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ANDREW HUBERMAN: Welcome | |
to Huberman Lab Essentials, | |
where we revisit past | |
episodes for the most | |
potent and actionable | |
science-based tools | |
for mental health, physical | |
health, and performance. | |
[MUSIC PLAYING] | |
My name is Andrew | |
Huberman, and I'm | |
a professor of neurobiology | |
and ophthalmology | |
at Stanford School of Medicine. | |
Today we're talking | |
about neuroplasticity, | |
which is this incredible feature | |
of our nervous system's that | |
allows it to change in | |
response to experience. | |
Neuroplasticity is arguably one | |
of the most important aspects | |
of our biology. | |
It holds the promise | |
for each and all of us | |
to think differently, | |
to learn new things, | |
to forget painful experiences, | |
and to essentially | |
adapt to anything that life | |
brings us by becoming better. | |
So let's get started. | |
Most people are familiar with | |
the word "neuroplasticity," | |
which is the brain and nervous | |
system's ability to change | |
itself. | |
All of us were born | |
with a nervous system | |
that isn't just | |
capable of change | |
but was designed to change. | |
When we enter the world, | |
our nervous system | |
is primed for learning. | |
The brain and nervous system of | |
a baby is wired very crudely. | |
The connections are | |
not precise, and we | |
can see evidence | |
of that in the fact | |
that babies are kind of flopping | |
there, like a little potato | |
bug with limbs. | |
They can't really do much in | |
terms of coordinated movement. | |
They certainly can't speak, | |
and they can't really | |
do anything with precision. | |
So I want you to | |
imagine in your mind | |
that when you were | |
brought into this world, | |
you were essentially a widely | |
connected web of connections | |
that was really poor | |
at doing any one thing, | |
and that through your | |
experience, what you were | |
exposed to by your parents | |
or other caretakers, | |
through your social | |
interactions, | |
through your thoughts, through | |
the languages that you learned, | |
through the places you | |
traveled or didn't travel, | |
your nervous system | |
became customized | |
to your unique experience. | |
Now, that's true for | |
certain parts of your brain | |
that are involved in what | |
we call representations | |
of the outside world. | |
A lot of your brain is designed | |
to represent the visual world, | |
or represent the auditory | |
world, or represent | |
the gallery of smells that | |
are possible in the world. | |
However, there are aspects | |
of your nervous system | |
that were designed | |
not to be plastic. | |
They were wired so that | |
plasticity or changes | |
in those circuits | |
is very unlikely. | |
Those circuits include | |
things like the ones | |
that control your heartbeat. | |
The ones that control | |
your breathing. | |
The ones that control | |
your digestion. | |
And thank goodness that | |
those circuits were set up | |
that way, because you want | |
those circuits to be extremely | |
reliable. | |
So many nervous system features, | |
like digestion and breathing | |
and heart rate, | |
are hard to change. | |
Other aspects of | |
our nervous system | |
are actually quite | |
easy to change. | |
And one of the great gifts | |
of childhood, adolescence, | |
and young adulthood is that | |
we can learn through almost | |
passive experience. | |
We don't have to focus that hard | |
in order to learn new things. | |
And then after | |
age 25, if we want | |
to change those connections, | |
those superhighways | |
of connectivity, we have to | |
engage in some very specific | |
processes. | |
And those processes, | |
as we'll soon learn, | |
are gated, meaning | |
you can't just | |
decide to change your brain. | |
You actually have to go | |
through a series of steps | |
to change your internal | |
state in ways that will | |
allow you to change your brain. | |
Many of us have been | |
captivated by the stories | |
in the popular press about | |
the addition of new neurons, | |
this idea, oh, if you go | |
running or you exercise, | |
your brain actually | |
makes new neurons. | |
Well, I'm going to give | |
you the bad news, which | |
is that after puberty, the | |
human brain and nervous system | |
adds very few, if | |
any, new neurons. | |
So even though we can't add new | |
neurons throughout our lifespan, | |
at least not in | |
very great numbers, | |
it's clear that we can | |
change our nervous system, | |
that the nervous system | |
is available for change, | |
that if we create the | |
right set of circumstances | |
in our brain, chemical | |
circumstances, | |
and if we create the right | |
environmental circumstances | |
around us, our | |
nervous system will | |
shift into a mode in which | |
change isn't just possible, | |
but it's probable. | |
As I mentioned | |
before, the hallmark | |
of the child nervous | |
system is change. | |
It wants to change. | |
One of the ways in which | |
we can all get plasticity | |
at any stage | |
throughout the lifespan | |
is through deficits | |
and impairments | |
in what we call our sensory | |
apparati-- our eyes, our ears, | |
our nose, our mouth. | |
In individuals that | |
are blind from birth, | |
the so-called occipital cortex, | |
the visual cortex in the back, | |
becomes overtaken by hearing. | |
The neurons there will start | |
to respond to sounds as well | |
as Braille touch. | |
And actually, there is one | |
particularly tragic incident | |
where a woman who | |
was blind since birth | |
and, because of | |
neuroimaging studies, | |
we knew her visual cortex | |
was no longer visual. | |
It was responsible for Braille | |
reading and for hearing. | |
She had a stroke that | |
actually took out | |
most of the function | |
of her visual cortex. | |
So then she was blind, she | |
couldn't Braille read, or hear. | |
She did recover some | |
aspect of function. | |
Now, most people, they don't end | |
up in that highly unfortunate | |
situation. | |
And what we know is that, for | |
instance, blind people who | |
use their visual cortex for | |
Braille reading and for hearing | |
have much better | |
auditory acuity and touch | |
acuity, meaning they can sense | |
things with their fingers | |
and they can sense | |
things with their hearing | |
that typical sighted | |
folks wouldn't be able to. | |
In fact, you will find | |
a much greater incidence | |
of perfect pitch in | |
people that are blind. | |
And that tells us that the brain | |
and, in particular, this area | |
we call the neocortex, | |
which is the outer part, | |
is really designed to be a | |
map of our own individual | |
experience. | |
So these, what I | |
call experiments | |
of impairment or | |
loss, where somebody | |
is blind from birth | |
or deaf from birth | |
or maybe has a limb development | |
impairment where they have | |
a stump instead of an entire | |
limb with a functioning hand, | |
their brain will represent the | |
body plan that they have, not | |
some other body plan. | |
But the beauty of the situation | |
is that the real estate | |
up in the skull, that | |
neocortex, the essence of it | |
is to be a customized | |
map of experience. | |
A few years ago, | |
I was at a course, | |
and a woman came up to me | |
and she said, you know, I-- | |
I wasn't teaching the course. | |
I was in the course. | |
And she said, I just | |
have to tell you | |
that every time you speak, | |
it really stresses me out. | |
And I said, well, I've | |
heard that before. | |
But do you want to | |
be more specific? | |
And she said, yeah, | |
your tone of voice | |
reminds me of somebody that I | |
had a really terrible experience | |
with. | |
I said, well, OK, well, | |
I can't change my voice, | |
but I really appreciate | |
that you acknowledge that. | |
And it also will | |
help explain why | |
you seem to cringe | |
every time I speak, | |
which I hadn't | |
noticed until then. | |
But after that, I | |
did notice she had | |
a very immediate and kind of | |
visceral response to my speech. | |
But in any event, over the | |
period of this two-week course, | |
she would come back every | |
once in a while and say, | |
you know what? | |
I think just by telling you that | |
your voice was really difficult | |
for me to listen | |
to, it's actually | |
becoming more tolerable to me. | |
And by the end, we actually | |
became pretty good friends, | |
and we're still in touch. | |
And so what this says is that | |
the recognition of something, | |
whether or not that's an | |
emotional thing or a desire | |
to learn something else, | |
is actually the first step | |
in neuroplasticity. | |
If I get up out of this chair | |
and walk out of the door, | |
I don't think about each | |
step that I'm taking. | |
And that's because I learned | |
how to walk during development. | |
But when we decide | |
that we're going | |
to shift some sort of | |
behavior or some reaction | |
or some new piece of information | |
that we want to learn | |
is something that we want to | |
bring into our consciousness, | |
that awareness is | |
a remarkable thing | |
because it cues the brain and | |
the rest of the nervous system | |
that when we engage in those | |
reflexive actions going forward, | |
that those reflexive actions are | |
no longer fated to be reflexive. | |
Now, if this sounds a | |
little bit abstract, | |
we're going to talk about | |
protocols for how to do this. | |
But the first step | |
in neuroplasticity | |
is recognizing that you | |
want to change something. | |
We have to know what it is | |
exactly that we want to change. | |
Or if we don't know exactly what | |
it is that we want to change, | |
we at least have to know that | |
we want to change something | |
about some specific experience. | |
Now, there are | |
specific protocols | |
that science tells us | |
we have to follow if we | |
want those changes to occur. | |
What it is, is | |
it's our forebrain, | |
in particular our | |
prefrontal cortex, | |
signaling the rest | |
of our nervous system | |
that something that we're about | |
to do, hear, feel, or experience | |
is worth paying attention to. | |
So we'll pause there, and then | |
I'm going to move forward. | |
One of the biggest lies | |
in the universe that | |
seems quite prominent right now | |
is that every experience you | |
have changes your brain. | |
People love to say this. | |
They love to say, | |
your brain is going | |
to be different | |
after this lecture, | |
or your brain is going to be | |
different after today's class | |
than it was two days ago. | |
And that's absolutely not true. | |
The nervous system | |
doesn't just change | |
because you experience | |
something unless you're | |
a very young child. | |
The nervous system changes | |
when certain neurochemicals | |
are released and | |
allow whatever neurons | |
are active in the period in | |
which those chemicals are | |
swimming around to | |
strengthen or weaken | |
the connections | |
of those neurons. | |
So when people tell you, oh, | |
at the end of today's lecture, | |
at the end of | |
something, your brain | |
is going to be completely | |
different, that's simply not | |
true. | |
If you're older | |
than 25, your brain | |
will not change unless | |
there's a selective shift | |
in your attention or a selective | |
shift in your experience | |
that tells the brain | |
it's time to change. | |
And those changes occur through | |
strengthening and weakening | |
of particular connections. | |
But the important | |
thing to understand | |
is that if we want | |
something to change, | |
we really need to bring an | |
immense amount of attention | |
to whatever it is that | |
we want to change. | |
This is very much | |
linked to the statement | |
I made earlier about it all | |
starts with an awareness. | |
Now, why is that | |
attention important? | |
In the early '90s, a graduate | |
student by the name of Gregg | |
Recanzone was in the laboratory | |
of a guy named Mike Merzenich | |
at UCSF. | |
And they set out | |
to test this idea | |
that if one wants to | |
change their brain, | |
they need to do it early in life | |
because the adult brain simply | |
isn't plastic. | |
It's not available | |
for these changes. | |
And they did a series | |
of absolutely beautiful | |
experiments, by | |
now, I think we can | |
say proving that the | |
adult brain can change, | |
provided certain | |
conditions are met. | |
Now, the experiments | |
they did are tough. | |
They were tough on | |
the experimenter, | |
and they were tough | |
on the subject. | |
I'll just describe one. | |
Let's say you were a subject | |
in one of their experiments. | |
You would come into the lab, | |
and you'd sit down at a table, | |
and they would record | |
from or image your brain | |
and look at the representation | |
of your fingers, the digits, | |
as we call them. | |
And there would be a spinning | |
drum, literally like a stone | |
drum in front of you, or metal | |
drum, that had little bumps. | |
Some of the bumps were spaced | |
close together, some of them | |
were spaced far apart. | |
And they would do | |
these experiments | |
where they would | |
expect their subjects | |
to press a lever whenever, for | |
instance, the bumps got closer | |
together or further apart. | |
And these were very | |
subtle differences. | |
So in order to do | |
this, you really | |
have to pay attention to the | |
distance between the bumps. | |
And these were not | |
Braille readers or anyone | |
skilled in doing these | |
kinds of experiments. | |
What they found | |
was that as people | |
paid more and more | |
attention to the distance | |
between these bumps-- | |
and they would | |
signal when there was | |
a change by pressing a lever. | |
As they did that, there | |
was very rapid changes, | |
plasticity in the | |
representation of the fingers. | |
And it could go in | |
either direction. | |
You could get people | |
very good at detecting | |
the distance between bumps that | |
the distance was getting smaller | |
or the distance was | |
getting greater. | |
So people could get very | |
good at these tasks that | |
are kind of hard | |
to imagine how they | |
would translate to the real | |
world for a non-Braille reader. | |
But what it told us is | |
that these maps of touch | |
were very much available | |
for plasticity, | |
and these were fully | |
adult subjects. | |
What it proved is that the | |
adult brain is very plastic. | |
And they did some beautiful | |
control experiments | |
that are important for | |
everyone to understand, | |
which is that sometimes | |
they would bring people in | |
and they would have | |
them touch these bumps | |
on this spinning drum, but | |
they would have the person pay | |
attention to an auditory cue. | |
Every time a tone | |
would go off or there | |
was a shift in the | |
pitch of that tone, | |
they would have to signal that. | |
So the subject thought | |
they were doing something | |
related to touch and hearing. | |
And all that showed | |
was that it wasn't just | |
the mere action of | |
touching these bumps; | |
they had to pay attention | |
to the bumps themselves. | |
If they were placing their | |
attention on the auditory cue, | |
on the tone, well, | |
then there was | |
plasticity in the auditory | |
portion of the brain, | |
but not on the touch | |
portion of the brain. | |
And this really spits in | |
the face of this thing | |
that you hear so often, | |
which is, every experience | |
that you have is going to | |
change the way your brain works. | |
Absolutely not. | |
The experiences that you pay | |
super careful attention to | |
are what open up plasticity, | |
and it opens up plasticity | |
to that specific experience. | |
So the question then is, why? | |
And Merzenich and his | |
graduate students and postdocs | |
went on to address | |
this question of why. | |
And it turns out, the answer | |
is a very straightforward | |
neurochemical answer. | |
And the first neurochemical is | |
epinephrine, also adrenaline. | |
We call it adrenaline when it's | |
released from the adrenal glands | |
above our kidneys. | |
That's in the body. | |
We call it epinephrine | |
in the brain, | |
but they are chemically | |
identical substances. | |
Epinephrine is released from a | |
region in the brainstem called | |
locus ceruleus. | |
Epinephrine is released | |
when we pay attention | |
and when we are alert. | |
But the most important | |
thing for getting plasticity | |
is that there be | |
epinephrine, which | |
equates to alertness, plus the | |
release of this neuromodulator | |
acetylcholine. | |
Now, acetylcholine is released | |
from two sites in the brain. | |
One is also in the brainstem, | |
and it's named different things | |
in different animals. | |
But in humans, the most rich | |
site of acetylcholine neurons, | |
or neurons that | |
make acetylcholine, | |
is the parabigeminal nucleus | |
or the parabrachial region. | |
All you need to know is that you | |
have an area in your brainstem, | |
and that area sends wires, | |
these axons, up into the area | |
of the brain that | |
filters sensory input. | |
So we have this area of the | |
brain called the thalamus, | |
and it is getting bombarded | |
with all sorts of sensory input | |
all the time. | |
But when I pay | |
attention to something, | |
I create a cone of attention, | |
and what we call signal to noise | |
goes up. | |
So those of you with an | |
engineering background | |
will be familiar | |
with signal to noise. | |
Those of you who do not have | |
an engineering background, | |
don't worry about it. | |
All it means is that one | |
particular shout in the crowd | |
comes through. | |
Acetylcholine acts | |
as a spotlight. | |
But epinephrine for alertness, | |
acetylcholine spotlighting | |
these inputs, those | |
two things alone | |
are not enough to | |
get plasticity. | |
There needs to be | |
this third component, | |
and the third component | |
is acetylcholine | |
released from an area | |
of the forebrain called | |
nucleus basalis. | |
If you really want | |
to get technical, | |
it's called nucleus | |
basalis of Meynert. | |
For any of you that are | |
budding physicians or going | |
to medical school, | |
you should know that. | |
If you have acetylcholine | |
released from the brainstem, | |
acetylcholine released | |
from nucleus basalis, | |
and epinephrine, you | |
can change your brain. | |
And this has been shown | |
again and again and again | |
in a variety of | |
papers, and it is now | |
considered a fundamental | |
principle of how | |
the nervous system works. | |
If you can access these | |
three things of epinephrine, | |
acetylcholine from | |
these two sources, | |
not only will the nervous | |
system change, it has to change. | |
It absolutely will change. | |
And that is the | |
most important thing | |
for people to understand if | |
they want to change their brain. | |
So now let's talk about | |
how we would translate | |
all this scientific | |
information into some protocols | |
that you can actually apply | |
because I think that's what | |
many of you are interested in. | |
What you do with your health and | |
your medical care is up to you. | |
You're responsible for | |
your health and well-being. | |
So I'm not going to tell you | |
what to do or what to take, | |
I'm going to describe what the | |
literature tells us and suggests | |
about ways to access plasticity. | |
We know we need epinephrine. | |
That means alertness. | |
Most people accomplish this | |
through a cup of coffee | |
and a good night's sleep. | |
So I will say you should | |
master your sleep schedule, | |
and you should figure out how | |
much sleep you need in order | |
to achieve alertness when | |
you sit down to learn. | |
But once that's in | |
place, the question | |
then is, how do I | |
access this alertness? | |
Well, there are | |
a number of ways. | |
Some people use some pretty | |
elaborate psychological | |
gymnastics. | |
They will tell | |
people that they're | |
going to do something and | |
create some accountability. | |
That could be really good. | |
Or they'll post a picture | |
of themselves online, | |
and they'll commit to | |
learning a certain amount-- | |
losing, excuse me, a certain | |
amount of weight or something | |
like this. | |
So they can use either | |
shame-based practices | |
to potentially | |
embarrass themselves | |
if they don't follow through. | |
They'll write checks | |
to organizations | |
that they hate and | |
insist that they'll | |
cash them if they don't | |
actually follow through. | |
Or they'll do it out of love. | |
They'll decide that they're | |
going to run a marathon | |
or learn a language or something | |
because of somebody they love, | |
or they want to | |
devote it to somebody. | |
The truth is that from the | |
standpoint of epinephrine | |
and getting alert and activated, | |
it doesn't really matter. | |
Epinephrine is a | |
chemical, and your brain | |
does not distinguish | |
between doing things out | |
of love or hate, anger, or fear. | |
It really doesn't. | |
All of those promote | |
autonomic arousal | |
and the release of epinephrine. | |
So I think for most | |
people, if you're | |
feeling not motivated to make | |
these changes, the key thing is | |
to identify not just one, but | |
probably a kit of reasons, | |
several reasons as | |
to why you would want | |
to make this particular change. | |
And being drawn toward | |
a particular goal | |
that you're excited | |
about can be one. | |
Also being motivated to not | |
be completely afraid, ashamed, | |
or humiliated for not following | |
through on a goal is another. | |
Come up with two | |
or three things, | |
fear-based, perhaps, love-based, | |
perhaps, or perhaps several | |
of those in order to ensure | |
alertness, energy, and attention | |
for the task. | |
And that brings us to | |
the attention part. | |
Now, it's one thing to | |
have an electrode embedded | |
into your brain and increase | |
the amount of acetylcholine. | |
It's another to exist | |
in the real world | |
outside the laboratory and have | |
trouble focusing, having trouble | |
bringing your attention to a | |
particular location in space | |
for a particular event. | |
And there's a lot of discussion | |
nowadays about smartphones | |
and devices creating a | |
sort of attention deficit, | |
almost at a clinical level for | |
many people, including adults. | |
I think that's largely true. | |
And what it means, | |
however, is that we all | |
are responsible for learning | |
how to create depth of focus. | |
There are some important | |
neuroscience principles | |
to get depth of focus. | |
I want to briefly talk | |
about the pharmacology first | |
because I always get | |
asked about this. | |
People say, what can | |
I take to increase | |
my levels of acetylcholine? | |
Well, there are | |
things you can take. | |
Nicotine is called nicotine | |
because acetylcholine binds | |
to the nicotinic receptor. | |
There are two kinds of | |
acetylcholine receptors, | |
muscarinic and nicotinic. | |
But the nicotinic | |
ones are involved | |
in attention and alertness. | |
I have colleagues-- these are | |
not my kind of like bro science | |
buddies. | |
I have those friends, too. | |
This is a Nobel | |
Prize-winning colleague who | |
chews Nicorette while he works. | |
But when I asked him, | |
why are you doing this, | |
he said, well, it increases | |
my alertness and focus. | |
Now, I've tried | |
chewing Nicorette. | |
It makes me super jittery. | |
I don't like it because | |
I can't focus very well. | |
It kind of takes me too far up | |
the level of autonomic arousal. | |
I've got friends that | |
dip Nicorette all day. | |
If you're going to | |
go down that route, | |
you want to be very | |
careful how much you rely | |
on those all the time because | |
the essence of plasticity | |
is to create a window | |
of attention and focus | |
that's distinct from | |
the rest of your day. | |
So what are some ways that you | |
can increase acetylcholine? | |
How do you increase focus? | |
The best way to get | |
better at focusing | |
is to use the mechanisms of | |
focus that you were born with. | |
And the key principle | |
here is that mental focus | |
follows visual focus. | |
We are all familiar | |
with the fact | |
that our visual system can be | |
unfocused, blurry, or jumping | |
around, or we can be | |
very laser-focused | |
on one location in space. | |
What's interesting and vitally | |
important to understanding | |
how to access | |
neuroplasticity is that you | |
can use your visual | |
focus, and you | |
can increase your | |
visual focus as a way | |
of increasing your mental | |
focus abilities more broadly. | |
So I'm going to | |
explain how to do that. | |
Plasticity starts | |
with alertness. | |
That alertness can come from a | |
sense of love, a sense of joy, | |
a sense of fear. | |
Doesn't matter. | |
There are pharmacologic ways | |
to access alertness, too. | |
The most common one is, | |
of course, caffeine. | |
Many people are now | |
also using Adderall. | |
Adderall will not | |
increase focus. | |
It increases alertness. | |
It does not touch the | |
acetylcholine system. | |
The acetylcholine system | |
and the focus that it brings | |
is available, as I mentioned, | |
through pharmacology, but also | |
through these | |
behavioral practices. | |
And the behavioral | |
practices that | |
are anchored in | |
visual focus are going | |
to be the ones that are going to | |
allow you to develop great depth | |
and duration of focus. | |
So let's think about | |
visual focus for a second. | |
When we focus on something | |
visually, we have two options. | |
We can either look at a | |
very small region of space | |
with a lot of detail | |
and a lot of precision, | |
or we can dilate | |
our gaze and we can | |
see big pieces of visual | |
space with very little detail. | |
It's a trade-off. | |
We can't look at everything | |
at high resolution. | |
This is why we have these. | |
The pupil more or less | |
relates to the fovea | |
of the eye, which is the area | |
in which we have the most | |
receptors, the highest | |
density of receptors | |
that perceive light. | |
And so our acuity is | |
much better in the center | |
of our visual field | |
than in our periphery. | |
When we focus our eyes, | |
we do a couple of things. | |
First of all, we tend | |
to do that in the center | |
of our visual field, | |
and our two eyes | |
tend to align in what's | |
called a vergence eye movement | |
towards a common point. | |
The other thing that happens | |
is the lens of our eye moves, | |
so that our brain, | |
now, no longer sees | |
the entire visual | |
world, but is seeing | |
a small cone of visual imagery. | |
That small cone | |
of visual imagery, | |
or soda straw view of the world, | |
has much higher acuity, higher | |
resolution, than if I were | |
to look at everything. | |
Now you say, of course, | |
this makes perfect sense. | |
But that's about visual | |
attention, not mental attention. | |
Well, it turns out | |
that focus in the brain | |
is anchored to | |
our visual system. | |
I'll talk about blind | |
people in a moment. | |
But assuming that | |
somebody is sighted, | |
the key is to learn how to | |
focus better visually if you | |
want to bring about higher | |
levels of cognitive or mental | |
focus. | |
When we move our eyes | |
slightly inward-- | |
maybe you can tell that I'm | |
doing this-- like so, basically | |
shortening or making the | |
interpupillary distance, | |
as it's called, smaller, | |
two things happen. | |
Not only do we develop a smaller | |
visual window into the world, | |
but we activate a set | |
of neurons in our brain | |
stem that trigger the release | |
of both norepinephrine, | |
epinephrine, and acetylcholine. | |
Norepinephrine is kind of | |
similar to epinephrine. | |
So in other words, | |
when our eyes are | |
relaxed in our head, | |
when we're just | |
kind of looking at our | |
entire visual environment, | |
moving our head around, | |
moving through space, | |
we're in optic flow, | |
things moving past us, | |
we're sitting still, we're | |
looking broadly at our space, | |
we're relaxed. | |
When our eyes move | |
slightly inward | |
toward a particular | |
visual target, | |
our visual world shrinks, our | |
level of visual focus goes up, | |
and we know that this relates | |
to the release of acetylcholine | |
and epinephrine at | |
the relevant sites | |
in the brain for plasticity. | |
Now, what this means is that if | |
you have a hard time focusing | |
your mind for sake of | |
reading or for listening, | |
you need to practice-- | |
and you can practice-- | |
focusing your visual system. | |
Now, this works | |
best if you practice | |
focusing your visual system | |
at the precise distance | |
from the work that you intend | |
to do for sake of plasticity. | |
So how would this look | |
in the real world? | |
Let's say I am trying to | |
concentrate on something related | |
to, I don't know, science. | |
I'm reading a science paper | |
and I'm having a hard time. | |
It's not absorbing. | |
Spending just 60 to 120 seconds | |
focusing my visual attention | |
on a small window of my screen, | |
meaning just on my screen | |
with nothing on it, | |
but bringing my eyes | |
to that particular | |
location increases not just | |
my visual acuity | |
for that location, | |
but it brings about an | |
increase in activity | |
in a bunch of other | |
brain areas that | |
are associated with gathering | |
information from this location. | |
So, put simply, if you want to | |
improve your ability to focus, | |
practice visual focus. | |
Now, you may ask, well, | |
what about the experiment | |
where people were feeling | |
this rotating drum | |
or listening to | |
the auditory cue? | |
That does involve vision at all. | |
Ah. | |
If you look at people | |
who are learning things | |
with their auditory system, they | |
will often close their eyes. | |
And that's not a coincidence. | |
If somebody is | |
listening very hard, | |
please don't ask them to | |
look you directly in the eye | |
while also asking that | |
they listen to you. | |
That's actually one | |
of the worst ways | |
to get somebody | |
to listen to you. | |
If you say, now listen to | |
me and look me in the eye, | |
the visual system will take over | |
and they'll see your mouth move, | |
but they're going to hear their | |
thoughts more than they're going | |
to hear what you're saying. | |
Closing the eyes is | |
one of the best ways | |
to create a cone of | |
auditory attention. | |
And this is what low-vision | |
or no-vision folks do. | |
They have tremendous capacity | |
to focus their attention | |
in particular locations. | |
And for most people, | |
vision is the primary way | |
to train up this focus ability | |
and these cones of attention. | |
So you absolutely have | |
to focus on the thing | |
that you're trying | |
to learn, and you | |
will feel some agitation | |
because of the epinephrine | |
in your system. | |
If you're feeling agitation | |
and it's challenging to focus | |
and you're feeling like | |
you're not doing it right, | |
chances are you're | |
doing it right. | |
So once you get this | |
epinephrine, this alertness, | |
you get the acetylcholine | |
released and you | |
can focus your attention, then | |
the question is, for how long? | |
And in an earlier | |
podcast, I talked | |
about these ultradian cycles | |
that last about 90 minutes. | |
The typical learning bout | |
should be about 90 minutes. | |
I think that learning bout will | |
no doubt include 5 to 10 minutes | |
of a warm-up period. | |
I think everyone | |
should give themselves | |
permission to not | |
be fully focused | |
in the early part of that | |
bout, but that in the middle | |
of that bout for the | |
middle hour or so, | |
you should be able to maintain | |
focus for about an hour or so. | |
So that, for me, means | |
eliminating distractions. | |
That means turning | |
off the Wi-Fi. | |
I put my phone in | |
the other room. | |
I encourage you to | |
try experiencing | |
what it is to be completely | |
immersed in an activity | |
where you feel the agitation | |
that your attention is drifting, | |
but you continually | |
bring it back. | |
And that's an important point, | |
which is that attention drifts, | |
but we have to re-anchor it. | |
We have to keep | |
grabbing it back. | |
And the way to do that, | |
if you're sighted, | |
is with your eyes, that as your | |
attention drifts and you look | |
away, you want to | |
try and literally | |
maintain visual | |
focus on the thing | |
that you're trying to learn. | |
That's the trigger | |
for plasticity. | |
But the real secret is | |
that neuroplasticity | |
doesn't occur | |
during wakefulness, | |
it occurs during sleep. | |
We now know that if you | |
focus very hard on something | |
for about 90 minutes | |
or so, maybe you even | |
do several bouts | |
of that per day, | |
if you can do that-- | |
some people can. | |
Some people can only do one | |
focus bout of learning-- | |
that night and the following | |
nights while you sleep, | |
the neural circuits that were | |
highlighted, if you will, | |
with acetylcholine | |
transmission, will strengthen. | |
And other ones | |
will be lost, which | |
is wonderful because that's | |
the essence of plasticity. | |
And what it means is | |
that when you eventually | |
wake up a couple of | |
days or a week later, | |
you will have acquired | |
the knowledge forever, | |
unless you go through some | |
process to actively unlearn it. | |
So mastering sleep | |
is key in order | |
to reinforce the | |
learning that occurs. | |
But let's say you get a | |
really poor night of sleep | |
after a bout of learning. | |
Chances are, if you sleep the | |
next night or the following | |
night, that learning will occur. | |
There's a stamp in the brain | |
where this acetylcholine was | |
released. | |
It actually marks those | |
synapses neurochemically and | |
metabolically so that | |
those synapses are more | |
biased to change. | |
Now, if you don't ever | |
get that deep sleep, | |
then you probably won't | |
get those changes. | |
There is also a way | |
in which you can | |
bypass the need for | |
deep sleep, at least | |
partially, by engaging in what | |
I call non-sleep deep rest, | |
these NSDR protocols. | |
But I just want to discuss | |
the science of this. | |
There was a paper | |
that was published | |
in Cell Reports last year that | |
shows that if people did-- | |
it was a spatial memory task, | |
actually quite difficult one, | |
where they had to remember the | |
sequence of lights lighting up. | |
And if there were just | |
two or three lights | |
in a particular | |
sequence, it's easy. | |
But as you get up to 15 | |
or 16 lights and numbers | |
in the sequence, it actually | |
gets quite challenging. | |
If immediately after-- and | |
it was immediately after | |
the learning, the actual | |
performance of this task, | |
people took a 20-minute | |
non-sleep deep-rest protocol | |
or took a shallow nap, so lying | |
down, feet slightly elevated, | |
perhaps, just closing their | |
eyes, no sensory input, | |
the rates of learning were | |
significantly higher for that | |
information than were they to | |
just had a good night's sleep | |
the following night. | |
So you can actually | |
accelerate learning | |
with these NSDR protocols or | |
with brief naps, 90 minutes | |
or less. | |
For many people, | |
letting the mind drift, | |
where it's not | |
organized in thought, | |
after a period of very | |
deliberate, focused effort, | |
is the best way to accelerate | |
learning and depth of learning. | |
I want to synthesize | |
some of the information | |
that we've covered up until now. | |
Today, I want to make sure | |
that these key elements that | |
form the backbone | |
of neuroplasticity | |
are really embedded | |
in people's minds. | |
First of all, plasticity | |
occurs throughout the lifespan. | |
If you want to learn as an | |
adult, you have to be alert. | |
It might seem so obvious, | |
but I think a lot of people | |
don't think about when in their | |
24-hour cycle they're most | |
alert. | |
Just ask yourself | |
when during the day | |
do you typically tend | |
to be most alert? | |
That will afford | |
you an advantage | |
in learning specific things | |
during that period of time. | |
So don't give up | |
that period of time | |
for things that are meaningless, | |
useless, or not aligned | |
with your goals. | |
That epinephrine released | |
from your brain stem is going | |
to occur more readily | |
at particular phases | |
of your 24-hour | |
cycle than others-- | |
during the waking | |
phase, of course. | |
You should know when those are. | |
Increasing acetylcholine can be | |
accomplished pharmacologically | |
through nicotine. | |
However, there are certain | |
dangers for many people | |
to do that, as well as a cost. | |
financial cost. | |
Learning how to engage | |
the cholinergic system | |
through the use of | |
the visual system. | |
Practicing; how long | |
can you maintain focus | |
with blinks as you need them. | |
But how long can you maintain | |
visual focus on a target, | |
just on a piece of paper set | |
a few feet away in the room, | |
or at the level of | |
your computer screen. | |
These are actually | |
things that people | |
do in communities where | |
high levels of visual focus | |
are necessary. | |
What we're really | |
talking about here | |
is trying to harness the | |
mechanisms of attention | |
and get better at | |
paying attention. | |
You may want to do that with | |
your auditory system, not | |
with your visual system, | |
either because you're | |
low-vision or no-vision, | |
or because you're | |
trying to learn something | |
that relates more to sounds. | |
You should also ask | |
yourself whether or not | |
you're trying to focus too much | |
for too long during the day. | |
I know some very | |
high-performing individuals, | |
very high-performing in | |
a variety of contexts, | |
and none of them are | |
focused all day long. | |
Many of them take | |
walks down the hallway, | |
sometimes mumbling to themselves | |
or not paying attention | |
to anything else. | |
They go for bike | |
rides, they take walks. | |
They are not trying to engage | |
their mind at maximum focus | |
all the time. | |
Very few people do that because | |
we learn best in these 90-minute | |
bouts inside of one of | |
these ultradian cycles. | |
And I should repeat again that | |
within that 90-minute cycle, | |
you should not expect yourself | |
to focus for the entire period | |
of one 90-minute cycle. | |
The beginning and end are | |
going to be a little bit | |
flickering in and out of focus. | |
How do you know when one of | |
these 90-minute cycles is | |
starting? | |
Well, typically when you wake | |
up is the beginning of the first | |
90-minute cycle, but it's | |
not down to the minute. | |
You'll be able to tap into your | |
sense of these 90-minute cycles | |
as you start to engage in | |
these learning practices, | |
should you choose. | |
And then, of course, getting | |
some non-sleep deep rest | |
or just deliberate | |
disengagement, | |
such as walking or | |
running or just sitting, | |
eyes closed or eyes open, kind | |
of mindlessly, it might seem, | |
in a chair. | |
Just letting your | |
thoughts move around | |
after a learning | |
bout will accelerate | |
the rate of plasticity. | |
And then, of course, deep sleep. | |
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very graciously asked | |
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