Hi. It's Paul Andersen and this Life Science Disciplinary Core Idea 1D (LS1D)
on Information Processing. It's really your brain learning about itself. So how do we
teach this progression in schools. Well in the lower elementary grades we want to talk
about signals in our environment and how they're picked up by organs that we have. And so how
do you sense light? Students would do fairly well. That we use our eyes to do that. Or
we pick up sound with our ears. They might now know how we sense temperature, but they
probably know how we sense touch and that's going to be through our skin. And so that's
a good place to start. This idea that our environment has signals that we can somehow
receive. Don't neglect plants though. Plants can also receive signals from their environment.
They can show what's called phototropism or they can grow towards light without muscles.
Without nerves. Without any of that. And they do that through the expansion of their cells.
And so this idea that plants and animals can sense their environment is a great place to
start. As we move forward in elementary you want to start talking about specific signals
and then where do they go? So where does vision go? Where does hearing go? Well basically
all of them are connected using nerves or neurons to our brain. And so that information
is going to be gathered throughout our body but it's all going to be moving towards our
brain so we can make sense of it. And the lower parts of your brain process that information.
So a good analogy is like a switchboard operator. The information comes in and then they have
to push it to the right part of the brain. And so we're going to move that out into our
brain. Now integration is probably too big of a word when you're in third grade, but
this idea that the brain is making sense of that information is a good place to start.
As we move forward we also want to explain that it's not just one way. That the brain
is then sending signals back to the rest of the body. So it's sending an action back to
the body. Sometimes that's immediate. Like a reflex. If I touch a hot pot I'm going to
move my hand away really quickly. But also some of it's going to be calculated behavior,
so learned behavior. So right now I'm using my brain to figure out what I'm going to say
next. Also we can use that information to store retrievable information inside our brain
in circuits within our brain. Or connections within our brain. And so at the elementary
level, that's were you want to start with. It's this idea of the importance of the brain
as a receiving and then also a responding organ. As we move forward into middle school
we want to talk about what those signals actually are and that they come in three general types,
electromagnetic, mechanical and then chemical signals. And so could you pause the video
and figure out which of these five fit with the electromagnetic, mechanical and chemical?
Well let me show you. It's this. Electromagnetic material is going to be picked up by your
eyes. Mechanical information is going to be sensed by your skin and your ears. And then
chemical through your nose and through your tongue. So let's look specifically at each
of those. So how does your eye work? Basically light's going to come in through a pupil.
You're going to focus that using a lens on the retina which is on the back of your eye.
Indifferent and specialized neurons are going to pick up those electromagnetic signals.
And so that light coming through your eye is going to be sensed by modified neurons
in the back of your eye. What about mechanical? So right now when you hear me, basically on
the inside of your ear, every part of the outside of your ear is funneling that sound,
but on the inside of the ear in a cochlea, you're going to have these tiny little hairs
that are vibrating. And that vibration is sending a signal through neurons to your brain
that are giving you different sounds. And when I talk really low, that's going to vibrate
different hairs then when I talk really high. And so that's mechanical receptors. But that's
also the way our skin works. The way if I push on my skin I can feel that as it were
mechanically changing a receptor. And that's sending a signal to the brain. And then we
have chemical reception as well. And so when you smell something what's going on, the chemicals
are actually moving up into your nose and they're hitting these receptors on the inside
of your nose. They're actually gathering these chemicals and there's a fit between the two
and that sends a signal to your brain. Same thing with taste, that there are chemicals
that are being received and you can see there's little hairs on our taste bud as well and
that's sending a signal to our brain saying "That's what this taste was." As we move in
to high school we want to get more into the brain and talk about the different parts of
the brain. First of all we should say that there are different parts of the brain. There
are regions of the brain that do different things. And so as that information moves in,
visual information is going to be pushed to what's called the visual cortex, when we make
sense of that. Auditory is going to move to a different part of the brain. We also have
a somatosensory. Basically what that means is that when you get touched or you sense
information on different parts of your body, it's going to go to an area in your brain
so you know where that is coming from. And we're going to have more nerves from organs
in our body that are highly sensitive. So the end of your finger's are going to have
a lot of neurons and that's going to take up a lot of regions in your brain as opposed
to like sensory systems on your back. You don't have as many neurons coming from that.
And then on the other side we have the motor cortex. Motor cortex is basically going to
send signals out to the rest of the body that tell my body what to do. To tell these fingers
to move. Or my hands to clap. And then we have what's called the prefrontal cortex.
And that's where some of our emotions are going to sit. And that's how we respond to
environments based on that. And so these are different areas of the brain but we're just
starting to figure out how they all work. You can think of it like these circuits or
these connecting circuits within your brain that give us memories and also give us emotions.
And they're used by animals and humans to seek reward, to avoid punishment, to develop
fear, to form attachment. But the big thing is that you understand that the brain and
the nervous system are integrated. That all of this information's coming in, we're processing
it, we're sending signals out and the whole thing works together. And I hope that was
helpful.