Tools to Enhance Working Memory & Attention

welcome to the huberman Lab podcast

where we discuss science and

science-based tools for everyday

[Music]

life I'm Andrew huberman and I'm a

professor of neurobiology and

Opthalmology at Stanford school of

medicine today we are discussing working

memory working memory is a special

category of memory in which we are able

to hold small amounts of information in

our mind for short periods of time

working memory is also very closely

related to attention so for any of you

that are interested in how to develop

better focus and attention understanding

what working memory is and some of the

things that you can do to improve your

working memory can be very beneficial

today I'm going to talk about what

working memory is including some of the

underlying biology although I promise

irrespective of whether or not you know

any biology or you are an expert in

biology I'll make the conversation

accessible to you in addition I will

talk about tools to improve working

memory and I'll also compare working

memory to other forms of memory memory

like long-term memory and short-term

memory and through that understanding

I'm confident that you'll be able to

develop better focus as well as be able

to commit certain forms of information

to your short and long-term memory

stores before we begin I'd like to

emphasize that this podcast is separate

for my teaching and research roles at

Stanford it is however part of my desire

and effort to bring zero cost to

Consumer information about science and

science related tools to the general

public in keeping with that theme I'd

like to thank the sponsors of today's

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free pillows okay let's talk about

working memory and let's start off this

discussion by comparing working memory

to other forms of memory that most

people are more familiar with or at

least when most people hear the word

memory they typically are thinking about

long-term memory like one's ability to

remember the capitals of states or

countries the different continents

directions from one location to another

even one's name all of those things are

examples of long-term memory now I want

to emphasize that long-term memory

really has two components there are what

we call declarative long-term memories

so these are the things that we can

declare things like facts about

ourselves or the world or others and

then there are procedural long-term

memories procedural long-term memories

as the name suggests are aspects of our

memory that allow us to perform certain

procedures they are literally action

steps that we take to for instance ride

a bicycle or drive a car which by the

way we might not be conscious of

ourselves doing after we learn that is

after we pass information into our

procedural long-term memory but even

once those things become reflexive they

are stored in our long-term memory now a

discussion of long-term memory is not

the focus today but me being a

neuroscientist and I like to think you

all generally being interested in the

underlying biology I'll just mention

that there's a key structure within the

brain that is part of a larger neural

network that is a collection of

structures which is absolutely essential

for the formation and storage of

long-term memories and that's the

hippocampus which in Latin means

seahorse and it does look a little bit

like a seahorse but you actually have

one on each side of your brain so we say

hippocampi plural and so what we know is

that if people have damage to their

hippocampus of any kind that people have

trouble accessing or forming long-term

memory sometimes both and there's a lot

more that we could say about long-term

memory indeed I did an entire episode of

The hubman Lab podcast about the

formation and storage of long-term

memories including some tools to improve

long-term memories we'll touch on a few

of those tools later today but you can

access that episode if you go to hubman

lab.com and just put memory into the

search function and you'll find it there

in the meantime if we want to understand

working memory we not only have to

understand how it's different from

long-term memory but also how it's

different from short-term memories

short-term memory is a capacity that we

all have that as the name suggests

represents a short-term memory bank for

information that may or may not get

passed into long-term memory so for

instance if you've learned anything and

of course you have if you can understand

what I'm saying you've learned English

language if you can write you've learned

how to write Etc well in order to learn

those things and to commit them to

long-term memory the information

required to do those things and to have

that knowledge needed to be held in

short-term memory and short-term

memories are the sorts of memories that

we maintain for somewhere between a few

minutes and potentially a few hours

maybe a little bit longer but only a

certain percentage of that is passed

into our long-term memory so for

instance if you listen to this podcast

or you go to a course lecture uh whether

or not that lecture is about cognitive

material or whether or not it's about

learning a new physical skill regardless

of what you learn you're only going to

learn a certain amount of that

information but were we to examine how

much of the information you just heard

or that you're hearing now you remember

immediately after this podcast episode

as compared to say a week later we know

based on gosh millions of scientific

papers and studies that you are going to

have more information in your short-term

memory stores shortly after being

exposed to new information then you will

later in other words only a small

percentage of what we perceive what we

see what we hear Etc gets passed into

short-term memory and then only a

fraction of that gets passed into

long-term memory now the neural circuits

for short-term memory and the passage of

short-term memories into long-term

memory involve a lot of different brain

structures but here again we can

implicate the hip hi campus Because the

actual passage of short-term memories

into long-term memories occurs in part

within the hippocampus and then a lot of

people don't know this some of the

memories that we think of as long-term

memories are actually distributed into

the neocortex which is the outer portion

of the brain now the point here is less

to fill your mind with different names

of things and nomenclature but rather to

get you thinking about what's involved

in creating short and long-term memories

and equally important that even though

the hippocampus is critically involved

in the formation of short and long-term

memories that the formation of short and

long-term memories is really a network

phenomenon in fact among the more

important themes that comes up again and

again on this podcast anytime that we're

talking about Neuroscience or actually

biology in any case is that rarely if

ever is there one location in the brain

where something happens typically it's a

network phenomenon meaning it's the

collaboration of a bunch of different

brain areas passing information from one

location to the next and storing it in a

kind of distributed way way now another

key thing to understand about working

memory and how it is different from

short and long-term memory is that the

formation of short and long-term

memories almost always involves

neuroplasticity neuroplasticity is the

nervous system's ability to change in

response to experience now there are

different types of neuroplasticity so

often when we hear about neuroplasticity

in the popular sphere people don't

emphasize that there are different types

of neuroplasticity and it's worth paying

a little bit of attention to what those

different typ are there is for instance

what we call long-term potentiation

long-term potentiation or ltp as the

acronym goes is the strengthening of

connections between neurons as a

consequence of their repeated firing

very closely together in time okay

there's a lot more to it but if you've

ever heard the phrase fire together wire

together sometimes that is misattributed

to Donald Hebb who did talk about

neuroplasticity by the way Donald Hebb

was a psychologist up in Canada who

talked about neuroplasticity in the

context of lots of different forms of

learning but that fire together wire

together phrase was not actually stated

by Donald Hebb it was stated by Carla

shatz my colleague at Stanford and she

was referring to ltp but other forms of

neuroplasticity that occur mainly in

development when neurons fire very

closely in time and thereby strengthen

those connections which can include ltp

okay so for now think of ltp as anytime

that some small group of neurons could

be two neurons

could be 2,000 neurons are very active

closely together in time and they have

access to one another physically and the

consequence is often not always but it's

often ltp that is the strengthening of

those connections such that after that

barrage of activity subsides those

neurons can speak to each other they can

communicate through electrical activity

and chemical activity much more easily

their communication is more robust it's

like removing a wall between a a

conversation such that the conversation

can take place more fluidly now there

are other forms of neuroplasticity

including LTD longterm depression which

unfortunately the name often calls to

mind ideas about depression as a

psychiatric or a psychological symptom

but has nothing to do with that

long-term depression is simply the

inverse of ltp it's actually the

weakening or the removal of connections

that we call synapses between neurons I

want to emphasize that both ltp and LTD

are both critically involved in lots of

different kinds of learning and both of

them tend to be involved in the

formation of both short-term memories

and long-term memories and this is very

important in the removal of short-term

memories and long-term memories

literally forgetting of certain things

because as we all know there are many

things that we will never forget and

there are also things that we almost

always forget now there's a third form

of neuroplasticity that's involved in

the formation of short and long-term

memories that's important for us to

discuss just briefly but I do want to

emphasize that there are not just three

forms of neuroplasticity there are many

other forms dozens if not more things

like Spike timing dependent plasticy

paired pulse facilitation and on and on

but the third type of neuroplasticity

that I'd like to mention now is

neurogenesis neurogenesis is the

formation of new neurons now

neurogenesis is robust in the developing

nervous system we know this it's robust

in the developing nervous system of

animals and humans however neurogenesis

the literal formation of new neurons in

the brain is a very exciting idea and it

does occur and it's very exciting in a

way that has motivated lots of popular

press Outlets to talk about or to

discuss papers that have discovered

neurogenesis in the adult brain because

let's be honest what's more exciting

than the idea that your brain can add

new brain cells later in life and indeed

that has been shown even in people well

into their 80s and 90s however it's very

important to know that the total amount

of neurogenesis that occurs in the adult

human brain is infantes small as a

mechanism for neuroplasticity and

learning as compared to the other forms

of neuroplasticity that we discussed

such as long-term potentiation and

long-term depression so I don't want to

you know throw cold water on the topic

of neurogenesis it's an incredibly

interesting and important topic but all

too often they tend to eclipse the much

more common mechanism for the formation

of short and long-term memories which

are those other forms we just talked

about ltp LTD Etc so the point here is

that yes indeed there are new neurons

that can be added in the adult brain

maybe even in the adult human brain and

there is some evidence that some of

those new neurons are added to the

hippocampus in fact a particular region

of the hippocampus called the dentate

gyrus of the hippocampus and there's

been a lot of controversy about how much

neurogenesis occurs or doesn't occur and

whether or not it occurs after puberty

or not there's a whole field of people

battling over this now for several

decades ades but one thing is very clear

neurogenesis while it's very exciting

and intriguing is not the main mechanism

by which the formation of short and

long-term memories occurs when you learn

new information as you are right now the

storage of that information in your

short-term memory networks which is then

passed on to your long-term memory

networks and that can be recalled that

allows you to State certain facts about

for instance the existence of this thing

called a hippocampus hopefully you will

remember that going forward or your

ability to perform any kind of motor

movement that you learned now or way

back in

childhood most of that is the

consequence of the strengthening of

particular connections and the weakening

of other types of connections those are

the two major forms of neuroplasticity

okay so I don't want you to get the

impression that there's something wrong

with my memory and that I forgot that

this episode is not about short or

long-term memory but it's about working

memory and indeed I have not forgotten

so now is where I tell you why I've been

talking about short and long-term memory

and the mechanisms of those because I

want them to provide a stark contrast

for what we call working memory working

memory as far as we know does not

involve neuroplasticity or at least if

it does it's not a particularly robust

aspect of working memory rather working

memory is the reflection of a particular

neural circuit running an algorithm over

and over and over for different types of

information but the information isn't

stored it is actually intentionally

discarded now what sorts of daily

activities and life activities would

require working memory the answer to

that is basically everything that you

need to do but that you don't want to

remember now what types of things would

those be well let's think about it most

all of us learned at some point in our

life to tie our own shoes presumably you

know how to tie your own shoes if you

don't perhaps you should learn or wear

velcro or slippers I don't know but

assuming you can tie your own shoes

that's something that you know how to do

and you can do it as a procedural

long-term memory you can do that action

you don't have to think about it too

much working memory would come into play

when say you wake up in the morning and

you know that you need to head out for a

jog but you also need to make a cup of

coffee first and you need to remember

where the coffee is where your shoes are

and perhaps you're making a phone call

or you're having a conversation while

you need to tie your shoes and so on and

so forth working memory is basically the

taking in of information that's critical

for you to sequence your actions over a

short period of time and then forget

that sequence for instance I'm willing

to bet that you put your shoes on to go

running before you go running that's

sort of a duh and if you're like me you

drink your water your coffee your yante

before you go running the point here is

that if you wake up in the morning and

you like caffeine before you go for a

run there are certain series of action

steps that you need to carry out to

hydrate make that cup of coffee or tea

drink it put on your shoes head out the

door you need to sequence things

properly but you don't want to to commit

your long-term or even your short-term

memory stores to carrying out that

sequence you simply want to be able to

carry out that sequence and then discard

that information about the sequence and

focus your attention on for instance

what trajectory you're going to run

through the park or around your

neighborhood then you want to discard

that information and you want to lean

into the next portion of your day and so

on and so on in fact working memory is

involved in essentially every activity

both cognitive and motor from the point

wake up in the morning until the time

you go to sleep at night for every

single day of your life and we know this

because there are indeed people who have

diminished working memory or even lack

working memory entirely although the

latter is somewhat rare it has happened

and as you can imagine they have a

complete failure of ability to sequence

activities and their lives are extremely

difficult they need a ton of assistance

from other people even more assistants

than do people who have minimal or no

long-term memory okay so this is really

highlighting just how important working

memory is working memory is basically

the way that you navigate any immediate

environment and as I mentioned earlier

it's very closely tied to attention

because in order to know what to do now

and then what to do subsequently and

then subsequent to that you need to be

able to hold your attention to the

things you need to do so working memory

and attention collaborate literally at a

neural circuit level and at a

neurochemical level in order to allow

you to move through your day in an

Adaptive functional way and people who

have challenges with attention or Focus

or working memory and sometimes it can

be hard to dissociate which one they're

having challenges with really have a

hard time moving through life as

compared to people whose attention and

working memory is more robust now the

good news is today we're going to talk

about working memory some of the neural

circuits involved and some of the

neurochemicals involved that can augment

or improve working memory and we're also

going to talk about what one can do to

directly increase the amount of

neurotransmission of those particular

chemicals within the circuits that

control working memory in other words to

improve your working memory now I can

talk about working memory and the

mechanisms Etc all day long but as is

often the case sometimes it's better to

not just learn about Concepts but

actually to experience them in real time

so what we're going to do now is I'm

actually going to give you a working

memory test this is the sort of working

memory test that you would take if you

were to go into a psychology laboratory

or a neuroscience Laboratory and they

were studying working memory in humans

now there's another advantage to us

doing this in real time right here as

you're listening or as you're listening

and watching and that's because you're

going to get data you're going to get

information about what your Baseline

working memory capacity is and you're

going to want to keep those data in your

short-term memory stores maybe even your

long-term memory stores but certainly

your short-term memory stores because

shortly later in this episode I'm going

to talk about different ways to improve

your working memory depending on where

your Baseline working memory starts

which by the way turns out to be a

pretty good proxy for the levels of a

neuromodulator called dopamine within

the neural circuits that control working

memory so right now let's take a working

memory task we're going to do this

purely through audio form because I

realize some people are watching and

listening to this on YouTube and others

are just listening to this episode so

there are not going to be any visual

cues or slides that I present and that's

perhaps what distinguishes what we're to

do most from what would happen in a

laboratory typically in a laboratory

there would be some visual presentation

of what I'm about to say but here

because of the format that most of you

are consuming this information by we're

going to do this purely by Audio so the

first test of your working memory is

very simple I'm going to read off a

series of letters and your task is to

remember as many of those letters as you

can the first string of letters is J K k

z p

i okay just to make this really easy I'm

going to say it twice although typically

in a working memory task it would just

be said once but I'm going to make this

extra easy j k z p

i okay now you in your own head can try

and recite back those letters if you

like okay second string of letters r r o

m k l

e I'm going to make this extra simple

and do it again not typical for a

working memory task but there are some

working memory tasks where that happens

r o m k l

e okay now a third string of letters

this one's going to be a little bit

longer so queue up that working memory

and

attention w a c q v d

n I'll repeat that again w a c q v d

n how many of the letters I just read

can you remember okay so depending on

how many letters you can remember

perhaps you have a low moderate or high

degree of working

memory keep in mind that some of you are

perhaps doing other things you're

attending to driving or other tasks

within your home or your office and so

perhaps you weren't able to pay full

attention so there'll be some variation

there but nonetheless after reading each

of those strings of letters you were

asked to recall those letters in your

mind and if you wrote them down and

you're rereading them yes that's

cheating but how about this what if I

were to ask you now about the simplest

first string of letters the one that

consisted of only five letters how many

of you can remember any of those five

letters

now okay I can't hear you if you're

shouting them out uh I can't see you if

you're raising your hand but chances are

most of you have forgotten the first

series of letters even though it was

quite short and you could remember it

early on that ability to remember that

string of letters when you first heard

them and indeed I read them twice so I'd

be very surprised if any of you couldn't

remember that string of letters after

hearing them twice but I also read you

some other letters in the interim okay

so that now just a couple minutes later

I'm asking you to remember that first

string of five letters and assuming that

you didn't write it down you're not

cheating chances are you remember

anywhere from two to zero of those

letters in that first word which is a

perfect example of your working memory

nothing got committed to short-term much

less long-term memory rather your

working memory was able to work with

that information hold it in mind for

just as long as you thought you needed

to know that information but then thank

goodness that information was discarded

you didn't know that I was going to ask

you for that first string of letters

again after reading you the longer

string of letters but I did that

deliberately to show you how your

working memory works so in some sense

the working memory task is a bit unusual

in that it's a test of yes memory in the

very very short term but also a test of

your ability to forget to discard

information that's not critical and that

gets us back to the original definition

of working memory which is our ability

to attend to specific small batches of

information remember it for just as long

as we think we need to and then to

discard that information and by the way

if you want to know what those first

five letters were they were j k z p i

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huberman so now is where we talk a

little bit about the neural circuitry

and the neurochemistry of working memory

now it's important that we do this

because in a few minutes you're also

going to learn that people generally

fall into two broad bins of having a

high or low Baseline of a certain

neurochemical in the brain that affords

them either high or low working memory

capacity now in reality it's a

distribution in fact it's what we call a

normal distribution so it really isn't

two bins but during today's discussion

and in fact in a lot of laboratory

studies we can actually bin people into

these two groups the neural circuitry

underlying working memory involves a lot

of different brain locations that is a

lot of different neural networks

collaborating to create this thing we

call working memory however there are a

couple of key hubs that is locations

within the brain that are especially

important for working memory the ones

that I'd like to focus focus on today

involve the prefrontal cortex so this is

neural real estate that resides just

behind the forehead and the neurons in

the brain stem so further back in the

brain that manufacture dopamine and that

send their little wires that we call

axons up to the prefrontal cortex to

release dopamine dopamine is a

neuromodulator many people are familiar

with dopamine and familiar with it in

the context of motivation and drive

sometimes people mistakenly think it's

only involved in pleasure but dopamine

is involved in motivation and drive when

dopamine systems go Ary that is if their

levels get too high that can create

manic States it can create addictive

States when dopamine levels are too low

you can get movement challenges such as

in Parkinson's which is a deficit or a

literal destruction of the neurons that

manufacture dopamine there are a bunch

of different areas of the brain that

those dopamine neurons in the brain stem

project to but for right now we're going

to focus almost entirely on the dopamine

projections from the brain stem to the

prefrontal cortex which is called the

misoc cortical circuitry I'm not going

to get into the origins or the meaning

of the misoc cortical versus other

dopamine projection systems I did that

in a couple of episodes about ADHD and

attention and dopamine in particular and

you can find those at huberman lab.com

just put dopamine and circuits into the

search function and it will take you to

those particular time stamps where I

describe that but since we want to keep

things fairly top Contour at the level

of neural circuit here just know that

there are a bunch of neurons that

manufacture dopamine back in the brain

stem that send their axons those little

wires up to the prefrontal cortex and

that the amount of dopamine

released per unit time so in a certain

amount of time strongly dictates the

extent to which working memory capacity

is going to be high medium or low now I

want to be very clear because I'm going

to come back to this a little bit later

again and

again it is the case that when dopamine

levels are lower that is either there

are fewer neurons that have the

potential to release dopamine in the

frontal cortex or for whatever reason

less is being released in the frontal

cortex that working memory performance

tends to be lower as compared to

conditions where dopamine release or the

availability of dopamine is higher

however it is not the case that more

dopamine is always going to equate to

improved working memory this is so

important that I'm going to say it again

it is not always the case that

increasing the amount of dopamine

Transmission in the frontal cortex leads

to improvements in working memory there

is a specific criteria that allows us to

predict whether or not it will improve

or maintain or actually degrade working

memory performance so before you head to

the end of the podcast to try and figure

out ways to increase dopamine to improve

working memory please keep that fact in

mind don't just commit it to your

working memory commit it to your short

and long-term memory because that's very

important if your goal is to improve

your working memory with that said I do

want to describe just a little little

bit of research showing the relationship

between having a low working memory span

as it's called the ability to only

remember a few letters or numbers or

short batches of information as compared

to a high working memory span meaning

longer strings of letters longer strings

of numbers which of course in the real

world translates to being able to carry

out shorter versus longer action

sequences as described earlier in the

scenario where you're getting up in the

morning and you're making coffee and

you're heading out for run etc etc

people do differ in terms of their

working memory capacity and there's a

classic study done by kols and desposito

and colleagues this was published in

2008 where they had a way to label the

amount of dopamine that is available for

release in the frontal cortex in human

subjects they did this by the injection

of a specific Dy that Dy gets taken up

specifically by the neurons in the brain

that manufacture dopamine then they were

able to image the brains of those people

while those people were Wide Awake using

something called positron emission

tomorrow graphy again the specific tool

isn't necessarily important but since

some of you like to know and what they

found is that for people that had a high

working memory span that is could

remember long strings of numbers or

letters or other information they tended

to be the people that had more dopamine

available for release in the frontal

cortex either because they had more of

the dopamine neurons themselves or

similar number of neurons but those

neurons had more dopamine to release

okay and they also found the converse

individuals that had a low working

memory span and ability had less

dopamine available for release so that

establishes a correlation but it's not

causal a different study which is also a

classic was carried out by brazowy Brown

roswold and Goldman and this is a really

important study because in this study

they were able to introduce small

amounts of dopamine directly into the

cortex and evaluate working memory

capacity now anytime working memory test

is done the same pattern always emerges

this is regardless of any dopamine being

infused into the brain which is people

and animals for that matter are very

good at remembering short spans of

numbers letters or other types of

information so if you tell them one

thing like the letter a and then you ask

them do you remember the letter almost

everybody remembers that but if you give

them a string of 10 letters they

remember fewer of those 10 letters

that's sort of obvious but it's an

important point to emphasize nonetheless

and so there's a kind of a dropping off

curve of performance as one progresses

from fewer to Greater number of items to

be remembered in this study when

dopamine was introduced to the frontal

cortex the number of things that

individuals could remember simply

increased it was a very straightforward

result more dopamine introduced allowed

longer letter number and information

strings to be remembered and of course

forgotten because that's what working

memory involves remembering and then

discarding of information shortly

thereafter now the findings I just

described complement what I said before

which is the naturally occurring

experiment bring people into the lab

measure their working memory span look

at how much dopamine they make higher

dopamine better working memory lower

dopamine lower working

memory the experiment I just described

was one in which dopamine is introduced

showing that dopamine is very likely the

rate limiting or the capacity limiting

it's probably the better way to put it

the capacity limiting neurom modulator

for improving working memory that's a

fancy nerd speaker way of saying more

dopamine allows for better working

memory but a critical feature of this

experiment is that they did a number of

experiments where they didn't introduce

dopamine but instead they introduced

other neuromodulators to the prefrontal

cortex such as

norepinephrine or serotonin and the

interesting finding is that the addition

of norepinephrine or serotonin which of

course are other neuromodulators that

can change the firing patterns of

neurons in the prefrontal cortex but

elsewhere as well it's just that in this

case they were added to the prefrontal

cortex had no effect on working memory

it neither improved nor degraded working

memory when those neuromodulators were

introduced in other words dopamine and

perhaps only dopamine seems to be the

dominant neuromodulator for regulating

the degree that is whether or not you

have small medium or large amounts of

working memory capacity in the

prefrontal cortex and of course there

have been a bunch of other experiments

that are worth mentioning briefly in

this context such as taking people that

have a high working memory capacity and

indeed have their brains imaged and one

sees that they have high levels of

Baseline dopamine especially the

dopamine projecting to the prefrontal

cortex and then they're given a drug

that depletes dopamine within the

prefrontal cortex and their performance

drops and so what's so nice about the

literature around working memory is that

while I'm not covering all of that

literature exhaustively it all tends to

Jive it all points in a direction

whereby the levels of of dopamine being

released in the prefrontal cortex during

working memory tasks correlates very

strongly with capacity to perform

working memory tasks lower dopamine

lower working memory span as it's called

higher dopamine higher working memory

span okay so next we're going to do

another working memory task different

than the one we did earlier and we're

going to do that with a specific purpose

in mind which is for you to be able to

determine what your working memory

capacity is and by extension your

Baseline levels of dopamine or at least

the levels of dopamine that are likely

being released into your prefrontal

cortex while you do these working memory

tasks in other words we're going to try

and figure out whether or not you are of

the low medium or high working memory

capacity and of course we're doing that

in part to try and establish whether or

not you likely have low medium or high

amounts of dopamine available for

release in the prefrontal cortex of

course we're not putting you into a

positron Omission tomography scanning

device we aren't able to do that for

obvious reasons but keep in mind that

what we about to do is very similar and

in some cases identical to laboratory

studies where the researchers were

trying to determine what people's levels

of dopamine within these particular

neural networks we've been discussing

the misoc cortical pathway are likely to

be in other words performance on The

Working memory task that we are about to

do is a decent indication of what the

dopamine levels that are available for

release in your prefrontal cortex

perhaps might be now I say perhaps might

be because I don't want to cause any

unnecessary alarm if for instance you

fall into the low working memory span

group in fact if you fall into the low

working memory span group there are

actually some terrific tools that you

can use to improve dopamine Transmission

in those Pathways and improve your

working memory I also don't want people

to get the impression that somehow

performance on this working memory task

is reflective of some larger dopamine

issue in the brain and certainly it is

not I repeat it is not diagnostic of

Parkinson's or any kind of neurod deener

generative condition although I will say

that deficits in working memory are

common in patients with Parkinson for

obvious reasons those patients have

deficits in dopamine neurons not only

production but the number of dopamine

neurons it's one of the Hallmark

features of Parkinson's but also in

things like traumatic brain injury Etc

but the working memory task that you're

about to take when given to a general

population or a group of undergraduates

or you know so-called normals or typical

control subjects which all of you are

okay so unless you're dealing with with

a traumatic brain injury or you know you

have Parkinson's we know that the data

that you're going to get back right now

is very similar to the data that people

get back when they do these sorts of

studies in a laboratory that is it's

typical for some people to have a short

working memory span some people to have

a medium working memory span and some

people that have a high working memory

span and today we're actually just going

to divide into two bins short working

memory span and high working memory span

and we can have some degree of

confidence that correlates with the

amount of dopamine available for release

in the front Al cortex but and this is a

very important Point as we progress

along this discussion of working memory

the neural circuits dopamine Etc I want

to make clear something that I said

earlier which is that it is not the case

that increasing the amount of dopamine

that's available always increases

working memory spin in fact there's a

common circumstance whereby people with

a relatively High degree of working

memory capacity increase their dopamine

levels even further using pharmacology

or other methods that we'll discuss and

their per performance actually can

degrade okay so if any of that is

confusing now we'll make it all very

simple going forward so that if you

decide to implement any of the protocols

discussed in this episode that you are

aware of what you can expect and whether

or not you in the category of people

that should or perhap should not

incorporate those protocols okay let's

test your working memory again this time

the working memory task is going to be a

little bit different than the one you

did previously this working memory task

involves me reading six different

sentences to you and your job is to pay

attention to these six sentences because

you're going to be asked some

information about these sentences in a

few moments the first sentence is real

estate costs are going

up the second sentence is the Atlantic

Ocean is warm in

summer the third sentence is there's a

lot of interest now in electric

cars the fourth sentence is some

reptiles eat only one once a

year the fifth sentence is kids nowadays

look at screens more than 60% of their

Waking

Life and the sixth and final sentence is

football can mean different sports

depending on the

country okay so I read you six sentences

they were moderately long I confess your

job for the working memory task is now

to recall as many of the final words of

each of those sentences as you can I'll

give you a few moments to do that now

before I tell you what the final word of

each of those sentences actually is I

want to remind everybody that working

memory capacity follows a normal

distribution so some of you will be able

to remember the final word of perhaps

five or even six of those sentences

although I must say that is exceedingly

rare some of you are going to be able to

remember three to four of the final

words of those sentences and that's more

typical that actually represents the

average or the mean as we call it and

then fewer people although still many of

you will only be able to remember one or

two of the final words of those

sentences okay so now I'm assuming that

most of you have tried to call to memory

the final word of as many of those six

sentences as you can and maybe you've

written them down or you've typed them

into your phone or you have some record

of what you recall those six final words

of those sentences are now I'm going to

tell you the actual final word of each

of those sentences the final word of the

first sentence was up because as you may

recall the sentence was real estate

costs are going up the final word of the

second sentence was summer because the

sentence was the Atlantic Ocean is warm

in summer the final word of the third

sentence was Cars because the sentence

was there is a lot of interest in

electric cars the final word of the

fourth sentence was year because the

sentence was some reptiles eat only once

a year the final word of the fifth

sentence was life because the sentence

was kids nowadays look at screens more

than 60% of their Waking Life and the

final word of the sixth sentence was

country because the sentence was

football can mean different sports

depending on the country okay so be

honest with yourself and tell yourself

and you don't have to tell anyone else

if you don't want to how many of the

final words of those six sentences you

could remember correctly it's important

that you remember them correctly again

the number of words that you can recall

that is your working memory span is

going to vary from person to person but

we can take the normal distribution of

those scores and sort of draw a line

down the middle and say that if you

could remember three to six of the final

words of those sentences correctly

you're going to fall into the high

working memory span group whereas if you

could only remember one or two or maybe

zero of the final words of those six

sent

then you're going to be in the low

working memory span group again I don't

want to alarm anybody this doesn't mean

that you have any Global memory deficits

or dopamine deficits but it is important

especially if you plan to apply any of

the protocols to improve working memory

that you Faithfully that is you

accurately report your working memory

performance at least to yourself now as

you recall whether or not you have low

or high and here we are just binning

into low and high there's no medium

we've divided right at that line we're

saying if you can remember 3 to six

we're calling that high working memory

span at least for this discussion and if

you can remember fewer than three even

down to zero of the final words of those

sentences that's low working memory span

we're dividing it in two we divided you

into two groups and we do know when this

has been done in large numbers of human

subjects and some in some cases all of

those subjects have their brains imaged

for the amount of dopamine available for

release in their prefrontal cortex that

short workking memory span correlates

with lower amounts of dopamine whereas

higher working memory span or longer

working memory span whatever you want to

call it correlates with more dopamine

available for release in the prefrontal

cortex now this is where things get

really interesting and frankly really

exciting for everybody especially the

folks in the low working memory span

group work from martus bazito and

colleagues at UC Berkeley as well as

other Laboratories have explored the

consequences of increasing dopamine

levels in the brain of typical

populations of individuals so these are

not people with Parkinson's or TBI but

undergraduate students which we do

realize is not completely representative

of the quote unquote normal population

outside the university but also people

from the community so people who are not

University students and so on and the

ways that they've increased dopamine in

those individuals had tended to rely on

pharmacology so these are prescription

drugs that most often have been

developed for theat treat M of

Parkinson's in order to increase

dopamine levels but for some other

purposes as well drugs like

bromocryptine which we know are

so-called dopamine agonis and agonis is

a drug that has the consequence of

increasing the amount of a given

neurochemical in this case dopamine

whereas an antagonist is a drug that

either blocks or prevents or somehow

lowers the total available amount of a

certain chemical such as dopamine or

serotonin Etc so bromocryptine is a drug

that increases dopamine so when human

subjects came into a laboratory didn't

take any drug no bromocryptine yet and

of course they were being evaluated for

whether or not they were taking any meds

for ADHD their caffeine consumption Etc

there were certain rule-in and Rule outs

for that study but certainly people that

were taking any kind of prescription

medication for ADHD were not included in

the study or were eliminated from the

study because those drugs can indeed

increase dopamine as well as some other

neuromodulators such as norepinephrine

and epinephrine I covered all that in

two ADHD episodes that I did which again

you can find at hubman lab.com just go

to the search function put in ADHD in

any event in these studies they took

people that had not taken any drugs to

increase

dopamine had their working memory

measured very similarly to the way that

you measured your working memory a few

minutes ago with the six sentence

business that we did and then they took

bromocryptine and they either took a low

a moderate or high dose of bromocryptine

and 90 minutes later they took a working

memory task and what was observed was

very interesting you can probably

predict what it is based on everything

I've set up until now individuals that

initially had low Baseline levels of

dopamine and therefore shorter working

memory span so they only remembered zero

to about three of the final words of

that six sentence

series their performance significantly

improved they were able to remember four

and in some cases up to six the final

words of those sentences now that is in

complete agreement with everything we

set up until now simply says that

dopamine is important for working memory

if you start off with lower dopamine

stores or dopamine availability for

releasing the prefrontal cortex lower

working memory performance increase

dopamine through ingestion of

bromocryptine which is this dopamine

Agonist all of the circuit changes that

we want and would expect to improve

working memory occur and indeed working

memory improves okay very

straightforward

that's interesting but the even more

interesting part of the study is that

individuals that already had high

working memory span when they took

bromocryptine at a low or a moderate

dose their working memory did not

increase further now if somebody was

already getting six of the final words

of those six sentences well then of

course they couldn't improve their

performance anymore but many of the

people in the high working memory span

group of course only remembered four in

some cases three typically it'll be four

five or six of the final words of those

sentences when they took bromocryptine

at low or moderate doses their working

memory did not improve significantly

there was either no change or a very

modest change and here's where things

get really interesting when individuals

who already had a high working memory

span took the highest dose of

bromocryptine and by the way studies

verified that the amount of dopamine

available indeed increased so that was

important to do and they did that well

their working memory performance

actually

decreased such that now they had a short

or a low working memory span so what

this tells us is that the relationship

between dopamine and working memory

follows an inverted u-shaped function so

imagine a u and then just flip it over

meaning if you have low dopamine

availability in the prefrontal cortex

working memory span is short as you

increase that amount working memory

becomes greater but if you increase the

amount of dopamine in the prefrontal

cortex too much working memory span

actually drops significantly below the

Baseline that you started with now this

is important for a number of reasons not

the least of which is the known

relationship between working memory and

attention now this is very important to

understand in the context of ADHD but

also for people who don't have ADHD and

are struggling to maintain focus and

attention and carry out working memory

tasks throughout their normal everyday

life not in the laboratory but just

moving through life because these days

we hear a lot a lot a lot about people

struggling with focus and attention

perhaps we don't know perhaps in part

due to overuse of smartphone social

media Etc although there's not yet a

direct causal relationship that's been

established the data that are emerging

suggests that indeed overuse of those

things can cause problems but regardless

of the source there does seem to be more

ADHD both in kids and in adults and

subclinical challenges in focus and

attention and here's where things get

really interesting as it relates to the

neural circuitry work from desposito and

colleagues and other Laboratories as

well have shown using the similar

Paradigm that I described before giving

people drugs to increase their Baseline

levels of dopamine above their initial

starting point of short or long-term

memory span capacity and then had people

can perform different types of working

memory tasks that tap into two different

aspects of attention in working memory

up until now we've been talking about

working memory it's kind of just one

thing but working memory actually

involves two things or at least two

things the first is that in order to

carry out a working memory task into to

attend to something to really focus we

need the ability to rule out distractors

we need to be able to not pay attention

to things that would otherwise distract

Us in addition to that we need to be

able to switch from one context to the

next right making the cup of coffee to

putting on one shoes and heading out the

door and in some cases layering

different contexts together talking on

the phone while tying one shoes and so

on and so forth what this work shows us

is that the ability to task switch and

context switch that is to shift around

what it is that we're paying attention

to and interleave different things that

we're paying attention to something

that's so critical for moving through

our daily lives is largely dependent on

the dopamine projections to a structure

in the brain called the basil ganglia

which is a structure I've talked about

before on this podcast but if you didn't

hear about it we can just broadly Define

this structure as being involved in

movement generation and stopping

movement generation in fact it's often

discussed as the neural circuitry that

generates go as in do commands and noo

don't do commands so the basil ganglia

are involved in task switching and they

involved in task switching in part by

sending certain commands to go do

certain things and no go to not do other

things okay task switching stop doing

this start doing that start doing that

stop doing this and sometimes to varying

extents right I mean we could take any

real world scenario of tying one shoes

while talking on the phone and we could

micro analyze it in the context of this

but I think uh if you think about it

just a little bit you understand that in

order to perform daily task we need to

be able to task switch and that's not

always a start one task end start a new

task end often times we're interleaving

different tasks to varying degrees now

the other aspect of working memory and

attention is to eliminate distractions

to not pay attention to the irrelevant

stuff in one's environment or even the

irrelevant stuff on your own body like

you can't get distracted by you know a

button that you know might be only

partially buttoned or maybe some little

something on your sleeve if you're

trying to do something else at that

moment okay and people with ADHD and

people who have subclin clinical

challenges and focus really have a hard

time with this right you know the the

sort of stereotype is you know the oh

look a squirrel that whole thing but

really this typically exists as a more

subtle and challenging phenomenon for

people where they either can't remember

what they were doing or they're simply

drawn down different trajectories

different thought trajectories or action

trajectories and then they have a hard

time making it back to the original

thing that they were trying to focus on

and we know based on these studies of

dopamine and neuroimaging that

eliminating distractors is largely the

consequence of dopamine neurons

projecting to the prefrontal cortex okay

now why am I telling you all this neural

circuitry stuff well yes there are a

bunch of studies showing that if you

selectively activate the neurons that

send dopamine into the basil ganglia you

improve Tas switching ability without an

improved ability to rule out distractors

or if you selectively increase the

amount of dopamine from neurons

projecting the prefrontal cortex that

you're able to selectively improve the

elimination of dist tractors without

improving task switching ability for

practical purposes in this discussion we

want to pay careful attention to whether

or not the data tell us that those

particular protocols those particular

approaches are globally increasing

dopamine that is increasing the activity

of dopamine neurons projecting to the

basil ganglia and the prefrontal cortex

or selectively to the basil ganglia or

selectively to the prefrontal cortex and

what I can tell you now is that

fortunately there are several prot some

of which are behavioral some of which

involve specific over-the-counter

supplements and some of which involve

prescription pharmacology that can tap

into each of these systems independently

as well as globally increased dopamine

to improve focus and working memory at

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huberman okay so let's talk about

protocols to improve working memory

specifically by way of changing levels

of dopamine in the brain now I've

discussed dopamine many times before in

this podcast in fact we have entire

episodes devoted to optimizing and

regulating dopamine and of course

dopamine comes up within the context of

the ADHD episodes and episodes as well

and again if you have specific questions

about dopamine or any other topic for

that matter if you go to huberman

lab.com that website has been engineered

so that you can put one word such as

dopamine but also multiple keywords so

perhaps dopamine exercise or dopamine

cold plunge Etc into the search function

and it will take you to the specific

timestamps of multiple episodes where

those topics were discussed as well as

newsletters where some of that

information has been condensed into

short PDF form Etc so we certainly are

going going to cover some material about

improving dopamine for sake of improving

working memory now but if you're

generally interested in the science and

pharmacology of dopamine and protocols

to modulate dopamine levels all of that

can be found at huberman lab.com okay so

let's say you have a short working

memory span or a moderate working memory

span and you want to experiment with

increasing levels of dopamine for sake

of improving working memory now there

are a lot of different ways that one

could imagine doing that let's start

with the behavioral tools known to

increase dopamine stores that is shown

in peer-reviewed studies to increase

dopamine stores within certain circuits

of the brain that are relevant for

working memory performance and the

protocol that immediately leaps to mind

is the use of certain non-sleep deep

rest protocols now non-sleep deep rest

or nsdr is actually a term that I coined

because there is a practice that's been

established for many hundreds of years

called Yoga Nidra which actually means

yoga sleep whereby individuals

potentially you if you decide to do them

lie down listen to to a script that is

listen to an audio script which

generally instructs you to do long

exhale breathing to deliberately relax

your musculature of your face and of

your body and Yoga Nidra typically also

involves doing certain intentions and

the instruction always given at the

beginning of Yoga Nidra is that you

should try to not fall asleep now some

people sometimes fall asleep some people

don't fall asleep but the idea and there

are data to support that Yoga Nidra puts

people into kind of a shallow pattern of

sleep um certainly not deep sleep s and

not rapid eye movement sleep but it's a

very interesting and unusual brain state

for which we're starting to understand

more and actually I have some plans in

the not too distant future to

collaborate with Matthew Walker the

author of the book why we sleep and some

other colleagues to try and figure out

what exact patterns of neural activity

are taking place in the brain and rest

of nervous system during Yoga Nidra and

this similar protocol which I call

nonsleep deep rest the difference

between Yoga Nidra and non-sleep deep

rest is that nonsleep deep rest doesn't

include any of the intentions and

removes a lot of the kind of opaque or

sometimes called mystical language from

the protocol now a great thing is that

yoga needra scripts or protocols as well

as nsdr scripts or Protocols are

available totally zero cost you can find

them certainly on apps like waking up

but also on YouTube for instance if you

put nsdr and my last name there's a

10-minute nsdr script there there are a

lot of yoga NRA scripts if you prefer a

female voice there are a lot of

different excellent female voices out

there one in particular particular that

I like very much is Kelly boy first name

Kelly last name b y s she has both yoga

NRA and ndr scripts of various durations

of anywhere from 8 minutes all the way

out to I believe 45 minutes why am I

telling you all this well there have

been several studies but in particular

one and I do realize we're talking about

only one study but the results are

really intriguing as it relates to what

we're talking about today in this study

they had individuals do effectively an

nsdr protocol they call it yoganidra and

the protocol they used was essentially a

yoga Nedra script they had people lie

down and listen to a yoga Nedra script

and to perform yoga Nedra and they

evaluated the amount of dopamine

available within the brain both prior to

and after performing this yoga NRA

script and what they discovered was that

after performing a Yoga Nidra protocol

the Baseline levels of dopamine that is

the amount of dopamine available in the

basil ganglia and a few other structures

of the human brain of course these are

humans was increased by as much as

60% as compared to individuals that did

a different protocol not yoganidra not

nsdr now did that study evaluate lots of

different durations of yoga Nedra AKA

nstr no they looked at fairly long hour

plus Yoga Nidra sessions however there's

some other data that have explored Yoga

Nidra AKA

nstr in the context of cognitive

performance and a few other

circumstances all of which point to the

fact that cognitive performance and in

particular cognitive performance tasks

that have a working memory element to

them so they weren't the exact working

memory task that you did earlier but

they have a working memory element to

them that is subjects had to keep

certain small batches of information in

mind and then discard that information

in order to be able to perform the task

well all of those show significant

improvements in task performance so

while something like nsdr or Yoga Nidra

might sound kind of mystical or kind of

you know wishy-washy or I guess as the

kids say weak sauce uh to some of you it

is anything but weak sauce it is really

powerful stuff and it's powerful stuff

as it relates to the very neurochemicals

and neuros circuits that are involved in

working memory so if I were to take a

step back and just say okay what are

some zeroc cost very low if any risk

protocols that one could perform in

order to improve dopamine levels without

having to ingest anything take anything

and really do much of anything at all

except lie there do this progressive

muscle relaxation there are a few other

things involved in nsdr as well which

you'll learn if you decide to try them

and improve or increase the levels of

dopamine availability in the brain

significantly well then nsdr and Yoga

Nidra really are the first line tools if

one wants to do that I think it's

reasonable to say that and as I

mentioned before there's no reason to

think that there's any risk of doing

nstr yoga NRA you know provide that

you're lying down in a safe place as

opposed to like in the middle of the

road or something but assuming you do it

in a safe location I would encourage you

to try it for really for 20 to 30

minutes when you first explore it

perhaps you do longer although I

personally have a hard time doing long

yoga needer scripts regularly a full

hour is a big commitment I don't

generally have that much time I often

will do a 10-minute nsdr have there been

brain Imaging experiments done for each

and all of these yoga needra scripts to

determine the amount or if there's any

dopamine increase within the brain no

but I think that we can safely

extrapolate from that wonderful study

out of Scandinavia that showed that when

human subjects do this yoga NRA protocol

that there's a significant increase in

Baseline dopamine levels within key

neural structures that relate to working

memory now many of you have perhaps

heard that getting in a cold plunge or

taking a cold shower or provided you can

do it safely getting into a cold ocean

or a cold lake can significantly maybe

even double or even triple your

circulating dopamine levels and indeed

that is true it has been shown that when

people get into cold water typically up

to their neck and that cold water by the

way can range in temperature anywhere

from low 40s to low 60s depending on how

long you stay in that there is a

significant increase in the so-called

circulating catac colomines what are the

catac colomines the catamin are dopamine

norepinephrine and epinephrine now the

evidence for the catac colomine increase

in response to cold water mainly stems

from two studies and in particular one

and in that particular study they had

people get into I wouldn't say super

cold water it was in the low 60° and by

the way I'm speaking in Fahrenheit here

and they had those human subjects

submerged in water up to their neck I

think they actually had them sitting in

lawn chairs on the bottom of a pool uh

but again their heads were above water

so they could breathe and they stayed in

for quite a long while you know 45

minutes or longer and it was observed

that there was a big big statistically

significant increase in epinephrine

norepinephrine in dopamine that lasted

several hours or more this is one of the

reasons why if you've ever done

deliberate cold exposure as it's called

it often is uncomfortable when you get

in but then when you get out you feel

different you feel really good in most

cases provided if you're me you take a

warm shower afterwards yes I like to do

that I realize if you want to increase

your metabolism perhaps it's better to

not warm up afterwards I like a nice

warm shower or to get in the sauna

afterwards that's just me but

nonetheless deliberate cold exposure

clearly induces a state shift of mind

and body that most people provided they

do it correctly and they don't go into

water that's far too cold for them for

too long they report as pleasant and I

think it's reasonable to assume that

some of that is the consequence of these

increases in catac colomines which is

why many people opt for a cold shower

which if you're me cold shower followed

by a warmer or hot shower or a cold

Plunge in the morning or maybe even just

once or twice a week many people like

them typically people like getting out

of them and the feeling that they have

after they do them although some of you

sickos really like the feeling of

getting in and being it but not me the

point here is that if we were to take a

look at the landscape of zeroc cost

behavioral Tools in fact behavioral

tools that could potentially save you

money meaning reduce your heating bill

that are known to increase the very

neurochemicals AKA dopamine that are

involved and improving working memory I

think it's reasonable to assume that a

cold shower about 30 to 60 minutes prior

to doing any kind of working memory task

or any kind of activity that would

require increased Focus could be okay we

don't know this specific Studies have

not been done but could be in theory it

makes sense mechanistically it's

logically

sound could be done after deliberate

cold exposure and indeed many people

report not just feeling a bit of you

know mild Euphoria or feeling good after

deliberate cold exposure but also an

increased capacity to focus in fact so

much so that a lot of people who do

deliberate cold exposure say that they

don't require as much caffeine in order

to maintain their alertness and energy

which shouldn't be surprising to us at

all right I mean it's increasing cacola

means we know this so that's another

protocol that you could explore as well

is there an important difference or not

between deliberate cold exposure done by

cold shower or deliberate cold exposure

in a cold plunge or the ocean frankly

there haven't been a lot of studies

comparing those but I think it stands to

reason that if you have access to a cold

plunge or a cold body of water that you

can safely get into up to your neck for

30 seconds to a minute if it's 50° or

less right if you get in colder water we

know for instance if you get into say 45

Dee water and you only get in for 30

seconds you're going to get a big

increase in the catacol amines perhaps

as big as the catacol amine increase

that you would get from being in 60°

water for 45 minutes most people don't

have 45 minutes to sit around in water

up to their neck so most people opt for

30 seconds to as much as 3 minutes

deliberate cold exposure in a shower or

cold plunge or other body of water again

only do this if you can do it safely

never ever please for the love of God

please never ever do any kind of

hyperventilation breathing or breath

holding while doing deliberate cold

exposure because you can pass out you

can die don't combine breath work and

deliberate cold exposure just don't

separate those two things completely

okay but deliberate coal exposure we

know is a very reliable way to increase

the catacol amines which includes

dopamine so if you want to explore

deliberate cold exposure protocols get

into the Nuance of temperature and

duration Etc you can find that

completely zero cost go to hubman

lab.com go to the menu tab scroll down

to newsletter and go to the cold

exposure news letter where it details

all of that in short PDF form now some

of you are probably asking hey what if I

was in the high or long working memory

span group I ought to have high Baseline

levels of dopamine should I not do Yoga

Nidra or nsdr should I not do deliberate

cold exposure well there you're just

going to have to experiment again

there's essentially zero risk to doing

yoganidra nsdr as I mentioned before

deliberate cold exposure there's always

some risk getting into water cold water

people always want to know how cold well

the newsletter gets to this but I'll

just tell you right now as well the

ideal temperature is the temperature

that you can safely get into and stay in

for a duration of 30 seconds to 3

minutes before getting out some people

op to go longer but I think 30 seconds

to 3 minutes is a good duration to work

with for most people especially if

you're going to do it frequently so the

temperature should be safe for you to

stay in for that duration but

uncomfortable enough that there's some

impulse to want to get out that you have

to of work to stay in there that you

have to kind of overcome that adrenaline

release and the impulse to get out okay

so for some people that's going to be

45° for some people be 40° depends on

how cold adapted you are depends on how

rested you are there is no specific

temperature you have to really gauge for

yourself and so airor on the side of

caution and you can experiment provided

you experiment within the margins of

safety so if you found during the

working memory task that you took today

that you have a very good working memory

I don't think there's any reason to

avoid yoganidra nsdr and deliberate cold

exposure in fact there may be reasons to

increase your dopamine and other catacol

amines by way of nsdr Yoga Nidra

deliberate cold exposure perhaps for

working memory performance maybe it

could increase

further perhaps it would decrease

performance in which case there you got

your answer you don't have to do those

protocols again and you certainly

wouldn't want to do them before anything

that involves a lot of working memory

and attention but of course those

protocols have other benefits as well so

there's no reason to avoid them entirely

just perhaps avoid them within the

context of trying to improve working

memory however if you're somebody that

has challenges with working memory

challenges with attention challenges

with Focus well then I think that the

protocols I've been talking about up

until now would be an excellent first

foray into the sorts of things that you

could do to increase dopamine and of

course those other catacol amines as a

way to see whether or not it augments

your focus and attention and working

memory capacity now some of you are

probably shouting shouting shouting what

about exercise does an exercise increase

dopamine it does yes there are other

things that increase dopamine it's not

just exercise there are activities that

increase dopamine some people are saying

wait doesn't playing video games

increase dopamine sex increases dopamine

chocolate increases dopamine yes yes

indeed those things can increase

dopamine what's interesting and

important about the protocols I've been

talking about however nsdr yoga Nedra

deliberate cold exposure is not just

that they increase dopamine but the

duration over which they increase

dopamine okay this is very important if

you want to understand more about the

relationship between dopamine spikes as

they're called and dopamine Baseline and

why I'm emphasizing these tools that

cause large longlasting increases in

Baseline dopamine check out the episodes

I did on optimizing dopamine we've got a

link to them in the show note captions

now before I talk about other ways to

increase dopamine for sake of improving

working memory things like

over-the-counter supplements like El

tyrosine makuna pururin things like that

I do briefly want to mention and I

promise briefly I know sometimes I say

briefly and then I spend 20 minutes

telling you about something but very

briefly I just want to spend two minutes

telling you about protocols that we do

not yet know whether or not they

increase dopamine levels but we do know

that they improve working memory because

after all this episode is about working

memory not just about dopamine in

working memory it has been shown that

the use of binaural beats okay binaural

beats being the presentation or the

listening to sounds of different

frequencies in the two ears typically by

headphones I think that's been shown to

work best and there's a subtraction

between the two frequencies such that

the brain tends to entrain or start to

follow a particular frequency within not

the entire brain but certain neural

circuits so if you've heard of say 15

Hertz binaural beats or 40 Herz binural

beats that doesn't mean that you listen

to a 15 Hertz sound or a 40 HZ sound you

listen to two different frequencies of

sound right Hertz is just a measurement

of sound frequency in each of the two

ears and then the difference between

them is 40 Herz or 15 Hertz and there

are several studies that show not

enormous okay I want to be clear small

to moderate improvements in working

memory performance but in some cases

significant Improvement and I'll provide

a link to these two papers in the show

note captions but I'll just briefly

describe them by way of their title and

their major conclusions the first is a

study entitled the effects of binaural

and monoral beat stimulation on

cognitive functioning in subjects with

different levels of emotionality a

really interesting study published in

2019 it was a relatively small number of

subjects only 24 participants 16 males

eight males between 19 and 31 years old

listen to these 40 Herz binaural beats

and by the way it's very easy easy to

find apps and other sources of 40 HZ

binaural beats at zero cost or nominal

cost out there um you would simply look

for 40 HZ binormal beats and looked at

performance on working memory tasks as

well as some other cognitive tasks and

found in some cases a small to moderate

but significant Improvement in cognitive

performance on working memory tasks the

aspect of the study looking at

emotionality did not find a significant

effect so it doesn't seem that

emotionality uh impacts things there but

nonetheless that study plus the other

one entitled the effect of binaural

beats on visual spatial working memory

and cortical connectivity this was a

study published in

2016 found generally something similar

in this case they were using 15 Herz

binaural beats and here I'm I'm

paraphrasing produced network activity

characteristic of high information

transfer with consistent connection

strengths what they're really talking

about is changes in neural activity

patterns within the brain that led to or

at least were correlated with with

improvements on visual spatial working

memory visual spatial working memory

tasks are different than the working

memory tasks that you performed earlier

visual spatial working memory tasks

involve the cognitive generation that is

within your head of the so-called Visos

spatial sketch pad so it's this idea

that you see something and then you got

of sketch it out in your mind you have

to know the relationships between things

in space pay attention to what they are

keep those in mind again because it's

working memory just as long as it's

necessary to perform a task that's what

viso spatial working memory is as you

can imagine it translates to an enormous

number of everyday activities required

for focus and attention and learning and

performance and indeed 15 Herz binaural

beats was able to produce a small but

significant Improvement in that sort of

working memory task so I want to

emphasize again we don't know the

relationship between binaural beats and

dopamine at least not from these studies

but I felt I'd be remiss if I didn't

mention these two studies that show that

40 Herz binaural beats 15 Herz binaural

beats can indeed improve working memory

performance and in these sorts of

scenarios individuals are listening to

the binaural beats while they are doing

the working memory task and in some

cases before they are doing the working

memory task either seems to work it

depends on the study there a bunch of

other studies but I thought I'd mention

binaural beats because I know a number

of people are interested in them again

non-pharmacologic zero cost because you

can find tools for bormal Beat

Generation zero cost out there

approaches to improving working memory

okay what about over-the-counter

compounds that are known to increase

circulating dopamine that can

potentially improve working memory and

that indeed have been shown in

peer-reviewed studies to improve working

memory by way of increasing circulating

presumably brain levels of dopamine well

I can think of two specific categories

of supplements that is over-the-counter

compounds that at least at this point in

time are legal in the United States that

can increase dopamine levels those two

are El tyrosine which is an amino acid

precursor to dopamine and Muna purines

which is a believe it or not it's the uh

a velvety Bean or the outer component of

this velvety Bean that contains or is

equivalent to

99% lopa L Doopa is a key component in

the biochemical Cascade leading to the

production of dopamine in fact lopa is

often prescribed for Parkinson patients

as a means to increase their dopamine

levels there are at least three studies

that I am aware of of the use of Muna

purines to increase dopamine for the

treatment of Parkinson's in other words

Muna purines increases dopamine levels

and yes it has been shown to improve

some of those symptoms of Parkinson's

patients we're not talking about

treatment of Parkinson's today I want to

caution people against any sort of use

of supplements to treat Parkinson's or

other conditions without consulting your

doctor all right that's very very

critical to point out if we're talking

about ways to increase dopamine for sake

of improving working memory by way of

supplementation I think we should start

with El tyos because El tyrosine unlike

Muna Pines is a bit further up actually

it's way further up the biochemical

Cascade leading to dopamine production

however it has been shown in several

studies that El tyrosine supplementation

can indeed increase dopamine and

moreover and here I'm quoting the title

of a study published in 1999 which I

realized is a few years back but of

course there's some excellent studies

from a few years back or more tyrosine

improves working memory in a

multitasking environment now this

particular study from Thomas at all has

some interesting aspects and some

aspects that made me go a little bit

wide-eyed but not necessarily wide-eyed

because the results are so dramatic in

fact when one looks at all of the data

in this paper what you find is that

supplementing with El tyrosine as they

did in this study did indeed lead to

improvements in working memory under

multitask conditions as the title

suggests those improvements were

significant but they weren't enormous

okay they were statistically significant

but they were not enormous increases now

what was enormous and the reason I got

wide-eyed and still get wide-eyed is

that the dosages of of tyrosine used in

the study are really big they had

subjects take 150 milligrams per

kilogram of el crystalline tyrosine I

had them take it in applesauce for

whatever reason or Placebo and they did

a number of different control conditions

to make sure that whatever effects of el

tyrosine they observed were in fact due

to El tyrosine supplementation why am I

going wide-eyed When I See This 150

milligrams per Kil

of tyrosine well I weigh 220 lb that's

about 100 kg so if I weigh 100 kilg and

it's 150 milligram for every kilogram

that means that if I were a subject in

the study that they would give me 15,000

milligram that is 15 gram of el tyrosine

prior to doing these cognitive tasks now

15 grams of tyrosine to me seems like a

very very high dose and I frankly can't

in good conscience recommend that why

well maybe I'm just hypers sensitive to

El tyroine but I've taken 1,000 or500

milligrams of el tyrosine and I've

definitely experienced an increase in

alertness from taking 1.5 gram not 15

1.5 grams of el tyrosine and in fact at

a subjective level I can feel a

meaningful increase in alertness and

focus from 500 milligrams of el tyrosine

so I can't in good conscience suest that

people replicate the exact do protocols

within the study nonetheless the study

as the title suggests shows that

supplementing with El tyrosine can

indeed increase working memory capacity

especially in a multitasking environment

which in many ways carries over to the

sorts of requirements for working memory

and attention capacity to get through

life in a very focused for lack of a

better word way in a very regimented do

this do that task switch multiple things

inter Lea that's what moving through

one's day or at least work day or

anything that requires cognition and

focus entails so first of all I'll just

say what I always say when discussing

any kind of compound or prescription

drug never add or remove any supplement

from your supplement regimen if you have

one without consulting with your health

provider first to make sure that you are

safe to take that particular supplement

now many Physicians MDS are not familiar

with most supplements so you'll probably

need to bring some literature um to the

phone call or to the visit but of course

there are many Healthcare Providers

including some MDS that are open to

supplementation especially these days um

as supplements have become uh I would

say generally more accepted I mean there

are certain ones like vitamin D3 that

and fish oils and things like that that

are more common than El tyrosine but

there are many Physicians who are open

to discussions about supplements such as

El tyrosine if you know that you can

supplement with El tyrosine safely and

you opt to do so what dosages would you

potentially take well here we have to

look at the dosages used in these

studies I think it's only fair it's only

safe that we acknowledge that these dose

just are really really high and I think

the logical the safe thing to do would

be to start with the minimal effective

dose so if you weigh 50

kilograms rather than start right off

with you know the equivalent dosage to

this study maybe you start with 250

milligrams of el tyrosine if you weigh a

bit more like me or 100 kgrs or 75 kilg

maybe you take 500 milligrams of el

tyrosine and see whether or not you

experience a significant effect on

working memory attention and performance

so the idea here is to establish the

minimal effective dose I should also

point out that some people not all but

some people experience a bit of a crash

after El tyrosine supplementation such

that they feel more alert more focused

better ability to perform working memory

tasks move about their day but then

three or four hours later experience

kind of a drop so you need to be mindful

of that in fact you need to be mindful

of any kind of pharmacology where you're

increasing dopamine this is one of the

reasons why I like the behavioral

protocols that we talked about earlier

because they're known to create big but

long lasting and slowly tapering off

increases in dopamine and other catacol

amines now for those who are curious

about and perhaps even want to try Muna

purines please absolutely talk to your

doctor first Muna perin is essentially

the equivalent of lopa lopa is a

prescription drug as I mentioned before

and Muna perin potently increases

dopamine what dosages of Muna Pines can

increase dopamine well typically in

studies of Parkinson's patients but also

studies exploring typical people who

don't have Parkinson's in tasks or in

sports performance have explored

anywhere from 1 to 5 gr of Muna purins

Muna purin again is a very potent way to

increase dopamine and here if your

healthc care provider approves it and

you decide to try it I would suggest

starting with a very very low dose again

to to find the minimal effective dose so

maybe even just 500 milligrams not even

going to the one gram dose maybe even

250 milligrams and really evaluating how

much Muna pance can produce a meaningful

impact on working memory and attention

for you so Muna pan is kind of a bridge

between over-the-counter supplements and

prescription drugs I say it's a bridge

because it is Oho similar to that

prescription drug L Doopa and of course

there is a long list of prescription

drugs that are known to be dopamine

Agonist several of which many of which

in fact have been shown to improve

working memory you already learned about

one of those before which is

bromocryptine now you need a

prescription from a physician to get

bromocryptine but bromocryptine we know

based on that work from desposito

colleagues that I talked about earlier

increases dopamine it does so in about

90 minutes it achieves Peak levels of

dopamine about 90 minutes and improves

working memory in individuals that start

off with a low working memory span and

we know from neuroimaging those are the

individuals with lower Baseline levels

of dopamine so should you run out and

ask your doctor for bromocryptine maybe

most doctors won't prescribe

bromocryptine for that reason I should

mention that work from desposito lab and

other Laboratories has shown that one of

the Hallmark features of traumatic brain

injury especially frontal lobe injury as

well as certain neurod degenerative

conditions like Parkinson's but other

forms of dementia as well as ADHD

involve deficits in working memory and

attention which makes sense given what

we know about the symptoms of those

conditions and that bromocryptine has

been prescribed off Lael for the

treatment of those conditions to some

degree of success however those are off

Lael circumstances right now as far as I

know bromocryptine is not prescribed

specifically for those conditions at a

kind of whole population level it's not

one of the drugs on the lookup table for

ADHD or TBI but certain well-informed

neurologists and Physicians do prescribe

it for that reason there are other

dopamine agonists that are relevant in

this context the ones that I think most

of you will be familiar with are the

drugs that increase dopamine and

norepinephrine for the treatment of ADHD

and I did an entire episode of The

hubman Lab podcast about those compounds

things like adderal things like rellin

which by by the way is quite different

than Aderall in terms of how much

dopamine relative to norepinephrine it

causes the increase of I cover all that

in those episodes again you can simply

go to hubman lab.com put ADHD Aderall or

ADHD riddlin and I talk about other

things as well I also took a little bit

about modafanil which is a entirely

different category of drug known to

improve cognitive performance in some

cases in ADHD but in everybody so there

are a lot of different drugs that can

improve working memory most of those do

so by increasing transmission of

dopamine or availability of dopamine

somehow changing dopamine levels in the

brain by increasing them so if you're

somebody that has challenges with

working memory focus and attention

please see those episodes and please

talk to your doctor about potentially

using pharmacology to increase dopamine

however and this is very important many

people who have challenges with Focus

attention and working memory and fall

under the category of subclinical levels

of ADHD and even some individuals with

88 she young and old manage their

symptoms and in some cases improve their

focus through the use of Behavioral

tools nutritional tools supplement based

Tools in ways that either allow them to

reduce their total prescription drug

dosages and in some cases come off them

entirely now I am definitely not saying

that people should come off those drugs

entirely and in fact I want to take a

really firm stand here because I know

this is a bit controversial but I'm just

going to tell you having evaluated the

whole literature several times over now

I do think I personally believe that

there is a strong case for certain

children and adults to take these

compounds that increase dopamine and

epinephrine yes those compounds are

different forms of amphetamine but those

compounds we know can increase

neuroplasticity the rewiring ltp LTD Etc

within the neural circuits that control

Focus attention and working memory and

so they do have their place for certain

individuals we don't want to rule those

out are they over prescribed my feeling

is that yes they are probably

overprescribed however there are a

number of individuals that strongly

benefit from them as well so if you are

going to explore the use of those

compounds for sake of improving working

memory certainly if you're going to

explore them for sake of improving

working memory and focus in young kids

please please please talk to your

physician because they're prescription

drugs you would need to talk to a

physician anyway but regardless of

whether or not you're trying to improve

focus and working memory in a child in

an adult someone with TBI someone with

Parkinson's

I think it stands to reason that you

would arrive to that conversation with

some knowledge of not just the

prescription drugs that are potentially

available but also some of the

supplement based tools some of the

behavioral tools because as we know and

as a good friend of mine who's an

excellent physician says Better Living

Through Chemistry still requires Better

Living meaning yes prescription drugs

can have a positive impact on these

aspects of brain function in a way that

can really improve lives but that

behavioral tools also work in fact they

can collaborate in a very synergistic

way to increase the amount of

neuroplasticity in the relevant circuits

so I'm of the mind and I think more and

more people out there I like to think

are of the mind that behaviors nutrition

supplement based tools and prescription

drugs all can have their place to

varying degrees depending on the

circumstances and the individual okay so

today we talked about working memory

this incredible capacity of our brain in

fact a specific set of brain circuits

designed for us to absorb absorb

information that is perceived in our

environment use the relevant parts and

then Chuck it just get rid of it forget

it so very different than short and

long-term memory which we also discussed

and we talked about a few of the

mechanisms as well I think you'll agree

that working memory is one of the more

incredible aspects to brain function I

mean if you think about this is a set of

neural circuits that engage the same

algorithm over and over in different

context in order for us to be able to

navigate new environments familiar

environments to interleave different

activities these different strategies to

task switch to rule out distractors it's

oh so critical to every aspect of our

Waking Life and fortunately there are

also zeroc cost and lowcost behavioral

supplement based and prescription drug

approaches to improving this incredible

thing we call working memory so it was a

pleasure to share some of those with you

today as well if you're learning from

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during today's episode and on many

previous episodes of The hubman Lab

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supplements aren't necessary for

everybody many people derive tremendous

benefit from them for things like

improving sleep for hormone support and

for focus us to learn more about the

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