The neurons that shaped civilization VS Ramachandran

I’d like to talk to you today about the

human brain which is what we do research

on at the University of California just

think about this problem for a second

here’s a lump of flesh about three

pounds but you can hold in the palm of

your hand but it can contemplate the

vastness of interstellar space it can

contemplate the meaning of infinity ask

questions about the meaning of its own

existence about the nature of God and

this is truly the most amazing thing in

the world it’s the greatest mystery

confronting human beings how does this

all come about well the brain as you

know is made up of neurons looking at

neurons here there are 100 billion

neurons in the adult human brain and

each neuron makes something like a

thousand to ten thousand contacts with

other neurons in the brain and based on

this people are calculated that the

number of permutations and combinations

of brain activity exceeds the number of

elementary particles in the universe so

how do you go about studying the brain

one approach is to look at patients who

have had lesions in different part of

the brain and study changes in their

behavior this is what I spoke about in

the last ten today I’ll talk about a

different approach which is to put

electrodes in different parts of the

brain and actually record the activity

of individual nerve cells in the brain

sort of eavesdrop on the activity of

nerve cells in the brain

now one recent discovery that has been

made by researchers in italy in parma by

giacomo rizzolatti and his colleagues is

a group of neurons called mirror neurons

which are in the front of the brain in

the frontal lobes now it turns out there

are neurons which are call ordinary

motor command neurons in the front of

the brain which have been known for over

50 years these neurons will fire when a

person performs a specific action for

example if I do that and reach and grab

an apple am order to command you run in

the front of my brain will fire if I

reach out and pull an object another

neuron will fire commanding me to pull

might pull that object these are called

motor command neurons be known for a

long time but what rijalallah found was

a subset of these neurons maybe about

20% of them will also fire when I’m

looking at somebody else performing the

same action so here’s a neuron that

fires when I reach and grab something

but it also fires when I watch Joe

reaching and grabbing something and this

is truly astonishing because as though

neuron is adopting the other person’s

point of view results almost as though

it’s perfect for mning a virtual reality

simulation of the other person’s action

now what is the significance of these

mirror neurons for one thing there must

be involved in things like imitation and

emulation because to imitate a complex

act it requires my brain to adopt the

other person’s point of view so this is

important for imitation and emulation

but why is that important well let’s

take a look at the next slide so how do

you do imitation why is imitation

important mirror neurons in imitation

emulation now let’s look at culture the

phenomenon of human culture if you go

back in time about seventy five hundred

thousand years ago let’s look at human

evolution it turns out there’s something

very important happened around five

thousand years ago and that is there’s a

sudden emergence and rapid spread of a

number of skills that are unique to

human beings like like tool use the use

of fire use of shelters and of course

language and the ability to read

somebody else’s mind and interpret that

person’s behavior all of that happened

relatively quickly even though the human

brain had achieved its present size

almost three or four hundred thousand

years ago 100 thousand years ago all of

this happened very very quickly and I

claim that what happened was the sudden

emergence of a sophisticated mirror

neuron system which allowed you to

emulate and imitate other people’s

actions so that when there was a sudden

accidental discovery by one member of

the group say use of fire or a

particular type of tool instead of dying

out the spread rapidly horizontally

across the population or was transmitted

vertically down the generations so this

made of illusion suddenly Lamarckian

instead of Darwinian in Darwinian

evolution is slow takes hundreds of

thousands of years a polar bear to

evolve a code will take thousands of

generations maybe a hundred thousand

years of human being a child can just

watch its parent kill another polar bear

and skinned it and put the skin on its

body for on the body and learn it in one

step what the polar bear took a hundred

thousand years to learn it can learn in

five minutes maybe ten minutes right and

then once it’s learned is it spreads by

in geometric proportion across a

population and this is the basis of this

mutation complex skills is what we call

culture in the basis of civilization

there’s another kind of mirror neuron

which is involved in something quite

different and that is that a minute

neuron justice with a million neurons

for action that a mirror neurons with

touch in other words if somebody touches

me my hand neuron in the somatosensory

cortex in the sensory region of the

brain fires but the same neuron in some

cases will fire when I simply watch

another person being touched

so it’s empathizing the other person

being touched so most of them will fire

when I am touched in different locations

different neuron for different occasions

but a subset of them will fire even when

I watch somebody else being touched in

the same location so here again you have

neurons which are enrolled in empathy

now the question then arises if I simply

watch another person being touched why

do I not get confused and literally feel

that touch sensation merely by watching

somebody being touched I empathize with

that person but I don’t literally feel

the touch well that’s because you’ve got

receptors in your skin touching pain

receptors going back into your brain

saying don’t water you’re not being

touched

so empathize by all means with the other

person but do not actually experience

the touch otherwise you’ll get confused

and muddled okay so there’s a feedback

signal that vetoes the signal of the

mirror neuron preventing you from

consciously experiencing that touch but

if you remove the arm

you simply anesthetize my arm so you put

an injection into my arm and it’s two

times the brachial plexus so the arm is

numb as no sensations coming in if I now

watch you being touched I literally feel

it in my hand in other words you’ve

dissolved the barrier between you and

other human beings so I call them

Gandhi neurons or empathy neurons and

this is not in some abstract

metaphorical sense all that’s separating

you from him from the other person is

your skin to remove the skin you

experience that person’s touch in your

mind you’ve dissolved the barrier

between you and other human beings and

this of course is the basis of much of

Eastern philosophy and that is there’s

no real independent self aloof from

other human beings inspecting the world

in inspecting other people you’re in

fact connected not just where Facebook

and the internet you’re actually quite

literally connected by your neurons and

it’s whole chains of neurons around this

room talking to each other and there is

no real distinctiveness of your

consciousness from somebody else’s

consciousness and this is not

mumbo-jumbo philosophy it emerges from

our understanding of basic neuroscience

so you have a patient with the phantom

limb arm has been removed and you’re a

phantom and you watch somebody else

being touched you feel it in your

phantom now the astonishing thing is if

you have pain in your phantom limb you

squeeze the other person’s hand massage

the other person’s hand that relieves

the pain in your phantom hand almost as

though the neuron were obtaining relief

for merely watching somebody else being

massaged so here you have my last slide

for the longest time people have

regarded science and Humanities as being

distinct see peace know spoke of the two

cultures science in the one hand

humanities on the other never the twain

shall meet

so I’m saying the mirror neuron system

lies the interface allowing you to think

think about issues like consciousness

representation of self what separates

you from other human beings what a love

allows you to empathize with other human

beings and also even things like the

emergence of culture and civilization

which is unique to human beings thank

you

you