All language subtitles for Lecture03 Scientific Secrets for Powerful Memory

Hello again.

I hope you're having fun trying out your major system and method of loci
to remember things, especially as you start to get good at it.

It's really fun in the 18th and even much of the 19th century.

Education included a lot of memorization, practice.

Kids were rarely taught the techniques that I've described to you,

but a lot of children discovered them or invented techniques like them
just to get through their classes.

Modern education emphasizes flexible thinking and creativity
much more than much more than it used to, and memorization much less

so for most of us. Having these memory tools is very new.

Like a new toy at your birthday party. It's just fun.

You may find yourself asking people to tell you their phone
numbers and birthdates, and once you encode them, they're yours forever.

Throughout this course,
I've talked about improving your memory as important for many reasons.

It's not just being able to do tricks to impress people,
like memorizing long strings of numbers or shopping lists.

As you improve your memory, you increase the amount of information
that you have available to you in your mind or thinking takes place.

If you remember things more,
I think it's clear that you experience them in more detail as well.

Memory is important.

The value of memory in our lives is perhaps most clear
when we consider people who've lost their memory.

When someone suffers a physical injury to the brain,
perhaps due to a stroke or illness or a physical trauma.

In some cases, the brain systems that support memory are damaged.

There are two very different classes of memory loss.

The one that's most often depicted in movies
and television is retrograde amnesia.

The loss of memories for events that took place prior to the injury.

Now I enjoy these television movies,
even if some of them are quite formulaic.

A patient awakes in a hospital with no idea of who they are
or how they got there.

Over the course of the next 60 to 90 minutes of the movie, they then
slowly rediscover some cases, reconstruct and reinvent who they are.

Now, I enjoyed the Bourne Identity as much as anyone else,
but this type of amnesia, the retrograde amnesia, is extremely rare.

Let me be clear here.

Someone who experiences a brain injury often loses memory
for the things that happened just prior to the injury.

For instance, it's
quite common for someone who's suffered a blow to the head

in a car accident to not remember the events that happened
just prior to or during the incident itself.

What's

happened there is that the process of storing
those memories was interrupted, stopped altogether actually

by the injury, but for the injury then to also disrupt
the recall of memories that are older weeks, months or years older.

That's just very, very rare.

The much more common type of amnesia is called anterograde amnesia.

In this case, the disease or injury damages
the brain such that the ability

to remember new things that have occurred
since the incident is disrupted or lost altogether.

With this type of amnesia, older memories remain fully intact,
just as detailed and accurate as they were prior to the brain injury.

What's lost is the ability to make new memories.

Brain injured patients who are the subject of research
are typically kept anonymous and referred to by made up initials.

I'll describe a patient here and refer to him as Eppie.

When he was in his mid-twenties, EPI became ill.

He had a very high fever caused by a form of the herpes virus.

This particular virus attacks the nervous system.

In each case, it attacked a part of his brain called the hippocampus.

After a week, the fever was gone, but the brain damage remained.

From that week
on, Eppie has been essentially unable to form and recall new memories.

Now, if you talked with Eppie, this might not be obvious to you.

Certainly, if no one told you to expect a problem,
Eppie is a smart and generally charming guy.

He can still do crossword puzzles.

He can still hold a conversation in a completely reasonable way.

If you happen to bring up current events, he'd be at a loss, of course.

But if you engaged him in conversation about, say, the events of World
War Two, you'd find that he's very knowledgeable, even insightful.

That said, if you asked him about something that you discussed
in the conversation, say, more than a minute ago,

he wouldn't know what you were talking about.

And if you walked down the hall to get something
and then came back, you'd have to reintroduce yourself.

I think it's worth pondering for a few minutes
what this experience must be like.

Eppie can still think and talk.

He can still answer questions.

She still feels emotions the same way that he did before the illness.

He still tears up when he learns about the birth of his
of his grandchildren.

That's a new any more.

But a few minutes after he learns that news, he's forgotten it again.

Our memory is one of the most important things that we have.

Without it, we can exist perfectly well in the moment,
but we cease to exist in a temporally extended fashion.

Our distant past is still there in our heads,
but the immediate past and the future are ripped away.

The effects of brain injuries can be fascinating in and of themselves,
but studying the effects of different brain

injuries is especially illuminating.

If it can tell us about how mental functions
occur in normal, uninjured brains.

That's certainly the case here.

The existence of anterograde amnesia
in so many patients over the years has led to the conclusion

that memory consists of at least two different types of information
storage, short term and long term.

First, there's short term memory,
sometimes referred to as working memory.

If I give you something to remember, say a string of letters,
you can immediately process them through your senses

and into your working memory.

Imagine, for instance, that it was very important for you
to keep the following letters in mind in order try to remember them now.

So here they come.

You i f c a, s b.

If you're like most people, you'll spontaneously begin
to repeat these letters over and over again, perhaps aloud.

But probably in your head.

You i f c as B you, ifc as B you, IFC as B

one big limitation of the rehearsal method
and your short term memory in general

is that it's limited in terms of the number of things
that you can hold in mind at one time

with the seven letters that I gave you rehearsals easy.

But if I gave you, say, ten or 20 letters to remember,
rehearsal wouldn't work.

By the time I'd finished saying all 20 of those letters, just once,
you would have forgotten some of them.

For most people, this short term memory seems to be limited
to about seven items, seven letters, seven numbers, seven images.

It doesn't seem to matter what the item is, but the number seven itself.

My favorite analogy here is imagining seven storage places,
perhaps hooks in a coat closet.

You can hang up to seven things on those hooks
and they'll stay there for a few moments.

Unfortunately, the hooks are slippery.

If you just leave an item there,
it will slowly slip off and be gone after a few seconds.

Only if you put the item back on to the hook onto the top of it.

With something like rehearsal every few seconds.

Only then will
it stay there for more than a few seconds before fading away.

If you want to remember those letters for a long time,
more than a few minutes or a few seconds,

you need to somehow
transfer them from your short term memory into your long term memory.

These long term memories are the ones that last for years and years,

and it's this long term memory
that has that limitless capacity that we've discussed.

Memory in its full, long term, seemingly limitless power
thus seems to involve at least three steps.

First,
we perceive of and understand some piece of information from the world.

This process delivers the information into our short term memory.

Second, we convert that information from the short term memory
into a long term memory.

Third, when it comes time to remember something,
we somehow retrieve that information,

pulling it back from the long term memory and into short term memory
where we can use the information again.

We can recall the information and report it to someone else.

Or we can think about it
how it relates to other sorts of information that we also possess.

In patient deep, the anterograde amnesia
that I described a few minutes ago,

his illness specifically damaged a particular brain structure
called the hippocampus.

Most humans have two of these, one on each side of the brain.

The hippocampus sits under the large cortical surfaces
on the top of the brain.

It's a long, curved brain structure.

Actually, it's named hippocampus, the Greek word for seahorse.

Because.

Because it's shaped much like a seahorse,
the networks of neurons in the hippocampus are extraordinarily complex

and have been shown to be involved
in in an enormous range of different types of brain functions.

In neuroscience classes, there's an old joke that if your exam asks you
what part of the brain is critical for X

where x is any mental function, then if you don't know the answer,
just guess hippocampus and you'll get at least partial credit.

One function that is clearly controlled by the hippocampus

is the second of our three steps of the memory process in patients
with severe damage to the hippocampus, like epi.

Almost all mental functions may be preserved,
but without that hippocampus, there seems to be a loss of the ability

to take information in short term memory
and encoded into a long term memory.

One note about the hippocampus.

That's interesting, given our discussion of the method of loci,
is its role in spatial navigation.

Researchers have discovered place cells within this particular
part of the brain in not just humans, but several mammalian species.

These researchers implant tiny electrodes in the brain
that can record when a particular neuron

or small group of neurons becomes active and produces
bursts of electrical activity in the hippocampus.

Cells have been identified that respond specifically to
when an animal is in a particular location in space.

When the animal when the animal moves away from that spot,
the cell becomes quiet again.

When it returns to the spot, the cell turns on again.

To the extent that our brain has mental

maps of the world around us that represent the structures
and relative positions of targets in our environment.

These cells in the hippocampus seem to implement those maps.

With this in mind, it makes total sense that memories should be
especially accurate when they're linked to a particular location

in space.

The same part of the brain that encodes locations is one
and the same as the part of the brain that encodes long term memories.

The hippocampus, incidentally, is located within a larger
brain structure called the limbic system.

This area of the brain
seems to be the seat of most of our emotional processing.

If you feel angry or frightened or excited, it's largely
due to the pattern of activity in this limbic system of the brain.

Emotion and memory, not surprisingly, seem to go together
closely as well.

Memories can inspire strong emotions and thinking about certain emotions
can the trigger can trigger particular memories.

Just like thinking about locations, the hippocampus serves
as a go between memory encoder, between short term and long term memory

items that are stored in those seven locations.

I've described them as those seven notebooks.

This limitation of seven items
seems to be a general property of the human brain.

Some people seem to have a somewhat smaller number of storage locations,
say five or six.

Others have a few more, maybe eight or very occasionally nine,
but seven plus or minus two seems to capture

essentially the full range of human variation in this department.

You can improve a lot of things
about how you encode and retrieve information

using techniques like the method of loci and the major system.

But this particular facet of your brain just can't be improved.

You get a certain number of storage slots and that's it.

But let's consider those letters again that I asked you to remember.

Any chance you remember them?

If you do, I'd be very impressed.

You ifcasb7 letters.

Seven storage locations. So this is no problem.

Let's add two more to the end of this string I and A

that gives us u i f c a sb i a.

Now we're pushing
beyond the limits of most people's short term memory. Right.

Watch what happens when I shift the positions of the letters.

Just shift them around a little bit.

USA, FBI, CIA.

Same number of letters.

Right? For most, this string of letters is trivial to remember.

In fact, I could add AFL-CIO and GOP to the list, and it still wouldn't.

Max out your short term memory. What's going on here?

I mentioned that you can hold about
seven letters or numbers in your short term memory.

I then stepped back and more broadly mentioned
that you can hold about seven things in your short term memory.

Those things, it turns out, can be almost anything
as long as they're meaningful.

Self coherent items. Memory researchers call these chunks.

You can only hold seven chunks in your short term.

Working memory,
but those chunks can actually be very detailed in complex items.

Individual letters and numbers, of course, can be chunks,
but so can words.

Sentence, even paragraphs.

Entire books could be on those socks
if you have them committed to memory.

Indeed, from this perspective, those seven storage locations
can actually hold an almost unlimited amount of things.

All you need to do is learn to pack more information
into each one of the seven chunks.

Of course, we've already talked about how to do that to some extent.

One might describe the major system as just one
big method of packing numbers into chunks formed around images.

The person with the long eyelashes
leering at the guy napping with the tater

tots is in essence,
just one chunk that you can later unpack into eight digits.

The method of loci is more than just an exercise in chunking.

I should note, since it capitalizes on the ability
of your long term memory to key off of particular spatial locations.

On the other hand, a particular memory path or memory palace
as a whole can be a single chunk that you could call to mind

better memory results when you engage in chunking.

But it's worth noting that the chunking itself
may not be the only key variable here.

For many memory researchers, the most important predictor of how
well you'll remember something in the future

has to do with the amount of effort devoted to processing
reasoning about it, encoding the information itself.

So chunking does result in better memory, but the chunking process
requires one to organize and relate items together.

What's more, that organization involves forming the chunks.

It's often related to knowledge that's already in our minds.

Many professors,
including myself, have had many conversations with students who

claim to have spent hours with their textbook prior to some exam.

And yet when the test arrived, they found
they were unable to correctly answer the questions.

How could that be?

The exasperated student often asked. It's just not fair.
I stared at the book for hours and hours.

How could I have not gotten an A on the test?

There are many reasons that poor test performance occurs,
but one of the most likely causes in this situation

isn't the time that the student has spent studying the material,
but how they've spent that time.

Many people have a sense
that if the words are poor, dejected onto your eyes

from the book, that some other knowledge and understanding
will also project into your brain that will just soak in somehow.

That's a very mistaken metaphor
that the people in many cases will work with.

Your memory doesn't function
like a camera or computer into which software is downloaded.

Hopefully it's already clear to you that this is a mistake in metaphor.

What we encode into our brains are meaningful items that are related
in some meaningful way to the things that are already stored there.

The more you mentally process the information
that you want to remember, the better you'll remember it.

Simple as that.

If you just stare at words on a page
that won't result in much memory at all.

Several classic experiments have been done on
something called the depth of processing effect.

The standard experiment involves asking people to study
some set of items, usually words, and to remember them for later.

Recall.

Experimenters manipulate the amount of thought people put into
those study words by varying the tasks that they ask them to perform.

For instance, the font group might be asked to read a list of words

and check off which of the words are printed in uppercase letters
and which, in lowercase letters.

They would repeat this task for several minutes. For example,
say 5 minutes.

A second group of participants would be assigned to the rhyme group
and they might be asked

to read through a list of words and indicate
which of the words do and don't rhyme with the word light.

Again, they would repeat this task for those same 5 minutes.

The final group of participants would be assigned to the sentence group
and they would spend their

5 minutes writing sentences that make sensible,
meaningful use of each one of the words.

So three groups all studying the same words for the same amount of time.

Then they all leave and wait for some delay period, say 24 hours after
which they're asked to recall as many of those study words as they can.

Which group do you think does best?

In study after study of this type?

The group that engages in the most meaningful
in-depth processing of the words recalls the most.

So the sentence group here almost always does best.

The rhyming group comes in a distant second
and the five group would be last.

This type of effect seems to apply

to almost any type of learning material across
a very wide range of study times and recall delay.

There's just something critical about thinking
about the meanings of items and how they relate to other things.

That boosts the likelihood of accurate, accurate memory.

The human brain works as a giant associative network.

If I ask you to think about the words doctor,
your brain will activate the word doctor.

But also the concept of nurse and hospital and medicine.

This is true for almost any word or concept that I could name.

When we remember new things, we seem to accomplish this by relating
the newly presented information to the things we already know.

If I were to show you a set of slightly different plumbing joints,
you might be able to later pick out some of them from a

a large selection of plumbing joints.

But you wouldn't want to challenge your plumber
to that memory competition.

There are similar charities in structure
and function of the different types of joints that you simply won't know

unless it now occurs to me you are a plumber yourself.

If you are, please substitute electrician and wire
coupling for plumber and plumbing joint in those sentences.

There are similarities in structure and function
that would be apparent to a plumber.

That will not be apparent to a layperson.

Even if you look at the same joints. They will mean much less to you.

And so you have a much harder time in coding them.

More meaning leads to stronger and more numerous connections
to existing knowledge, which leads to faster and more accurate memory.

So encoding is a key step in the memory process.

Without shifting information from short term to long term memory,
you will lose it.

This encoding to long term memory can be very hard, and that's good.

The harder it is, the harder you work on it.

At least the better your later recall will be.

I think of these facts often when I'm being introduced to a new person.

I meet a lot of new people in my area for people at conferences,
students, colleagues at my own and other universities,

people at government agencies.

I also meet new friends around town all the time. I see their faces.

I introduce myself. Then they look at me.
They look me in the eye and they state their name

at some later time.

There's a particular problem that arises.

I'm in a social situation in which I recognize the face of a person
whom I know I've met in the past.

I might even be able to remember where I met him or her.

What is less likely to come to mind
is what that person's actual name is.

I can usually just avoid their name in conversation.

Hey, you. It's nice to see you again.

How've you been?

Of course.

That only kicks the can down the road
a bit and sowed the seeds of actually a much greater problem.

Once I've seen and talked to the person several times,
maybe even half a dozen times now, I really feel awkward.

If I don't know his or her name
and it seems too late to ask at that point.

The real nightmare emerges, of course.

Months later, I'll be talking to this name unknown person,
whom I've known now for a long time.

Sort of.

When someone else comes up
who knows me, knows me, but doesn't know this name, unknown person.

Having been through this many times,
I will never subject a friend of mine to the following statements.

Just in the off chance that he doesn't know the person's name.

This person who knows me and not the unknown name
person looks at me and says, Well, aren't you going to introduce us?

Of course. Sorry, I replied.

Playing for time as I struggle for any inkling of the name.

I look at the name Unknown Person and ask,
How do you pronounce your name again?

As often or

not, I get a quizzical I pronounce it Fred or something like that.

Now this doesn't happen all the time, or even most of the time.

I've gotten better over the years at encoding those names,
but this remains an ongoing challenge for me and for many people.

There are some very obvious reasons that this occurs and a few tricks
that you can use to reduce the frequency of name forgetting.

The first big reason that it happens is that when you meet someone new,
remembering their name is just not the first thing on your mind.

You probably hear the name and then immediately jump into a conversation
about the party or event or the weather.

As you do this, of course.

Your short term memory becomes occupied with something
other than the new name, and it's lost.

The first

and easiest step to take to better remember names is quite simply
to make a point of looking the person in the face and encoding it.

Think about it for a few seconds
before you move on to the next statement.

I'll list a couple of other tricks here,

but if you just do that, I think you'll find that the frequency of name
forgetting will drop by about half.

That isn't based on any empirical evidence other than my own experience.

It is, however, based on what we know about how memory works.

Unless you encode something from short term into long term memory,
within a few seconds it's lost forever.

The second thing to try and it's related to
the first is to say the person's name out loud.

Fred, it's good to meet you. It's
good to meet you, Fred. My name's Peter.

This will force you to slow down for a moment, for one thing,
and also to hear the name spoken aloud a few more times.

Anything you can do to enhance the salience and multisensory
nature of some experience

increases the likelihood of successful retention of that memory.

The next trick forces the delay and adds a level of meaning
that works really well.

The trick here is to imagine this newly introduced person
engaging in some task

or using some object
that is phonetically similar to the sound of their name.

I recently moved to a new house and met my new neighbor, Jack.

I imagined him in as much vivid detail
as I could muster, using a jack to elevate a car with a flat tire.

Jack has a wife.

His wife, Sharon, came to our house with him,
and she brought a cake with her to.

To welcome us to the neighborhood.
This is a very sweet thing to do, by the way.

This one was easy.

I imagined her sharing a cake with me.

Sharon and sharing are very close and sounds.

Their daughter Courtney came along with them.

I imagined her sitting in a judge's seat with robes, a gavel,
and all in a courtroom.

Whenever I see my neighbors.

These images are sparked by the presence of their faces,
and the name comes rolling along with it very easily.

Again, we're really good with remembering images.

If you can just get the name to meaningfully connect with one of those
images, you've won more than half the battle of successful recall.

If all else fails, there's one last trick that you might try.

Most people think of memories as explicit, conscious experiences either
remember someone's name or I don't.

If I fail to recall it, then I must not know it, right?

Well, not exactly.

It's often the case that a memory that you have encoded
isn't clear enough to recall,

but it's left a trace in your mind
that can later influence your behavior.

Often, this is referred to as an implicit memory,
even if you don't know the person's name.

Just guess the first letter.

Not allowed now.

Just guess the letter in your head.

Say, for instance,
I guess m next start to think of names that start with that letter.

Mike Martin. Mel. Mark.

As you list those names to yourself,
you just might hear one that rings a bell.

Now, this isn't all that likely to work,

but there is significantly better than a one in 26 chance
that you'll guess that letter correctly.

If you've met the person earlier
and they've left some trace of their name in your mind.

If a name rings a bell in your mind, there's a similarly better
than than average chance that this is the correct name.

Even if it's wrong, there's a decent, decent chance that you got close.

And that's not so bad.

In this session, we've talked about the three steps
of successful memory perception to short term memory.

Short term term encoding to long term
encoding and retrieval from long term memory.

I've described how that process can be disrupted by damage
to the hippocampus and talked about some of the properties

of our short term memory.

I've also suggested some ways around the limitations of short term
memory, mostly having to do with enhancing the quality

and effort you put into encoding the short term
information into your long term memories.

I hope you'll find the application of those ideas to the task of better
remembering names useful.

I know that I have.

In our next session I want to talk about the other side
of successful memory and talk about forgetting.

Why do we forget? What does it mean to forget?

If we can reduce the frequency of forgetting, of course,
that's really the same thing as increasing the frequency of remembering.

So don't forget to watch session for I0.