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.

I'm Andrew Huberman, and I'm a professor

of neurobiology and opthalmology at

Stanford School of Medicine. Today we

are discussing memory. In particular,

how to improve your memory. We are

constantly being bombarded with physical

stimula, patterns of touch on our skin,

light to our eyes, light to our skin for

that matter, smells, tastes, and sound

waves. Each one of and all of those

sensory stimula are converted into

electricity and chemical signals by your

so-called nervous system, your brain,

your spinal cord, and all their

connections with the organs of the body

and all the connections of your organs

of the body back to your brain and

spinal cord. For instance, if you can

hear me speaking right now, you are

perceiving my voice, but you are also

most likely neglecting the feeling of

the contact of your skin with whichever

surface you happen to be sitting or

standing on. It is only by perceiving a

subset, a small fraction of the sensory

events in our environment that we can

make sense of the world around us.

Otherwise, we would just be overwhelmed

with all the things that are happening

in any one given moment. Now, memory is

simply a bias in which perceptions will

be replayed again in the future. Now,

this might seem immensely simple, but it

raises this really interesting question

which we talked about before, which is

why do we remember certain things and

not others? Because according to what

I've just said, as you go through life,

you're experiencing things all the time.

You're constantly being bombarded with

sensory stimula. Some of those sensory

stimula you perceive and only some of

those perceptions get stamped down as

memories. Today I'm going to teach you

how certain things get stamped down as

memories. And I'm going to teach you how

to leverage that process in order to

remember the information that you want

far better. Each individual thing that

we remember or that we want to remember

is linked to something by either a

close, a medium or a very distant

association. This turns out to be

immensely important. I know many of you

will read or will encounter programs

that are designed to help you enhance

your memory. You know, you have these uh

phenoms that can remember 50 names in a

in a room full of people or they can

remember a bunch of names of novel

objects or maybe even in different

languages. And often times that's done

by association. So people will come up

with little mental tricks to, you know,

either link the sound of a word or the

meaning of a word in some way that's

meaningful for them and will enhance

their memory. that can be done and is

impressive when we see it. And for those

of you who can do that, congratulations.

Most of us can't do that or at least it

requires a lot of effort and training.

However, there are things that we can do

that leverage the natural biology of our

nervous system to enhance learning and

memory of particular perceptions and

particular information. So, let's talk

about tools for enhancing memory. Now,

there's one tool that is absolutely

clear works and that's repetition.

The more often that you perform

something or that you recite something,

the more likely you are to remember it

in the future. And while that might seem

obvious, it's worth thinking about

what's happening when you repeat

something. But when I say what's

happening, I mean at the neural level,

what's happening is that you're

encouraging the firing of particular

chains of neurons that reside in a

particular circuit. Right? So a

particular sequence of neurons playing

neuron A, B, C, D played in that

particular sequence over and over and

over again. And with more repetitions,

you get more strengthening of those

nerve connections. The problem for most

people is that they either don't have

the patience, they don't have the time,

and sometimes they literally don't have

the time because they've got a deadline

on something that they're trying to

remember and learn, or they simply would

like to be able to remember things

better in general, remember them more

quickly. this process of accelerating

repetition-based learning so that your

learning curve doesn't go from having to

perform something a thousand times and

then gradually over time it's 1,00 750

times a day 500 times a day 300 times a

day and down to no repetitions right you

can just perform that thing the first

time and every time well there is a way

to shift that curve so that you can

essentially establish stronger

connections between the neurons that are

involved in generating that memory

memory or behavior more quickly. How do

you do that? Well, in order to answer

that, we have to look at the beautiful

work of James McGaw and Larry Kah Hill.

James McGaw and Larry Kah Hill did a

number of experiments over several

decades really that really established

what's required to get better at

remembering things and to do so very

quickly. They evaluated the capacity for

stress and for particular neurochemicals

associated with stress to improve our

ability to learn information not just

information that is emotional but

information of all kinds. So I'm going

to describe some experiments done in

animal models just very briefly and then

experiments done on human subjects. If

you take a rat or a mouse and put it in

an arena where at one location the

animal receives an electrical shock and

then you come back the next day, you

remove the shock evoking device and you

let the animal move around that arena,

that animal will quite understandably

avoid the location where it was shocked.

So-called conditioned place aversion.

That effect of avoiding that particular

location occurs in one trial. That's a

good example of one trial learning. So

somehow the animal knows that it was

shocked at that location. It remembers

that. It is a hippocample dependent

learning. They remember it after the

first time and every time unless

you are to block the release of certain

chemicals in the brain and body and the

chemicals I'm referring to are

epinephrine, adrenaline, and to some

extent cortisol. Now we know that the

effect of getting one trial learning

somehow involves epinephrine at least in

this particular experimental scenario

because if researchers do the exact same

experiment and they have done the exact

same experiment but they introduce a

pharmacological blocker of epinephrine

so that epinephrine is released in

response to the shock but it cannot

actually bind to its receptors and have

all of its biological effects. Well,

then the animal is perfectly happy to

tread back into the area where it

received the shock. It's almost as if it

didn't know or we have to assume it

didn't remember that it received a shock

at that location. So, it all seems

pretty obvious when you hear it.

Something bad happens in a location,

you'll go back to that location. But it

turns out that the opposite is also

true. Meaning for something called

condition place preference. You can take

an animal, put it into an arena, feed it

or reward it somehow at one location,

take the animal out, come back the next

day. No food is introduced, but it'll go

back to the location where it received

the food. Or you can do any variant of

this. You can make the arena a little

bit chilly and provide warmth at that

location. Or you can take a male animal,

it turns out male rats and mice will

mate at any point. Or a female animal

that's at the particular so-called

receptive phase of her mating cycle and

give them an opportunity to mate at a

given location. They'll go back to that

location and wait and wait. This is

perhaps why people go back to the same

bar or the bar seat at the bar or the

same restaurant and wait for because of

the one time they, you know, things

worked out for them. What whatever the

context was. Condition place preference

as with condition place avoidance

depends on the release of adrenaline.

Right? It's not just about stress. It's

about a heightened emotional state in

the brain and body. Okay, this is really

important. It's not just about stress.

You can get one trial learning for

positive events condition place

preference and you can get one trial

learning for negative events. This turns

out all to be true for humans as well.

We know that because McGon Cahill did

experiments where they gave people a

boring paragraph to read and only a

boring paragraph to read. But one group

of subjects was asked to read the

paragraph and then to place their arm

into very very cold water. In fact, it

was ice water. We know that placing

one's arm into ice water, especially if

it's up to the shoulder or near to it,

evokes the release of adrenaline in the

body. It's not an enormous release, but

it's a significant increase. And yes,

they measured adrenaline release. In

some cases, they also measured for

things like cortisol, etc. And what they

found is that if one evokes the release

of adrenaline through this arm into ice

water approach, the information that

they read previously, just a few minutes

before, was remembered. It was retained

as well as emotionally intense

information. But keep in mind the

information that they read was not

interesting at all or at least it wasn't

emotionally laden.

This had to be the effect of adrenaline

released into the brain and body because

if they blocked the release or the

function of adrenaline in the brain and

or body, they could block this effect.

This is absolutely important in terms of

thinking about tools to improve your

memory. It is the presence of high

adrenaline, high amounts of

norepinephrine and epinephrine that

allows a memory to be stamped down

quickly and far and away different than

the idea that we remember things because

they're important to us or because they

evoke emotion. That's true. But the real

reason, the neurochemical reason, the

mechanism behind all that is

neurochemicals have the ability to

strengthen neural connections by making

them active just once. There's something

truly magic about that neurochemical

cocktail that removes the need for

repetition. Okay. So, let's apply this

knowledge. Let's establish a

scientifically grounded set of tools.

meaning tools that take into account the

identity of the neurochemicals that are

important for enhancing learning and the

timing of the release of those chemicals

in order to enhance learning. Caffeine

in the form of coffee or yerba mate or

any other form of caffeine does create a

sense of alertness in our brain and

body. So my typical way of approaching

learning and memory would be to drink

some caffeine and then focus really hard

on whatever it is that I'm trying to

learn. try and eliminate distractions

and then hope hope or try try to

remember that information as best as I

could. And frankly, I felt like it was

working pretty well for me. And

typically, if I leveraged other forms of

pharmarmacology in order to enhance

learning and memory, things like alpha

GPC or phosphotidal serereine, I would

do that by taking those things before I

sat down to learn a particular set of

information or before I went off to

learn a particular physical skill. For

those of you out there listening to

this, you're probably thinking, well,

okay, the results of McGawan Kill

pointed to the fact that having

adrenaline released after

learning something, enhanced learning of

that thing. But a lot of these things

like caffeine or alpha GPC can increase

epinephrine and adrenaline or dopamine

or other molecules in the brain and body

that can enhance memory for a long

period of time. So it makes sense to

take it first or even during learning

and then allow that increase to occur

and the increase will occur over a long

period of time and will enhance learning

and memory. While that is partially

true, it is not entirely true and it

turns out it's not optimal. And it turns

out that the best time window to evoke

the release of these chemicals if the

goal is to enhance learning and memory

of the material is either immediately

after or just a few minutes, five, 10,

maybe 15 minutes after you're repeating

that information. You're trying to learn

that information. Again, this could be

cognitive information or this could be a

physical skill. Now, this really spits

in the face of the way that most of us

approach learning and memory. Most of

us, if we use stimulants like caffeine

or alpha GPC, we're taking those before

or during an attempt to learn, not

afterwards. If you're using those

compounds in order to enhance learning

and memory, well, then I encourage you

to try and take them either late in the

learning episode or immediately after

the learning episode. Now, given

everything I've told you up until now,

why would I say late in the learning

episode or immediately after? Well, when

you ingest something by drinking it or

you take it in capsule form, there's a

period of time before that gets absorbed

into the body and different substances

such as caffeine, alpha GPC, etc. are

absorbed in from the gut and into the

bloodstream and reach the brain and

trigger these effects in the brain and

body at different rates. So, it's not

instantaneous. Some have effects within

minutes, others within, you know, tens

of minutes and so on. It's really going

to depend on the pharmarmacology of

those things. And it's also going to

depend on whether or not you have food

in your gut, what else you happen to

have circulating in your bloodstream,

etc. But at a very basic level, we can

confidently say that there are not one,

not dozens, but as I mentioned before,

hundreds of studies in animals and in

humans that point to the fact that

triggering the increase of adrenaline

late in learning or immediately after

learning is going to be most beneficial

if your goal is to retain that

information for some period of time and

to reduce the number of repetitions

required in order to learn that

information. Now, I want to acknowledge

that on previous episodes of this

podcast, I've talked a lot about things

like non-sleep, deep rest, and naps and

sleep as vital to the learning process.

And I want to emphasize that none of

that information has changed. Right? I

don't look at any of that information

differently as the consequence of what

I'm talking about today. It is still

true that the strengthening of

connections in the brain, the literal

neuroplasticity, the changing of the

circuits occurs during deep sleep and

non-sleep deep rest. And it is also true

and I've mentioned these results earlier

that two papers were published in cell

reports cell press journal excellent

journal over the last few years showing

that brief naps of about 20 to up to 90

minutes in some period of time after an

attempt to learn can enhance the rate of

learning and memory that still can be

performed but it can be performed some

hours later even an hour later it can be

performed 2 hours later 4 hours later.

Remember, it's in these naps and in deep

sleep that the actual reconfiguration of

the neural circuits occurs. The

strengthening of those neural circuits

occurs. It is not the case that you need

to finish a bout of learning and drop

immediately into a nap or sleep. Some

people might do that, but if you're

really trying to optimize and enhance

and improve your memory,

the data from McGau and Kahill and many

other laboratories that stemmed out from

their initial work really point to the

fact that the ideal protocol would be

focus on the thing you're trying to

learn very intensely. Still try and get

excellent sleep. Again, fundamentally

important for mental health, physical

health, and performance. And we can now

extend from performance to saying

including learning and memory. nap if it

doesn't interrupt your nighttime sleep.

Naps of anywhere from 10 to 90 minutes

or non-sleep deep rest protocols will

enhance learning and memory. But we can

now add to that that spiking adrenaline

provided it can be done in a safe way is

going to reduce the number of

repetitions required to learn and that

should be done at the very tail end or

immediately after a learning bout which

is compatible with all the other

protocols that I mentioned. And the

reason I'm revisiting the stuff about

sleep and non-sleep deep rest is I think

that some people got the impression that

they need to do that immediately after

learning. And today I'm saying to the

contrary, immediately after learning,

you need to go into a heightened state

of emotionality and alertness. Now, it's

vitally important to point out that you

do not need pharmarmacology. You don't

need caffeine. You don't need alpha GPC.

You don't need any pharmacologic

substance to spike adrenaline unless

that's something that you already are

doing or that you can do safely or that

you know that you can do safely. So if

you're somebody who's not used to

drinking caffeine and you suddenly drink

four espresso after trying to learn

something, you are going to have a

severe increase in alertness and

probably even anxiety. If you're panic

attack prone, please don't start taking

stimulants in order to learn things

better. You could take a cold shower.

You could do an ice bath or get into a

cold circulating bath in order to evoke

epinephrine and dopamine release. You

could go out for a hard run. You could

do any number of things that would

increase adrenaline in your body. Which

things you choose is up to you. But the

overall takeaway is that anything that

increases adrenaline will increase

learning and memory and will reduce the

number of repetitions required to learn

something. And as a cautionary note,

don't think that you can push this

entire system to the extreme over and

over again or chronically as we say and

get away with it. In other words, you're

not going to be able to take a alpha GPC

and a double espresso, do your focus

bout of work, cognitive or physical

work, and then spike adrenaline again

afterwards and remember that stuff even

better. Right? I'm not encouraging you.

In fact, I'm discouraging you from

chronically increasing adrenaline both

during and after a given bout of work if

the goal is to learn. Why do I say that?

Well, work from Macau and Cahill and

others has shown that it's not the

absolute amount of adrenaline that you

release in your brain and body that

matters for enhancing memory. It's the

amount of adrenaline that you release

relative to the amount of adrenaline

that was in your system just prior in

particular in the hour or two prior. So

again, it's the delta, as we say. It's

the difference. So if you're going to

chronically increase adrenaline, you're

not going to learn as well. The real key

is to have adrenaline modestly low,

perhaps even just as much as you need in

order to be able to focus on something,

pay attention to it, and then spike it

afterwards. This is immensely important

because while much of what we're talking

about is actually a form of inducing a

neurochemical acute stress, meaning a

brief and rapid onset of stress. Well,

chronic stress, the chronic elevation of

epinephrine and cortisol is actually

detrimental to learning. And there's an

entire category of literature mainly

from the work of the great and sadly the

late Bruce Mchuan from the Rockefeller

University and some of his scientific

offspring like the great Robert

Seapolski showing that chronic stress

chronic elevation of epinephrine

actually inhibits learning and memory

and also can inhibit immune system

function. Whereas acute sharp increases

in adrenaline and cortisol actually can

enhance learning and indeed can enhance

the immune system. So, if you really

want to leverage this information, you

might consider getting your brain and

body into a very calm and yet alert

state. So, a high attentional state that

will allow you to focus on what it is

that you're trying to learn. We know

focus is vital for encoding information

and for triggering neuroplasticity, but

remaining calm throughout that time and

then afterwards spiking adrenaline and

allowing adrenaline to have these

incredible effects on reducing the

number of repetitions required to learn.

So if you're like me, you're learning

about this information, this beautiful

work of Macau and Cahill and others and

thinking, "Wow, I should perhaps

consider spiking my adrenaline in one

form or another at the tail end or

immediately following an attempt to

learn something." And yet we are not the

first to have this conversation. Nor

were McGon Kahill or any other

researchers that I've discussed today

the first to start using this technique.

In fact, there is a beautiful review

that was published in the journal Neuron

Cellpress Journal. Excellent journal

called Mechanisms of Memory Under

Stress. And I just want to read to you

the first opening paragraph of this

review. So here I'm reading and I quote,

"In medieval times, communities threw

young children in the river when they

wanted them to remember important

events. They believe that throwing a

child in the water after witnessing

historic proceedings would leave a

lifelong memory for the events in the

child." Believe it or not, this is true.

This is a practice that somehow people

arrived at. I don't know if they were

aware of what adrenaline was, probably

not. But somehow in medieval times, it

was understood that spiking adrenaline

or creating a robust emotional

experience after an experience that one

hoped a child would learn would

encourage the child's nervous system.

and they even know what a nervous system

was, but would encourage the brain and

body of that child to remember those

particular events.

Very counterintuitive if you ask me. I

would have thought that the kid would

remember only being thrown into the

river. My guess is that they remember

that, but that they the idea here anyway

is that they also remember the things

that preceded being thrown into the

river. So both interesting and amusing

and somewhat um I should say thought

stimulating really that this is a

practice that has been going on for many

hundreds of years. And we are not the

first to start thinking about using cold

water as an adrenaline stimulus. Nor are

we the first to start thinking about

using cold water induced adrenaline as a

way to enhance learning and memory. This

has been happening since medieval times.

So now I'd like to talk about other

tools that you can leverage that have

been shown in quality peer-reviewed

studies to enhance learning and memory.

And perhaps one of the most potent of

those tools is exercise. There are

numerous studies on this in both animal

models and fortunately now also in

humans thanks to the beautiful work of

people like Wendy Suzuki from New York

University. If you recall earlier, I

mentioned that learning and memory

almost always involves the strengthening

of particular synapses and neural

circuits in the brain. There is one

exception, however, and we now have both

animal data and some human data to

support the fact that cardiovascular

exercise seems to increase what we call

dentate gyrus neurogenesis. Neurogenesis

is the creation of new neurons. The

dentate gyrus is a sub region of the

hippocampus that's involved in learning

and memory of particular kinds. It's

very clear that getting a minimum of 180

to 200 minutes of so-called zone 2

cardiovascular exercise. So this is

cardiovascular exercise that can be

performed at a pretty steady state. We

believe that it is indirectly I should

say indirectly through enhancements in

cardiovascular fitness that there are

improvements in hippocample dentate

gyrus neurogenesis. What does that mean?

the improvements in cardiovascular

function are indirectly impacting the

ability of the dentate gyrus to create

these new neurons. To my knowledge,

there's no direct relationship between

exercise and stimulating the production

of new neurons in the brain.

It seems that it's the improvements in

blood flow that also relate to

improvements in things like lymphatic

flow, the circulation of lymph fluid

within the brain that are enhancing

neurogenesis. And that neurogenesis is

it appears is important. Now in fairness

to the landscape of neuroscience and my

colleagues at Stanford and elsewhere

there is a lot of debate as to whether

or not there is much if any neurogenesis

in the adult human brain. But regardless

I think the data are quite clear that

the 180 to 200 minutes minimum of

cardiovascular exercise is going to be

important for other health metrics. Now

it is clear that exercise can impact

learning and memory through other

non-neurogenesis non-new neuron type

mechanisms. And one of the more exciting

ones that has been studied over the

years is this notion of hormones from

bone traveling in the bloodstream to the

brain and enhancing the function of the

hippocampus. Yes indeed your bones make

hormones. We call these endocrine

effects. So they're effectively acting

as hormones. And one such chemical is

something called osteocalin. Now these

findings arrive to us through various

labs but one of the more important labs

for sake of this discussion today is the

laboratory of Eric Kandell at Colombia

medical school. His laboratory has

studied the effects of exercise on

hippocample function and memory and

other laboratories have done that as

well. And what they found is that

cardiovascular exercise and perhaps

other forms of exercise too, but mainly

cardiovascular exercise creates the

release of osteocalin from the bones

that travels to the brain and to sub

regions of the hippocampus and

encourages the electrical activity and

the formation and maintenance of

connections within the hippocampus and

keeps the hippocampus functioning well

in order to lay down new memories. So

much of our brain real estate is devoted

to movement that it's been hypothesized

for more than a half century, but

especially in recent years as we've

learned more about the function of the

brain at a really detailed circuit level

that the relationship between the brain

and body and the maintenance and perhaps

even the improvement of neural circuitry

in the brain depends on our body

movements and the signal from the body

that our brain is still moving. the fact

that osteocalin

is released from bone and in particular

can be released in response to

loadbearing exercise. So this would be

running again weightlifting hasn't been

tested directly but one would imagine

anything that involves jumping and

landing or weight lifting or body uh

body weight movements and things of that

sort. That's a signal to release

osteocalin and we know that signal

occurs that is directly reflective of

the fact that the body was moving and

moving in particular ways. In fact, you

could imagine that big bones like your

femur are going to release more

osteocalin or be in a position to

release more osteoccalin than five move

five movements like the movements of the

digits. And this idea that the body is

constantly signaling to the brain about

the status of the body and the varying

needs of the brain to update its brain

circuitry is a really attractive idea

that fits entirely with the biology of

exercise, osteocalin, and hippocample

function. Now, I certainly don't want to

give the message that just moving, just

exercise is sufficient to keep the

neural architecture of your brain

healthy, young, and able to learn. While

that might be true, it's also important

to actually engage in attempts to learn

new material, either physical material,

so new types of movements and skills

and/or new types of cognitive

information, languages, mathematics,

history, uh current events, uh all sorts

of things um that involve your brain.

Nonetheless, it's clear that physical

movement and cognitive ability and the

potential to enhance cognitive ability

and the ability to learn new physical

skills are intimately connected and

osteocalin appears to be at least one

way in which that brain body

relationship is established and

maintained. Next, I'm going to tell you

about a study which points out the

immense value of visual images for

laying down memories. And you can

leverage this information. And this

involves both the taking of photographs,

something that's actually quite easily

done these days with your phone as well

as your ability to take mental

photographs by literally snapping your

eyelids shut. So, I just briefly want to

describe this paper because it provides

a tool that you can leverage in your

attempt to learn and remember things

better. The title of this paper is

photographic memory. The effects of our

voluitional photo takingaking on memory

for visual and auditory aspects of an

experience. It refers to photographic

memory not in the context of

photographic memory that we normally

hear about where people are truly

photographic. Look at a page and somehow

absorb all that information and commit

it to memory. But rather the use of

camera photographs or the use of mental

camera photographs. literally looking at

something and deciding blink and

snapping a so to speak snapping a

snapshot of whatever it is that you were

looking at and remembering the content.

Two years ago I was in an Uber and I

looked out the window and it was a

street scene. I was actually in New York

at the time and I decided for reasons

that are still unclear to me to take a

mental snapshot of this city street

image even though nothing interesting in

particular was happening. And um I do

recall that there was a guy wearing a

yellow shirt walking. there was some

construction etc. I can still see that

image in my mind's eye because I took

this mental snapshot. This paper

addresses whether or not this mental

snapshotting thing is real and raise the

hypothesis that if people are allowed to

choose what they take photos of that

taking photos again this is with a

camera not mental snapshotting that

taking those photos would actually

enhance their memory for those objects

those places those people and in fact

details of those object places and

people and indeed that's what they

found. What does this mean? It means if

you really want to remember something or

somebody, take a photo of that thing or

person, pay attention while you take the

photo, but it doesn't really matter if

you look at the photo again. That

framing up of the photograph stamps down

a visual image in your mind that is more

robust at serving a memory than had you

just looked at that thing with your own

eyes. Very interesting and raises all

sorts of questions for me about whether

or not it's because you're framing up a

small aperture, a small portion of the

visual scene. That's one logical

interpretation, although they didn't

test that. The reason I find this so

interesting is that a lot of what we try

and learn is visual. And for a lot of

people, the ability to learn visual

information feels challenging. And we'll

look at something and we'll try and

create some detailed understanding of

it. We'll try and understand the

relationships between things in that

scene. It does appear based on the study

that the mere decision to take a mental

snapshot like okay I'm going to blink my

eyelids and I'm going to take a snapshot

of whatever it is I see can actually

stamp down a visual memory much in the

same way that a camera can stamp down a

visual memory of course through vastly

distinct mechanisms. No discussion of

memory would be complete without a

discussion of the ever intriguing

phenomena known as deja vu. The way this

works has been defined largely by the

wonderful work of Susumu Tonagawa at

Massachusetts Institute of Technology,

MIT. I should also mention the beautiful

work of Mark Mayford at the Scripps

Institute and UC San Diego. Here's what

they discovered. They evaluated the

patterns of neural firing in the

hippocampus as subjects learn new

things. Neuron A fires, then neuron B

fires, then neuron C fires in a

particular sequence. Again, the firing

of neurons in a particular sequence,

like the playing of keys on a piano in a

particular sequence, leads to a

particular song on the piano and leads

to a particular memory of an experience

within the brain.

They then used some molecular tools and

tricks to label and capture those

neurons such that they could go back

later and activate those neurons in

either the same sequence or in a

different sequence to the one that

occurred during the formation of the

memory. And to make a long story short

and to summarize multiple papers

published in incredibly high tier

journals, journals like Nature and

Science which are extremely stringent

found that

whether or not those particular neurons

were played in the precise sequence that

happened when they encoded the memory or

whether or not those neurons were played

in a different sequence or even if those

neurons were played activated. that is

all at once with no temporal sequence

all firing in concert all at once

evoked the same behavior and in some

sense the same memory. So at a neural

circuit level this is deja vu whether or

not the same sort of phenomenon occurs

when you're walking down the street and

suddenly you feel as if wow I feel like

I've been here before. You meet someone

and you feel like gosh I feel like I

know you. I feel like there's some

familiarity here that I can't quite put

my finger on. We don't know for sure

that that's what's happening, but this

is the most mechanistic and logical

explanation for what has for many

decades, if not hundreds of years, has

been described as déja vu. I'd like to

cover one additional tool that you can

use to improve learning and memory. This

is based on a paper from none other than

Wendy Suzuki at New York University. The

title of this paper will tell you a lot

about where we're going. The title is

brief daily meditation enhances

attention, memory, mood, and emotional

regulation in non-experienced

meditators. This is a study that

involved subjects aged 18 to 45, none of

whom were experienced meditators prior

to this study.

There were two general groups in this

study.

One group did a 13minute long

meditation. And this meditation was a

fairly conventional meditation. They

would sit or lie down. They would do

somewhat of a body scan, evaluating, for

instance, how tense or relaxed they felt

throughout their body, and they would

focus on their breathing, trying to

bring their attention back to their

breathing and to the state of their body

as the meditation progressed. The other

group, which we can call the control

group, listen to, of all things, a

podcast for an equivalent amount of

time, but they were not instructed to do

any kind of body scan or pay attention

to their breathing. Every subject in the

study either meditated daily or listened

to a equivalent duration podcast daily

for a period of eight weeks. So the

takeaways from the study are

severalfold. First of all, that daily

meditation of 13 minutes can enhance

your ability to pay attention and to

learn. It can truly enhance memory.

However, you need to do that for at

least 8 weeks in order to start to see

the effects to occur. and we have to

presume that you have to continue those

uh meditation training sessions. In

fact, they found that if people only did

four weeks of meditation, these effects

didn't show up. Now, eight weeks might

seem like a long time, but I think that

13 minutes a day is not actually that

big of a time commitment. And the

results of this study certainly

incentivize me to start adopting a I'm

going for 15 minutes a day now. I've

been a on andoff meditator for a number

of years. I've been pretty good about it

lately, but I confess I've been doing

far shorter meditations of anywhere from

3 to five or maybe 10 minutes. I'm going

to ramp that up to 15 minutes a day. And

I'm doing that specifically to try and

access these improvements in cognitive

ability and our abilities to learn.

Today, we covered a lot of aspects of

memory and how to improve your memory.

However, for sake of what was discussed

today, please understand that any number

of different neurochemicals can evoke or

can increase the amount of adrenaline

that's circulating in your brain and

body. It really doesn't matter how you

evoke the adrenaline release because

remember adrenaline is the final common

pathway by which particular experiences,

particular perceptions are stamped into

memory, which answers our very first

question raised at the beginning of the

episode, which is why do we remember

anything at all? Right? That was the

question that we raised. Why is it that

from morning till night and throughout

your entire life you have tons of

sensory experience, tons of perceptions?

Why is it that some are remembered and

others are not? And while I would never

want to distill an important question

such as that down to a one molecule type

of answer, I think we can confidently

say based on the vast amount of animal

and human research data that

epinephrine, adrenaline, and some of the

other chemicals that it acts with in

concert is in fact the way that we

remember particular events and not all

events. Once again, thank you for

joining me today to discuss the

neurobiology of learning and memory and

how to improve your memory using

science-based tools. And last, but

certainly not least, thank you for your

interest in science.