August 17, 2019 • 49 mins
When you hear the word “neuroplasticity,” you probably think of it in terms of a young brain’s ability to learn or an older brain’s struggles to rebound from injury. The possibility of a neuroplasticity-boosting drug remains one of medicine's true holy grails, but is there a dark side? Robert and Joe discuss the balance of plasticity and stability in the human mind. (Originally published July 5, 2018)
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Episode Transcript
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Speaker 1 (00:05):
Hey, you welcome to stuff to blow your mind. My
name is Robert Lamb and I'm Joe McCormick. In It's Saturday.
Time to go into the old vault? Robert, is this
one where I did the Sean Connery voice? Now, I'm
just remembering in this moment, remember, oh no, are we were? Okay? Well,
I We'll just have to deal with it. This originally
published July, and this is an episode we did about neuroplasticity. Now,
(00:29):
we were just saying before we started recording this intro,
uh that after having done all the stuff on psychedelics
we just went through we we we may, we may
approach this subject to it from a kind of different angle. Now,
I wonder if I don't know, if you listen to
this episode and you want to hear you want to
hear us revisit the topic with with new wisdom let
(00:49):
us know. Yeah, I feel like it would this would
have been a different episode if we had recorded it
after the psychedelic episodes. But I still think it holds
up as a solid vault entry. So dr jessup, do
you expect me to talk? Oh this this isn't a
standard interrogation. Inject him watch this now, poison truth Serer.
(01:10):
None of the above. No, this is something far more experimental.
But perhaps a notorious secret agents such as yourself has
heard of induced neuroplasticity. What you're talking of experimental neurotherapy drugs,
your math? Neuroplasticity is far more than that. Yes, yes, this,
this sort of treatment will soon revolutionize the way we
(01:34):
deal with addictions and brain disease. It will allow adults
of any age to learn new languages with the aptitude
of a young child. But that's not why I've injected
you with it. No, we've We've romanticized neuroplasticity. You see,
we forget the importance of neuro stability. As children, we
have an amazing ability to adapt to any environment, any language.
(01:57):
Were open to the world. We're also open to try.
But then everything has to settle. We put aside those
childish things and we become bia then doctors, secret agents.
What do you want from me? Why? I want to
change your life? Hans Roll the film? Wait, what what
are you showing me? Joseph are YouTube playlist, Oh please,
(02:20):
hours upon hours of let's call it informative content from
some of the platforms. Leading personality No, not dish influencers.
I'll tell you anything for medians, no commentators, unboxes. No.
(02:42):
Welcome to Stuff to Blow your Mind from How Stuff
Works dot com. Hey, welcome to Stuff to Blow your Mind.
My name is Robert Lamb and I'm Joe McCormick. And
today we're gonna be talking about another topic that's sort
of a fall up from Robert's visit this year to
the World Science Festival. We're gonna be talking about neuroplasticity.
(03:06):
That's right. This, uh, this particular panel that that I attended,
and this one is also available online. Will make sure
there's a link to the YouTube video on the landing
page for this episode Acceptable in your Mind dot com. Uh.
The particular panel was called Nuts and Bolts of Better Brains.
It was hosted by Guy mccon, a neurosurgeon, neuroscientist, Alvero
pascal Leoni, neuroscientist, uh Nim Tottenham, developmental law psychologist, and
(03:31):
Carlas Shots, a neuroscientist, and they discussed neuroplasticity, which is
something that we've we've touched on on the show before
and I think a lot of people have kind of
a general concept of yeah, neuroplasticity is one of those
words that I think has suffered a lot of abuse
in the press um because I mean, there are words
(03:51):
that have a good meaning in science, and there's nothing
wrong with the concept itself. But in today's neuroscience, neuroplasticity
does have a me ng and it does have a
useful meaning. But you see it in a lot of
hype and bs on the internet. Yeah, Like I noticed,
when when you do a search for neuroplasticity you want
(04:11):
to read things about it, you get mostly content at
one of two levels. Either content for experts and neuroscientists,
like actual scientific literature that the average reader can't penetrate,
and then you get also a whole lot of hype
and bs that is telling you about I don't know,
about how you're going to revolutionize your brain and you'll
(04:31):
become like a child again and become a master of
your own abilities. Yeah. I mean, it's already become something
of a buzzword, for instance, with with certain uh like
supplement manufacturers and take this neuroplasticity vitamin. Yeah, okay, thanks,
But but the neuroplasticity is a real thing. It is
you can think of it simply as the brain's ability
(04:52):
to adapt and humans most incredible powers of neuroplasticity, especially
during the so called critical periods of early childhood. Yeah.
One of the things to think about this kind of
weird is um how well humans adapt to such different
life conditions. Like if you take most animals out of
(05:15):
the environment and condition conditions that they're best adapted to,
they don't do very well. There are some exceptions, but
most of the time an animal has evolved to have
certain instincts. It's got sort of like pretty hardwired behaviors.
It can live, you know, it can be born where
it is supposed to be born and live encountering the
(05:35):
kind of stimuli it would normally encounter, and you know,
it can do its thing that nature has shaped it for.
But humans can do all kinds of stuff. We can
live in the snow, we can live in the desert,
we can live in cities, we can live in it planes,
we can be farmers, we can be doctors. We can
do so many different kinds of things with our brains.
(05:56):
And there are no other animals like this really. Yeah.
The in the talk, they brought up the example of
the logerhead turtle as an example of a creature that
is not a paragon of neuroplasticity but neuro stability. A
creature that, upon birth is just ready to go and
do a very specific thing exceedingly well in a very
specific environment. But if you put some major obstacles in
(06:19):
that turtle's way, the turtle probably would not find a
way to adapt to those obstacles and survive around them.
It would probably just not survive to adulthood, right, I mean,
the the turtle is a good example of that, because,
I mean, with with with various sea turtles, we've seen
examples of how just artificial lighting can screw up a
very particular approach to going about its life cycle. Yeah,
(06:41):
but so your brain. One of the reasons your brain
is so powerful compared to the brains of animals is
that it can be adapted to so many different scenarios
and so many different types of tasks depending on what
sorts of environments you're exposed to when you're very young. Yeah, languages,
of course one of the great examples. And I think
(07:01):
everyone has at least some awareness of this. Certainly, anybody
out there who's a parent has has read about this
or experience this with their own children. Is that during
certain critical periods, they have an amazing ability to not
only pick up a language, but to just perfectly pick
it up, to just breathe it in and and and
become fluent in it without with without any of the
(07:23):
challenges that are generally encountered by adults trying to learn
a second language. I mean, one of the ways that
it's often put is that with great effort, and adult
can learn to speak a language they don't already speak,
but they will pretty much always speak it with an accent.
Children can learn to speak all kinds of and can
learn to speak multiple languages at the same time, and
(07:44):
can generally learn to speak them without an accent. Right.
But then of course it goes beyond this too, because
there there's so many other things that are being absorbed
during childhood. You know, the social norms, cultural norms, just
how one interacts with your environment, and that has enabled
humans to thrive all over the world, you know, obviously
with technological aids in many cases, but still it it
(08:08):
underlies the diversity and success of our species. Then again,
there are some reasons to think that you don't want
the brain to be sort of infinitely plastic right, Because
if we consider plasticity the ability of the brain to
adapt to new scenarios and change itself to work better,
you also need cases where the brain knows what to
(08:29):
do and does it instead of keeps being influenced and
changing right right, and knows where to where to where
to stop. You know what, what avenues to stop exploring
because basically what happens is their neural circuitry branches out
to master the skills necessary for survival. And then, uh,
and then after it does this, after you know, some
of the branches have been prune back. Uh. You can
(08:49):
think of it like a you know, like one of
those shrub sculptures from the Shining from you know, the
original novel. If you've read that, you know you you
you prune everything down, cut it away until it's the
the appropriate ape. Yeah. That's an interesting thing that the
speakers in this event talk about, is the idea of
pruning in childhood. How it starts off with way more
connections than it needs, and then through this process it
(09:10):
sort of pairs back the stuff that says, Okay, it
looks like I'm not going to need that in life.
We can just sever all those Yeah, I mean it
kind of matches up with the cliche of the child
who can grow up to be anything, right, which you know,
obviously any given child can't grow up to be absolutely anything.
But there is a there. There is a lot of
room for specialization and and and and diverse growth there. Yeah,
(09:32):
we have natural tendencies and natural potentials, and some of
that is genetic. But then also we were extremely adaptable
as children, right. But then of course in neural stability
has to kick in. That's important too, a necessary balance
in the human brain. Um, you're going to grow up
and become this thing we call an adult. But what
(09:53):
if I am Peter Pan and I don't want to
grow up and be an adult because growing up and
being an adult and having neuro stability limits my potential.
What if I decide I don't want to be somebody
who only speaks English. I want to be somebody who
speaks Chinese and speaks French and speaks the click languages.
And you know what if I want to speak all
(10:15):
those languages without an accent, Why can't I do that? Yeah?
I want to have infinite potential. Again, I want to
go back to I want to be able to grow
up to be anything. You know. I think we've all
had moments like that where we we we we we
look at where we are and we think, well, if
I could go back and open myself up to this
language or this ability or what have you, then I
(10:35):
would love to do that, you know, or just the
idea that nobody wants to. You don't want to feel stagnant.
You want to feel like you're continuing to grow and
uh and you know, keep up with the young ones.
And so scientists have continually looked to possible ways of
essentially rewidening the doorways of of neuroplasticity. That's one of
(10:56):
the metaphors it's often used, right, is that when you're
a child, the the door is open, the window is
open for you to grasp onto anything. But then depending
on who's throwing the metaphor around, you can say, well
it closes when you become an adult, but it doesn't
really close. It gets sort of like it gets almost closed, right,
it narrows. And so we've looked ways to to widen
(11:19):
it in adulthood. And and it goes beyond this mirror
um you know, intellectual vanity as well. Right, It's not
just Peter Pan saying, I want this, I want that.
There's also the idea of treating problems in the adult
brain by reintroducing plasticity, right, it would it would give
us a way to treat various neurodegenerative disorders, anxiety, depression,
(11:42):
even post traumatic stress disorder. Like anytime there's a there's
a potential for for growth and change, positive growth and
change in the brain to help with a given condition.
Neuroplasticity is often brought up as a as a potential cure,
but it's a challenge to do this sort of thing.
As a Columbia University developmental psychologist Dr Nim Totenham, who
were referenced already, as she stated in the in that
(12:04):
World Science festifal discussion, the brain actually extends expends a
lot of energy to keep critical periods from reopening. Yeah,
we there there seems to be some logic underlying this,
this move the evolution took right. It says, you know,
you don't stay a plastic child forever. At some point
the brain needs to figure out what to be and
be that right. And that's one of the reasons we're
(12:27):
calling this episode the Dark Side of Neural plasticity, not
that neuroplasticity. It necessarily has this deep, dark underbelly, but
the sort of public awareness tends to lean so heavily
towards neuroplastics is just an absolute good. I want as
much of it as I can get. We want to
counter the hype. Neuroplasticity is a good thing, but it's
also not an uh It's not a good thing in
(12:49):
every possible case, in every possible sense. Right, and towards
the end of the episode, Will will speculate a little
bit and look at some some speculation from experts about
what some of the possible pitfalls could be, What are
some and even what are some of the black mirror
esque possibilities in a world full of neuroplasticity inducing drugs. Yeah, now,
(13:10):
the question about these drugs, though, is still wide open.
I mean it's sort of h I hate to use
the metaphor the wild West. What's a better metaphor for
an arena in which there is still much much new
ground being forged? Welcome to the jungle, baby. How about
some spelunking. We're spelunking. Yeah, those are close confines, though,
I guess, Okay, I think I think wild West is
(13:32):
still pretty good. Well, whatever it is. I mean, we're
still trying to figure out what kinds of drugs might
do this, what side effects they might have, if they
are effective at doing it, And we'll talk more later
in the episode about what some of these specific drugs
might be. Yeah, because to master neuroplus this day, we're
going to have to establish the molecules that close the doors.
(13:52):
I mean, the thing is, it is possible to extend
critical periods and manipulate them, and experts do, in fact
think that will one day be able to do this
with a pill, with some sort of medication. So it's
not a question of if. It's a question of when
the groundwork is already being laid for this. Uh, it's
just how are we going to be ready for it
when it happens. Well, I think we should take a
(14:13):
quick break and then when we come back we will
discuss a few things about the history of the idea
of neuroplasticity. Than alright, we're back. So Charles Darwin actually
offered some thoughts about how the brain changes in response
to the environment in his book The Descent of Man,
which published in eighteen seventy four, and though We should
note that he did not use the term plasticity. He
(14:36):
did sort of write about the idea of of the
brain adapting. He wrote, quote, I have shown that the
brains of domestic rabbits are considerably reduced in bulk in
comparison with those of the wild rabbit or hair, and
this may be attributed to their having been closely confined
during many generations, so that they have exerted their intellect, instincts, senses,
(14:58):
and voluntary movements. But little uh, note that he's imagining
this adaptation of the brain taking place over multiple generations
through inheritance, which is very different from the kind of
plasticity that we're talking about, which takes place within a
single body within a single lifetime. But he is at
least offering an image. They're saying like, Okay, maybe the
(15:18):
brain can kind of be molded to what it best
does given its environmental circumstances. Right. If you, if you're
a wild hair and you need to be crafty and
wildly and use all your senses to survive out in
the brush, uh, you you will grow these bulky brains.
But if you're a domestic hair and all you do
is sit around and get fed, then you don't need
(15:39):
all that stuff and the brain will adapt. This touches
on a fact that we've discussed before, and that is
that that the that the brain like evolution, is a
miser and it's cheap. Yeah, it's it's cheap and once
the most economic model for functionality it is. It is
the Ebenezer Scrooge of the body. No, the whole body
is cheap. Actually, you know, it makes sense. You don't
want to be wasting energy in an environment where energy
(16:02):
is hard to come by, living in a world of
technology and abundance. Uh, you know, we should stop to
think how, you know, if if you have food to eat,
if you're not wondering where your next meal comes from,
you should think about how lucky you are. But you
should also think about how, in many ways your body
and the bodies of every other creature in the world,
we're sort of designed for scenarios where you would be
(16:23):
constantly living on the edge of starvation. But back to
neuro plasticity. So the term plasticity emerged from the work
of American psychologist William James who lived eighteen forty two
to nineteen ten, and James defined it the following way
he said, it's quote the possession of a structure weak
enough to yield an influence, but strong enough not to
(16:45):
yield all at once. Yeah, I mean that makes sense.
It's ideal for a young child to be open to
their environment and not so open that they're just completely overwhelmed. Right.
So I want to read a quote from William James
from his from his seminar work on psychology, where he
started deposit that the brain might have some kind of
(17:05):
might have some kind of like changeable structure. So he says, quote,
if habits are due to the plasticity of materials to
outward agents, we can immediately see to what outward influences,
if to any the brain matter is plastic, not too
mechanical pressures, not to thermal changes, not to any of
(17:26):
the forces to which all the other organs of our
body are exposed. For nature has so blanketed and wrapped
the brain about that the only impressions that can be
made upon it are through the blood on the one hand,
and the sensory nerve roots on the other. And it
is to the infinitely attenuated currents that pour in through
(17:46):
these latter channels that the hemispherical cortex shows itself to
be so peculiarly susceptible. The currents, once in, must find
a way out. In getting out, they leave their traces
in the paths which they take. The only thing they
can do, in short, is to deepen old paths or
to make new ones. And the whole plasticity of the
(18:09):
brain sums itself up in two words when we call
it an organ in which currents pouring in from the
sense organs make with extreme facility paths which do not
easily disappear. For, of course, a simple habit, like every
other nervous event, the habit of snuffling, for example, or
putting one's hands into one's pockets or biting one's nails,
(18:32):
is mechanically nothing but a reflex discharge, and its anatomical
substratum must be a path in the system. The most
complex habits, as we shall presently see more fully, are,
from the same point of view, nothing but concatenated discharges
of the nerve centers, due to the presence there of
systems of reflex paths so organized as to wake each
(18:56):
other up successively. The impression produced by one skill or
contractions serving as a stimulus to provoke the next until
a final impression inhibits the process and closes the chain.
So that was very forward thinking on William James's part.
He's so, he's got a very rudimentary nineteenth century understanding
(19:17):
of brain function here, but it does get some some
interesting basic insights right. One of them is that habits
or tendencies of the brain consist of a kind of
reinforcing of pathways of activities. Another is that complex brain
functions are built out of many less complex brain functions
happening together in sequence. Another is that the potential and
(19:39):
predispositions of an individual brain like your brain, can be
changed based on repeated interaction with chemicals in the blood
or with the data of the senses. And that last
part is just as a tangent, one of those utterly
mundane facts that I often have to stop and force
myself to be amazed by over and over again, Like
(19:59):
think about this. It sounds kind of stupid to say,
but by making acoustic vibrations in the air with my
mouth that you can hear, or by like drawing a
picture on a chalkboard and putting it in front of
your eyes, I can literally change the physical configuration of
your brain. I make changes inside your skull by doing
(20:21):
things you can see in here. Isn't that bizarre? Yeah?
I mean if you and if you extend it to
written language, you can think, oh, well, somebody who wrote something, uh,
inscribed something down a thousand, two thousand, three thousand years ago.
They can speak across all those uh, those dead millennia,
and they can speak right to our brain and make
(20:42):
changes in it. It's unbelievable. Now. I mentioned earlier that
the term plasticity in the context of neuroscience had been
used to mean a lot of different things. There was
one particular paper I looked at about this by Giovanni
Berluki and Henry book Tool from two thousand nine and
Experimental Brain Research, and they talk about how the term
plasticity has been used over the past century to refer
(21:03):
to quote changes in neural organization, which may account for
various forms of behavioral modifiability, either short lasting or enduring,
including maturation, adaptation to a mutable environment, specific and unspecific
kinds of learning, and compensatory adjustments in response to functional
losses from aging or brain damage. So that that's a
(21:25):
lot of different meanings encompassed in the idea of plasticity,
but it does sort of apply to all of those,
so it's subject to generalization. But then also is sort
of uh is a turn It sort of refers to
general change in the brain. Yeah, a kind of adaptation
that has come to be associated with pressures put on
the brain from the environment. Right. So, with modern techniques,
(21:46):
we've discovered that the way these pathways are forged and
reinforced in the brain depends largely on the crucial element
of the synapps or you know, the bridge of space
that connects to nerve cells and allows impulses to pass
between the cells. And in eight three, the Italian neuropsychiatrist
Eugenio Tanzi first proposed that the basis of practice based
(22:09):
learning and associative memory was these connections between nerve cells
in the brain. Because Tanzi knew that there are other
scientists who had observed the slowing of the passage of
nerve impulses through the gray matter in the brain, and
so he hypothesized that maybe what's going on in that
slow down is that there's difficulty for the impulses to
(22:31):
cross the gaps between neurons, These gaps that we now
call synapses or synaptic fissures, and based on that assumption,
Tansi argued that the way the brain adapts, the way
it learns through practice and creates associations between things, the
way it sort of enacts its plastic potential is by
a kind of exercise. When you perform a repetitious activity
(22:54):
in the brain, the same pathways of neurons repeatedly communicate
with each other, and by doing this you cause a
kind of hypertrophy or strengthening of the connections between those
specific neurons. The more you do a certain thing in
the brain, the easier that that thing becomes to do
in the brain. And then the next year. In the
(23:14):
Spanish neuroscientists Santiago Ramoni Kahal, who I've thought before we
should do a whole episode on this guy. Perhaps he
also speculated that learning was based on the creation and
strengthening of connections between neurons. I feel like this is
something that has been I think over the years, it's
just been so well demonstrated, or not really demonstrated, but
(23:35):
illustrated with animations and and uh and and art that
I have it like well ingrained in my head, Like
when people talk start talking about synopsis firing. I picture it,
and maybe I also kind of think of it in
terms of of playing an instrument, like the physical act
of playing an instrument of linking, um, you know, of
(23:56):
finger movements on say a trumpet or French worn to
the note that you're playing, and then linking those in
order to create, uh, the notes in a particular tune,
which of course is both literally a synaptic learning exercise,
but also kind of an illustration of what's going on,
like making this, connecting it to that, and then leading
(24:16):
onto the next note. Yeah, we we've learned this in
the modern age, and so it's easy for us to picture,
but we should appreciate how how interesting of an insight
this was for for the people at the time, because
there were also competing hypotheses in the late nineteenth and
early twentieth century, like Berlukian book Toll show that in
the first couple of decades of the twentieth century that
(24:38):
this idea of the sort of learning through quote reduced
resistance that exercise synapses, uh, that that idea was pretty
widely accepted in that first couple of decades, and then
for a while it really went into decline. This the
synaptic model of plasticity due to arise in the popularity
of competing ideas about all this weird stuff about the
(24:58):
equipotential version end of the brain. But anyway, in the
late nineteen forties it came back. It was sort of
rehabilitated by scientists like the Polish neuroscientists Jersey Konorski and
the Canadian psychologist Donald Hebb, and Hebb was particularly influential,
and then experimental evidence accumulated during the twentieth century, especially
during the mid and later twentieth century, from the likes
(25:20):
of David Hubel and Torsten VISal, Michael Merzenek, and Eleanor McGuire. Now,
the work of each of those individuals is is fascinating,
and I would love to come back and look at
them in greater detail. There's some wonderful work they're regarding, uh,
you know, how how we see the world. I mean,
some of the very basic questions about the human experience,
(25:40):
how how do we perceive the world and how is
it processed in the brain are explored by by by
their work. But the interesting thing is there's still something
of a controversy about exactly how plastic the adult human
brain is, if much at all like For most of
the history of neuroscience. Up until very recently, a lot
of experts believed that the human adult brain had almost
(26:04):
no plasticity, you know, that it was fixed and stable.
But at the same time, it's obvious that adults can
learn new things and adapt. Yeah, we can change, and
then we don't have to undergo, you know, catastrophic brain
injury for it to happen, right, So exactly how much
potential for change in plasticity is there in the adult
brain and in what areas like? It appears much easier
(26:25):
for adults to learn and adapt in some ways than
it does in others. Language acquisition, as we've talked about
as a classic example, Um, you know, children are just
so so much better at learning a language than adults are.
Another one is certain aspects of music learning. Have you
read about perfect pitch? Probably, yes, Yeah, you have to
get it early or you're not gonna you're not gonna
(26:46):
get it later on. Yeah. This is a commonly cited example.
Robert sing a middle c oh, I I don't. I
don't do music like that, Joe, Almost no adults do
unless you've you've trained on it before you were roughly
six years old. Right, So if you have this skill
known as perfect pitch, you should be able to recognize
or produce not just tones relative to other tones, but
(27:10):
like you could call out a note and the person
would know what that pitch actually was. They could sing it,
or they could recognize it in hearing it. Yeah. I
My my reaction to that question is the same as
the other day when my son asked me what Thursday
plus Thursday equals, and it's just like, I can't. That
just broke my brain a little bit to even try
and answer that question. It sounds like a three key
(27:31):
Thursday probably, But yeah, So Supposedly the idea is if
you teach children to recognize pitches in an absolute sense
before they're roughly six years older, so they can potentially
acquire this skill. It's just like you've got to You've
got to get going within that window. Yeah, I feel
like I'm I'm wasting my time reading the hobbit to
my son. We should be we should be working on
(27:52):
this pitch thing. Well, there are all kinds of things
potentially like this that you don't even know about that
maybe you should be teaching your son at this critical
age before the window doesn't close but gets very narrow. Yeah. Well,
I mean there is a lot of a lot of
discussion of this out there in parenting forums and actual
you know, pure viewed child rearing material just about Yeah,
(28:14):
these are the ages of childhood when you want to
throw a bunch of different activities at them. You want
them to have some sort of musical training, some sort
of uh training in another language, etcetera like this, This
is when the this is when the windows are open,
so you want to just throw as much stuff there
there as possible. But I mean, wouldn't it be great
if you could be like that again as an adult?
(28:35):
As we were talking about earlier, the desire to be
Peter Pan, are are there things that we could do
to make the adult brain a learning and adaptation machine
like the young child's brain. A lot of people have
been asking that question, and so I guess that's what
we should explore now, the idea of induced to neuroplasticity
and adults. That's right. And as as we said earlier,
(28:57):
it's it's generally accepted that we and do this. It's
it's what we have to do is figure out exactly
how to do it. It's it's basically we want to
be neural puppet masters, but we are only just beginning
to really understand where all the strings are and then
what happens when you pull those strings? And then how
(29:18):
do you pull those strings? Do you just yank on them?
Or is it more of a delicate thing. We were
trying to to to master an art form of puppetry
that is currently beyond us. Right. It's not can we
do this at all? We're pretty sure we will be
able to do this to some extent. It's how well
can you do it? How well can you target it
for the kinds of things you want to do with it,
how well can you avoid negative side effects coming with it?
(29:41):
All that kind of stuff, and what are the best
drugs to do it with? Right? And there there have
been some experiments involving induced neuro plasticity and mice, a
lot of those, Yeah, and uh, you know, those show
a lot of promise in my understanding, But then anytime
we're looking at experiments with with mice, yes, mice are
are our great stand ins for human physiology, but there,
(30:04):
of course are not humans. So and there are a
lot of differences between rodents and humans, especially in the brain. Right. Yes,
so there are a lot of questions that are that
are not really going to be answered until we we
we better understand what we're doing with the mice and
also get more and more into actually testing some of
these treatments on humans. Well, let's look at a couple
(30:25):
of examples of research on drug induced neuroplasticity. Yeah, and uh,
you know, we're certainly not gonna be able to cover
all of it. As you mentioned earlier, a lot of
the research out there is either is either the deep
end of the pool or the obscenely shallow end of
the pool. And uh, and it's sometimes difficult to make
sense even for us, of the deeper end of the
(30:48):
neuroscientific pool. Well, we'll try to walk you up just
to your armpits or so. Yeah, this first study actually
emerged this year. So psychedelic drugs have long been associated
with an opening of the mind, right, and a June two,
eighteen study published in Cell Press points to evidence of
psychedelic induced neuroplasticity in rats and flies. And um, I
(31:10):
have to say I found this very interesting too, because
there's actually a part in alan Moore's v for Vendetta,
the original graphic novel. I don't think this is represented
in the film version, but you see one of the
main characters take l s D at the side of
a government resettlement camp. Uh, kind of opening himself up
to the full horror of the place and his connection
(31:31):
to it. It's a it's a very powerful scene. But
that doesn't directly relate to this study. So this University
of California Davis study examine the effects of several drugs
in test tube and animal experience experiments, including M d
m A, d m T, l s D, and the
ephetamine d O I, and they found that d o I,
(31:52):
d m T, and l s D in particular made
neurons more likely to branch out and develop. Based on
their findings, the u C. Davis team thinks that psychedelic
compounds such as DO d O I, d m T
analyst may eventually pave the way for prescription neuroplasticity drugs.
It's just all a matter of capitalizing on their ability
(32:12):
to expand the very neural circuits observed to atrophy during depression, anxiety,
and PTSD, so they observe functional and structural changes in
cortical neurons for both vertebrates and invertebrates exposed to psychedelic
compounds and isolated activity to the to the protein called
brain derived neurotrophic factor or b d n F, and
(32:36):
when b d n F was blocked, the psychedelics lost
their ability to promote neural growth. And the case proved
to be the same with the m tour signaling pathway,
which plays a role in creating proteins for new sign
apps formation. If you think of the brain as a
complex map, then this research places two key markers on
what could one day prove the pathway to induce neuro plasticity.
(32:59):
Though judging from what I've read that it seems like
there could be a lot of pathway. Yeah, oh yes.
And senior author and U. C. Davis Assistant chemistry Professor
David E. Olsen on this these stresses that there's there's
still a lot to learn here and that his team's
experiments didn't entail human trials, of course, but but it
is enough to suggest that the mind expanding aspects of
psychedelics as we understand them may one day adis and
(33:22):
creating new treatments. So I want to underline that the
researchers here are not saying go and take a bunch
of LSD and then try and learn Mandarin or develop
perfect pitch. They're saying that there are potentially things in
these substances that we could utilize to create far better,
far more targeted substances in the future. Now, though there
(33:43):
are some results indicating the possibility of induced neuroplasticity and
adults and adult humans, these are preliminary, intentative. As we
want to keep stressing this is one of those areas
where I would really expect to continue to see a
lot of controversy about the validity of results over the
next decade or the next couple of decades or so. UM.
(34:04):
I think it's it's important to stress amidst all of
the hype and the advertising and all that about neuroplasticity,
become a master of your brain, that that we're not
there yet. This stuff is not ready for prime time. Right.
I can't remember who made this comparison, but I believe
it was pointed out that when when we tinker with
(34:24):
the with the way our brain and even the way
our bodies work, especially with with various pharmaceuticals, it's kind
of like trying to change the oil in a car
by just dumping the motor oil direct, like opening the
hood and dumping it into the engine. Um, you know,
things are not nearly as targeted as they as we
want them to be. Yeah, that's great, that's a good metaphor.
(34:44):
So I want to cite a few claims a few
other claims about induced neuroplasticity and adult humans that have
appeared in the press. One is one what I've seen
referenced a lot is a article and New Scientist by
Helen Thompson about neuroplastics, city drugs, And one of the
research teams that Thompson talks about is led by the
(35:05):
Harvard Professor of Neurology, Takeo. Hinch, who's been doing one
one line of research, and the basic gist is that
one of the physiological changes that appears to close the
window of neuroplasticity and children and bring on this period
of adult neuro stability is the proliferation of a particular
enzyme in the brain, the enzyme histone D A claise
(35:28):
or h d A C. And according to Thompson, this
enzyme primarily serves to inhibit the activation and deactivation of
genes in our DNA, so we know that genes and
the DNA. It's not like all the genes are all
doing their thing all at the same time. Genes can
be activated and deactivated, turned on and turned off, and
(35:49):
apparently the proliferation of the enzyme h D a C
prevents this turning on and off. It's like, okay, settle down,
stop flipping the switches. So if this enzyme is a
so seated with the end of the neuroplasticity window, what
if we could simply inhibit this enzyme right, would plasticity
open back up? So in two thousand ten, Hinge and
(36:09):
colleagues found found this to be the case in rodents
at least. They used a drug called valproate, which is
a drug that specifically restricts his stone d C LAS
or h D a C, and usually valparade is used
to treat conditions like epilepsy and bipolar disorder. In this case,
it appeared to cure amblopia in adult rodents, which is
often caused by reduced sight in one eye during the
(36:31):
period in childhood when the senses are developing. If you
don't fix it during that neuroplastic window in childhood, you're
usually stuck with it as an adult. Yeah, and this
is something that played into some of those twentieth century
uh uh discoveries related to plasticity that I referenced earlier. Yeah,
but would this kind of thing actually work in humans?
So Hinge work together with Alan Young at King's College,
(36:52):
London and some other colleagues to see if this drug
could allow adults to acquire a skill it's usually only
acquired during that highly plastic period of childhood. And they
went with perfect pitch again uh, calling out that that
note knowing exactly what the note is not relative to
other notes, but just hearing it or being able to
produce it. So they did a study with twenty four
(37:14):
men who had no perfect pitch, no musical training, and
these men were treated with either valperoid or placebo daily
for about two weeks, and during the second half of
the treatment period, they watched training videos on how to
identify absolute musical tones by associating them with names like
Sarah and Jimmy. The reason they did names was to
rule out any potential pre existing associations that the men
(37:37):
might have with pitches in the note names. But I
like the idea of it's like you know, sing me
a middle Jimmy. On the last day of the trial,
the group was given a test. They had to listen
to eighteen notes and see if they could correctly identify
the absolute pitches by name. The control group who took
the placebo got an average of about three point five notes,
which was performance at chance. The test group who took
(37:58):
the valpoid got a little over five notes right on average,
which was significantly better than chance. So this was a
small study, maybe kind of small effect, but it caught
plenty of attention from other from other researchers, and Thompson
reports that there are also neuroplasticity induction trials with drugs
like dnepazil, which is used to treat Alzheimer's, or the
(38:20):
common antidepressant prozac. So you know, of course, you see
a lot of hype in the headlines like you know,
learn like a child again, rewire your brain to be
a super learner. But despite these early, kind of promising
seeming trials, we should remember to slow down. Even if
we didn't know anything except the fact that our bodies
were created by natural selection, we could conclude that the
(38:42):
brain shuts down it's hyperplastic period for a reason. Do
we really want to go messing around with the stability
of our brain without a good reason behind it. Yeah,
we kind of just trying to solve the lament configuration
here without any real understanding of what is going to happen.
So let's take another quick break, and when we come back,
we will briefly discuss some of the potential downsides of neuroplasticity,
(39:06):
the pros and cons. All right, we're back, so we
we we discussed the idea that neuroplasticity could have not
just pros but also cons. If you extend euro plasticity
into adulthood, that's not necessarily a perfectly good thing right now. Now,
certainly that the potential pros are really attractive because we
(39:27):
could invoke brief widenings of neuroplasticity to aid in recovery
from various illnesses and injuries. We could treat neurological diseases
and fight the effects of Alzheimer's. We could also use
it to treat trauma. One of the things I think
about is that in his presentation at the World Science
Festival at the beginning of this panel, ma Con talks
about how hard it is to retrain people to walk.
(39:51):
After they've had some kind of like stroke or brain
injury that damages their motor areas, they forget how to
walk and they need to learn how to walk again.
It's really hard for an adult to learn how to walk,
even if your brain is you know, you're in a
healing phase, because walking is difficult. It's like a super
hard thing to learn how to do. You're doing all
this intuitive math all the time to keep your balance,
(40:13):
to do everything right. It's not easy, but we learn
it during this period when our brains are in this
super learning phase as children. So if if you could say,
have somebody with a brain injury they need to relearn
how to walk, and you could reinduce that kind of
childhood motor learning neuro plasticity, then they could potentially have
a lot more success and have an easier time getting
(40:35):
back on their feet and relearning these kinds of tasks
that we take for granted. But of course the potential
from misuse and even abuse is obviously high. Here, neuro
plasticity has already become, as we've discussed, something of a
buzzword in the realm of supplements and self help and
we focus again on this Nero definition of neuroplasticity most
(40:55):
of the time, the idea that neuroplasticity equals good and
assume that any sort of boost year is a good thing.
But indeed, what would the downsides to even therapeutic use
be if someone were to take such a drug unregulated
to aid and study perhaps or or to work on
some purely for some purely recreational purpose. You know, what
would be the cost? We again, we don't know for certain,
(41:17):
but but there are some possibilities and some of these
were discussed in that World Science Festival panel. What did
they talk about, Well, they said, for one thing, there
is this potential link between too much plasticity and say,
savant abilities. Uh. Savant syndrome is when individuals with mental
disabilities exhibit advanced abilities and specific areas such as recall,
(41:38):
calculation or musical skill. So, under under their characterizations, savant
syndrome could be sort of a byproduct of of unregulated
plasticity in the brain. Yeah, or at the very least,
it's a situation where if you're saying, yeah, give me
all the plasticity you got, what could go wrong? And
they're saying, well, Uh, here, here is something. Here's an
(41:59):
example of a case where they may be linked to
too much plasticity. Yeah. They also say that too much
plasticity may yield too much to the environment. Yeah. How
about um, when children are young, they're emotionally vulnerable. Yeah.
Or it makes me again think of that v for
Vendetta example of a character essentially, you know, tormenting himself
(42:20):
by by taking a psychedelic at a at a place
of intense historic trauma. Yeah. Now, I can definitely see
ways that if you were to say, make my brain
sort of a vessel, make it, make it play. Though
we can shape it, however, we want the first really
bad thing to happen to you while you're in that
state could have really traumatic effects. Yeah, indeed, I mean
(42:42):
ultimately it can make for a more chaotic system of
the mind. Uh, in a time, during a time in
which you're not supposed to have that much chaos. Also,
they point out that autism may be a situation that
entails too much neuroplasticity. It's been pointed out that transcranial
magnetic stimulation looks it works longer on autistic individuals, so
(43:03):
there is stronger perturbation there and transcranial magnetic stimulation that
just be where you put like a magnetic coil over
the head to induce current in the brain, and that
sort of stimulates certain brain areas or or actually I
think often suppresses or sort of like shuts down certain
brain areas. But they're saying that in certain in certain cases,
(43:24):
it appears that some individuals with some types of autism
are more susceptible to the brain being manipulated by that
kind of thing. Yeah, exactly. And then on the other hand,
they say that schizophrenia may, according to some recent studies,
be tied to synaptic pruning again the process by which
the brain sheds weak connections between neurons. In other words,
(43:46):
that it might be more associated with the brain sort
of being the opposite of two neuroplastic to neurostable. Yeah, yeah, again,
just showing that there is a balance in that there
seems to be a balance in the brain, and we
really need to know what we're doing before we disrupt it,
even for very noble purposes and very targeted purposes um point.
For instance, during adolescence and even early adulthood, we see
(44:07):
this in the pre frontal cortex, the center of you know,
thinking and planning skills. People with genes that accelerate or
at intensify pruning or at higher risk for schizophrenia, according
to a two thousand sixteen Columbia University study published in Nature.
And then it's worth driving home too that this would
(44:27):
in no way be a magic pill. This would not
be like some some movie pill where you just take
it and oh, I'm suddenly, uh, you know, a complete genius.
Suddenly I'm a master of every art I attempt to
take up. Well, yeah, I mean we should keep in
mind we don't want to overstate the effects too much,
are over generalized too much. But with the caveat that
this is just a metaphor, you should be careful about
(44:50):
anything that makes your mind more like the mind of
a child. Yeah, that makes your mind more like I mean,
there are great things about being a child, but there
are also ways in which being a child is a
position of vulnerability. There's a reason we protect children, yes,
And who's going to protect you if you're you know,
if you're taking a whole bunch of illegally obtained neuroplasticity pills,
(45:14):
Like there's there's not a direct comparison to be made
here between say potential neuroplasticity drug abuse and say steroid abuse.
But but but I think you can you can draw
some very rough comparisons. You know, an individual who who
takes too much of this substance in order to artificially
bulk up muscles in an in what is ultimately an
(45:36):
unhelpful way, you know, like muscles that are too big
to really function for what you you need them for,
and then that occurring with with various side effects as well,
both mental and physical. So I feel like we we
we risk similar situations, certainly if we're talking about any
future abuse of these or even just recreational use of
(45:59):
neuroplastics the drugs, As is often the case with with
great possibility for rewards comes great possibility for risks. So
this is this is something where you should keep an
eye on it. This is a field that could have
great promise for really helping people's lives. But but you know,
be careful, don't buy into the hype, and definitely don't
buy anything somebody selling. Yeah, yeah, be care because there,
(46:20):
as was pointed out there, there are already products in
the market that are using vineero plasticity buzzword to to
to reach you. Uh. And at the same time, if
you're thinking, well, Robert, Joe, I'm getting a little older,
and I want to I want to stay sharp. I
wanna I want to do what I can to to
keep those doors a little bit wide. I want to
I don't want to go into neural stagnation. What can
(46:42):
I do? Well, there are safe things that we do
know about. In fact, there is one of them is sleep,
getting plenty of sleep, exercise and nutrition. Uh. Using your brain,
like stimulation of the brain, both intellectually and socially. Yeah,
and you know your you might think, well, these don't
sound very fun, but I hate stimulated. It's like you
(47:06):
like keep telling us to take our vitamins. But in
a way, it's like that. It's like we're not talking
about magic fixes here, but we're talking about things that
that that have done regularly over the course of a
lifetime have been shown to have positive effects. Why can't
I just have a pill? I know that's that's what
we really want. But but I do think when you
when you look at it, like more often than not,
it's certainly with more complex things related to human physiology
(47:28):
and and and certainly the mind the quick fixes is
not necessarily what we think it is. Yeah. Now, I
want to come back on what I just said there.
I am certainly not somebody who wants to demonize medication
of any kind, demonized psychiatric medication or or you know,
neurological medication. I that's a thing you sometimes hear people,
do you know, like oh, why don't you just you know,
(47:49):
you need a pill for that? Why don't you just
whip your life into shape? That That is a fatally
reductionist st atitude that does not properly understand the way
that our body and behaviors are controlled by chemicals in
the brain. Yes, and certainly all the various differences from
brain to brain. Uh. Yeah, So so I'm very much
in the same same boat. I think that the future
(48:11):
for neuro plasticity is bright. There there is a lot
of good that is going to come of these future
treatments and medications. But it does benefit us to to
understand uh, what we're actually talking about and the the
the both negative and positive potential of the technology. Yeah,
so hold hold the hype, listen to the researchers. All right,
(48:32):
So there you have it. Uh. In the meantime, if
you want to check out more episodes of Stuff to
Blow Your Mind, head on over to stuff to Blow
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(48:52):
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how stuff works dot com for more on this and
(49:19):
thousands of other topics. Is it how stuff works dot
com b
Hey, you welcome to stuff to blow your mind. My
name is Robert Lamb and I'm Joe McCormick. In It's Saturday.
Time to go into the old vault? Robert, is this
one where I did the Sean Connery voice? Now, I'm
just remembering in this moment, remember, oh no, are we were? Okay? Well,
I We'll just have to deal with it. This originally
published July, and this is an episode we did about neuroplasticity. Now,
(00:29):
we were just saying before we started recording this intro,
uh that after having done all the stuff on psychedelics
we just went through we we we may, we may
approach this subject to it from a kind of different angle. Now,
I wonder if I don't know, if you listen to
this episode and you want to hear you want to
hear us revisit the topic with with new wisdom let
(00:49):
us know. Yeah, I feel like it would this would
have been a different episode if we had recorded it
after the psychedelic episodes. But I still think it holds
up as a solid vault entry. So dr jessup, do
you expect me to talk? Oh this this isn't a
standard interrogation. Inject him watch this now, poison truth Serer.
(01:10):
None of the above. No, this is something far more experimental.
But perhaps a notorious secret agents such as yourself has
heard of induced neuroplasticity. What you're talking of experimental neurotherapy drugs,
your math? Neuroplasticity is far more than that. Yes, yes, this,
this sort of treatment will soon revolutionize the way we
(01:34):
deal with addictions and brain disease. It will allow adults
of any age to learn new languages with the aptitude
of a young child. But that's not why I've injected
you with it. No, we've We've romanticized neuroplasticity. You see,
we forget the importance of neuro stability. As children, we
have an amazing ability to adapt to any environment, any language.
(01:57):
Were open to the world. We're also open to try.
But then everything has to settle. We put aside those
childish things and we become bia then doctors, secret agents.
What do you want from me? Why? I want to
change your life? Hans Roll the film? Wait, what what
are you showing me? Joseph are YouTube playlist, Oh please,
(02:20):
hours upon hours of let's call it informative content from
some of the platforms. Leading personality No, not dish influencers.
I'll tell you anything for medians, no commentators, unboxes. No.
(02:42):
Welcome to Stuff to Blow your Mind from How Stuff
Works dot com. Hey, welcome to Stuff to Blow your Mind.
My name is Robert Lamb and I'm Joe McCormick. And
today we're gonna be talking about another topic that's sort
of a fall up from Robert's visit this year to
the World Science Festival. We're gonna be talking about neuroplasticity.
(03:06):
That's right. This, uh, this particular panel that that I attended,
and this one is also available online. Will make sure
there's a link to the YouTube video on the landing
page for this episode Acceptable in your Mind dot com. Uh.
The particular panel was called Nuts and Bolts of Better Brains.
It was hosted by Guy mccon, a neurosurgeon, neuroscientist, Alvero
pascal Leoni, neuroscientist, uh Nim Tottenham, developmental law psychologist, and
(03:31):
Carlas Shots, a neuroscientist, and they discussed neuroplasticity, which is
something that we've we've touched on on the show before
and I think a lot of people have kind of
a general concept of yeah, neuroplasticity is one of those
words that I think has suffered a lot of abuse
in the press um because I mean, there are words
(03:51):
that have a good meaning in science, and there's nothing
wrong with the concept itself. But in today's neuroscience, neuroplasticity
does have a me ng and it does have a
useful meaning. But you see it in a lot of
hype and bs on the internet. Yeah, Like I noticed,
when when you do a search for neuroplasticity you want
(04:11):
to read things about it, you get mostly content at
one of two levels. Either content for experts and neuroscientists,
like actual scientific literature that the average reader can't penetrate,
and then you get also a whole lot of hype
and bs that is telling you about I don't know,
about how you're going to revolutionize your brain and you'll
(04:31):
become like a child again and become a master of
your own abilities. Yeah. I mean, it's already become something
of a buzzword, for instance, with with certain uh like
supplement manufacturers and take this neuroplasticity vitamin. Yeah, okay, thanks,
But but the neuroplasticity is a real thing. It is
you can think of it simply as the brain's ability
(04:52):
to adapt and humans most incredible powers of neuroplasticity, especially
during the so called critical periods of early childhood. Yeah.
One of the things to think about this kind of
weird is um how well humans adapt to such different
life conditions. Like if you take most animals out of
(05:15):
the environment and condition conditions that they're best adapted to,
they don't do very well. There are some exceptions, but
most of the time an animal has evolved to have
certain instincts. It's got sort of like pretty hardwired behaviors.
It can live, you know, it can be born where
it is supposed to be born and live encountering the
(05:35):
kind of stimuli it would normally encounter, and you know,
it can do its thing that nature has shaped it for.
But humans can do all kinds of stuff. We can
live in the snow, we can live in the desert,
we can live in cities, we can live in it planes,
we can be farmers, we can be doctors. We can
do so many different kinds of things with our brains.
(05:56):
And there are no other animals like this really. Yeah.
The in the talk, they brought up the example of
the logerhead turtle as an example of a creature that
is not a paragon of neuroplasticity but neuro stability. A
creature that, upon birth is just ready to go and
do a very specific thing exceedingly well in a very
specific environment. But if you put some major obstacles in
(06:19):
that turtle's way, the turtle probably would not find a
way to adapt to those obstacles and survive around them.
It would probably just not survive to adulthood, right, I mean,
the the turtle is a good example of that, because,
I mean, with with with various sea turtles, we've seen
examples of how just artificial lighting can screw up a
very particular approach to going about its life cycle. Yeah,
(06:41):
but so your brain. One of the reasons your brain
is so powerful compared to the brains of animals is
that it can be adapted to so many different scenarios
and so many different types of tasks depending on what
sorts of environments you're exposed to when you're very young. Yeah, languages,
of course one of the great examples. And I think
(07:01):
everyone has at least some awareness of this. Certainly, anybody
out there who's a parent has has read about this
or experience this with their own children. Is that during
certain critical periods, they have an amazing ability to not
only pick up a language, but to just perfectly pick
it up, to just breathe it in and and and
become fluent in it without with without any of the
(07:23):
challenges that are generally encountered by adults trying to learn
a second language. I mean, one of the ways that
it's often put is that with great effort, and adult
can learn to speak a language they don't already speak,
but they will pretty much always speak it with an accent.
Children can learn to speak all kinds of and can
learn to speak multiple languages at the same time, and
(07:44):
can generally learn to speak them without an accent. Right.
But then of course it goes beyond this too, because
there there's so many other things that are being absorbed
during childhood. You know, the social norms, cultural norms, just
how one interacts with your environment, and that has enabled
humans to thrive all over the world, you know, obviously
with technological aids in many cases, but still it it
(08:08):
underlies the diversity and success of our species. Then again,
there are some reasons to think that you don't want
the brain to be sort of infinitely plastic right, Because
if we consider plasticity the ability of the brain to
adapt to new scenarios and change itself to work better,
you also need cases where the brain knows what to
(08:29):
do and does it instead of keeps being influenced and
changing right right, and knows where to where to where
to stop. You know what, what avenues to stop exploring
because basically what happens is their neural circuitry branches out
to master the skills necessary for survival. And then, uh,
and then after it does this, after you know, some
of the branches have been prune back. Uh. You can
(08:49):
think of it like a you know, like one of
those shrub sculptures from the Shining from you know, the
original novel. If you've read that, you know you you
you prune everything down, cut it away until it's the
the appropriate ape. Yeah. That's an interesting thing that the
speakers in this event talk about, is the idea of
pruning in childhood. How it starts off with way more
connections than it needs, and then through this process it
(09:10):
sort of pairs back the stuff that says, Okay, it
looks like I'm not going to need that in life.
We can just sever all those Yeah, I mean it
kind of matches up with the cliche of the child
who can grow up to be anything, right, which you know,
obviously any given child can't grow up to be absolutely anything.
But there is a there. There is a lot of
room for specialization and and and and diverse growth there. Yeah,
(09:32):
we have natural tendencies and natural potentials, and some of
that is genetic. But then also we were extremely adaptable
as children, right. But then of course in neural stability
has to kick in. That's important too, a necessary balance
in the human brain. Um, you're going to grow up
and become this thing we call an adult. But what
(09:53):
if I am Peter Pan and I don't want to
grow up and be an adult because growing up and
being an adult and having neuro stability limits my potential.
What if I decide I don't want to be somebody
who only speaks English. I want to be somebody who
speaks Chinese and speaks French and speaks the click languages.
And you know what if I want to speak all
(10:15):
those languages without an accent, Why can't I do that? Yeah?
I want to have infinite potential. Again, I want to
go back to I want to be able to grow
up to be anything. You know. I think we've all
had moments like that where we we we we we
look at where we are and we think, well, if
I could go back and open myself up to this
language or this ability or what have you, then I
(10:35):
would love to do that, you know, or just the
idea that nobody wants to. You don't want to feel stagnant.
You want to feel like you're continuing to grow and
uh and you know, keep up with the young ones.
And so scientists have continually looked to possible ways of
essentially rewidening the doorways of of neuroplasticity. That's one of
(10:56):
the metaphors it's often used, right, is that when you're
a child, the the door is open, the window is
open for you to grasp onto anything. But then depending
on who's throwing the metaphor around, you can say, well
it closes when you become an adult, but it doesn't
really close. It gets sort of like it gets almost closed, right,
it narrows. And so we've looked ways to to widen
(11:19):
it in adulthood. And and it goes beyond this mirror
um you know, intellectual vanity as well. Right, It's not
just Peter Pan saying, I want this, I want that.
There's also the idea of treating problems in the adult
brain by reintroducing plasticity, right, it would it would give
us a way to treat various neurodegenerative disorders, anxiety, depression,
(11:42):
even post traumatic stress disorder. Like anytime there's a there's
a potential for for growth and change, positive growth and
change in the brain to help with a given condition.
Neuroplasticity is often brought up as a as a potential cure,
but it's a challenge to do this sort of thing.
As a Columbia University developmental psychologist Dr Nim Totenham, who
were referenced already, as she stated in the in that
(12:04):
World Science festifal discussion, the brain actually extends expends a
lot of energy to keep critical periods from reopening. Yeah,
we there there seems to be some logic underlying this,
this move the evolution took right. It says, you know,
you don't stay a plastic child forever. At some point
the brain needs to figure out what to be and
be that right. And that's one of the reasons we're
(12:27):
calling this episode the Dark Side of Neural plasticity, not
that neuroplasticity. It necessarily has this deep, dark underbelly, but
the sort of public awareness tends to lean so heavily
towards neuroplastics is just an absolute good. I want as
much of it as I can get. We want to
counter the hype. Neuroplasticity is a good thing, but it's
also not an uh It's not a good thing in
(12:49):
every possible case, in every possible sense. Right, and towards
the end of the episode, Will will speculate a little
bit and look at some some speculation from experts about
what some of the possible pitfalls could be, What are
some and even what are some of the black mirror
esque possibilities in a world full of neuroplasticity inducing drugs. Yeah, now,
(13:10):
the question about these drugs, though, is still wide open.
I mean it's sort of h I hate to use
the metaphor the wild West. What's a better metaphor for
an arena in which there is still much much new
ground being forged? Welcome to the jungle, baby. How about
some spelunking. We're spelunking. Yeah, those are close confines, though,
I guess, Okay, I think I think wild West is
(13:32):
still pretty good. Well, whatever it is. I mean, we're
still trying to figure out what kinds of drugs might
do this, what side effects they might have, if they
are effective at doing it, And we'll talk more later
in the episode about what some of these specific drugs
might be. Yeah, because to master neuroplus this day, we're
going to have to establish the molecules that close the doors.
(13:52):
I mean, the thing is, it is possible to extend
critical periods and manipulate them, and experts do, in fact
think that will one day be able to do this
with a pill, with some sort of medication. So it's
not a question of if. It's a question of when
the groundwork is already being laid for this. Uh, it's
just how are we going to be ready for it
when it happens. Well, I think we should take a
(14:13):
quick break and then when we come back we will
discuss a few things about the history of the idea
of neuroplasticity. Than alright, we're back. So Charles Darwin actually
offered some thoughts about how the brain changes in response
to the environment in his book The Descent of Man,
which published in eighteen seventy four, and though We should
note that he did not use the term plasticity. He
(14:36):
did sort of write about the idea of of the
brain adapting. He wrote, quote, I have shown that the
brains of domestic rabbits are considerably reduced in bulk in
comparison with those of the wild rabbit or hair, and
this may be attributed to their having been closely confined
during many generations, so that they have exerted their intellect, instincts, senses,
(14:58):
and voluntary movements. But little uh, note that he's imagining
this adaptation of the brain taking place over multiple generations
through inheritance, which is very different from the kind of
plasticity that we're talking about, which takes place within a
single body within a single lifetime. But he is at
least offering an image. They're saying like, Okay, maybe the
(15:18):
brain can kind of be molded to what it best
does given its environmental circumstances. Right. If you, if you're
a wild hair and you need to be crafty and
wildly and use all your senses to survive out in
the brush, uh, you you will grow these bulky brains.
But if you're a domestic hair and all you do
is sit around and get fed, then you don't need
(15:39):
all that stuff and the brain will adapt. This touches
on a fact that we've discussed before, and that is
that that the that the brain like evolution, is a
miser and it's cheap. Yeah, it's it's cheap and once
the most economic model for functionality it is. It is
the Ebenezer Scrooge of the body. No, the whole body
is cheap. Actually, you know, it makes sense. You don't
want to be wasting energy in an environment where energy
(16:02):
is hard to come by, living in a world of
technology and abundance. Uh, you know, we should stop to
think how, you know, if if you have food to eat,
if you're not wondering where your next meal comes from,
you should think about how lucky you are. But you
should also think about how, in many ways your body
and the bodies of every other creature in the world,
we're sort of designed for scenarios where you would be
(16:23):
constantly living on the edge of starvation. But back to
neuro plasticity. So the term plasticity emerged from the work
of American psychologist William James who lived eighteen forty two
to nineteen ten, and James defined it the following way
he said, it's quote the possession of a structure weak
enough to yield an influence, but strong enough not to
(16:45):
yield all at once. Yeah, I mean that makes sense.
It's ideal for a young child to be open to
their environment and not so open that they're just completely overwhelmed. Right.
So I want to read a quote from William James
from his from his seminar work on psychology, where he
started deposit that the brain might have some kind of
(17:05):
might have some kind of like changeable structure. So he says, quote,
if habits are due to the plasticity of materials to
outward agents, we can immediately see to what outward influences,
if to any the brain matter is plastic, not too
mechanical pressures, not to thermal changes, not to any of
(17:26):
the forces to which all the other organs of our
body are exposed. For nature has so blanketed and wrapped
the brain about that the only impressions that can be
made upon it are through the blood on the one hand,
and the sensory nerve roots on the other. And it
is to the infinitely attenuated currents that pour in through
(17:46):
these latter channels that the hemispherical cortex shows itself to
be so peculiarly susceptible. The currents, once in, must find
a way out. In getting out, they leave their traces
in the paths which they take. The only thing they
can do, in short, is to deepen old paths or
to make new ones. And the whole plasticity of the
(18:09):
brain sums itself up in two words when we call
it an organ in which currents pouring in from the
sense organs make with extreme facility paths which do not
easily disappear. For, of course, a simple habit, like every
other nervous event, the habit of snuffling, for example, or
putting one's hands into one's pockets or biting one's nails,
(18:32):
is mechanically nothing but a reflex discharge, and its anatomical
substratum must be a path in the system. The most
complex habits, as we shall presently see more fully, are,
from the same point of view, nothing but concatenated discharges
of the nerve centers, due to the presence there of
systems of reflex paths so organized as to wake each
(18:56):
other up successively. The impression produced by one skill or
contractions serving as a stimulus to provoke the next until
a final impression inhibits the process and closes the chain.
So that was very forward thinking on William James's part.
He's so, he's got a very rudimentary nineteenth century understanding
(19:17):
of brain function here, but it does get some some
interesting basic insights right. One of them is that habits
or tendencies of the brain consist of a kind of
reinforcing of pathways of activities. Another is that complex brain
functions are built out of many less complex brain functions
happening together in sequence. Another is that the potential and
(19:39):
predispositions of an individual brain like your brain, can be
changed based on repeated interaction with chemicals in the blood
or with the data of the senses. And that last
part is just as a tangent, one of those utterly
mundane facts that I often have to stop and force
myself to be amazed by over and over again, Like
(19:59):
think about this. It sounds kind of stupid to say,
but by making acoustic vibrations in the air with my
mouth that you can hear, or by like drawing a
picture on a chalkboard and putting it in front of
your eyes, I can literally change the physical configuration of
your brain. I make changes inside your skull by doing
(20:21):
things you can see in here. Isn't that bizarre? Yeah?
I mean if you and if you extend it to
written language, you can think, oh, well, somebody who wrote something, uh,
inscribed something down a thousand, two thousand, three thousand years ago.
They can speak across all those uh, those dead millennia,
and they can speak right to our brain and make
(20:42):
changes in it. It's unbelievable. Now. I mentioned earlier that
the term plasticity in the context of neuroscience had been
used to mean a lot of different things. There was
one particular paper I looked at about this by Giovanni
Berluki and Henry book Tool from two thousand nine and
Experimental Brain Research, and they talk about how the term
plasticity has been used over the past century to refer
(21:03):
to quote changes in neural organization, which may account for
various forms of behavioral modifiability, either short lasting or enduring,
including maturation, adaptation to a mutable environment, specific and unspecific
kinds of learning, and compensatory adjustments in response to functional
losses from aging or brain damage. So that that's a
(21:25):
lot of different meanings encompassed in the idea of plasticity,
but it does sort of apply to all of those,
so it's subject to generalization. But then also is sort
of uh is a turn It sort of refers to
general change in the brain. Yeah, a kind of adaptation
that has come to be associated with pressures put on
the brain from the environment. Right. So, with modern techniques,
(21:46):
we've discovered that the way these pathways are forged and
reinforced in the brain depends largely on the crucial element
of the synapps or you know, the bridge of space
that connects to nerve cells and allows impulses to pass
between the cells. And in eight three, the Italian neuropsychiatrist
Eugenio Tanzi first proposed that the basis of practice based
(22:09):
learning and associative memory was these connections between nerve cells
in the brain. Because Tanzi knew that there are other
scientists who had observed the slowing of the passage of
nerve impulses through the gray matter in the brain, and
so he hypothesized that maybe what's going on in that
slow down is that there's difficulty for the impulses to
(22:31):
cross the gaps between neurons, These gaps that we now
call synapses or synaptic fissures, and based on that assumption,
Tansi argued that the way the brain adapts, the way
it learns through practice and creates associations between things, the
way it sort of enacts its plastic potential is by
a kind of exercise. When you perform a repetitious activity
(22:54):
in the brain, the same pathways of neurons repeatedly communicate
with each other, and by doing this you cause a
kind of hypertrophy or strengthening of the connections between those
specific neurons. The more you do a certain thing in
the brain, the easier that that thing becomes to do
in the brain. And then the next year. In the
(23:14):
Spanish neuroscientists Santiago Ramoni Kahal, who I've thought before we
should do a whole episode on this guy. Perhaps he
also speculated that learning was based on the creation and
strengthening of connections between neurons. I feel like this is
something that has been I think over the years, it's
just been so well demonstrated, or not really demonstrated, but
(23:35):
illustrated with animations and and uh and and art that
I have it like well ingrained in my head, Like
when people talk start talking about synopsis firing. I picture it,
and maybe I also kind of think of it in
terms of of playing an instrument, like the physical act
of playing an instrument of linking, um, you know, of
(23:56):
finger movements on say a trumpet or French worn to
the note that you're playing, and then linking those in
order to create, uh, the notes in a particular tune,
which of course is both literally a synaptic learning exercise,
but also kind of an illustration of what's going on,
like making this, connecting it to that, and then leading
(24:16):
onto the next note. Yeah, we we've learned this in
the modern age, and so it's easy for us to picture,
but we should appreciate how how interesting of an insight
this was for for the people at the time, because
there were also competing hypotheses in the late nineteenth and
early twentieth century, like Berlukian book Toll show that in
the first couple of decades of the twentieth century that
(24:38):
this idea of the sort of learning through quote reduced
resistance that exercise synapses, uh, that that idea was pretty
widely accepted in that first couple of decades, and then
for a while it really went into decline. This the
synaptic model of plasticity due to arise in the popularity
of competing ideas about all this weird stuff about the
(24:58):
equipotential version end of the brain. But anyway, in the
late nineteen forties it came back. It was sort of
rehabilitated by scientists like the Polish neuroscientists Jersey Konorski and
the Canadian psychologist Donald Hebb, and Hebb was particularly influential,
and then experimental evidence accumulated during the twentieth century, especially
during the mid and later twentieth century, from the likes
(25:20):
of David Hubel and Torsten VISal, Michael Merzenek, and Eleanor McGuire. Now,
the work of each of those individuals is is fascinating,
and I would love to come back and look at
them in greater detail. There's some wonderful work they're regarding, uh,
you know, how how we see the world. I mean,
some of the very basic questions about the human experience,
(25:40):
how how do we perceive the world and how is
it processed in the brain are explored by by by
their work. But the interesting thing is there's still something
of a controversy about exactly how plastic the adult human
brain is, if much at all like For most of
the history of neuroscience. Up until very recently, a lot
of experts believed that the human adult brain had almost
(26:04):
no plasticity, you know, that it was fixed and stable.
But at the same time, it's obvious that adults can
learn new things and adapt. Yeah, we can change, and
then we don't have to undergo, you know, catastrophic brain
injury for it to happen, right, So exactly how much
potential for change in plasticity is there in the adult
brain and in what areas like? It appears much easier
(26:25):
for adults to learn and adapt in some ways than
it does in others. Language acquisition, as we've talked about
as a classic example, Um, you know, children are just
so so much better at learning a language than adults are.
Another one is certain aspects of music learning. Have you
read about perfect pitch? Probably, yes, Yeah, you have to
get it early or you're not gonna you're not gonna
(26:46):
get it later on. Yeah. This is a commonly cited example.
Robert sing a middle c oh, I I don't. I
don't do music like that, Joe, Almost no adults do
unless you've you've trained on it before you were roughly
six years old. Right, So if you have this skill
known as perfect pitch, you should be able to recognize
or produce not just tones relative to other tones, but
(27:10):
like you could call out a note and the person
would know what that pitch actually was. They could sing it,
or they could recognize it in hearing it. Yeah. I
My my reaction to that question is the same as
the other day when my son asked me what Thursday
plus Thursday equals, and it's just like, I can't. That
just broke my brain a little bit to even try
and answer that question. It sounds like a three key
(27:31):
Thursday probably, But yeah, So Supposedly the idea is if
you teach children to recognize pitches in an absolute sense
before they're roughly six years older, so they can potentially
acquire this skill. It's just like you've got to You've
got to get going within that window. Yeah, I feel
like I'm I'm wasting my time reading the hobbit to
my son. We should be we should be working on
(27:52):
this pitch thing. Well, there are all kinds of things
potentially like this that you don't even know about that
maybe you should be teaching your son at this critical
age before the window doesn't close but gets very narrow. Yeah. Well,
I mean there is a lot of a lot of
discussion of this out there in parenting forums and actual
you know, pure viewed child rearing material just about Yeah,
(28:14):
these are the ages of childhood when you want to
throw a bunch of different activities at them. You want
them to have some sort of musical training, some sort
of uh training in another language, etcetera like this, This
is when the this is when the windows are open,
so you want to just throw as much stuff there
there as possible. But I mean, wouldn't it be great
if you could be like that again as an adult?
(28:35):
As we were talking about earlier, the desire to be
Peter Pan, are are there things that we could do
to make the adult brain a learning and adaptation machine
like the young child's brain. A lot of people have
been asking that question, and so I guess that's what
we should explore now, the idea of induced to neuroplasticity
and adults. That's right. And as as we said earlier,
(28:57):
it's it's generally accepted that we and do this. It's
it's what we have to do is figure out exactly
how to do it. It's it's basically we want to
be neural puppet masters, but we are only just beginning
to really understand where all the strings are and then
what happens when you pull those strings? And then how
(29:18):
do you pull those strings? Do you just yank on them?
Or is it more of a delicate thing. We were
trying to to to master an art form of puppetry
that is currently beyond us. Right. It's not can we
do this at all? We're pretty sure we will be
able to do this to some extent. It's how well
can you do it? How well can you target it
for the kinds of things you want to do with it,
how well can you avoid negative side effects coming with it?
(29:41):
All that kind of stuff, and what are the best
drugs to do it with? Right? And there there have
been some experiments involving induced neuro plasticity and mice, a
lot of those, Yeah, and uh, you know, those show
a lot of promise in my understanding, But then anytime
we're looking at experiments with with mice, yes, mice are
are our great stand ins for human physiology, but there,
(30:04):
of course are not humans. So and there are a
lot of differences between rodents and humans, especially in the brain. Right. Yes,
so there are a lot of questions that are that
are not really going to be answered until we we
we better understand what we're doing with the mice and
also get more and more into actually testing some of
these treatments on humans. Well, let's look at a couple
(30:25):
of examples of research on drug induced neuroplasticity. Yeah, and uh,
you know, we're certainly not gonna be able to cover
all of it. As you mentioned earlier, a lot of
the research out there is either is either the deep
end of the pool or the obscenely shallow end of
the pool. And uh, and it's sometimes difficult to make
sense even for us, of the deeper end of the
(30:48):
neuroscientific pool. Well, we'll try to walk you up just
to your armpits or so. Yeah, this first study actually
emerged this year. So psychedelic drugs have long been associated
with an opening of the mind, right, and a June two,
eighteen study published in Cell Press points to evidence of
psychedelic induced neuroplasticity in rats and flies. And um, I
(31:10):
have to say I found this very interesting too, because
there's actually a part in alan Moore's v for Vendetta,
the original graphic novel. I don't think this is represented
in the film version, but you see one of the
main characters take l s D at the side of
a government resettlement camp. Uh, kind of opening himself up
to the full horror of the place and his connection
(31:31):
to it. It's a it's a very powerful scene. But
that doesn't directly relate to this study. So this University
of California Davis study examine the effects of several drugs
in test tube and animal experience experiments, including M d
m A, d m T, l s D, and the
ephetamine d O I, and they found that d o I,
(31:52):
d m T, and l s D in particular made
neurons more likely to branch out and develop. Based on
their findings, the u C. Davis team thinks that psychedelic
compounds such as DO d O I, d m T
analyst may eventually pave the way for prescription neuroplasticity drugs.
It's just all a matter of capitalizing on their ability
(32:12):
to expand the very neural circuits observed to atrophy during depression, anxiety,
and PTSD, so they observe functional and structural changes in
cortical neurons for both vertebrates and invertebrates exposed to psychedelic
compounds and isolated activity to the to the protein called
brain derived neurotrophic factor or b d n F, and
(32:36):
when b d n F was blocked, the psychedelics lost
their ability to promote neural growth. And the case proved
to be the same with the m tour signaling pathway,
which plays a role in creating proteins for new sign
apps formation. If you think of the brain as a
complex map, then this research places two key markers on
what could one day prove the pathway to induce neuro plasticity.
(32:59):
Though judging from what I've read that it seems like
there could be a lot of pathway. Yeah, oh yes.
And senior author and U. C. Davis Assistant chemistry Professor
David E. Olsen on this these stresses that there's there's
still a lot to learn here and that his team's
experiments didn't entail human trials, of course, but but it
is enough to suggest that the mind expanding aspects of
psychedelics as we understand them may one day adis and
(33:22):
creating new treatments. So I want to underline that the
researchers here are not saying go and take a bunch
of LSD and then try and learn Mandarin or develop
perfect pitch. They're saying that there are potentially things in
these substances that we could utilize to create far better,
far more targeted substances in the future. Now, though there
(33:43):
are some results indicating the possibility of induced neuroplasticity and
adults and adult humans, these are preliminary, intentative. As we
want to keep stressing this is one of those areas
where I would really expect to continue to see a
lot of controversy about the validity of results over the
next decade or the next couple of decades or so. UM.
(34:04):
I think it's it's important to stress amidst all of
the hype and the advertising and all that about neuroplasticity,
become a master of your brain, that that we're not
there yet. This stuff is not ready for prime time. Right.
I can't remember who made this comparison, but I believe
it was pointed out that when when we tinker with
(34:24):
the with the way our brain and even the way
our bodies work, especially with with various pharmaceuticals, it's kind
of like trying to change the oil in a car
by just dumping the motor oil direct, like opening the
hood and dumping it into the engine. Um, you know,
things are not nearly as targeted as they as we
want them to be. Yeah, that's great, that's a good metaphor.
(34:44):
So I want to cite a few claims a few
other claims about induced neuroplasticity and adult humans that have
appeared in the press. One is one what I've seen
referenced a lot is a article and New Scientist by
Helen Thompson about neuroplastics, city drugs, And one of the
research teams that Thompson talks about is led by the
(35:05):
Harvard Professor of Neurology, Takeo. Hinch, who's been doing one
one line of research, and the basic gist is that
one of the physiological changes that appears to close the
window of neuroplasticity and children and bring on this period
of adult neuro stability is the proliferation of a particular
enzyme in the brain, the enzyme histone D A claise
(35:28):
or h d A C. And according to Thompson, this
enzyme primarily serves to inhibit the activation and deactivation of
genes in our DNA, so we know that genes and
the DNA. It's not like all the genes are all
doing their thing all at the same time. Genes can
be activated and deactivated, turned on and turned off, and
(35:49):
apparently the proliferation of the enzyme h D a C
prevents this turning on and off. It's like, okay, settle down,
stop flipping the switches. So if this enzyme is a
so seated with the end of the neuroplasticity window, what
if we could simply inhibit this enzyme right, would plasticity
open back up? So in two thousand ten, Hinge and
(36:09):
colleagues found found this to be the case in rodents
at least. They used a drug called valproate, which is
a drug that specifically restricts his stone d C LAS
or h D a C, and usually valparade is used
to treat conditions like epilepsy and bipolar disorder. In this case,
it appeared to cure amblopia in adult rodents, which is
often caused by reduced sight in one eye during the
(36:31):
period in childhood when the senses are developing. If you
don't fix it during that neuroplastic window in childhood, you're
usually stuck with it as an adult. Yeah, and this
is something that played into some of those twentieth century
uh uh discoveries related to plasticity that I referenced earlier. Yeah,
but would this kind of thing actually work in humans?
So Hinge work together with Alan Young at King's College,
(36:52):
London and some other colleagues to see if this drug
could allow adults to acquire a skill it's usually only
acquired during that highly plastic period of childhood. And they
went with perfect pitch again uh, calling out that that
note knowing exactly what the note is not relative to
other notes, but just hearing it or being able to
produce it. So they did a study with twenty four
(37:14):
men who had no perfect pitch, no musical training, and
these men were treated with either valperoid or placebo daily
for about two weeks, and during the second half of
the treatment period, they watched training videos on how to
identify absolute musical tones by associating them with names like
Sarah and Jimmy. The reason they did names was to
rule out any potential pre existing associations that the men
(37:37):
might have with pitches in the note names. But I
like the idea of it's like you know, sing me
a middle Jimmy. On the last day of the trial,
the group was given a test. They had to listen
to eighteen notes and see if they could correctly identify
the absolute pitches by name. The control group who took
the placebo got an average of about three point five notes,
which was performance at chance. The test group who took
(37:58):
the valpoid got a little over five notes right on average,
which was significantly better than chance. So this was a
small study, maybe kind of small effect, but it caught
plenty of attention from other from other researchers, and Thompson
reports that there are also neuroplasticity induction trials with drugs
like dnepazil, which is used to treat Alzheimer's, or the
(38:20):
common antidepressant prozac. So you know, of course, you see
a lot of hype in the headlines like you know,
learn like a child again, rewire your brain to be
a super learner. But despite these early, kind of promising
seeming trials, we should remember to slow down. Even if
we didn't know anything except the fact that our bodies
were created by natural selection, we could conclude that the
(38:42):
brain shuts down it's hyperplastic period for a reason. Do
we really want to go messing around with the stability
of our brain without a good reason behind it. Yeah,
we kind of just trying to solve the lament configuration
here without any real understanding of what is going to happen.
So let's take another quick break, and when we come back,
we will briefly discuss some of the potential downsides of neuroplasticity,
(39:06):
the pros and cons. All right, we're back, so we
we we discussed the idea that neuroplasticity could have not
just pros but also cons. If you extend euro plasticity
into adulthood, that's not necessarily a perfectly good thing right now. Now,
certainly that the potential pros are really attractive because we
(39:27):
could invoke brief widenings of neuroplasticity to aid in recovery
from various illnesses and injuries. We could treat neurological diseases
and fight the effects of Alzheimer's. We could also use
it to treat trauma. One of the things I think
about is that in his presentation at the World Science
Festival at the beginning of this panel, ma Con talks
about how hard it is to retrain people to walk.
(39:51):
After they've had some kind of like stroke or brain
injury that damages their motor areas, they forget how to
walk and they need to learn how to walk again.
It's really hard for an adult to learn how to walk,
even if your brain is you know, you're in a
healing phase, because walking is difficult. It's like a super
hard thing to learn how to do. You're doing all
this intuitive math all the time to keep your balance,
(40:13):
to do everything right. It's not easy, but we learn
it during this period when our brains are in this
super learning phase as children. So if if you could say,
have somebody with a brain injury they need to relearn
how to walk, and you could reinduce that kind of
childhood motor learning neuro plasticity, then they could potentially have
a lot more success and have an easier time getting
(40:35):
back on their feet and relearning these kinds of tasks
that we take for granted. But of course the potential
from misuse and even abuse is obviously high. Here, neuro
plasticity has already become, as we've discussed, something of a
buzzword in the realm of supplements and self help and
we focus again on this Nero definition of neuroplasticity most
(40:55):
of the time, the idea that neuroplasticity equals good and
assume that any sort of boost year is a good thing.
But indeed, what would the downsides to even therapeutic use
be if someone were to take such a drug unregulated
to aid and study perhaps or or to work on
some purely for some purely recreational purpose. You know, what
would be the cost? We again, we don't know for certain,
(41:17):
but but there are some possibilities and some of these
were discussed in that World Science Festival panel. What did
they talk about, Well, they said, for one thing, there
is this potential link between too much plasticity and say,
savant abilities. Uh. Savant syndrome is when individuals with mental
disabilities exhibit advanced abilities and specific areas such as recall,
(41:38):
calculation or musical skill. So, under under their characterizations, savant
syndrome could be sort of a byproduct of of unregulated
plasticity in the brain. Yeah, or at the very least,
it's a situation where if you're saying, yeah, give me
all the plasticity you got, what could go wrong? And
they're saying, well, Uh, here, here is something. Here's an
(41:59):
example of a case where they may be linked to
too much plasticity. Yeah. They also say that too much
plasticity may yield too much to the environment. Yeah. How
about um, when children are young, they're emotionally vulnerable. Yeah.
Or it makes me again think of that v for
Vendetta example of a character essentially, you know, tormenting himself
(42:20):
by by taking a psychedelic at a at a place
of intense historic trauma. Yeah. Now, I can definitely see
ways that if you were to say, make my brain
sort of a vessel, make it, make it play. Though
we can shape it, however, we want the first really
bad thing to happen to you while you're in that
state could have really traumatic effects. Yeah, indeed, I mean
(42:42):
ultimately it can make for a more chaotic system of
the mind. Uh, in a time, during a time in
which you're not supposed to have that much chaos. Also,
they point out that autism may be a situation that
entails too much neuroplasticity. It's been pointed out that transcranial
magnetic stimulation looks it works longer on autistic individuals, so
(43:03):
there is stronger perturbation there and transcranial magnetic stimulation that
just be where you put like a magnetic coil over
the head to induce current in the brain, and that
sort of stimulates certain brain areas or or actually I
think often suppresses or sort of like shuts down certain
brain areas. But they're saying that in certain in certain cases,
(43:24):
it appears that some individuals with some types of autism
are more susceptible to the brain being manipulated by that
kind of thing. Yeah, exactly. And then on the other hand,
they say that schizophrenia may, according to some recent studies,
be tied to synaptic pruning again the process by which
the brain sheds weak connections between neurons. In other words,
(43:46):
that it might be more associated with the brain sort
of being the opposite of two neuroplastic to neurostable. Yeah, yeah, again,
just showing that there is a balance in that there
seems to be a balance in the brain, and we
really need to know what we're doing before we disrupt it,
even for very noble purposes and very targeted purposes um point.
For instance, during adolescence and even early adulthood, we see
(44:07):
this in the pre frontal cortex, the center of you know,
thinking and planning skills. People with genes that accelerate or
at intensify pruning or at higher risk for schizophrenia, according
to a two thousand sixteen Columbia University study published in Nature.
And then it's worth driving home too that this would
(44:27):
in no way be a magic pill. This would not
be like some some movie pill where you just take
it and oh, I'm suddenly, uh, you know, a complete genius.
Suddenly I'm a master of every art I attempt to
take up. Well, yeah, I mean we should keep in
mind we don't want to overstate the effects too much,
are over generalized too much. But with the caveat that
this is just a metaphor, you should be careful about
(44:50):
anything that makes your mind more like the mind of
a child. Yeah, that makes your mind more like I mean,
there are great things about being a child, but there
are also ways in which being a child is a
position of vulnerability. There's a reason we protect children, yes,
And who's going to protect you if you're you know,
if you're taking a whole bunch of illegally obtained neuroplasticity pills,
(45:14):
Like there's there's not a direct comparison to be made
here between say potential neuroplasticity drug abuse and say steroid abuse.
But but but I think you can you can draw
some very rough comparisons. You know, an individual who who
takes too much of this substance in order to artificially
bulk up muscles in an in what is ultimately an
(45:36):
unhelpful way, you know, like muscles that are too big
to really function for what you you need them for,
and then that occurring with with various side effects as well,
both mental and physical. So I feel like we we
we risk similar situations, certainly if we're talking about any
future abuse of these or even just recreational use of
(45:59):
neuroplastics the drugs, As is often the case with with
great possibility for rewards comes great possibility for risks. So
this is this is something where you should keep an
eye on it. This is a field that could have
great promise for really helping people's lives. But but you know,
be careful, don't buy into the hype, and definitely don't
buy anything somebody selling. Yeah, yeah, be care because there,
(46:20):
as was pointed out there, there are already products in
the market that are using vineero plasticity buzzword to to
to reach you. Uh. And at the same time, if
you're thinking, well, Robert, Joe, I'm getting a little older,
and I want to I want to stay sharp. I
wanna I want to do what I can to to
keep those doors a little bit wide. I want to
I don't want to go into neural stagnation. What can
(46:42):
I do? Well, there are safe things that we do
know about. In fact, there is one of them is sleep,
getting plenty of sleep, exercise and nutrition. Uh. Using your brain,
like stimulation of the brain, both intellectually and socially. Yeah,
and you know your you might think, well, these don't
sound very fun, but I hate stimulated. It's like you
(47:06):
like keep telling us to take our vitamins. But in
a way, it's like that. It's like we're not talking
about magic fixes here, but we're talking about things that
that that have done regularly over the course of a
lifetime have been shown to have positive effects. Why can't
I just have a pill? I know that's that's what
we really want. But but I do think when you
when you look at it, like more often than not,
it's certainly with more complex things related to human physiology
(47:28):
and and and certainly the mind the quick fixes is
not necessarily what we think it is. Yeah. Now, I
want to come back on what I just said there.
I am certainly not somebody who wants to demonize medication
of any kind, demonized psychiatric medication or or you know,
neurological medication. I that's a thing you sometimes hear people,
do you know, like oh, why don't you just you know,
(47:49):
you need a pill for that? Why don't you just
whip your life into shape? That That is a fatally
reductionist st atitude that does not properly understand the way
that our body and behaviors are controlled by chemicals in
the brain. Yes, and certainly all the various differences from
brain to brain. Uh. Yeah, So so I'm very much
in the same same boat. I think that the future
(48:11):
for neuro plasticity is bright. There there is a lot
of good that is going to come of these future
treatments and medications. But it does benefit us to to
understand uh, what we're actually talking about and the the
the both negative and positive potential of the technology. Yeah,
so hold hold the hype, listen to the researchers. All right,
(48:32):
So there you have it. Uh. In the meantime, if
you want to check out more episodes of Stuff to
Blow Your Mind, head on over to stuff to Blow
your Mind dot com. That's the mother ship. That's where
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stars and a few kind words big things, as always
(48:52):
to our wonderful audio producers Alex Williams and Tarry Harrison.
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(49:19):
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