[MUSIC]
Okay, so what locked-in syndrome, the
locked-in syndrome that, that Jean Dominique Bauby suffered from.
It tells us about the four basic functions
of the brain, of the central nervous system.
And those are; voluntary movement, perception, homeostasis and
something that is oddly described as abstract or higher functions, cognition.
There are a lot of words for this, none of them exactly perfect.
Okay.
So, let's just go through what these various functions mean.
So, voluntary movement is everything that we do.
And, when I say voluntary, I kind of mean voluntary, and I kind of don't.
What I mean is something that is driven by the brain.
And that can be something that
I do completely volitionally, completely deliberately.
Like I say, I'm going to raise my hand, and I raise my hand.
That's a voluntary volitional movement.
But, if I step on something and I wince in pain.
That's an emotional movement.
Both of them, are, we're classifying for right now as voluntary movements.
They're self generated.
They are, they come from ourselves.
And these voluntary movements are the only way that we have to express ourselves.
I know that in the popular press there
is a difference between words and, and, and actions.
Sticks and stones can break my bones but words can never hurt me.
Well actions and, and talk, talk and
actions, they're, they're all, they're all one action.
[LAUGH] So talk is an action, and we use are laryngeal muscles.
Our diaphragm our the, the muscles of the
upper airway including their tongue, and pharyngeal muscles.
These are all muscles that we use to actually express ourselves.
So, talking, writing.
Having a facial expression.
Raising your hand.
Jumping up and down.
Doing a new da, dance step.
All of these are voluntary movements, and these were
definitely lost in Bauby, all he could do and
all many of people in, with locked-in syndrome
can do is, is move their eyelid.
Okay.
So that's voluntary movement.
Perception, is distinct from sensation.
And that's a very important, concept.
Perception is what we consciously appreciate about sensation.
So, what, I sense all sorts of stuff that I have no perception about.
So, for instance.
My brain senses how much CO2 there is in my blood.
Well, I have no idea how much CO2 there is in my blood.
I mean, I could take a guess.
But, that's because I'm a scientist, and I kind of know how much there should be.
but, but there's all the, there, there's sensors that tell
us how long our muscles are, where our, our joints are.
None of that actually reaches conscious perception.
The perceptions that we have include vision and hearing,
smell and taste, the sense of balance, the sense of position in the world.
Where are we?
Where is our head in the world?
A sense of equilibrium.
All of those are perceptions that we have.
They actually reach conscious, a conscious level.
The third function, major function, that we're going to talk about, is homeostasis.
And homeostasis is what we use to keep our body in physiological limits.
To make sure that we have enough oxygen to our brain, and to the rest of our body.
We are going to focus very much on brain [LAUGH] in this course.
so, we have to make sure that the, that, that there's enough oxygen
delivered to the body, that there's enough blood pressure that keeps us upright.
We have to make sure that our body temperature stays within limits.
The physiological limits that the body will tolerate.
We -- there are life cycle events that are challenges to our, our being.
And these include giving birth, and nursing a newborn, suckling from a mother.
All of these things are part of homeostasis.
They're part of the package that keeps us alive.
Another part of homeostasis is a rhythm.
The rhythm of our lives.
The daily rhythm.
The wake and the sleep.
And the seasonal rhythm.
Rhythm, the seasonal rhythm that has a little bit less
of an obvious influence on us than, the daily rhythm.
And then, the cycle of life.
So we go from infancy, to childhood, to adolescence.
To early adulthood, to middle age, to being older.
And so, these are all part of homeostasis.
It's all part of the challenge of staying alive, and as far as abstract functions,
these are things like thinking, and feeling emotions, and motivation.
And language, and memory, and learning.
All of these are part of our higher abstract functions.
Another incredibly important abstract function, is how we interact.
How, how do we play well with others?
How do we get in that sandbox and, and, and survive it?
So these are all part of abstract functions.
And they're a very important part of being a, a human.
So, in the next segment, what we're going to do is, we're going to
assign each one of these functions to a part
of the central nervous system.
[MUSIC]