0:00

time itself doesn't really exist

0:02

in memory. And I would

0:04

argue that time doesn't really

0:06

exist after a few seconds,

0:09

that it's really about where

0:11

we're putting our attention, our

0:13

internal mental context, how we're

0:16

basically orchestrating our mind, what

0:18

we're orchestrating our minds to

0:20

think about. Hi, I'm Elizabeth Coke.

0:22

We all live inside our

0:25

own personal private perception box.

0:27

built by our genes and

0:29

the physical, social, and cultural

0:31

environment in which we were

0:33

born and raised. In this

0:35

podcast, we explore how although

0:38

the walls of this mental

0:40

box are always present, they

0:42

can expand in states like

0:44

awe, wonder, and curiosity,

0:47

or contract in response

0:49

to anxiety, fear, and anger.

0:51

I'd like to introduce our

0:54

esteemed hosts. to incredible and

0:56

distinguished minds. Dr. Heather Berlin,

0:58

professor of psychiatry and neuroscience

1:01

at the Icon School of

1:03

Medicine at Mount Sinai in New

1:05

York City. And Dr. Kristof Koch,

1:07

chief scientist for the Tiny Blue

1:10

Dot Foundation, and the current

1:12

meritorious investigator and former president

1:15

of the Allen Institute for

1:17

Brain Science. Welcome to the

1:19

Science of Perception Box. Hi

1:25

everybody, welcome to Science and Perception

1:27

Box. I'm your co-host, Dr. Heather

1:29

Berlin. And I'm your co-host, Dr. Chris

1:32

of Koch. Every week we feature

1:34

an aspect of the Science of

1:36

Perception Box, highlighting the latest research

1:38

together with our expert guests. This

1:40

week, we're exploring the relationship

1:42

between memory, time, and perception.

1:44

I'm thrilled to welcome Dr.

1:47

Lela Devachi, a leading neuroscientist

1:49

at Columbia University, whose groundbreaking

1:51

work sheds light on the

1:53

mysteries of the brain and

1:55

its relationship with time. Dr.

1:57

Devachi investigates how we encode

1:59

and retrieve memories. Her work reveals

2:01

that our perception of time is more

2:04

fluid than we might think. In her

2:06

research, she uncovers how the richness of

2:08

our experiences, how varied and eventful they

2:11

are, can stretch or compress our sense

2:13

of time. Through fascinating MRI experiments, she

2:15

shows that the brain's hippocampus plays a

2:18

pivotal role in memory creation, while our

2:20

internal experience can transform the way we

2:22

perceive the external world. First, we want

2:25

to share our own connection to memory.

2:27

So, Krista, what do you see is

2:29

the relationship between perception and memory? Well,

2:32

what do you expect from a guy

2:34

who wears all yellow? Is this how

2:36

you want to be remembered? I maintain

2:39

my sunny disposition because I think partially

2:41

because what I choose to remember and

2:43

how whether those are positive or negative

2:46

effects. So I think there's a strong

2:48

relationship between the way you perceive the

2:50

world and what you focus on and

2:53

then what you remember. And that makes

2:55

up your experienced reality or perception walks.

2:57

Well, there's two different issues there. I

3:00

think one is, do you think that

3:02

very strong pronounced stimuli will help you

3:04

remember something better or is it that

3:07

you just want the memory to be

3:09

associated with a very positive emotion? the

3:11

latter primarily. I choose to, I think,

3:14

constantly choose to primarily remember good things

3:16

about the world. You choose to remember

3:18

good things about the world. That's the

3:21

way how I do it. And I

3:23

think we can all do that. We

3:25

can choose to remember troubled things or

3:28

insults or slides, and we can just

3:30

choose to remember the positive things that

3:32

we encounter. So basically, if we both

3:35

encounter the same scene or other people

3:37

encounter the same scene, what people remember

3:39

from that scene can vary based on

3:42

what their... sort of perception is or

3:44

what they focus on. Yes. What they

3:46

focus on it. I mean, so a

3:49

person who's depressed might just pick up

3:51

on all the sort of negative aspects

3:53

that's more salient to them versus somebody

3:56

who has a happy disposition might remember.

3:58

And if you do this consistently as

4:00

a... I think it builds up your

4:03

view of reality, your reality, because it's

4:05

the only one you have. Well, I

4:07

mean, we have an expert here

4:09

who can help us with answering

4:12

some of these questions. So, Leila,

4:14

welcome to the podcast. Thank you.

4:16

It's great to be here. Well,

4:19

it turns out that... emotions

4:21

do influence memory and negative

4:23

and positive emotions do so

4:25

in different ways, which is

4:27

relevant to what you were

4:29

just saying. Really negative experiences

4:31

produce a very vivid memory,

4:33

but that memory is fragmented

4:36

and it doesn't include the

4:38

context, what happened before, what

4:40

happened after, but you can

4:42

have a really sort of

4:44

invasive, almost ruminative, negative memory,

4:46

but positive experiences on the

4:48

other hand tend to produce

4:50

more flexible integrated memory so that

4:53

there's almost a bigger memory. There's

4:55

more to remember and it's more

4:57

flexible and research has shown that

5:00

when you're in an experience and

5:02

you're positively motivated, let's say searching

5:04

for reward, that you do activate

5:07

the hippocampus more and that creates

5:09

a more flexible memory representation. But

5:11

if you're in that same environment,

5:14

but you're avoiding a threat, you're

5:16

trying to escape, you don't activate

5:18

the hippocampus. In fact, you activate

5:21

cortical structures, and later on you

5:23

do remember that event, but you

5:25

don't remember much about it. It's

5:27

fragmented. So the central parts... of

5:29

a negative experience are remembered probably

5:31

too well, but all of the

5:33

important and interesting other parts of

5:35

that memory are not there for

5:37

negative experiences. That's really interesting. So

5:39

it's the first time I've heard

5:41

of this that... When it's a highly

5:44

negative experience, it doesn't activate the

5:46

hippocampus. That's been shown in human

5:48

fMRI and in some rodent work,

5:51

yes. But a positive experience would

5:53

activate the hippocampus. So patient who

5:55

doesn't have a hippocampus anymore because

5:58

it's been surgical or more... that

6:00

they would not remember truly negative

6:02

aversive event. Well, no, they remember

6:04

it from, it, she's, you know, it

6:07

activates the cortex, so there's, there's memory

6:09

areas in the cortex as well. Right,

6:11

so patient, this is really interesting, patients

6:13

with complete hippocampal damage who were amnesic

6:16

still retain some aversive memories that they

6:18

show in their behavior. So one of

6:20

my favorite examples of this had to

6:23

do with, patient HM who's very famous,

6:25

who had no memory. If I walked,

6:27

if I was him and I walked

6:30

out the door, I would never even

6:32

remember meeting you. But if you had

6:34

shook my hand and you had a

6:36

little sharp pin on the inside of

6:38

your palm, I would recoil. And if

6:40

I left the room, I would come

6:42

back and not remember you, even with

6:44

your yellow outfit, but I might not

6:46

want to shake your hand anymore. That

6:48

was an experiment that was shown. So

6:50

they avoid engaging with a person who

6:53

shocked them. So that tells you that

6:55

there's something that remained about that negative

6:57

experience. But it's unconscious. Without a hippocampus

6:59

campus, yeah. It appears unconscious, because they

7:01

can't really tell you much about the

7:03

past. But it can't be that negative

7:05

experiences. Sometimes they're sort of... hyper remembered,

7:07

you know, like when people

7:09

have PTSD and they can't

7:11

stop thinking about these negative

7:13

experiences. Yeah, no, no, no,

7:15

completely. So the central core. of

7:17

the experience in that moment when

7:19

something really negative is happening, your

7:21

pupil dilates, you're taking actually time

7:23

slows down, you're taking in a

7:25

lot more information in that moment,

7:27

at least that's the hypothesis, and

7:29

that's central information as well remembered,

7:31

but nothing in the surround, the

7:33

contextual stuff, actually contrary to what

7:35

people believe, they will claim. after

7:37

a negative experience that their memory

7:39

is really, really good. And we

7:41

call this flashball memories. But actually,

7:43

when tested, their memory for what

7:45

happened that day and the general context

7:48

is no better than remembering what you had

7:50

for lunch. It's not really special. But the

7:52

central core information is really well remembered. Oh,

7:54

that's interesting. And I do want to get

7:56

into in a little bit. I want to

7:59

get into time. perception during these experiences, because that's

8:01

something I'm actually really interested in, and had done

8:03

some research on time perception as well. So I want

8:05

to dig in there. But first, I just want

8:07

to ask a general question of just, what

8:09

do you think the purpose of memory is? I'm

8:12

so glad that you're asking that

8:15

question, because 10 years ago, no

8:17

one was asking that question. People

8:19

were asking, how does memory work?

8:21

With the assumption that memory is

8:23

there to remember, and

8:26

I don't think that's what memory

8:28

is for. I think now after

8:30

dedicating 25 years of my life

8:32

to studying memory, that memory is

8:34

there to help us understand the

8:36

world, to build knowledge. So in

8:38

other words, our memory

8:41

systems are built to care

8:43

about what's prioritized, what's

8:45

important to learn from every

8:47

day. And that's why

8:49

probably the thing you can rely

8:51

on the most about your memory is

8:53

forgetting. I think once you go

8:55

to sleep, the memory system just doesn't

8:57

consolidate and sort of literally trashes

8:59

most of the day, because it's not

9:01

relevant to your survival. In other

9:03

words, you've already learned so much about

9:05

the world. So what tends to

9:07

get consolidated during sleep, and this is

9:09

when the memory system really gears

9:12

up in action, is what is it

9:14

going to keep around? What kinds

9:16

of memories are going to undergo synaptic

9:18

plasticity? And that's when you're increasing

9:20

the communication between neurons so that you can

9:22

remember that information later. is doing

9:24

specifically during slow -wave sleep. This happens during

9:26

slow -wave sleep, and we actually have evidence that that

9:28

might be tagged during awake

9:30

resting states as well. That's what

9:32

we've been looking at recently. So

9:34

there's an interplay, I think, between

9:37

the awake brain at rest and

9:39

sleep. But so your memory system

9:41

is trying to figure out, did

9:43

you learn anything new today that

9:45

is important to keep around? And

9:48

it updates the cortex. It

9:50

tells, so during sleep, it's

9:52

teaching cortical neurons how to

9:54

represent any kind of new

9:57

important information. So really memory

9:59

isn't for remembering we think it's

10:01

really for gathering knowledge and updating

10:03

our knowledge of the world. So

10:05

would it make sense though and

10:07

I think this leads into the

10:09

time perception but the older you

10:11

get and the more buildup you've

10:13

had of knowledge so that maybe

10:16

we the less you needed the

10:18

less you need to remember in

10:20

a way right because I know

10:22

you know my children they're like

10:24

seven and ten now they remember

10:26

exquisite details of things that I

10:28

just They soak up everything. Everything,

10:30

and they remember everything. And, you

10:32

know, I forget most things. But

10:34

maybe that's adaptive. Maybe it's just

10:36

because my brain, it doesn't need

10:39

that information as much anymore. Absolutely.

10:41

I think that instead of continuing

10:43

to talk about aging as a

10:45

deficit model, like memory in the

10:47

lab, like little details aren't as

10:49

well remembered, it's important socially to

10:51

remember people's names, but people are.

10:53

generally bad at remembering people's names

10:55

no matter how old you are.

10:57

But it's true this could explain

10:59

this could explain what's typically thought

11:02

of as a deficit that as

11:04

you age your memories get worse

11:06

but what you are better at

11:08

are knowing how the world works

11:10

and you can call that wisdom

11:12

you can call that making predictions

11:14

and there is research now showing

11:16

that when Older adults are facing

11:18

the same memory question, or when

11:20

they're encoding what's thought of as

11:22

a novel item context experience in

11:25

the lab, they're activating more of

11:27

their cortex than their hippocampus. And

11:29

younger adults or children are activating

11:31

more of their hippocampus, and that's

11:33

another way of saying they're gathering

11:35

those details to be replayed during

11:37

sleep. But older people, maybe, you

11:39

know, if your brain were talking,

11:41

might be saying, oh yeah, I

11:43

know what's going to happen. No

11:46

need to. How much is this

11:48

process on a voluntary control? So

11:50

to what extent can I choose

11:52

to remember, for instance, negative events,

11:54

you know, some perceived insult that

11:56

I may not want to recall

11:58

and primarily focus on? positive memories

12:00

or is an illusion. Each of

12:02

us have our own natural

12:04

orientation but that doesn't mean

12:07

it can't be changed. Let's say

12:09

like Christoph you're up here and

12:11

you think of you see the

12:13

world through this like rosy glasses

12:15

and you're picking in that moment

12:17

if you're able to attend to

12:20

the positive aspects or reappraise in

12:22

the moment if someone is being

12:24

rude to you in New York City,

12:26

but you're thinking, oh, you probably had

12:28

a bad day, it's not about me.

12:30

Like that kind of thinking may now,

12:32

after many years, be where you are.

12:34

And I may be down here. I

12:37

may be really sensitive to perceived slights

12:39

in my environment, and that means when

12:41

I leave an experience, those memories are

12:43

going to pop up into my mind,

12:45

and then I can choose to ruminate

12:47

on them or not. I do believe

12:49

that everyone can shift a little bit.

12:51

Maybe, if I work on it. But

12:54

I don't think we're stuck, but I

12:56

do think that there are going to

12:58

be individual differences. And knowing where you

13:00

are is important in figuring out how

13:03

to move that. But I also believe

13:05

that it's much easier. If you can

13:07

change the memory before it's become a

13:09

memory, in the moment, if your interpretation

13:11

is there and the rosiness is already

13:14

there, then that memory is more likely

13:16

to be positive. It's much harder to

13:18

change a memory once it's become consolidated.

13:20

Once it's there is a memory, then

13:23

you're more suppressing it. And that is

13:25

only minimally effective. Suppression only

13:27

works in the moment, but it

13:29

doesn't seem to work in the

13:31

long term. I'm thinking of it

13:33

in terms of therapy, right? Therapy

13:35

can be used, like I say,

13:37

cognitive behavioral therapy, cognitive reframing, to

13:39

move you up a bit, you know, move the

13:42

needle up, but there is a limit in

13:44

terms of, say, our genetic predisposition or

13:46

the way our brains are wired. So

13:48

there's certain, our boundaries might be set,

13:50

but within a range, and that therapy

13:52

can get you a little higher, you

13:54

know, so we do have the ability

13:57

to change over time, we're not sort

13:59

of stuck in that. remember something, you

14:01

can rewrite it. And that part

14:03

of maybe also what therapy can

14:05

do is help you rewrite it

14:07

in a more positive way, in

14:09

a more beneficial way. Yeah, that's

14:12

the big hope. Definitely, every time

14:14

you reactivate a memory, it becomes

14:16

labile and open to change. But

14:18

so far how much you can

14:20

change that it's really hard to

14:22

make a memory more positive Not

14:24

that it's impossible, but you can

14:26

make it slightly more neutral Well,

14:28

so you're telling us I'm the

14:30

distinct memory of my first kids

14:32

when I was 15 and are

14:34

you telling me that every time

14:37

I recall that? I re-encoded. That

14:39

is what we think. So when

14:41

you activate a memory in the

14:43

brain, when the neural ensemble or

14:45

the n-gram is activated, it enters

14:47

into a state of being moderately

14:49

activated. And then that process can

14:51

lead to either elements dropping out

14:53

or elements coming in. Like if

14:55

you're thinking about your 15-year-old self

14:57

and your first kiss, and then

15:00

you quickly moved the kiss you

15:02

had last Saturday. in your mind

15:04

and they're co-activated. Not that you

15:06

would necessarily confuse them, that would

15:08

be the extreme, you might confuse

15:10

them, but they can become integrated

15:12

in the brain. But that really

15:14

means, A, the memory is radical,

15:16

different from a computer memory, right?

15:18

Absolutely. And it also means that

15:20

my memory is then amenable to

15:22

being reinterpreted by myself. Yeah. Or

15:25

what I tell myself about who

15:27

I was. Exactly. And that's why

15:29

therapy should work. Yeah. So in

15:31

the moment activating the memory and

15:33

then rethinking it, maybe perspective taking,

15:35

even just being calm, if your

15:37

body is not aroused in a

15:39

negative way when you're recalling a

15:41

negative memory, that can help to

15:43

disentangle the, I call it the,

15:45

the body memory, the fear memory,

15:48

the heart rate increase, you know,

15:50

the sweatiness. If you can feel

15:52

calm, that's why Propranolol all works,

15:54

because if you have a beta

15:56

blocker. which is

15:58

a drug that's

16:00

often used to, I'm

16:03

not a medical doctor. A beta blockers

16:05

are used for like stage fright. It's

16:07

often given to patients with cardiac issues.

16:09

It kind of calms down the nervous

16:12

system. So you're, you know. Keeps your

16:14

heart rate steady. When you're

16:16

re -remembering your memory while you take

16:18

that. While you're taking a beta blocker, what

16:20

you're doing is, if you're

16:22

retrieving a negative memory that would normally

16:24

cause a lot of heart rate increase

16:26

and now your heart's not increasing, the

16:28

brain has an opportunity to disentangle or

16:30

separate those two events. That's like the

16:33

hope for a lot of the use

16:35

of propanolol. It hasn't been super successful

16:37

yet, I will say, but there's still

16:39

hope in trying to use. For phobias,

16:41

if you give people propanololol and then

16:43

introduce them to, let's say, a spider

16:45

or something, you can actually unlearn a

16:47

fear. In that even one

16:49

trial, there's some studies that were done in

16:51

the Netherlands on that. the

16:56

brain has an disentangle But if you

16:58

mentioned a small plane, I might jump

17:00

away. But there is this idea with

17:02

therapy as well. You bring up a

17:04

sort of very negative emotion or memory

17:06

in a neutral context with a safe

17:08

person in a safe space that you

17:10

can sort of re -encode it in

17:12

a way that dissociates the negative feeling

17:14

from the memory itself. Why

17:16

does this sort of not work for PTSD? Well,

17:20

it could just be that memories are

17:22

so strong. I have my own

17:24

experience with using propranolol to get

17:26

rid of a fear of

17:28

flying. So when I was

17:30

on the job market for my very

17:33

first job and I was lucky enough

17:35

to have multiple interviews, I

17:37

would get on a

17:39

plane to go to the

17:41

interview. And my interpretation

17:43

is that I was preparing

17:45

and anxious for the

17:47

interview, preparing my job talk.

17:49

What was I gonna

17:51

say to the professors I

17:53

was meeting? And so

17:56

my physiology was up -regulated

17:58

on the plane. And then

18:00

there I was on

18:02

a plane that was like

18:04

shaking. Maybe there was

18:06

turbulence. So I think that

18:08

my brain is so... associated

18:10

the plane context and the turbulence with my internal

18:12

anxiety. So after the job market was done and

18:14

I landed my job, yay, I found out that

18:16

before all this I never was afraid on planes.

18:18

And now even getting on a plane to go

18:20

to the beach, I was anxious. All of the

18:22

turbulence bothered me. I became really afraid of flying.

18:24

And I first tried like, you know. alcohol consumption.

18:26

It didn't really work for me. I was still

18:28

afraid. Alcohol consumption. It didn't work in the

18:31

longs. And then I tried other medications

18:33

that would knock me out and make

18:35

me feel tired but didn't get rid

18:37

of my... my anxiety and fear of

18:39

flying. So then I thought, I need

18:42

to use science. And so my dad,

18:44

who was a cardiologist, gave me prescription

18:46

for a propranolololol, and I took beta

18:48

blockers on one, two, three, or maybe

18:51

six flights every time. And frankly, you

18:53

know, I was a little headache. I

18:55

didn't notice anything in the moment. I

18:57

still had that fear, but after... six

19:00

or seven times taking it, I now

19:02

am much more calm on flights. I

19:04

feel like I've unlearned that, my body

19:06

has unlearned that association. So it is

19:08

possible. I don't know, has it learned

19:10

this new association, this new positive

19:12

association, flying doesn't have to be

19:14

associated with the racing heart. That is

19:17

a great question and I don't, I think,

19:19

you know, I would like to say the

19:21

answer is usually in the middle. It's probably

19:23

a little bit of both. So

19:25

I did want to bring

19:27

in time, because this is

19:30

something that fascinates me. So,

19:32

you know, what is the

19:34

relationship between time and memory

19:36

and experience? And, you know,

19:39

why is it that sort

19:41

of time seems to expand?

19:43

I actually just, I recently

19:45

testified as an expert witness

19:48

in a court case, and it was

19:50

about this woman, she died.

19:52

unfortunately, in a

19:54

motorcycle accident. But she was

19:56

conscious and aware during that

19:58

time and how even though was just

20:00

a few seconds, when you're

20:02

in that moment of sheer

20:05

terror and you, you know,

20:07

impending death, that it can feel

20:09

way longer in those moments,

20:11

right? So subjectively,

20:13

you know, how do you

20:16

explain that? What's a relationship

20:18

between memory and experience

20:21

and time? So what I know about

20:23

that is that... And we've all maybe

20:25

had an experience where there's something

20:27

really arousing that demands our attention

20:30

in the moment that it can

20:32

feel like the world is slowing

20:34

down a little. So those experiences

20:36

are happening at a slightly slower

20:38

rate so that you can take

20:40

in more information. Bullet time in

20:42

the Matrix movie. Oh, bullet time.

20:45

When they shootness, bullet goes

20:47

incredible slowly towards a meal.

20:49

You're aware that that's fiction, but we'll

20:51

go on. Oh. Oh. So to make sure...

20:53

But it's a cinematic depiction

20:55

of the experience that you

20:57

mentioned. Yes, yes. So there

20:59

is a lot of data

21:01

suggesting that subjective measurements of

21:04

time, your experience of time

21:06

slows down in those really

21:08

highly arousing moments. What we

21:10

study in the lab is

21:12

understanding whether that how that

21:14

translates into memories and how

21:16

we remember time. And so...

21:18

That is what most of

21:20

our research focuses on is

21:22

memory for time. And in

21:24

that case, what we're seeing

21:26

is that time itself doesn't really

21:28

exist in memory. And I would

21:31

argue that time doesn't really exist

21:33

after a few seconds, that it's

21:35

really about where we're putting our

21:37

attention, our internal mental context, what

21:40

we're, how we're basically orchestrating our

21:42

mind, what we're orchestrating our minds

21:44

to think about. This is such

21:46

an extreme, so you're saying time

21:49

does not exist in our memory.

21:51

So something that occurred in, let's

21:53

say, real clock time that was only

21:55

a couple of seconds could feel like

21:57

an hour in your memory or something.

22:00

that lasted five hours could feel

22:02

like a few minutes in your

22:04

memory. Yeah, so we don't really

22:06

ask how long it feels in

22:08

objective time because I think people

22:10

don't even know how to do

22:12

that. I mean, in general, if

22:14

I ask you to retrieve a

22:16

memory from your traveling here this

22:18

morning, subjectively what you get is

22:21

not a continuous unfolding of the

22:23

trip, you get these like... Slightly

22:25

movements, just little snapshots of where

22:27

you were. And those snapshots are

22:29

probably happening at the times you

22:31

made a turn in the car.

22:33

Right, so there are these moments

22:35

that these experiences that we think

22:37

tile our experiences, these boundaries between

22:39

events. So whenever the context changes

22:42

a little, the brain is taking

22:44

in those moments. But how much

22:46

time is in between, whether it

22:48

was a really long trip on

22:50

Broadway or just two blocks? takes

22:52

up the same space in our

22:54

brain. From just a neural perspective,

22:56

when there's change, this variation, there's

22:58

dopamine that is released for novelty,

23:01

and that that might tag these

23:03

moments as being important to remember?

23:05

Yeah, absolutely. There's dopamine, there's also

23:07

norepine, which is related to our

23:09

attentional systems, and the norepinephrine is...

23:11

allowing, we think, is telling us

23:13

to take in, where are you?

23:15

Where's your contacts? Like when your

23:17

viewpoint changes in perception, the brain

23:20

really quickly wants to know where

23:22

it is. it really needs to

23:24

have a sense of the context

23:26

that it's in. And some people

23:28

refer to that as the event

23:30

model. What context am I in?

23:32

What behaviors are required of me

23:34

in this context? So that's what

23:36

the brain is really good about,

23:38

within a few hundred milliseconds knowing

23:41

exactly if it needs to change

23:43

what active representations are available to

23:45

you. Dopamine is also released, and

23:47

Dopamine has been correlated with your

23:49

ability to now form a new

23:51

memory of that experience. So it

23:53

has a more long term. effect

23:55

on the formation of the memory.

23:57

And this is an area that

24:00

is really kind of hot right now,

24:02

and there's a lot of work that's

24:04

being done to look at more epinephrin

24:07

and dopamine at event boundaries. So

24:09

tell me, what happened doing lockdown,

24:11

COVID, right, with time perception,

24:13

when you talk about that, because most

24:15

of us had this feeling, on the one

24:17

end, it was way in the past,

24:19

most of us don't even remember anymore.

24:22

On the other hand, this year collapsed

24:24

to one or two points. So what

24:26

happened there. We all went through this

24:28

similar experience and it was

24:30

very difficult for everyone, including

24:32

me, but it was also

24:34

very motivating for our research.

24:36

Before the pandemic, we had

24:38

already been studying event boundaries

24:40

and event representations and what's

24:42

the relationship between kind of the

24:45

ebb and flow of our daily lives and

24:47

what's a memory? We had been studying that.

24:49

The pandemic... You mean the beginning and the

24:51

end of a memory? Yeah, what is one

24:53

episodic memory? Where does it start? Where

24:55

does it end? And those are at

24:58

these moments of change, we've discovered. But

25:00

at the pandemic, there was no beginning

25:02

and middle and end. We were always

25:04

in the same context, the same, and

25:06

definitely so we were in the same

25:08

apartment, in the same house. Maybe you

25:10

were lucky enough to have a backyard.

25:12

You were in your backyard. We all

25:14

were having groceries delivered delivered delivered to

25:16

us. And so what I think has

25:18

happened is that there's been a global

25:20

reduction in overall brain health over the

25:22

pandemic. So not having those moments

25:24

of novelty where nor epinephrine is

25:26

released, your pupil's dilate, the brain

25:29

is taking in information. It's like

25:31

a muscle, like really, like the

25:33

brain is like a muscle. If

25:35

you're not using it in the

25:37

proper way, you're going to see

25:39

a deterioration. And so... If we're in

25:41

that same context for months, let's say

25:43

March 2020, until if you were lucky

25:45

enough, September, you had some normalcy, but

25:47

here in New York, really it wasn't

25:50

until a year later where there was

25:52

people, you were able to go out. You

25:54

had those experiences at the end of the

25:56

day, you knew what had happened that day.

25:58

You still had like a... like a little

26:00

memory, a short-term memory, but now trying

26:03

to recall all those memories, they're all

26:05

represented in the same context, and so

26:07

they're completely interfering with each other. So

26:09

our normal consolidation mechanisms, when you go

26:12

to sleep, like I said, are built

26:14

to kind of rehearse. The brain rehearses

26:16

the important events, but it also rehearses

26:18

the context. When did it happen? Where

26:21

did it happened? And those keys help

26:23

you to unlock the memory later on.

26:25

So again, if I ask you, like,

26:27

what did you have for lunch yesterday?

26:30

Your brain is first going to go

26:32

to where were you? What context was

26:34

I in? And that's going to help

26:36

you to think about, oh, where was

26:38

the plate situated? Where did it come

26:41

in? Was I at a restaurant? But

26:43

if you had 100 meals in the

26:45

same room you're in, would not be

26:47

a key, that would work. for a

26:50

specific memory. It would work to tell

26:52

you generally where did we eat, but

26:54

it wouldn't really give you any information

26:56

about specifics. So we're all left with

26:59

very few memories from the pandemic. That's

27:01

so interesting. So it's really memory is

27:03

tagged to like sort of changes and

27:05

you tag it to things in the

27:07

environment and in your context. But if

27:10

everything is remaining the same. all the

27:12

time. You don't really have anything to

27:14

kind of latch on. What do you

27:16

latch on to? So it's not a

27:19

faithful record of what happened, but more

27:21

of the salient events at a new

27:23

novel and interesting. And so that seems

27:25

to explain then the paradox that seemingly

27:28

time was very slow during the pandemic.

27:30

Very slow. And in hindsight, I can't

27:32

even say what actually what nothing much

27:34

happened. Right. The other side of that

27:37

coin is when there's a lot happening.

27:39

in your day. Let's say you live

27:41

a really busy life and you're constantly

27:43

going from meeting to meeting or you're

27:45

on a vacation and you know you're

27:48

moving quickly through experiences. If you stop

27:50

in that moment and someone asked you,

27:52

how is your day going? How does

27:54

time feel? You would report it going

27:57

too fast. Like time is going too

27:59

fast. I kind of almost like you

28:01

don't like it. It's too much. Like

28:03

I feel frazzled. But that evening, in

28:06

retrospect, you actually have, you have all

28:08

these memories you can pick up and

28:10

recall in detail. And so your memory

28:12

for time expands. Later on, in the

28:14

moment, you say, I have no time,

28:17

time is short, time is short. Later

28:19

on, as you're retrieving the memories, you're

28:21

using those memories to infer time.

28:23

That's the paradox. And then you say,

28:25

oh, it was a really long day. I

28:27

had a lot going on. So much. So

28:30

what's the best for mental health? So

28:32

this is what I was thinking

28:34

about on the way. So the

28:36

best is not one or the

28:38

other. The best is, again, something

28:40

in the middle. And I actually

28:42

think it's even more precision focused

28:44

than that. I think what might be good

28:46

for you might be different than

28:48

what's good for me. And

28:50

unfortunately... our world, especially the

28:52

Western world, is built up

28:54

on from the time kids

28:56

are three years old, they're

28:58

being told when they need to

29:01

do things and how long they

29:03

need to be doing things. And

29:05

so we're trying to push people

29:07

into this box of 40-minute class,

29:10

five-minute break, and then in college,

29:12

and then in our jobs. And

29:14

I think that at some point,

29:16

what we should do for

29:18

ourselves... as adults, and then

29:21

hopefully in the educational system,

29:23

is figure out what timescale

29:25

works for us. In other

29:27

words, we need to figure out

29:29

how to interleave moments of stability,

29:32

so we're forming these integrative memories

29:34

and moments of change. So we need

29:36

to have both in the day. And not

29:38

all one or all the other. And what

29:40

about these flow states too when you get

29:42

into kind of a flow state and you...

29:44

You mean when you are now when you're focused

29:47

on... Something really intensely and it

29:49

feels like time flies by and you

29:51

know where does that fit in? I can't say

29:53

that I have been in a flow state ever

29:56

in my life. I'm feeling... Why don't you

29:58

describe it more? We need to talk... about

30:00

this. It's a feeling where you lose your

30:02

sense of time and self in place. You're

30:04

fully engaged with the world, like

30:06

when climb or long distance runings

30:08

you have to be hyper focused

30:11

in one sense, but it's not about

30:13

the ego. You experience time as Heather

30:15

said, suddenly you sort of become too

30:17

and realize, oh, here I am climbing

30:20

or running or writing code. A lot

30:22

of people have it when they've write

30:24

code, totally absorbs you, but you're very

30:26

content, very happy. I have an

30:28

example of where my perception of

30:30

time was completely distorted in my

30:32

memory and it happened when I

30:35

was giving birth. I'll tell you

30:37

my experience and maybe it's similar. No,

30:39

not in the full, but where time changed.

30:41

If only. If only. It was the last

30:43

like moments, what it felt like last

30:45

moments when you had to like push

30:48

and push and but eventually I had

30:50

to have an emergency C section because she

30:52

couldn't come out. But this pushing part of

30:54

it. Like you would have to wait until

30:56

the contractions come and then they would have

30:58

you push and push. And to me it

31:00

felt like I tried doing that for like

31:02

maybe 20 minutes or so until they said, you

31:04

know, it's just not going to work and we're going

31:06

to have to go for the C section. It

31:08

turned out it was like three hours or something

31:11

like that, which I still can't grasp my mind

31:13

around. Oh, you expensive. It's 20 minutes. Yeah, I

31:15

thought I tried pushing a few times and then they

31:17

were like, no, we got to go to go

31:19

to go to go to go to go to

31:22

go to go to the C section. I had

31:24

been in labor already for hours and hours and

31:26

hours so this was like at the tail end

31:28

of it because I was like you gave up

31:30

so quickly and took me to the C section

31:33

like couldn't we try it harder and they were

31:35

like you were there for three hours I did

31:37

not feel that at all I don't remember any

31:39

of that I just remember about 20

31:42

minutes of pushing but what was

31:44

your experience was it different

31:46

similar? almost 72 hours, mostly at home,

31:48

and it wasn't constant. So I would

31:50

be in active labor Monday to Thursday.

31:53

All night I was in active labor

31:55

about four or five minutes apart, and

31:57

they tell you to go to the

31:59

hospital. three or four. So I was

32:01

waiting to cross that threshold. Active labor

32:04

all night and then as soon as

32:06

the sun would come up it would

32:08

slow down. It was still there but

32:10

it would slow down. So this went

32:13

on for three days and it felt

32:15

forever. I had three turns of the

32:17

sun really slow, never left the apartment,

32:19

would slowly, tried all kinds of things

32:21

and it just felt like it was

32:24

never going to end. It felt very

32:26

long and extended. And I like to

32:28

contrast that with like the one minute

32:30

between. actually giving birth to my daughter

32:33

and being able to see her face

32:35

and holding her. And in that, literally,

32:37

I didn't, you know, it felt like

32:39

one or two minutes. I was looking

32:42

up at the clock and I heard

32:44

everyone in the room and you heard

32:46

the gel and the weight being called

32:48

out and my husband went and picked

32:50

her up and she came and looked

32:53

at me. And so now I have

32:55

this very rich memory of the sequence

32:57

of events that occurred in that two

32:59

minute period. But my memory of the

33:02

labor is... just I don't know me

33:04

floating around in a room is very

33:06

small and very short even though it

33:08

was a much longer period of time

33:10

so I think that exemplifies some of

33:13

the ideas that we're talking about. Yeah

33:15

I think really it does exemplify this

33:17

this what I find fascinating it really

33:19

explains a lot for me as well

33:22

as that the more sort of monotonous

33:24

the time is it could be really

33:26

long in real time but your memory

33:28

of it is much is contracted the

33:31

more either numerous changing events that occur

33:33

within a period of time or you

33:35

know emotionally salient events that occur can

33:37

be short in the real time but

33:39

in retrospect in your memory can be

33:42

expanded. Exactly that's the paradox so yeah

33:44

in some ways I think we like

33:46

to prioritize the experience if you're prioritizing

33:48

your experience then having that stability is

33:51

nice. So think of, you know, a

33:53

long day on the beach or a

33:55

Sunday where you decide you're just going

33:57

to stay home because you need to

33:59

recoup. You need time in the moment

34:02

to rest. But that's not going to

34:04

be a day that you remember later on.

34:06

And that's okay. Like sometimes we

34:08

need to have those moments. But

34:10

you don't want to have too

34:12

many of those because that is

34:14

what depression feels like. Nothing changes.

34:16

Your mental state is constantly in

34:19

the same space. And even though

34:21

you're walking around the world and

34:23

things are changing. I think that

34:25

depression is another way of thinking

34:27

about it is that you're being

34:29

drawn to this local minima of

34:31

your brain always working in a similar

34:33

way. The depressive people have worse memory

34:36

than non-deprest? They do. Yeah.

34:38

What many fallacies and computational people

34:40

emphasize these days that time itself

34:43

is a construct of your mind. Yeah.

34:45

doesn't really exist. It's not a

34:47

natural mapping between external time and

34:49

time in our head. It's a

34:52

construct. Yeah. Imagine then the ultimate

34:54

freedom where instead of waking up

34:56

the way we wake up, most

34:58

people wake up and think, oh, I

35:00

got to get to work, got to

35:02

have a meeting, what's your day look

35:05

like, your calendars? We have the spatial

35:07

representation of our day. Imagine waking waking

35:09

up and thinking, well, what do

35:11

I want to do today? What do

35:14

I want to accomplish? the space to

35:16

get deep into that context, your mental

35:18

context, to really let yourself sort out

35:20

problems. No, but we feel like some

35:23

of us have that freedom. We should.

35:25

Once you're tired, if you have a

35:27

bit tired. No, but I feel like that's

35:29

the problem. I think that's a

35:31

big problem with our field as

35:33

scientists, like universities and institutes hire

35:36

who they deem to be like

35:38

the most. you know, productive creative

35:40

people, and then they put them

35:42

on this crazy schedule that doesn't

35:44

allow their brains to be creative. So

35:47

do they have different memories? Do they,

35:49

because they don't have this busy, oh

35:51

my God, my first Zoom call is

35:53

in 10 minutes? That's a good question.

35:55

I don't know the answer to that, but

35:57

I do tend to notice people who

35:59

take up a new skill. They learn

36:01

the piano or they learn painting. They

36:03

allow themselves to get, skill learning is

36:06

really hard. It takes many hours and

36:08

you know, and I think they allow

36:10

themselves to pick up skills that are

36:12

quite impressive and we think of as

36:15

mostly children are good at picking up

36:17

those skills. But I don't know the

36:19

answer to how they feel about time

36:21

and memory. I think there's something to

36:23

be said with not over scheduling and

36:26

you know, allowing yourself to... Take the

36:28

time you need to think deeply or

36:30

get deep into something. Can you please

36:32

discuss this discussion? I was on the

36:34

phone call. And the last thing, you

36:37

know, I think time does exist in

36:39

the physical world. Like there is, you

36:41

know, time is a dimension in physics,

36:43

but our perception of time is a

36:45

creation of our minds. And I've even

36:48

looked at some of the research that

36:50

I would disagree with that. There's this

36:52

block time universe that says everything is

36:54

simultaneous. Like the block time. Maybe there's

36:57

no such thing as time, but our

36:59

perception of time. research that I've done

37:01

looks at when people have brain damage

37:03

to certain parts of the brain, the

37:05

dorsal lateral prefrontal cortex in particular, it

37:08

really affects their perception of time. People

37:10

who have also orbital prefrontal cortex lesions,

37:12

it affects their perception of time. So

37:14

we know that it's, our perception is

37:16

created in our brain and it can

37:19

vary depending on that neurochemistry or, you

37:21

know, the neuroanotomy. And we should just

37:23

take it all with sort of a

37:25

grain of a grain of salt, right?

37:27

It's all a construct. So

37:33

we end every episode asking a

37:36

perception box question. And we don't

37:38

know, I don't know what question

37:40

Christoph has chosen. He doesn't know

37:42

what I've chosen. So we're going

37:44

to throw it out there and

37:46

we all can answer the question

37:48

or not, depending on how you

37:50

feel. So do you have a

37:52

question? Yes and no. Okay, go

37:54

for it. What is the one

37:56

memory that you keep on returning

37:58

to? Is there a sort of

38:00

a dominant memory that you keep

38:02

on returning to? And why would

38:04

that be so? I have to

38:06

think of this. Is there a

38:08

dominant memory? Or something that sort

38:10

of spontaneously unbidden keeps on coming

38:12

back once a day? My mind

38:14

is like a playground, right? And

38:16

you get to choose where you

38:18

go in it, right? When you're

38:20

just sort of daydreaming. So I

38:22

have less intrusive. I don't have

38:24

so many intrusive thoughts or memories,

38:26

but sometimes I'm like, it would

38:28

be fun to remember this right

38:30

now, or I want to go

38:32

live in this place for a

38:34

moment. I had to go into

38:36

general anesthesia just one time in

38:38

my life for back surgery, and

38:40

I was very nervous about it.

38:42

And I was told to just

38:44

like, as you're getting wheeled into

38:46

the OR, like, before you go

38:48

under, like, try to kind of

38:50

think of something, a memory that

38:52

brings you to a sort of

38:54

your happy place. So I did,

38:56

you know, my PhD was at

38:58

Oxford at this at Maldon College,

39:00

this beautiful college that was like

39:02

magic to me. C.S. Lewis went

39:04

there and, but it had these,

39:06

this like the cloisters. And whenever

39:08

I'd walk in these cloisters, it

39:10

just brought me such peace and

39:12

comfort and just like I was

39:14

connected to like history and whatever,

39:16

and it's beautiful like wisteria growing.

39:18

And that is my happy place.

39:20

So whenever I feel nervous or

39:22

anxious, I will just go back.

39:24

And in my mind, it's like

39:26

so vivid, I can see every

39:28

detail, I can see myself walking

39:30

through these cloisters and the bells

39:32

chiming in the background, it brings

39:34

me such peace and joy. So

39:36

that's a memory I go back

39:38

to a lot on purpose. Yeah.

39:40

Yeah. Yeah. I don't have an

39:42

answer for you. I mean, I'm

39:44

cued by what you said and

39:46

I can think I love nature

39:49

and I would choose to be

39:51

in nature because I feel more

39:53

calm. But I'm constantly planning. And

39:55

so I like I'm a listmaker

39:57

so my brain is oriented towards

39:59

the future I can't recommend Matt

40:01

for everyone. Every researcher who's focused

40:03

on the future. Right. So I

40:05

am efficient. I'm reading a book

40:07

by Miranda July and there's a

40:09

distinction between people who are parkers

40:11

versus drivers. Like are you a

40:14

parker or a driver? And I

40:16

love that distinction because I'm definitely

40:18

a parker. I'm a parker even

40:21

about driving. So unfortunately,

40:23

I can't, I don't have, I mean, I

40:25

do, my brain does tend to. I will admit,

40:27

it does tend to reactivate situations

40:29

that I wish would have gone

40:32

differently. Like I play a lot

40:34

of counterfactual thinking from the past,

40:36

but I'm often planning. What about

40:38

you? Could he answer your own question?

40:40

Yeah. Well, so I too incredible

40:42

meaningful, one this near-death experience that

40:44

I think about every day, it

40:46

happened almost, you know, for an

40:49

years ago, I returned to time

40:51

after time, because it was so

40:53

meaningful, and then I had this...

40:55

sort of what people call a

40:57

mystical experience again, and you come back

40:59

to this bidden or unbidden

41:02

constantly. Both, by the

41:04

way, have no time. So my question

41:06

is, is there any action that

41:08

you or something you want to

41:10

do that or actually want to

41:12

take that you just don't feel

41:14

ready yet to do or to take?

41:17

Yes, and it's what you alluded to.

41:19

To go to the state where I

41:21

wake up and the entire day... There's

41:23

nothing planned. I'm not doing anything.

41:25

I'm not giving a Zoom talk

41:27

or, you know, writing a paper

41:29

or a book or whatever. But

41:31

I'm also afraid of getting to

41:33

that state. So what about you? Yeah.

41:35

Well, I would think that you should be

41:38

able to do that any time. I think

41:40

that that is a great goal for all

41:42

of us. Again, but the plan for mine.

41:44

But then you actually have to

41:46

do it for you. That's more

41:48

challenging. Oh my God. I'm not

41:51

going to do anything today. How

41:53

does it make me feel and

41:55

look? Yeah. I think for me,

41:57

I think a lot about wanting

41:59

to be... in a state

42:01

where I'm closer to nature and

42:03

particularly animals. I have this dream

42:05

to swim next to a whale.

42:07

So this is like this, and

42:09

I don't think that will ever

42:11

happen in my lifetime. So I

42:13

think that I think of myself

42:15

as diving into the water. I

42:17

have this image of complete freedom.

42:19

I could swim with dolphins. It's

42:21

true. I can probably make. But

42:23

that would be in a like

42:25

a closed. I think in a

42:27

big ocean. I would like to

42:29

be able to be more comfortable

42:31

with letting go of control. And

42:33

I love water and I feel

42:35

completely free when I dive into

42:38

the water. And so I would

42:40

love, that's what I think about,

42:42

I would love to be in

42:44

that space one day where I

42:46

jump off a boat and I'm

42:48

swimming with a well. I love

42:50

that. I would like to be

42:52

able to be more comfortable with

42:54

letting go of control. And it's,

42:56

you know. It's something I want

42:58

to work towards where, because I

43:00

always feel like I'm more comfortable

43:02

when I'm in control of things.

43:04

And I don't like surprises, I

43:06

don't like not knowing, and I

43:08

just, it's hard. It's easy for

43:10

me to let go in certain

43:12

contexts, like if I'm painting or

43:14

in a flow state or whatever,

43:16

then I can let go, but

43:18

like letting go in like the

43:20

external world and it scares me.

43:22

So I want to work toward

43:24

that. You're a park or two.

43:26

Yeah, and I'm really good at

43:28

panel of parking. Yeah, exactly. So

43:30

good that people clock. Yes. So

43:32

yeah, I want to be able

43:34

to figure out how to let

43:36

go of control a little bit

43:38

more. Well, I want to thank

43:40

you, Lila, for of... wonderful conversation

43:42

and for joining us today. And

43:44

if you'd like to learn more

43:46

about your own perception box, spend

43:48

some time this week answering the

43:50

same perception box questions that we

43:52

asked our guest and check out

43:54

other questions on our website at

43:56

unlikely collaborators.com. You can also subscribe

43:58

to our YouTube channel. and watch

44:00

the show or listen wherever you

44:02

get your podcasts. This

44:05

has been Science of

44:07

Perception Box created by

44:09

unlikely collaborators in partnership

44:11

with pot people. I'm Dr.

44:14

Heather Berlin. And I'm Dr.

44:16

Kristof Koch. Thank you very

44:18

much.