The predictive brain is this idea that I only pretty much know from you.
I'd never heard it before.
When we say the predictive brain, what does that mean?
And what does it not mean?
So when you are living your everyday life.
Yeah.
Like right now.
Like right now.
So right now, I'm guessing that I'm saying things to you and you're perceiving what I'm saying and then you're reacting to it.
That's how it feels to you, right?
Yes.
Okay.
And that's how it feels to me too.
So we sense and then we react.
That's the way most people experience themselves in the world.
That's not actually what's happening under the hood.
Really what's happening is that the brain, your brain is not reacting, it's predicting.
And what that means is, If we were to stop time right now, just freeze time, your brain would be in a state and it would be remembering past experiences that are similar to this state as a way of predicting what to do next, like literally in the next moment.
Should your eyes move?
Should your heart rate go up?
Should your breathing change?
Should your blood vessels dilate or should they constrict?
Should you prepare to stand?
Right?
Movements.
And these movements, the preparation for movement, literal copies of those signals become predictions for what you will see and hear and smell, and taste, and think and feel.
So, under the hood, your brain is predicting what movements it should engage in next and, as a consequence, what you will experience because of those movements.
So you act first and then you sense.
You don't sense and then react.
You predict action and then you sense.
So give me an example, which brings this to light, of how my brain is predicting and then taking action.
Okay.
So right now you and I are having a conversation and I'm speaking and you're listening.
And what's really happening in your brain is that, based on many gazillion repetitions of listening to language, and your brain is predicting, literally predicting every single word that will come out of my Yeah, okay.
And how surprising would it have been if I didn't say mouth.
I said some other orifice of my body that words were coming out of.
That would have been pretty surprising.
Because your brain is predicting that.
Your brain is always predicting that.
And it's correcting those predictions when they're incorrect.
And you know I have this video that I often show when I'm giving a talk to scientists or to civilians.
I'm giving a talk and it creates a situation where they can predict something and they can feel that a prediction is not just this abstract kind of thought.
It's your brain is is literally changing the firing of its own sensory neurons to anticipate incoming sensations.
So you start to feel these sensations before the signals actually arrive for you to perceive them.
You start to have the experience before the world gives you those signals.
I've read I think it was in your book, but it might have been elsewhere about the example of being thirsty.
Yes.
So when you drink, so say you're super thirsty and you drink a big glass of water.
When do you stop being thirsty?
Almost immediately.
But actually it takes 20 minutes for that water to be absorbed into your bloodstream and make its way to the brain, to tell the brain that you are no longer in need of fluid.
Because across...
Millions of opportunities.
You have learned that certain movements now and certain sensory signals now will result in that mental state.
Or here's another example.
So right now, keep your eyes on me.
You're looking right at me.
And in your mind's eye, I want you to imagine a Macintosh apple like not a computer, but like an actual piece of fruit.
Okay.
Can you do it?
Can you see it?
Yeah.
What color is it?
Green.
Okay.
Does it have any red?
No.
Okay.
So it's a Granny Smith apple.
Yeah.
Okay.
What does it taste like?
Like imagine grabbing it, biting into it, hearing the crunch of the apple.
What does it taste like?
It's like sweet apple.
Like a little tart maybe?
Yeah, yeah.
Yeah.
Is it juicy?
It's very juicy.
Yeah.
Okay.
So if I were imaging your brain right now, what I would see is I would see changes in the signal that is related to neural activity in your visual cortex, even though there is no apple in front of you.
And I would see a change in activity in your auditory cortex, even though you didn't really hear the crunch.
My mouth was watering as well.
And your mouth is watering.
And in fact...
Every time you sit down for a meal, your brain directs your saliva glands to produce more saliva to prepare you to eat and digest the food.
So that usually happens in advance of even sitting down to a meal.
That is all prediction.
That's all of that.
Is your brain preparing itself for what's coming, because predicting and correcting is a much more efficient way to run a nervous system really any system than reacting to the world.
Here's another example.
Do you drink coffee?
Yes.
Okay.
Do you drink coffee every day at the same time?
Usually, yeah.
Okay.
And are you one of these people that if you miss having coffee at that time, you get a headache?
I mean, it's happened before, yes.
Well, I used to be a person who drank a lot of coffee.
And I love coffee, but I don't drink it anymore.
But I loved it, and I drank it always at the same time every day.
And if I didn't drink it, I would get, at that time of day, I would get a massive headache.
And the reason why and this is true really of every medicine you take anything which affects your physiology.
If you do it on a regular basis, your brain will come to expect it.
And what that means come to expect it is that coffee has chemicals in it that will constrict your blood vessels everywhere.
But in the brain, the brain is attempting to keep the blood flow pretty constant and even.
And so if every day, at eight o'clock in the morning, you're drinking something that's going to constrict your blood vessels, then at 755 approximately I don't know the exact timing, but a little bit before you know ate, your brain will dilate the blood vessels in preparation for that constriction.
So they remain constant.
And if you don't drink that substance, then you have this big dilation and you get a very, very bad headache.
I was just wondering then about, as you were talking, I thought you were going to talk about how sometimes, when I set an alarm, I seem to wake up like five minutes before the alarm.
Yeah, sure.
That's an example.
Here's another example.
Exercise, okay?
If you wanna play tennis better, if you wanna run a faster mile, what do you do?
Train.
Train and you do the same thing over and over and, over and over again and you get better and faster and you burn fewer calories, you get more efficient.
Why?
Because your brain's predicting really well.
That's what muscle memory is.
It's not literally a memory in your muscles.
It's a memory in your brain.
Your brain is controlling your muscles, And so if you practice the same set of movements over and over and over again, you just get really efficient at them because your brain is able to predict better.
Now, if you're somebody who's exercising because you want to become healthier or you want to lose weight, right.
You don't want to practice the same exercise over and over and over again, because you will be burning fewer calories, because you're being efficient.
That's the goal, right?
So instead, you do interval training, right?
If somebody's calling out to you every 30 seconds a different set of movements and you can't predict what they are, then you're your brain will make a prediction.
It'll be wrong.
You'll have to adjust.
And so you end up burning more calories and you end up throwing yourself out of balance, which we call allostasis.
So you become dysregulated and then your brain has to work to get itself back in again.
And so that's a different kind of workout.
These two different kinds of workouts are completely predicated on the fact that sometimes you want to be able to predict better and sometimes you want to be able to disrupt yourself and get back into the pocket quickly, right?
So basically, you're learning how to take in prediction error signals you didn't predict and adjust to them.
What does this say about the nature of trauma and other mental health illnesses like depression anxiety, et cetera?
Because is this a misfiring of my?
I say this because predictions reliant on something happening in the past and forming a pattern, like a pattern recognition system.
So if I grew up and there were certain patterns that are now not the case.
So if I grew up and every time a man walked into the room, he hit me.
And now, when a man walks into the room and I'm 35 years old, I'm getting that same sort of prediction in my brain.
So I've got a fear of men, for example.
Does this somewhat explain childhood trauma and why it's so hard to shake and why, as adults, we can sometimes have dysfunctional lives?
I would say as a general principle, yes.
There are a lot of, you know, the devil is in the details, right?
But yeah, sure.
So trauma is not something that happens in the world to you.
Everything you experience is a combination of the remembered past and the sensory present.
So there could be an adverse event that occurs.
You're in an earthquake.
Someone dies who's close to you.
Something bad happens to you.
Someone hurts you in some way.
There could be an adverse event that is not traumatic to you because you're not using past experiences to make sense of it as a trauma.
On the other hand, something that is could be like an everyday experience to somebody else to you, it links to a set of memories that are very traumatic.
We're very traumatic.
Those events were very traumatic.
And so to you, it is a trauma.
So trauma is not an objective thing in the world.
It's also not all in your head.
Trauma is a property of the relation between what has happened to you in the past and what is occurring in the present.
So here's an example.
There is an anthropologist who works at Emory University and she studies people in a lot of different cultures and she studies trauma in a lot of different cultures.
And there was this one girl that she wrote about, a case study of, a girl named Maria, who was a young adolescent girl.
And she lived in a culture where it was – more normative for men to be very physical with women and girls.
So in our culture, we would say it's physical abuse.
But in her culture, this is just what men did.
So her stepfather would slap her around and she didn't like it, but she didn't show any sign of trauma.
The way she made sense of it was that men are just assholes.
It was very much a, this is not about me.
This is about them.
It's not pleasant, but she slept okay.
Her grades were okay in school.
She had friends.
She didn't have any signs of trauma at all.
Then she watched Oprah.
And she heard all of these women talk about having been abused, the subject of physical abuse from their boyfriends or their fathers or, you know, their husbands.
And she recognized the similarity in the physical circumstances of these women's descriptions and her physical circumstances.
And she also observed them experiencing trauma, like, symptoms of trauma.
And all of a sudden she started to have difficulty sleeping and her grades dropped and she had trouble concentrating and she became socially withdrawn.
Her way of making meaning, her way of If you think about physical movements as actions, she made different meaning of those actions.
And she experienced trauma where she didn't before.
Now, if you're somebody who believes that there is an objective world out there where you know Cause and effect,
Yeah, that really there was some kind of latent trauma in her and she didn't experience it before, but then it was like triggered and then she'd be.
You could tell a whole story like that.
And people do tell whole stories like that.
But...
That's not what the best scientific evidence suggests is happening.
What's happening is that the physical movements were the same.
The psychological experience of those movements was different, because experience is a combination of the sensory present, the physical present and the remembered past.
And you need both. in order to have a particular kind of experience.
So the way to describe what happened to Maria's trajectory was that she experienced something as an unfortunate aspect of, like physical life.
And then it became about her.
It became something.
Not this person was doing something bad, but this person was doing something bad to her because of who she is.
And she was also shown how she should be responding to that by watching Oprah's show and watching these other individuals responding in a certain way.
Right.
So it became about her as a person, not just about her stepfather was an asshole.
And, if you think about it, what we do in this culture when people go into therapy for trauma right is we're attempting to actually reverse the narrative.
So we try to teach people that it's not When something traumatic happens to them, and I want to be really clear what I'm saying right?
I'm not saying that when people experience trauma, it's their fault.
I'm not in any way saying they're culpable for what's happened to them.
But sometimes in life you are responsible for changing something, not because you're to blame, but because you're the only person who can change.
The responsibility falls to you.
And so in this culture we try to teach people who've experienced trauma that they can experience those physical events that happened to them in the past in some other way.
And when they do, they no longer feel traumatized anymore.
My mind's a little bit blown.
For a number of different reasons, because it's a real paradigm shift to think that we are giving meaning to the thing that happened in our past.
And sometimes that meaning is coming from watching other people give it meaning.
And we're inheriting that meaning that... Oh, yes.
That's called cultural inheritance.
It's like a cultural... It's like a contagion.
So it turns out that, you know, there's one kind of old evolutionary theory, right?
This is called the modern synthesis, where...
Inheritance is really your genes.
Whatever you inherit, you inherit by your genes.
And then natural selection chooses some gene patterns and not others.
And that's really how inheritance works across generations.
Most evolutionary biologists don't hold to that view anymore because for the most part, there are many, many ways to inherit things.
And a lot of what we think of as inheritance is really more what's called epigenetic meaning it doesn't really involve DNA very much.
And I would say the way I like to say it is that we have the kinds of nature that requires a nurture.
We have the kind of genes that require experience before anything is wired into our brains.
And most of our characteristics work that way.
Very few characteristics work just by genes alone.
What always happens in a neurotypical environment brain is that you're born with your brain incomplete right.
An adult brain has, we say that it's wired to its world.
That world includes your own body.
But a baby's brain is not a miniature adult brain.
It's a brain that's waiting for wiring instructions from the world and from its own body.
So your brain is wired for you to see out of eyes that are the exact distance of your eyes from each other.
If somehow magically, we could transplant your brain into somebody else's skull, you would not be able to see out of that skull.
You would not be able to see out of those eyes because they're not in the right place.
You hear with ears.
Your ability to hear comes from signals that are shaped by the shape of your ear.
So your brain is wired to hear out of these ears, not any ears, these ears.
Similarly, you as a baby, you are taught the meanings of physical signals.
You're taught how to make sense of these things.
That's called cultural inheritance.
Many things that we think of as hardwired into the brain are actually culturally inherited across generations.
That's how people survive in a particular environment.
So like in the 1800s and 1900s, when explorers would go off, and they would go off to Antarctica or here or there, and they would very quickly die.
The Inuit lived there.
They lived perfectly fine.
Well, because they had culturally inherited knowledge.
We're always transmitting knowledge to each other.
And that knowledge... becomes fodder for our own predictions.
So your predictions don't just come from your personal experience.
They also come from you watching television, you talking to guests, you reading books, watching movies.
Also, your brain, like most human brains, can do something really fantastic, which is you can take bits and pieces of past experience and put them together in a brand new way so that you can use the past to experience something new that you've never experienced before.
You talked a second ago about therapists try and make you think about the past differently.
But I do think there's an underlying belief in our culture and society and on social media that if something happens to you almost like this Freudian approach of if this happens to you this is who you become.
And I was reading that book, The Courage to be Disliked over Christmas and it kind of it changed my view on this quite profoundly in an important way, because it helped me to understand.
I think it basically says that what happens to us doesn't create who we are.
We use what happened to us and we apply meaning to it, which then determines the behavior we have.
And really interestingly in that it means that many of the beliefs I have about myself, who I say I am, my identity and therefore like the ways that I behave every day, whether they're productive or unproductive, are actually just choices I've made, apply meaning to the past.
Does that make sense?
It completely makes sense.
And this is really.
This is such like a profound.
I don't know if whoever's listening now understands what I'm saying here, but we said at the start of this conversation you go through life thinking you're a puppet and you're being controlled by what happened to you, who you are, your identity.
But actually your identity is just this, this construction of meaning that you've given to the past.
To serve your purpose now, as it says in the book.
Yes.
I would say it slightly differently, but the message is the same.
I think there are, in the sensory present, right?
There are sights, there are sounds, there are smells.
Some stuff's going on inside your own body, right?
And these signals are going to your brain.
They have no inherent psychological meanings.
They have no inherent emotional meaning.
They have no inherent mental meaning.
What gives them meaning are your memories from the past.
You are a meaning maker.
Meaning isn't a set of features like a dictionary definition.
So the meaning of this cup isn't that it's made of metal.
I mean, we certainly can talk about those features, but The meaning of this cup in this moment is what I do with it.
So it could be a vessel for drinking.
It could be a weapon.
It could be a flower holder.
It could be a measuring cup.
The meaning of the vessel is what I do with it in the moment.
That's its meaning.
And so the meaning of the vessel isn't in the vessel itself.
And it's also not only in my head.
The meaning is the transaction.
It's the relationship between the features of this vessel, this object, and the signals in my brain which are creating my actions.
In fact, even the fact that this is a solid object, the property of solidity is not in the object.
It's because I have a body of a certain type, with certain features that makes me experience this as solid.
The solidity isn't in me and it's not in the object.
It's in the relationship between the two.
That means everything, everything you experience is partly of your own making.
You don't have a sense of agency about it because it happens really automatically.
It's happening automatically. automatically now as we're talking.
It's happening faster than you can blink your eyes.
But it's still happening.
And that means if you are partly, even though you don't have a sense of agency, you are partly in control and also therefore responsible for the meaning that is being made.
And when I said at the outset of our conversation that my goal was to try to you know as a science communicator, was to try to explain to people that they have more control over their lives.
They have more control over who they are in any given moment than they think they do, to give them more agency in their lives.
This is exactly what I mean.
You...
You don't have an enduring identity.
You are who you are in the moment of your action.
And actions are a combination of the remembered past.
So stuff your brain is using to predict that your brain's assembling super automatically and the sensory present right.
So if you want to change who you are, you want to change what you feel, you want to change what your impact is on someone else, You have a couple of choices.
You can try to go back into the past and change the meaning of what's happened before, so that you'll remember differently.
You'll predict differently in the future.
That's what psychotherapy is.
That's what heartfelt conversations at 2 o'clock in the morning are with your friends or whatever.
That's really hard shit.
It doesn't always work so well.
The other thing that you can do, though, is...
If you realize that whatever you experience now becomes the seeds for predictions later, then you can invest in creating new experiences quite deliberately for yourself now.
You can expose yourself to new ideas.
You can expose yourself to people who are different than you.
You can practice cultivating particular experiences, like you would practice any skill and that will Any new concepts.
You learn new experiences you have in the moment.
If you practice them, they become automatic predictions in the future.
So let me take that and try and apply it to this example of this silver cup in my hand.
So psychotherapy would try and go back into the past and explain to me why this actually isn't something I should drink out of and that it could be other things.
Whereas what you're saying is.
Another approach is, if I go and get some flowers right now and I put them in there, I'm creating a new prediction for the future because I've created a new pattern in the present of this actually being a vase for flowers.
And I can start to create a new pattern, that silver cups like this one aren't just for drinking out of.
They are also vases for flowers.
Exactly.
Exactly.
Okay, so I can either go back in the past and try and convince myself that a cup isn't a cup, or I can, in the present moment, create a new pattern which will mean that in the future my brain will predict next time it sees a silver cup, it won't just think drink out of it Steve, it'll think pop some flowers in it.
Right.
And remember, it's actually the thinking comes after the action, right?
So what will happen is...
The next time that you are approaching a table where a silver cup might be, your brain will already be starting to prepare the actions to go get the flowers.
And then you will think, oh, right, I can use this as a, oh, look, there's a great vase.
So in your brain, it's action.
First, your brain is controlling, it's preparing the actions of the viscera, what we call visceromotor.
So does your heart rate need to change?
Do your blood vessels need to dilate?
Do you need to breathe differently?
It's basically anticipating the needs of the body and attempting to meet those needs before they arise.
That supports your physical movements, right?
So if you're walking over somewhere to pick up some flowers and cut the stems and whatever, those are all physical movements that require glucose and oxygen and shit like.
So all of that has to get prepared in advance, milliseconds before the actions start to be prepared.
So it's not what you think determines what you feel.
It's what you prepare to do determines your thoughts and your feelings and the sights and sounds and smells and sensations.
That's how it really works under the hood.
So meaning is in terms of what you do.
And then as a consequence of that, meaning becomes what you feel and what you think and so on.
So let me give you some specific examples then.
So if I'm scared of spiders, how would I go about overcoming that fear of spiders?
Using route number two that you described there?
So one of the ways that you change to change predictions.
You can't just will yourself to change a prediction.
I am really afraid of bees.
I had a traumatic experience when I was five.
I'm afraid of bees.
I know a lot about bees.
I'm actually a gardener.
And I know a lot about the evolutionary biology of bees.
But when I am outside, if a bee comes around, my first reaction is to either run or to freeze right.
I'm afraid of bees.
I could talk to myself until the cows come home.
It won't matter, right?
So what I have to do is dose myself with prediction error.
Meaning I have to interact with bees in a way that changes my actions, which will change my lived experience.
And I can't just do it all at once.
It's not like a good idea, would not be for me to say, would not have been for me to go to somebody who has beehives and put on a suit and go work.
I mean, that would be overwhelming, right?
So instead, maybe I don't run.
Maybe I stand and watch.
Maybe I get closer to a bee.
Maybe I plant bushes and flowers that bees like a lot to bring bees to me so that I can sit and just be around them while they're buzzing and doing their thing.
Maybe I deliberately let myself get stung at some point, which I did.
But you're dosing yourself with Your brain is making a set of predictions.
Those predictions, there are a set of predictions.
That means your brain isn't preparing one action, it's preparing multiple actions.
So you need to prove to your brain that those predictions are wrong.
Yes, so exactly.
You are setting up circumstances so you can prove to yourself that your predictions are wrong.
What you just listened to was a most replayed moment from a previous episode.
If you want to listen to that full episode, I've linked it down below.
Check the description.
Thank you.
