George Lakoff: How Brains Think: The Embodiment Hypothesis
(Keynote address recorded March 14, 2015 at the inaugural International Convention of Psychological Science in Amsterdam)
Initial Remarks (0:03--7:00)
-
Most thought it unconscious.
-
The usual estimate is 98%, but it's probably even more than that.
-
Consciousness is the tip of the iceberg of thought where things are put together in an interesting way.
-
The interesting way: Before consciousness, your brain unconsciously changes what you perceive or what you think.
-
-
@0:55 in the video Lakoff covers the details of several experiments that show that
-
These scientific studies demonstrate how the brain alters reality by assimilating what occurs to patterns it already knows.
-
The brain and body can have "real" sense perception (seeing, hearing, feeling) of something that is not there, but rather what optimally fits your prior understandings.
-
-
The McGurk Effect:
-
Try for yourself here: youtube.com/watch?v=G-lN8vWm3m0
-
-
-
-
What's conscious and what is unconscious?
-
All meaningful thought is embodied
-
You have connections to your body in all parts of your brain
-
Imagine you had a complete brain map of all connections in the brain not connected to the body, just connected to each other. Could you have meaningful thought? The answer is no. There would be nothing to think about. You can only have meaningful thought through the body.
-
Neural circuits in the brain with no connections to the body would not be about anything, and so could not characterize meaningful thought
-
-
When you see brain maps that show networks connected to each other, you must remember that this is just a computer model, and in fact nothing in your brain touches like that.
-
They're synapses -- everything goes across a synapse.
-
All the computer--generated pictures of how things in the brain are "connected" are representing something that is not connected -- they work through chemistry and physics.
-
-
-
-
-
Our brains' sensory-motor circuitry is also present in animal brains and appears to have been re-purposed ("exapted") by human beings for thought and language
-
This is an important feature of what our thinking is.
-
Also suggests animals think, which they do.
-
Some Basics (7:00--10:50)
-
100 billion neurons create 1 quadrillion connections all over the brain
-
We are born with about 100 billion neurons on our brains.
-
Each has about 1,000-10,000 connections to other neural sites => between100 trillion - 1 quadrillion connections
-
-
-
We're also born with all sorts of emobodied structures in place
-
i.e. Topographic maps of the visual field develop in the womb; Connetions to internal organs (heart, lungs, etc.), muscles, ears, eyes and skin.
-
A fetus in the womb will move its arms, legs, mouth -- in order to do this it must have a neural system working to make that happen.
-
Every time they move the arms or legs in the same way, those neural connections get strengthened.
-
Hebbian Learning -- "Neurons that fire together wire together."
-
-
-
The way these embodied structures get there is called Neural Recruitment
-
i.e. If you can put your thumb in your mouth in the womb , and you do it repeatedly, the neurons for that are strong so that you can do it at birth. The neural structure has to be there in order for you to use it (i.e. to move your thumb to your mouth.)
-
Whenever you learn anything, it has to be there already in order to be recruited. If it isn't already there and firing, it cannot be recruited.
-
Everything you have learned depends on the structures that you were born with, i.e.:
-
Topographic maps of the visual fields
-
Motor cortex (allows you to move your body)
-
Somoto-Sensory cortex (connects you ot everything in your body that feels anything)
-
-
All these things are there, and they structure what you learn next.
-
You don't randomly learn anything. Changes are not random, things change relative to what you already have. This is a big deal.
-
Called Neural Darwinism
-
If your connections are in the right place to be able to do it, they will be strengthened and then you will learn those.
-
-
-
-
You can only acquire new circuitry via the strengthening of pre-existing neural connections. You are born with so many neurons and connections that there are networks for many things ready to be strengthened at the synapses through use.
-
-
-
-
Constrains on the Brain's Neural System (10:50--18:27)
-
Embodiment Before Birth
-
Primitives for controlling movement, space, force, etc.
-
-
Synaptic changes
-
Some are Hebbian (see above)
-
Some are STDP (spike-time dependent plasticity)
-
When neurons form connections, the neuron that regularly fires first is strengthened in that direction, the others weaken in the opposite direction
-
This allows you do to do things in sequence. You can't do anything in sequence if it doesn't have asymmetry. You . cannot move anything if there is not an asymmetry.
-
-
STDP allows you to do anything at all in sequence, and it also permits metaphor.
-
-
-
Energy Minimization
-
The least energy it takes to fire, the more likely the firing will take place.
-
The easier it is to recruit -- it's easier to recruit things that can fire more easily.
-
Very important principle for language and thought
-
-
-
-
Neural Reward System
-
Dopamine, Norepinephrine (good and bad rewards)
-
Important for the moral system and understanding what morality is
-
-
-
Human perceptual and conceptual systems are shaped by these constraints.
-
This basic set of constraints means that what is permanently acquired is constrained by these mechanisms. These commonalities of brains and bodies that we all share allow us to learn a certain set of ideas that appear to be universal; Others combine differently in different cultures.
-
You live in a gravitational field, the sun rises every day, you're born to parents, you have to eat, excrete, breathe, do all these things -- and they shape how you think. We're going to talk about how that works.
-
-
-
One of the things very improtant has to do with generalizations.
-
Frame Genrealizations are acquired automatically and unconsciously and arise via the above constraints.
-
A "frame" is a neural structre that allows you to organize your experience.
-
i.e. The notion of motion: There's a source, a goal (and endpoint of the motion) and the motion itself
-
i.e. A frame like a commercial event. A commerical event has 4 elements
-
A buyer
-
A seller
-
Goods
-
Money
-
It has a structure and a scenario: The buyer has money and wants some goods. The seller has the goods and wants the money. They exchange. Then the opposite is true (the seller hast he money and the buyer has the goods).
-
-
You can put these things together. i.e. A restaurant is partly a business and partly a food service. There is a host-guest relationship. We put these frames together, but they are in different places in the brain. So how do we put them together? It's called Neural Binding
-
There is a neural connection between the two. These can apply separately (i.e. business that is not food service, food service at home, etc.)
-
To bring them together the brain must have connections that go in both directions and give simultaneous firing. In order for that to happen these connections must be gated.
-
Gates modulate.
-
They bring together the embodied ideas that you have in order to have any complex thought at all, and most of your ideas are very complex.
-
-
-
-
-
-
-
Embodiment: 1975--Present
-
1975 - Color, basic-level, image-schemas, frames
-
1978 - Conceptual Metaphor and Embodied Cognition
-
1983 - Emotion metaphors
-
1987 - Embodied Construction Grammar
-
1989 - Blends
-
1992 - X-nets and Structured Neural Computation; Exaptation
-
1990s - Experimental embodied cognition
-
1997 - Neural modeling of metaphor, Primary Metaphor
-
1999 - The Metaphor System and Philosophical Theories
-
2000 - Cognitive Foundations for Mathematics
-
2001 - Present: Working Out Details
"Very often the best thing that ever happens to you is that you learn a lot and you fail." @20:35
20:35
-
In Lakoff's first 10 years as a linguist was find examples where Chomsky's theory of grammar didn't work because it was purely based on grammar and not on meaning. It has symbols which were uninterpreted symbols, independent of meaning and communication.
-
"That sounded pretty weird to me"
-
"so I started finding examples that didn't work."
-
-
Wanted to make a theory of meaning.
-
At this time (1962-3) meaning meant logic.
-
But there isn't one logic, there are hundreds of logics, maybe thousands of logics. And they're all different.
-
The job of a logician is to make up a logic to deal with some phenomenon.
-
-
-
-
-
Color vision -- depend on wavelenghts in the world, which are not colors. The color cones in your eye connect with the neural circuitry in your brain which creates color.
-
Color cones are dependent on X chromosomes. 2 versions for men, 16 for women. Women have a larger color vocabulary - and some women can see colors that to a man don't even exist. We literally don't see the same thing.
-
In fact: There is no color in the world.
-
Applied to the above problem by Paul Kay.
-
Logic is defined in terms of truth conditions.
-
If something says "The chair is green" it means "that thing you're referring to as a chair is in the set of green things in the world." But if there is no set of green things in the world, that can't work. Logic can't work.
-
-
-
-
-
Elanor Ross - lecture on basic level categories
-
You have category hierarchies (i.e. Furniture, chair, rocking chair)
-
The one in the middle has special properties
-
A chair is defined by three things: Mental imagery, gestalt perception and motor programs.
-
-
-
-
-
Mental imagery and visual perception use the same neural structures in the brain (Martha Pharrah 1989)
-
Mirror neuron circuitry
-
Not just the neurons, you have circuits that connect from the premotor cortex to the motor cortex, and also to the parietal lobe behind that which integrates with vision.
-
Connections integrate your motor programs with your gestalt perception with your mental imagery in a single loop
-
That is why you have basic level categories.
-
-
-
-