Brain tissue samples suggest we stop growing new neurons in our early teens • Hacker News Board

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#41

Post by 52-6F-62 » Thu, Mar 08, 2018, 3:23 PM UTC

CuriouslyC wrote: post #32

kristiandupont wrote: post #17

Absolute pitch is something that supposedly can only be learned before the age of 6 but the drug Valproate seems to reopen this window. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3848041/

I suspect that valproate works by increasing BDNF levels. Exercise also increases BDNF levels, and a diet high in fermentable fiber has been linked to increases in BDNF as well, through increased short chain fatty acid production. It is worth mentioning that valproic acid is just a branched-chain short chain fatty acid, so it is likely that many of its effects are similar to those from short chain fatty acids derived…

Wait... so exercise and beer? Heavenly.

Mix in some oatmeal and eat your vegetables. Who would have guessed.

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#42

Post by sevenfive » Thu, Mar 08, 2018, 3:25 PM UTC

jmkni wrote: post #29

sevenfive wrote: post #22

Earlier quoted context omitted.

I mean, we already know the differences between 20- and 30- year olds from simple observation. So it's not really positive or negative.

What would you say the differences are, based on your observations?

Not my observations, observational studies.

Regardless of the exact reasons why plasticity declines with age, it's obvious that any fix is a long way off. I wouldn't take this news as positive, rather negative, actually, since it just means we have yet more work to do

Like, instead of saying "I always lamented the idea that as we grew older we generated less and less neurons" the GP can now say "I always lamented the idea that [other unknown mechanism behind declining plasticity]". Hardly good news.

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#43

Post by [deleted] » Thu, Mar 08, 2018, 4:01 PM UTC

punkbit wrote: post #31

ramblerman wrote: post #21

I see this as a positive. I always lamented the idea that as we grew older we generated less and less neurons, and thus our learning capacity decreased (I thought). But it seems even young university students are no longer generating neurons. Nor are the 30 year olds learning new languages or switching careers. It seems neuron growth thus has nothing to do with 'plasticity' or our capability to learn. * disclaimer: I…

True! But someone who learns to play the guitar, or a language at 8 ~ 15 years old shows skills that are very difficult to master (if not impossible) when you are older. There's a lot of evidence of this if you talk with guitar teachers, someone who moved and start speaking a different language when adult, etc...

[deleted]

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#44

Post by punkbit » Thu, Mar 08, 2018, 4:04 PM UTC

StavrosK wrote: post #40

punkbit wrote: post #31

Earlier quoted context omitted.

True! But someone who learns to play the guitar, or a language at 8 ~ 15 years old shows skills that are very difficult to master (if not impossible) when you are older. There's a lot of evidence of this if you talk with guitar teachers, someone who moved and start speaking a different language when adult, etc...

Can you point to any studies? I don't know if this is because our brains get less plastic, or because we just stop bothering when we get older. I have personally noticed some drop in language acquisition skills, but I'm learning Spanish at 35 and I wouldn't say it's significantly harder than learning English at 12 (apart from the fact that English is everywhere around me all the time, but Spanish is very hard to come…

I've got Japanese friends who live in the UK for more than 10 years now, and it's more Engrish then English, than anything else. My english sucks by the way.

Maybe this will help you?

http://www.jneurosci.org/content/36/3/755

http://pandora.cii.wwu.edu/vajda/ling201/test4materials/seco...

https://www.sciencedaily.com/releases/2012/03/120328172212.h...

https://www.sciencedirect.com/science/article/pii/S0093934X0...

https://books.google.co.uk/books?id=5vvY2BDWZjEC&pg=PA251&dq...

https://www.justinguitar.com/en/BC-101-CommonQuestions.php

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#45

Post by Tharkun » Thu, Mar 08, 2018, 4:13 PM UTC

NutriSugar wrote: post #38

ramblerman wrote: post #21

I see this as a positive. I always lamented the idea that as we grew older we generated less and less neurons, and thus our learning capacity decreased (I thought). But it seems even young university students are no longer generating neurons. Nor are the 30 year olds learning new languages or switching careers. It seems neuron growth thus has nothing to do with 'plasticity' or our capability to learn. * disclaimer: I…

I think learning is more about losing neurons, not creating it. Or meatspace neural netowrks are less about changing weights and more about pruning connections.

I can't find the link, but I recently read an article that sugggested people with autism did less connection pruning during puberty than people without autism.

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#46

Post by StavrosK » Thu, Mar 08, 2018, 4:14 PM UTC

punkbit wrote: post #44

StavrosK wrote: post #40

Earlier quoted context omitted.

Can you point to any studies? I don't know if this is because our brains get less plastic, or because we just stop bothering when we get older. I have personally noticed some drop in language acquisition skills, but I'm learning Spanish at 35 and I wouldn't say it's significantly harder than learning English at 12 (apart from the fact that English is everywhere around me all the time, but Spanish is very hard to come…

I've got Japanese friends who live in the UK for more than 10 years now, and it's more Engrish then English, than anything else. My english sucks by the way. Maybe this will help you? http://www.jneurosci.org/content/36/3/755 http://pandora.cii.wwu.edu/vajda/ling201/test4materials/seco... https://www.sciencedaily.com/releases/2012/03/120328172212.h... https://www.sciencedirect.com/science/article/pii/S0093934X0... ht…

Hmm, I don't see anything in there related to skill acquisition in younger vs older people, I'm afraid. Most of the links are about skill acquisition in general, and how the brain changes. One is to a Google book that won't show the page (I don't know why, it says the page is unavailable), and the last link is a teacher saying he guesses children learn more quickly because they're more plastic (but I guess they learn faster because they have more free time/willingness to practice)...

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#47

Post by MarlonPro » Thu, Mar 08, 2018, 6:15 PM UTC

Is this a blow to neuroplasticity?

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#48

Post by jateenjoshi » Thu, Mar 08, 2018, 7:03 PM UTC

MarlonPro wrote: post #47

Is this a blow to neuroplasticity?

Not this result in itself. Neuroplasticity refers to the ability of existing neurons of creating/pruning connections to other neurons.

However, separately, there is scientific evidence to show that neuroplasticity decreases after adolescence.

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#49

Post by sireat » Thu, Mar 08, 2018, 10:04 PM UTC

punkbit wrote: post #31

ramblerman wrote: post #21

I see this as a positive. I always lamented the idea that as we grew older we generated less and less neurons, and thus our learning capacity decreased (I thought). But it seems even young university students are no longer generating neurons. Nor are the 30 year olds learning new languages or switching careers. It seems neuron growth thus has nothing to do with 'plasticity' or our capability to learn. * disclaimer: I…

True! But someone who learns to play the guitar, or a language at 8 ~ 15 years old shows skills that are very difficult to master (if not impossible) when you are older. There's a lot of evidence of this if you talk with guitar teachers, someone who moved and start speaking a different language when adult, etc...

Same goes for chess.

15 is already considered very late to start serious study in chess. You simply do not develop the unconscious mastery the blink like ability to play a good move instantly.

It is not the lack of time in older players either. Tales abound of players of independent means dedicating themselves to chess and getting nowhere near master level.

By reverse, no chess player started at 25 and made Grandmaster.

A huge outlier is https://en.wikipedia.org/wiki/John_K._Shaw who was a club level player at 19.

Re: Brain tissue samples suggest we stop growing new neurons in our early teens

#50

Post by otakucode » Thu, Mar 08, 2018, 10:32 PM UTC

This worries me. First, any study of neurology it must be kept in mind is done on a specific population. The neurology of a Papua New Guinea highlander and an upper middle class white kid from the suburbs of NYC are not going to have the same brain development. Brain development does NOT proceed as a consequence of aging. This is a dangerous and destructive myth that gets perpetuated all the time. Brain development proceeds as a consequence of experience. If you eliminate experience from a persons life, you will eliminate brain development.

We can see this clearly in the very young. An infant must master binocular vision by about 3 weeks old, or else they will never master it. Putting an eyepatch on an infant because they are "not ready" for binocular vision or because their brain "isn't mature" in the region responsible for that would damage them for life. A child must be exposed to the general concepts of language before about age 5 or else they will remain incapable of learning any sort of language-based communication for their entire life. Likewise if you were to restrict them and keep them away from language exposure because their brains are 'not mature' or because they're 'not ready' for it or whatever, you would do them grievous harm by actively preventing brain development.

There are similar critical periods and developmental milestones like the Existential Crisis where children develop an understanding of death as the end to life and understand their own mortality around age 10. It was always thought that neuroplasticity pretty much disappeared after adolescence. I've always wondered if that was a consequence of the way the life experience of a person in a western society changes after adolescence. That is typically when almost all experience of novelty comes to a grinding halt. Jobs are taken up, spouses found, routines established. And without unique experience providing intense stimulus to a brain, it will stop developing. Absent those stimuli, it never would have developed in the first place. It is the origin of growth.

If we start to see neuroplasticity decreasing even earlier in members of our society, I would not be terribly surprised given the degree to which adolescence has been either criminalized or heavily regulated. And we will pay the price for that.