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  • I'm here to talk about

  • the wonder and the mystery

  • of conscious minds.

  • The wonder is about the fact

  • that we all woke up this morning

  • and we had with it

  • the amazing return of our conscious mind.

  • We recovered minds with a complete sense of self

  • and a complete sense of our own existence,

  • yet we hardly ever pause to consider this wonder.

  • We should, in fact,

  • because without having this possibility of conscious minds,

  • we would have no knowledge whatsoever

  • about our humanity;

  • we would have no knowledge whatsoever about the world.

  • We would have no pains, but also no joys.

  • We would have no access to love

  • or to the ability to create.

  • And of course, Scott Fitzgerald said famously

  • that "he who invented consciousness

  • would have a lot to be blamed for."

  • But he also forgot

  • that without consciousness,

  • he would have no access to true happiness

  • and even the possibility of transcendence.

  • So much for the wonder, now for the mystery.

  • This is a mystery

  • that has really been extremely hard to elucidate.

  • All the way back into early philosophy

  • and certainly throughout the history of neuroscience,

  • this has been one mystery

  • that has always resisted elucidation,

  • has got major controversies.

  • And there are actually many people

  • that think we should not even touch it;

  • we should just leave it alone, it's not to be solved.

  • I don't believe that,

  • and I think the situation is changing.

  • It would be ridiculous to claim

  • that we know how we make consciousness

  • in our brains,

  • but we certainly can begin

  • to approach the question,

  • and we can begin to see the shape of a solution.

  • And one more wonder to celebrate

  • is the fact that we have imaging technologies

  • that now allow us to go inside the human brain

  • and be able to do, for example,

  • what you're seeing right now.

  • These are images that come from Hanna Damasio's lab,

  • and which show you, in a living brain,

  • the reconstruction of that brain.

  • And this is a person who is alive.

  • This is not a person

  • that is being studied at autopsy.

  • And even more --

  • and this is something that one can be really amazed about --

  • is what I'm going to show you next,

  • which is going underneath the surface of the brain

  • and actually looking in the living brain

  • at real connections, real pathways.

  • So all of those colored lines

  • correspond to bunches of axons,

  • the fibers that join cell bodies

  • to synapses.

  • And I'm sorry to disappoint you, they don't come in color.

  • But at any rate, they are there.

  • The colors are codes for the direction,

  • from whether it is back to front

  • or vice versa.

  • At any rate, what is consciousness?

  • What is a conscious mind?

  • And we could take a very simple view

  • and say, well, it is that which we lose

  • when we fall into deep sleep without dreams,

  • or when we go under anesthesia,

  • and it is what we regain

  • when we recover from sleep

  • or from anesthesia.

  • But what is exactly that stuff that we lose under anesthesia,

  • or when we are in deep, dreamless sleep?

  • Well first of all,

  • it is a mind,

  • which is a flow of mental images.

  • And of course consider images

  • that can be sensory patterns,

  • visual, such as you're having right now

  • in relation to the stage and me,

  • or auditory images,

  • as you are having now in relation to my words.

  • That flow of mental images

  • is mind.

  • But there is something else

  • that we are all experiencing in this room.

  • We are not passive exhibitors

  • of visual or auditory

  • or tactile images.

  • We have selves.

  • We have a Me

  • that is automatically present

  • in our minds right now.

  • We own our minds.

  • And we have a sense that it's everyone of us

  • that is experiencing this --

  • not the person who is sitting next to you.

  • So in order to have a conscious mind,

  • you have a self within the conscious mind.

  • So a conscious mind is a mind with a self in it.

  • The self introduces the subjective perspective in the mind,

  • and we are only fully conscious

  • when self comes to mind.

  • So what we need to know to even address this mystery

  • is, number one, how are minds are put together in the brain,

  • and, number two, how selves are constructed.

  • Now the first part, the first problem,

  • is relatively easy -- it's not easy at all --

  • but it is something that has been approached gradually in neuroscience.

  • And it's quite clear that, in order to make minds,

  • we need to construct neural maps.

  • So imagine a grid, like the one I'm showing you right now,

  • and now imagine, within that grid,

  • that two-dimensional sheet,

  • imagine neurons.

  • And picture, if you will,

  • a billboard, a digital billboard,

  • where you have elements

  • that can be either lit or not.

  • And depending on how you create the pattern

  • of lighting or not lighting,

  • the digital elements,

  • or, for that matter, the neurons in the sheet,

  • you're going to be able to construct a map.

  • This, of course, is a visual map that I'm showing you,

  • but this applies to any kind of map --

  • auditory, for example, in relation to sound frequencies,

  • or to the maps that we construct with our skin

  • in relation to an object that we palpate.

  • Now to bring home the point

  • of how close it is --

  • the relationship between the grid of neurons

  • and the topographical arrangement

  • of the activity of the neurons

  • and our mental experience --

  • I'm going to tell you a personal story.

  • So if I cover my left eye --

  • I'm talking about me personally, not all of you --

  • if I cover my left eye,

  • I look at the grid -- pretty much like the one I'm showing you.

  • Everything is nice and fine and perpendicular.

  • But sometime ago, I discovered

  • that if I cover my left eye,

  • instead what I get is this.

  • I look at the grid and I see a warping

  • at the edge of my central-left field.

  • Very odd -- I've analyzed this for a while.

  • But sometime ago,

  • through the help of an opthamologist colleague of mine,

  • Carmen Puliafito,

  • who developed a laser scanner of the retina,

  • I found out the the following.

  • If I scan my retina

  • through the horizontal plane that you see there in the little corner,

  • what I get is the following.

  • On the right side, my retina is perfectly symmetrical.

  • You see the going down towards the fovea

  • where the optic nerve begins.

  • But on my left retina there is a bump,

  • which is marked there by the red arrow.

  • And it corresponds to a little cyst

  • that is located below.

  • And that is exactly what causes

  • the warping of my visual image.

  • So just think of this:

  • you have a grid of neurons,

  • and now you have a plane mechanical change

  • in the position of the grid,

  • and you get a warping of your mental experience.

  • So this is how close

  • your mental experience

  • and the activity of the neurons in the retina,

  • which is a part of the brain located in the eyeball,

  • or, for that matter, a sheet of visual cortex.

  • So from the retina

  • you go onto visual cortex.

  • And of course, the brain adds on

  • a lot of information

  • to what is going on

  • in the signals that come from the retina.

  • And in that image there,

  • you see a variety of islands

  • of what I call image-making regions in the brain.

  • You have the green for example,

  • that corresponds to tactile information,

  • or the blue that corresponds to auditory information.

  • And something else that happens

  • is that those image-making regions

  • where you have the plotting

  • of all these neural maps,

  • can then provide signals

  • to this ocean of purple that you see around,

  • which is the association cortex,

  • where you can make records of what went on

  • in those islands of image-making.

  • And the great beauty

  • is that you can then go from memory,

  • out of those association cortices,

  • and produce back images

  • in the very same regions that have perception.

  • So think about how wonderfully convenient and lazy

  • the brain is.

  • So it provides certain areas

  • for perception and image-making.

  • And those are exactly the same

  • that are going to be used for image-making

  • when we recall information.

  • So far the mystery of the conscious mind

  • is diminishing a little bit

  • because we have a general sense

  • of how we make these images.

  • But what about the self?

  • The self is really the elusive problem.

  • And for a long time,

  • people did not even want to touch it,

  • because they'd say,

  • "How can you have this reference point, this stability,

  • that is required to maintain

  • the continuity of selves day after day?"

  • And I thought about a solution to this problem.

  • It's the following.

  • We generate brain maps

  • of the body's interior

  • and use them as the reference for all other maps.

  • So let me tell you just a little bit about how I came to this.

  • I came to this because,

  • if you're going to have a reference that we know as self --

  • the Me, the I

  • in our own processing --

  • we need to have something that is stable,

  • something that does not deviate much

  • from day to day.

  • Well it so happens that we have a singular body.

  • We have one body, not two, not three.

  • And so that is a beginning.

  • There is just one reference point, which is the body.

  • But then, of course, the body has many parts,

  • and things grow at different rates,

  • and they have different sizes and different people;

  • however, not so with the interior.

  • The things that have to do

  • with what is known as our internal milieu --

  • for example, the whole management

  • of the chemistries within our body

  • are, in fact, extremely maintained

  • day after day

  • for one very good reason.

  • If you deviate too much

  • in the parameters

  • that are close to the midline

  • of that life-permitting survival range,

  • you go into disease or death.

  • So we have an in-built system

  • within our own lives