Hundreds of cells in some small worms in fact.
And when we presume that when the smaller the brain the less sentient, and
the less intelligence you have less to work with.
So clearly, intelligence and sentience are going to grow together to some extent.
Insects of course, we know mosquitos, these tiny little things,
they must have tiny little brains, but of course, cells are quite small.
How many cells do they have?
Thousands.
Bees, for example, and
flies have tens of thousands, hundreds of thousands in some cases.
You and I, of course, have tens of billions,
maybe hundreds of billions of cells.
>> Can you show us some of these small ones, like the frog and the snake.
>> So these are all vertebrate brains.
Even the smallest vertebrate brains from fish for
example, are some of the largest brains on the planet.
And so these are brains all captured in plastic and they're tiny little things.
Snakes, this is a pigeon, the biggest one's a pigeon for example.
But down here we see fish and snakes and frogs.
Tiny little things, and
yet I would argue that they also have some degree of intelligence.
That is, they have to predict their world,
they have to predict the effects of their own behaviors on the world.
And in so doing they have to in a sense take in themselves.
You become part of your worldif you can change what's going on around you.
>> Does sentience involve awareness of pain too then?
>> Clearly it has to,
because one of the things you have to do is avoid those sorts of things.
If you're rooted to the ground and you can't avoid things, pain is not so
important except that you've gotta fix the damage.
So plants do respond to damage by creating wounds and so on and repairing themselves.
But they don't pull away as easily because they don't have that kind of mobility.
Even so some plants do back away from noxious uncomfortable stimuli.
But when you're an animal and
you can move your position in space now you can completely avoid pain.
You can anticipate pain.
>> Could we even say something about sentience like there's different
types of sentience that are developed in these various animals and
what would that look like?
>> First of all, sentience has to do with senses, right.
It has to do with what you can take in.
We have a sentience that will be reflective of the fact that
we're very visual, that we're very tactile.
That a lot of information that comes into our brain is from the surface of our
bodies, touch, pain, heat, cold, and so on.
Sound, all of these are part of our sentience.
We're responsive to the world this way.
We have something in addition and that is we are also sentient in a symbolic way.
We think in abstract terms.
That in effect is a different whole level of this process.
But now we are also insentient in some ways.
There many fish for example that are very sensitive to electricity.
They feel the space around them in terms of the electric charge that's around them.
They generate it by tensing muscles.
Muscles that are specialized to generate electric current.
And then they sense how the electric current bounces back, so to speak, or
gets absorbed in the world around them.
So they have a sentience that we lack.
>> So the extraordinary thing, really, is that this earth process has brought forth,
we could say, a multi-sentience, plethora of life.
>> That's right.
>> Which has different types of qualities that are navigating through the world.
>> Right, and what it also says is that as one gets more complex,
as you have more of these to compare.
Where you have to integrate signs of danger,
you have to integrate sights at a distance.
Odors are something that might have sometime ago.
And make a decision on that basis.
Now you can't just be responsive to them individually, you have to
be responsive to the complicated relationships that they setup for you.
>> That's a fascinating thing that I was thinking about, the sentience of
migrations that require collective thinking and
patternings and connection to wind, star,
perhaps magnetic planetary sensibilities too.
Can you say something about the sensibilities of migrations of birds or
fish, turtles, mammals?
>> One of the things we've learned a lot about because in some sense the sentience
is distributed, it's not in an individual alone.
>> In terms of migrations?
>> In terms of migrations, in terms of the schooling of fish.
>> Yes.
The vast hoards of locusts for example that migrate to eat from place to place.
We're learning that their responses are not to the world at large.
They're not thinking ahead so to speak.
By taking very close bits of information of their neighbors but
the collective, again like the collection of neurons in your brain.
The collective itself has a kind of intelligence incentives, responsiveness
because of the individual responsiveness not just the individuals to the world but
to their neighbors, to their nearest neighbors.
One of the things that has been discovered for example about locust migration
is it looks as though they don't migrate to find food so
much, as to avoid being eaten by other locusts.
Their neighbors are after them so to speak, because the food has run out.
And so they fly away, and their neighbors follow to eat them.
But in effect, they land on other food and they get distracted.
And eventually the bites start to happen and you got to run.
But as a result, everybody's trying to stay away from everybody but
trying to catch up with everybody, holds this group together, finding food.
Because that's when they can settle and stop.
>> Does this kind of collective sentience apply as well to the mammalian world?
Obviously migrations, but what is collective sentience?
>> Brains are also made up of little micro sentient creatures,
we call them neurons, single cells.
A single cell could in some places in the world live on their own, neurons can't.
They're basically parasitic on the rest of the body.
But their little sentient creatures and
they're interacting with their nearest neighbors.
Sending signals back that are really simple.
Back and forth, back and forth.
But it's that collective interaction that produces the sentience
that we have as a whole brain.
So in one sense there's not a fundamental difference
between that kind of sentience that holds the school of fish together or
the swarming starlings together and the way brains work.
>> I love that.
Let's go backwards to discuss this evolution of the brain.
And then bring it forward to discuss kind of collective sentience.
And what it's implications are for the evolutionary story today.
But give us a picture Terry, of how did brains develop.
>> I'll go all the way back to other vertebrates.
>> Please. >> Because it turns out that brains
are not all that different from each other.
We think of our brains as so different from other brains, but the more we've
learned about how they're structured and how the genes have structured brains.
And so on, we realize that the way brains are segmented that sort of theme and
variation structure of brains is an old one.
That all vertebrates in fact, from fish to eels to
snakes to rabbits to birds to us are all segmented the same way.
The brains are all laid out with the same basic principles.
Not just the same basic neurons but even the same basic chunks.
>> A couple of chunks like what?
>> Well, the big part of the brain that we think about in the front of our brains
is the cerebrum or the cerebral cortex.
We have a structure like that that stands out as that folded thing
that we all recognize but there is a cerebrum in every single vertebrate brain.
There is a cerebellum this little brain in the back
in every single vertebrate to some extent they're smaller or
larger they're at different proportions, but they're all there.
>> So the structures are the same?
>> The structures are the same so
one myth about brains is that things have been added,
new stuff has been added like a new kind of structure has been popped on to it.
Not very likely, for the most part,
Darwin's theme and variation story is right.
That is, descent with modification.
>> Mm-hm.
>> The same basic structure gets modified,
each of these components gets modified in subtle ways.
But it's in the same place doing the same kind of thing.
Those parts that are towards the front are doing more of the prediction,
the long distance prediction.
As you move back in the brain down towards the tail so
to speak, down in us those are things that are doing more automatic stuff.
Again the head end of moving organisms has to do all the prediction.
Interestingly enough the two things that are most predictive are eyes and nose.
They come in at the very front.
Now we think about eyes as being long distance predictors.
We can predict things sometimes miles away from moving forward.