Thought doesn't just happen in the brain | Barbara Tversky

0:00 The people sit on their hands,

0:02 it's harder for them to find [music] words to explain

0:05 how to get from their house to the train.

0:09 And when they explain those things,

0:11 they generally gesture, and the gestures precede the words.

0:16 So, they're somehow facilitating not just the words, but the thinking,

0:20 [music] and that's a bit of a mystery to me.

0:25 Why movements of the body uh seem to be core [music] to thinking.

0:37 Barbara [music] Tversky, welcome to How the Light Gets In.

0:40 Thank you.

0:40 I'm delighted to be here.

0:42 [music] So, in your um book Mind in Motion,

0:45 you argue that thinking is fundamentally spatial and embodied.

0:49 Can you explain how this changes the way that we understand [music] the mind?

0:53 So, uh the our spatial thinking takes up half our cortex.

1:00 It evolved long before language.

1:03 We communicate, create, and so forth with our bodies.

1:07 And again, it goes back evolutionarily

1:11 to one-celled creatures that either approach

1:15 things that are attractive or nutritious or avoid things that are noxious.

1:21 And that's the first kind of interaction with the world.

1:25 And again, before any language gets in there.

1:30 So, humans use spatial thinking in many different ways.

1:35 How we get around the world,

1:37 how we grasp objects in the world, and then how we communicate.

1:43 So, if I'm reaching for a glass, you know what I'm doing.

1:48 And I can use grasp as the word or um

1:53 the action as a way of communicating to you.

1:56 So, I grasp ideas and pass them on to you.

2:02 And those are all actions in the world,

2:05 but get into our language as actions on thought.

2:10 And which forms of thinking would you say are spatial and embodied?

2:14 And which forms of thinking aren't uh spatial and embodied?

2:17 So, for example, people might point

2:19 to things like linguistic reasoning and mathematical abstraction.

2:23 I think you touched on it there,

2:24 but would you say that those are also spatial and embodied as well?

2:28 In in many cases, they're going to be spatial.

2:32 They're going to be uh mathematicians will draw functions,

2:36 they'll draw spaces on pieces of paper,

2:40 they'll they'll gesture them with their hands.

2:44 Um and the that again will be spatial.

2:47 Even reasoning is one step after another.

2:53 So, is that spatial, temporal?

2:57 Um it's hard to separate what's spatial and what's temporal.

3:01 One step after another, even if it's not a two-dimensional,

3:05 three-dimensional, or n-dimensional space, it's still linear in some sense.

3:12 So, it's hard to think of things that can't in some way be reduced to spatial.

3:19 I mean, if we get into terms like justice, freedom, those are hard to grasp.

3:26 And and talking about them spatially is

3:29 a little harder or grasping them spatially.

3:32 So, there are limits, but I think a great deal of scientific

3:37 and mathematical thinking is as a spatial basis.

3:42 And why do you think this recognition is is an important one?

3:45 Because it seems like you're pushing back against a certain type of view

3:49 where thinking is something that just primarily

3:51 happens in the head and the brain.

3:54 And that's that is arguably been quite central in a lot of Western philosophy,

4:01 especially in the past few centuries.

4:03 Do you see it as in as you pushing back against a type of view

4:08 that is that is the idea that thinking happens primarily sort of up here?

4:13 So, there are two ways of approaching that.

4:16 One is thinking only in the brain or does the body contribute?

4:20 And another is pushing back against language-based view.

4:25 So, I can talk about the first, and it puzzles me.

4:30 So, we find These are old experiments.

4:34 If people sit on their hands, it's harder for them to find words to explain

4:40 how to get from their house to the train.

4:43 And when they explain those things,

4:46 they generally gesture, and the gestures precede the words.

4:51 So, they're somehow facilitating not just the words, but the thinking,

4:56 and that's a bit of a mystery to me.

4:59 Why movements of the body uh seem to be core to thinking.

5:06 And I think the neuroscientist will work that through.

5:10 Is it through It must be reflected in the brain,

5:14 but how necessary is the body for that kind of thinking?

5:19 So, clearly, we can do that kind of thinking.

5:22 People without arms, without sensation below the neck can think and can explain.

5:29 So, we have alternative bases.

5:32 Um just like blind people can navigate without vision.

5:37 So, that's part of it, and it remains a bit of a mystery to me

5:41 how the body seems to be important for thinking.

5:45 I mean, another thing we know is if we

5:48 put people deprive of them any sensation, their mind wanders.

5:54 They can't keep control of the mind.

5:58 And that again indicates something about the body

6:01 promoting the thinking independent of the brain.

6:05 The brain is still active, but the body is desensitized and not moving.

6:11 Um the other part is language, and there I think Western philosophy,

6:17 certainly educated people, is very dominated by language.

6:22 And language can mean many things.

6:24 Some of it is highly codified system of words organized by rules.

6:31 And there, things like gestures, body movements can't be discretized in the way

6:40 that language can be coded into words, nor are there rules.

6:45 So, if I'm giving you directions and I say there's an intersection or there's

6:50 an intersection or there's All of that sort of captures the same meaning,

6:56 but it's not the same way of expressing it.

7:00 And if I get to vague concepts like it's rocky,

7:04 uh that's going to be again not something that's easily codified.

7:10 Conductors use very different ways of communicating with their orchestras.

7:16 Their orchestras somehow get it and play music,

7:20 but it's not easily codified in the way that language is.

7:24 So, that would be another contrast where thinking

7:28 with the body and space is different from language.

7:33 And um people say this intuitively,

7:36 but I think there are some studies that also suggest

7:38 this, which is that there are a group of people

7:41 in the world um who primarily feel that they reason more

7:46 with with with spatial images and and pictures and things like that.

7:52 And there are some people who um think more in words essentially.

7:55 They think in sentences.

7:57 And then there are another group of people who just say,

7:59 "Oh, well, um they I have an internal monologue in my head,

8:03 and that's how I come to think about

8:05 things and I come to conclusions." How would you

8:08 say this sort of understanding or this research interacts

8:11 with what you say about in in bodied thinking?

8:14 So, we'd need evidence that people really are thinking differently,

8:20 and I'm open to that kind of evidence.

8:23 Um and I do know people who think who don't have spatial imaginations at all.

8:30 They can't find their way in environments easily.

8:34 And they're brilliant people who think one step after another.

8:38 And again, that would be linear thinking,

8:40 whether we want to call that spatial or not, simplify.

8:45 So, yeah.

8:46 Um Most people that I encounter are pretty flexible

8:52 in in the way that they think, again varying.

8:56 Um I don't think we think in words.

9:02 The words kind of come after the thoughts.

9:06 And we don't really have access to the thoughts.

9:09 We can sometimes into introspect on that.

9:13 And if you look at at athletes, and they're going to often do mental practice.

9:21 How do I do a dive?

9:23 How do I dance a step?

9:25 That again isn't words.

9:27 It's somehow encoded in their body in some way,

9:31 and they might be making miniature movements doing that.

9:36 And again, I think many people can do a bit of this and a bit of that.

9:40 We aren't restricted to one way of thinking.

9:45 But the individual difference work needs to be done,

9:49 and I think it would be fascinating.

9:52 I want to separate images from spatial because again,

9:59 blind people can have excellent spatial memory and spatial thinking.

10:04 They often gesture.

10:06 Children blind from birth gesture.

10:09 And it seems to help their thinking.

10:11 Adults who are blind gesture and it seems to help their thinking.

10:15 These are spatial motoric sorts of things don't come with visual images.

10:22 So I want to keep those things separate.

10:26 I mean there are people who say they don't

10:28 have visual images and you I trust them although again,

10:33 I'd love to know the neuroscience behind it.

10:37 On this like side note because you mentioned blind people,

10:41 is there any literature on the difference in the way

10:43 in which blind people from birth think and interact with the environment

10:48 in the way in which people who weren't blind from birth

10:51 but were blind in became blind in later years think?

10:56 Um What what is that?

10:59 Again, you'd have to know what you mean by thinking.

11:03 I don't mean I don't think the literature there is very rich

11:07 but there are blind mathematicians who've been

11:11 blind from birth and who think spatially,

11:14 blind physicists blind from who think spatially.

11:18 They do need to reach for things, interact with things in the world,

11:24 get around their houses and they learn to do that spatially.

11:28 The sorts of things they pick up, the ground, the texture of the ground,

11:33 wind, smells and things that we might

11:37 be picking up but not necessarily consciously.

11:41 So they're using those cues of from the world around them,

11:45 sensory cues that are different from vision.

11:49 So many of them can navigate quite well

11:52 and better than I can from their spatial sense.

11:58 Is there is evidence that people blind from birth or deaf

12:01 from birth different parts of the brain pick up different things?

12:05 So for blind people often the back of the brain,

12:10 the occipital lobes will pick up all sorts of spatial things even tactile

12:15 things that aren't that that in sighted people are used for other things.

12:22 So especially people who are blind or deaf from birth,

12:27 the brain will will accommodate in many ways.

12:32 Um some like Iain McGilchrist have put forward the view that cognition

12:36 and thinking is fundamentally made up of two hemispheres of the brain.

12:41 The right brain which sees things in a more

12:43 holistic and contextual way and would maybe map

12:46 onto the sort of embodied thinking that you're talking

12:49 about and the left that's more sort of analytical,

12:52 instrumental and linguistic and logically based.

12:56 Um and and both these sides, the the left and right hemisphere have their own

13:01 personalities and are kind of vying for power.

13:03 Does this share similarities with your embodied thinking of view?

13:07 Do you have any thoughts on that kind of view?

13:10 Yeah, I mean people love dichotomies or there

13:13 are two kinds of people in the world,

13:15 those who love dichotomies and those who don't.

13:19 So it's probably saying the whole hemisphere is one

13:22 thing or another is a little extreme but language does

13:26 tend to be left-sided and is more sequential logical

13:32 and the right side is seems to be more holistic.

13:36 So on a very abstract way, there's something to that.

13:41 He's not the only one who's made that distinction.

13:44 Many people before him have.

13:48 So sure that but it it's it doesn't

13:53 respect the complexity of the brain and right.

13:58 In what ways do you think it doesn't respect the complexity of the brain?

14:01 Oh, you know there there are places in the brain that are specialized for faces.

14:07 There are places in the brain

14:09 that are specialized for certain objects, recognizing them.

14:13 So the brain is there's a place in the brain that recognizes mirror

14:22 that that recognizes that a small b and a small d are mirror images.

14:28 They aren't the same.

14:29 The many other visual portions of the brain

14:34 don't care if something is mirror reversed.

14:37 There's one tiny place in the brain

14:40 that does care if something's mirror reversed.

14:43 That tiny place is used for recognizing reading.

14:48 Now the brain didn't evolve with reading but that area of the brain capitalizes

14:55 on small b and small d are mirror images and and distinguishes between them.

15:01 So looking at that complexity of the brain is

15:04 fascinating and if you just split hemispheres, you'll miss that.

15:11 Okay.

15:12 A lot of philosophy from Plato to Descartes and Christian theology has placed,

15:17 I think you said earlier, premium on logos, language and reason.

15:21 Do you think this has been a mistake

15:23 in causing confusion about the way we think about thinking?

15:28 A mistake I wouldn't say.

15:30 I mean we're we're settling on one theory or another is difficult.

15:37 Data keep coming in, views keep coming out and that makes

15:41 life very interesting that we like to have things

15:46 permanent and and complete and a way of dealing

15:51 with the world but the world doesn't behave in that way.

15:56 So we have to keep adapting and changing.

15:59 Things unexpected things keep happening that aren't under our control.

16:04 So it feels to me like relying on one

16:07 system or another is is relying on shaky grounds.

16:13 Um And you mentioned earlier which

16:16 was interesting that um with embodied thinking, when we start to get to concepts

16:22 like justice or equality or fairness or infinity,

16:27 it then starts becoming quite difficult to to apply

16:31 the embodied or spatial thinking hypothesis to it.

16:36 Do you think these are things that will be

16:38 accounted for within that framework or do you think

16:42 they'll sort of be mysteries outside of that framework

16:44 or things that aren't fundamentally just not embodied thinking?

16:49 So we can talk about justice using this kind of um this kind of gesture,

16:56 are things balanced in unjust equal?

17:00 I mean that kind of gesture and I remember one

17:03 of my grandchildren at three or four was using that kind of gesture.

17:08 And we know that babies respond to unjust actions viscerally.

17:17 So if they watch, you know, puppets and one is grabbing something from another,

17:22 these are kids that don't yet conceptualize in language,

17:27 they will react viscerally.

17:29 They'll be they won't like the puppet that grabbed from another puppet.

17:36 So it it that's embodied in a way.

17:40 We have a visceral response to watching injustice and then

17:47 the concept can get generalized in some way from that.

17:51 It's again going back to the primary response is emotional.

17:58 Are we going to approach something or avoid it?

18:02 And we don't want to approach something that's doing harm to another thing.

18:09 Um Freud stated Sigmund Freud stated that philosophy sometimes seems to me

18:16 like a person who keeps cleaning their glasses and they still stay dim.

18:21 And it seems in a lot of empirical

18:23 psychology has done away with the need of philosophy.

18:28 In your view, what is the role of philosophy in psychology?

18:33 That's a hard one cuz I get puzzled about philosophy [laughter] as well.

18:38 So you agree with Freud's view or And I studied philosophy

18:42 as an undergraduate and psychology and I it came to a point where should

18:47 I specialize in one or the other and I went to my philosophy

18:51 teacher and he said you'll do just fine but let me tell you,

18:56 you don't think like a philosopher.

18:59 And he was absolutely right.

19:01 I think empirically.

19:02 How would you answer that question using data?

19:06 And I think that's my lens on the world

19:09 and I don't completely grasp the lens of philosophers.

19:13 Partly, there are so many different kinds of philosophers.

19:18 And the ones I'm most familiar with are seem

19:21 to be concerned with the way I use language.

19:25 And and they're sure philosophy has

19:30 a role in sharpening concepts and making clear

19:35 and that can be the basis for empirical empirical research, the kind that I do.

19:43 So I I appreciate philosophers for their clarity

19:48 or that kind of philosophy for the clarity it provides.

19:55 Barbara [music] Tuchman, thank you very much.

19:57 Thank you.

20:03 [music]