing and some people will come out of that process knowing a lot and others will just know that they hate the sound of paper turning.
IQ seems to be correlated some to cortical thickness and fairly well to cortical surface area. This may or may not correlate with knowledge retention (probably it does).
I’m not sure how the density of the cerebral cortex relates to white and other matter but that’s probably going to be the central crux of the question.
Poor choice of a description on my part. Someone who is keenly observing life and looking for patterns and connections could be exercising their brain as much as someone studying math or history. Just watching life go by thoughtlessly is not what I intended to convey. More to the point, a farmer who has to work out his planting selection and schedule, preparing for pests that might attack, collecting feed for livestock and building barns and fences, and getting his crops to market for the best price could be using his brain as effectively as someone studying agriculture in school.
The op in that thread overlooked that a drive’s arrangement of 1’s and 0’s when “full” of data could also make it weight slightly less than when “empty” (containing a random arrangement). Another poster addresses it further down.
What are “SES Americans”?
The full phrase was “lower SES Americans”, in which context SES means “socio-economic status”.
Ah, thanks! The only thing I could think of was racist, which I didn’t want to believe was being used here.
Ah. Then completely agree.
Undergrad days I had the great privilege to be working in the lab of a professor who was famous for studies on the impact of “enriched environments” on brain/neuronal structures. His position was that it is very hard to have a not learning control arm. One group learns to jump on to a platform to avoid a shock after a tone plays, and another just gets the shock? Both are learning. The second group just learning they get a shock no matter what they do. So his approach was to have one group be treated as standard lab rats and another in rat paradise for play and exploration - brain differences were at least likely candidates for the substrate of learning. Of course it doesn’t answer what counts as enrichment for humans.
Still I’ll count learning formally or informally as education for my read of the OP. Looking it up I was wrong on blood volume - it does increase during cognitive work - but the understanding is that it draws fluid out of tissues to allow for it, the total volume of fluid in brain staying the same as more would increase brain pressure, a bad thing.
So I’m sticking with increased myelination with learning means less density in the same volume.
Yes on SES btw.
But doesn’t a hard drive with random bits on it have higher entropy, and hence a lower energetic state, than one with meaningful, i.e. ordered, bits?
Many data storage mediums involve different energy states, which may or may not be dependent on entropy. For a simple example, suppose that I have an abacus, with a whole bunch of wires and a bead on each wire. If I move the bead to the top of the wire, that represents a 1, and if I move it to the bottom of the wire, that represents a 0. In this data storage device, the energy is directly proportional to how many 1s I have. Storage of all 1s would have the maximum amount of energy, storage of all 0s would have the minimum, and storage of a random (or high-information-content) number would probably have an energy about midway in between.
Of course, abaci aren’t used in computers, but every computer data storage device has something analogous. It might be magnetic materials organized one way or another, or capacitors that are charged or discharged, or high or low voltages, or many other possible systems. Some of these will have an energy that just depends on the state of each individual bit, some will have an energy that depends on how each bit compares to neighboring bits, most will have some combination of the two. And of the ones where the energy depends on comparison to neighboring bits, sometimes it’ll be high energy when a bit is the same as its neighbors and low when it’s opposite, and sometimes vice-versa.