The undiscovered cortex
August 6, 2009 6:40 PM   Subscribe

'cause it's old.
posted by mr_crash_davis mark II: Jazz Odyssey at 6:45 PM on August 6, 2009 [2 favorites]

Pickled it with booze.
posted by Abiezer at 6:47 PM on August 6, 2009 [1 favorite]

Thought origami.
posted by The Whelk at 6:47 PM on August 6, 2009 [4 favorites]

Because you get more surface area that way.
posted by delmoi at 6:48 PM on August 6, 2009 [2 favorites]

Woke up too late to iron. Tuh!
posted by juniper at 6:49 PM on August 6, 2009 [5 favorites]

MetaFilter: The difference between your cortex and mine
posted by davejay at 6:51 PM on August 6, 2009

Because this water is cold, alright? It gets bigger when I think ...
posted by nonspecialist at 6:54 PM on August 6, 2009 [8 favorites]

I had a scan and mine is perfectly smooth...nooks and crannies come from wory worry worry. stop thinking and it will revert to virginal state.
posted by Postroad at 6:56 PM on August 6, 2009 [1 favorite]

Higher surface area to volume ratio. I thought.

/reads article.

Ah. There we go.
posted by six-or-six-thirty at 7:00 PM on August 6, 2009 [1 favorite]

nothing's ever smooth, postroad. now i get to worry if things are troughing where they should be peaking.
posted by de at 7:00 PM on August 6, 2009

Whenever I think about the wrinkles in brains, I think about my driver's ed teacher from high school. We were all 15 years old and getting our learner's permit, but he was exactly like a character out of one of those kid's shows they show on public television. Whenever we were driving in the driver's ed car and I performed some driving rule correctly, he'd say, "Look, SkylitDrawl! You just made a wrinkle!"

He was terrifying.
posted by SkylitDrawl at 7:01 PM on August 6, 2009

Dear Mr. Vernon, we accept the fact that we had to sacrifice a whole Saturday in detention for whatever it was we did wrong. But we think you're crazy to make us write an essay telling you who we think we are. You see us as you want to see us... In the simplest terms, in the most convenient definitions. But what we found out is that each one of us is a brain...
posted by collywobbles at 7:09 PM on August 6, 2009 [3 favorites]

I have a Mandelbrot brain.
posted by Greg_Ace at 7:10 PM on August 6, 2009

"There's this large expanse of cortex, much of which is like South America to a 17th century cartographer"

He's not that big. Have you seen how big donuts are in his tiny hands? Maybe if you're a micro-cartographer. Sheesh, some guys ...
posted by filthy light thief at 7:12 PM on August 6, 2009 [1 favorite]

There was SHRINKAGE!
posted by briank at 7:17 PM on August 6, 2009 [2 favorites]

I slept in it.
posted by ColdChef at 7:19 PM on August 6, 2009 [3 favorites]

Actually, the article doesn't begin to answer the question of why the brain is wrinkled. It tells you what the wrinkles look like over the course of development; it tells you that people with some psychological disorders have disordered folding; etc. But it doesn't say what the folding is for or how it works. One gets the impression that we don't know.

"More surface area" is of course a good generic answer for questions in biology, but I have no idea why it's a good answer here. It's not like there are important chemical reactions between the surface of the brain and the buffer fluid, is it?

I would love to hear if someone knows the answer!
posted by grobstein at 7:20 PM on August 6, 2009 [2 favorites]

Cuz the warranty expired. Wish the parents would have shelled out a little extra for the lifetime warranty.
posted by Ding! at 7:21 PM on August 6, 2009

My wild theory is that it's a backdoor way to bridge gaps in nerve connections: points that are distant within the topology of the brain can be brought close together by folding the brain between them. But of course I don't know enough about neurology to say whether this is at all plausible -- does distance matter in the brain? I guess so, on the evidence that brain processes tend to be at least somewhat localized. But I can't really say.
posted by grobstein at 7:23 PM on August 6, 2009

Brain folding tends to increase with complexity of cognition. We, elephants, dolphins, etc. have very folded brains; mice have very smooth brains.
posted by kldickson at 7:23 PM on August 6, 2009

Mr. Padraigin theorizes that babies are born with perfectly smooth brains, and that the wrinkles are caused by the zapping of realizations and awareness. He claims that if you watch a baby closely, you can witness the moments at which a baby's synapses fire, and that the zap is audible if you're quiet enough.
posted by padraigin at 7:24 PM on August 6, 2009 [3 favorites]

I've got no wisecrack, I just thought that this was genuinely awesome. I like brains.
posted by grapefruitmoon at 7:27 PM on August 6, 2009

Previously: How to mail a fresh brain.
posted by ColdChef at 7:36 PM on August 6, 2009 [1 favorite]

I called it out of the pool twenty minutes ago. If I have to go in there and get it, it's going to be sorry.
posted by jfuller at 7:38 PM on August 6, 2009 [1 favorite]

Other research has shown that autistic children seem to have overly folded brains. This extra folding is significant enough that it actually increases the surface area of the cortex, said Antonio Hardan, a child psychiatrist at Lucile Packard Children’s Hospital at Stanford in Palo Alto, Calif., who conducted the research.

The finding is consistent with earlier discoveries that children with autism have bigger brains than their peers.

Huh. Interesting. If that were a causitive factor it would help explain why men are more susceptible to autism than women.
posted by rodgerd at 7:50 PM on August 6, 2009

You know, for the music.
Brain Folds Five.
ha! har! uh..bye

posted by Cat Pie Hurts at 7:54 PM on August 6, 2009

Brains are folded to keep specific things closer together, while allowing for the expansion and development of the brain as a whole, over time.

Or so I've been told.
posted by herrdoktor at 8:01 PM on August 6, 2009

Huh? More surface area, of course. Why? More surface area means more neurons in the top layer, the neocortex.
posted by orthogonality at 8:02 PM on August 6, 2009 [1 favorite]

'cause it's cold.
posted by Sys Rq at 8:13 PM on August 6, 2009

I think brain research is really unfolding. I took a whole class this last year in grad school on the adolescent brain and it's development and cognition. You can actually see the differences in connections in the brain on scans between 15 year old and a 20 year old brains. Amazing!
posted by garnetgirl at 8:13 PM on August 6, 2009

I thought it was to hold the melted butter.

(NOTE TO SELF: Find out where all that molted buttzwEr wemnet.)
posted by PlusDistance at 8:20 PM on August 6, 2009

Wow, what's next? "Why is the sky blue?"
posted by Eideteker at 8:44 PM on August 6, 2009

Eideteker, why don't you take off the invisible knapsack and have some goddamn compassion and understanding for the color blind.
posted by Brandon Blatcher at 8:58 PM on August 6, 2009

To me, the answer is obvious.
posted by brain_drain at 9:06 PM on August 6, 2009 [1 favorite]

To match my testicles?
posted by PeterMcDermott at 9:41 PM on August 6, 2009

Not everyone's brain is wrinkled.
posted by Crabby Appleton at 9:50 PM on August 6, 2009 [1 favorite]

The undiscovered cortex
August 6, 2009 6:40 PM
Why is your brain wrinkled?

Twenty bucks, same as in town.
posted by grouse at 9:52 PM on August 6, 2009

needs more botox
posted by liza at 9:59 PM on August 6, 2009

Crabby Appleton -

posted by kldickson at 10:14 PM on August 6, 2009

Maybe surface brain does not have to be insulated as much (less nearby brain to create interference); interior brain is myelinated but surface brain is not. If that's "good" for some reason then there would be benefits to increasing the quantity of surface brain. Hence wrinkles. (Yay, surface area!)
posted by grobstein at 10:31 PM on August 6, 2009

A high surface area to volume ratio is important when you care about getting lots of "stuff" through the surface and into the volume.

Imagine a sphere (okay, standard physics joke intro, but bear with me) which is ten centimeters in radius. Take the outer centimeter of thickness. The volume is easy to calculate. Now, if you made that outer centimeter wrinkled, but packed within the same ten centimeter radius boundary, you are definitely not getting any more volume in there. So that isn't extra neurons. If neuronal volume was the most important thing, it would be solid, without a wrinkled surface, because that would give you more volume than a wrinkled surface, so long as you are confined to the same radius.

"More connections" does not make sense to me, either. Take our same outer shell and fill them with dots, a micrometer apart, in a cubic lattice, for simplicity's sake. Give each one a link in each of the six directions. That's a goodly number of connections. Now, if you begin cleaving into that outer surface, you will end up with fewer connections.

Now, if you had something wherein you had certain kinds of neurons you wanted more of, but they could only function within a certain distance of the surface (like the above case), then wrinkling makes sense. Is there some kind of transfer going on which we have overlooked? Are the neurons in the outer layer specialized in some way that they are both valuable, but also unable to function effectively too far from the surface?

Alternately, is it perhaps that connections are good, but the cleaving itself is better? That is, "too many connections" is non-optimal, in the same way that a block of stone is generally less useful than cleaving it into a crude hammer and some spear tips?

Either way, "more" is not what the wrinkles are about. It's either "strategically less" or some kind of prioritized transfer to specialized neurons.

Or you could go with the old nihilistic standby — this was a function once useful many millions of years ago, and, while no longer handy, hasn't been sufficiently detrimental enough to get rid of.
posted by adipocere at 11:01 PM on August 6, 2009 [2 favorites]

The greater surface area is for cooling. It took some serious overclocking to become the dominant species.
posted by ceribus peribus at 11:08 PM on August 6, 2009 [1 favorite]

The point of folding is to allow you to mix the two parts without deflating all the bubbles that you just worked so hard to whip into the eggs. The air bubbles are vital to keeping the dish you are making light and airy.

Um, sorry... what were we talking about again?
posted by twoleftfeet at 11:29 PM on August 6, 2009

I like brains.

Me too, but I can never finish a whole one.
posted by Mr. Bad Example at 12:22 AM on August 7, 2009 [3 favorites]

I found the claim that cortex is the least well understood areas of the brain strange. Cortex is the surface of the sea and we have at least some ways to observe the waves on that sea and most of the brain science and imaging techniques have always been about cortex. What goes on deep waters, that is the great unknown. Luckily it seems be that nothing much relevant for cognition happens there, that white matter may all be about maintenance: plumbing, cooling and feeding the surface.

We may have a big balloon of brain where the balloon is filled with irrelevant stuffing just to allow the surface to stretch to larger area. Which is that kind of clunky design that evolution tends to end up with. Wrinkling is a better way to achieve the same effect, so both have happened, but better ways, wrinkling and folding many times over itself or other geometrical shapes that would allow maximum surface with minimal volume may be unreachable with evolutionary steps from a basic mammal brain. Earlier thread about hollow brain. See the comparison image on the right side.
posted by Free word order! at 1:35 AM on August 7, 2009

What happens to a cortex crinkled?

Does it dry up
like a tater in the sun?
Or pester for a pony
And then run?
Does it stink like rotten meta?
Or crust and sugar over
like a snarky sweet?

Maybe it just flags and moves on
like a fruitless F5 re-load.

Or does it explode?
posted by iamkimiam at 2:05 AM on August 7, 2009 [3 favorites]

His musical stylings are impressive, and he always has a witty bon mot-

er, I'm sorry, thought we were talking about cortex.
posted by Pope Guilty at 2:20 AM on August 7, 2009

MetaFilter: The difference between your cortex and mine

MetaFilter: The difference between your cortex and ours

posted by bwg at 3:01 AM on August 7, 2009

adipocere -

Cerebral cortex is organised into 'columns' that are oriented perpendicular to the surface - more surface area means more columns. Cortex has a layered structure - there are 6 layers of neurons (layer 1 at the surface, down to layer 6 just above the white matter), and the layers differ in their neuronal types and density. A 'column' is a network of neurons connected together in a specific way between these layers. This columnar structure is very closely related to function - for example, in the first stages of visual cortex the columns define populations of neurons that have the same selectivity for a particular orientation of line segment.

All of this is a roundabout way of saying that cortical neurons are not simply an amorphous mass packed densely in to grey matter - cortex is highly organised structure, and this organisation is essential to cortical function. So in a sense you are right, more surface area is not important because it means more neurons, but because more surface area means more columns.
posted by aiglet at 3:17 AM on August 7, 2009 [8 favorites]

I am skeptical of the hydrocephalus story, to say the least.

If there was evidence that the brain wasn't necessary for thinking, it would be quite a big story. The medical story of the century, really.
posted by empath at 4:20 AM on August 7, 2009

The brain is not for thinking. It is an antenna for 2-way communication between itself and the mind, which is somewhere else. The precise nature of the wrinkles determine the quality of reception, and that determines apparent intelligence. This is why SCIENCE! is so convinced the brain does the thinking, since the brain is the only effective means of communication with the mind. Other bits of our bodies are also receptive, but at a far more primitive level.

Besides, if the brain wasn't wrinkled, it wouldn't resemble a walnut.
posted by Goofyy at 6:42 AM on August 7, 2009

Stress. I need to chill out.
posted by molecicco at 7:02 AM on August 7, 2009

Just wait until the collagen and botox crowd hears about this, those wrinkles will be a thing of the past!
posted by tommasz at 7:45 AM on August 7, 2009

I don't know, but I do know that Medical Mechanica are going to do something about it.
posted by teresci at 9:09 AM on August 7, 2009

MetaFilter: There's this large expanse of cortex
posted by nonmerci at 10:14 AM on August 7, 2009

Same reason as my scrotum.*

*Still trying to figure out the whole deal with the scrotum.**

**Scrotum? Didn't know 'um!

posted by Halloween Jack at 10:43 AM on August 7, 2009 [1 favorite]

Ok, the author of the article is one Emily Anthes. In the linked article she stated "The folds create more surface area, increasing the size of the cerebral cortex that can fit in our skulls,..." which is at best vague and counter-intuitive as adipocere explained so succinctly above. I've heard similar explanations for years and their lack of sense always bugged me. In previous years I've googled to no avail and I knew I wasn't the only one this was bothering. So with this little nag now in my head I kept reading and 7 comments down, my hero for 8/7/09, aiglet, explained in 190 words what Ms. Anthes failed to in 1,012.

So I thought I'd be helpful and smug in the bargain by writing Ms. Anthes with the information from aiglet above. It turns out she is a contributor and not a member of the staff of the Boston Globe so I googled. Emily Anthes, it turns out, " a freelance science journalist. Her work has appeared in Seed, Scientific American Mind, Discover, Slate, Good, New York, and the Boston Globe. She has a master's degree in science writing from MIT and a bachelor's degree in the history of science and medicine from Yale, where she also studied creative writing."

So I again say thanks aiglet and

Emily Anthes
posted by vapidave at 11:04 AM on August 7, 2009

I have the brain of a 20-year-old

You better give it back. You're getting it all wrinkled.

posted by jfrancis at 11:23 AM on August 7, 2009

Imagine a sphere...

But the brain isn't shaped like a sphere, so does that matter? I honestly don't know. Perhaps the wrinkling helps compact the same surface volume in a smaller area? It's combination of what aiglet said with the cortex's specific structure. There's a practical limit to how big the human head can get before it turns into a negative trait in terms of weight, energy, balance and being able to fit in small spaces that tigers can't get to.
posted by Brandon Blatcher at 4:12 PM on August 7, 2009

So I again say thanks aiglet and

Emily Anthes

But who is aiglet? He / she apparently joined just to post this one comment!

As to Anthes, the quality of science writing generally is just shitty. I'm not sure what the problem is. How can you presume to write an article -- even a "popular" article -- about something you didn't bother to thoroughly understand?
posted by grobstein at 4:40 PM on August 7, 2009

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