Greg: So how did Santiago become such an incredible scientist?
It wasn’t easy.
We don’t have a picture of Santiago as a teenager, but we do have a picture of him
as a university student.
One of Santiago’s hands is always hidden in the photos he took of himself, because
it’s pushing the button to take the picture.
Santiago took one of the first selfies!
Santiago’s dad realized that his son needed a different approach.
His dad decided to show him what real bodies looked like, to encourage him to become a
doctor.
Being able to see, touch, and draw what he was learning about fuelled Santiago’s interest.
He went back to learn the math and science he had missed when he was a boy.
This time, he paid attention.
He worked hard to build the mouse paths that he hadn’t built when he was younger.
Santiago wondered whether neurons change when you learn—whether learning can “upgrade”
your brain.
Barbara: So, we have to stop here and ask you a question.
Wouldn’t you love to get an upgrade in your brain?
Your brain-links tightened?
It turns out that you get this upgrade every single day.
Or I should say—every night!
Let’s explore this for a few moments and then, I promise, we’ll return to Santiago.
Terry: When you learn something new during the day, the buds of tiny new dendritic spines
begin to peek out of your dendrites.
They really bust loose and grow, though, when you’re asleep.
These new “grown up” dendritic spines form connections with the axons of other neurons
through the synapses.
Wow!
This means that brain-links come together when you are sleeping!
Barbara: When you are sleeping, your brain practices what it has learned during the day.
We can see the electrical signals traveling again and again through the same sets of neurons.
It’s as if, while we’re dreaming, the space aliens have a chance to pass along some
friendly, reassuring shocks over and over again.
Another way to think of it is that during the night, your little mental mouse has a
chance to run again and again along the neural pathway.
(Mice like to run around at night, remember!)
It’s the “nighttime practice” during sleep that allows the dendritic spines to
get bigger.
Terry: When the dendritic spine grows big, the synapse gets stronger.
That is, the space alien can send a more powerful shock.
Your brain-links get a tiny bit stronger.
This makes it easier to think about what you are learning.
It’s like walking on a nice, wide, smooth path instead of trying to push your way through
the weeds and bushes.
Greg: Incidentally, just watching this video—if you’re focusing, that is—is helping new
dendritic spines to start to form.
Your brain changes when you learn!
Dendritic spines are a little like lie detectors.
The new spines and their synapses only begin growing if you’re really focusing on the
new information you want to learn.
Greg: Dendritic spines can’t be fooled—they can tell whether you’ve been playing video
games or texting your friends instead of doing your homework.
Terry: But it’s important to realize that even after you pull new dendritic spines to
life because you’re started to learn something, the spines will wilt and disappear if you
don’t practice with them.
Your “synaptic janitor” removes the dendritic spines because they’re not being used.
Use them or lose them!
Barbara: Have you ever understood something in class, but a few days later, when you looked
again at your notes, found yourself lost?
This happens because your synaptic janitors cleaned away the budding dendritic spines—after
all, they weren’t being used.
To prevent this from happening, look over your notes soon after you’ve made them.
Explain the ideas to a friend.
Make flash-cards.
Remember—brief practice sessions over several days are better than one long practice session.
Greg: Learning grows in your brain sort of like brick walls—gradual layers, day by
day.
Learn and sleep, learn and sleep.
Practicing over several days allows for new synaptic links to get stronger and helps the
new learning to really take hold.
If you try to cram, your neural “mortar” doesn’t have a chance to dry!
It’s a poor foundation for learning.
Practice helps make permanent—or at least a lot stronger.
Next, we’re on to the value of metaphors—one of the most enjoyable parts of learning!
Then to finish the story of Santiago.
Barbara: I’m Barbara Oakley Greg: I’m Greg Hammons
Terry: and I’m Terry Sejnowski Barbara: we, and Arizona State University,
wish you happy learning!