00:05
Barb, it was really helpful understanding the cellular basis
of learning. I have to
say my students are always asking for practical advice. So,
do you have any ways
to apply some of this neurobiology and help them in their
studies? Peter, got you
covered. The thing is, when you're learning you often have
these tendencies to
resort to certain tried and true, or at least you think
they're tried and true, ways of
learning. So for example you might do something like
underline or you might
highlight text or reread what you're doing whatever you've
been learning or you
might try retrieval practice so like looking at a flash card
and checking to see if
you have it in mind or you might even try something called
concept mapping.
01:03
So, that's where you write down key concepts and try to tie
them together. So if
you look here, there are 4 different options for you. So
it's highlighting, rereading,
and retrieval practice or concept mapping. Which of those 4
do you think is the best
for helping you learn? Stop the video now and check which
ones you think it is.
01:37
So, here you are, we're back again and the answer to the
question is it's retrieval
practice that is by far the best way to learn effectively.
In fact, when researcher
Jeff Karpicke did the study, it turned out that of those 4
different options that I
discussed, retrieval practice was by far and away the best
technique for learning.
02:05
It's not like you're just memorizing the material. By
retrieving that idea, pulling it
to mind, you're actually knowing both what that information
is and what it is not.
02:23
So, retrieval practice really consists of retrieving,
retrieving, retrieving that initial
faint information that you put in your long-term memory. So
the more you retrieve,
the better it is because it'll strengthen those links of
learning. But let's say that you
are really busy with things. So, you understand the material
as it's taught in class,
but then you don't have a chance to look at it for several
weeks. So, what happens
during those several weeks? Well, because you're not using
those links of learning,
those synaptic connections, your little synaptic janitors
can more or less sweep
those connections away. So, suddenly a concept that you did
somewhat understand
before disappears from memory. We can also see, if you look
at this image here,
it shows this upper image is what a dendrite looks like
before learning and before
sleep. And if you look at this lower image, that is the same
exact living neuron
after learning and after sleep. And wherever you see those
little blue triangles, you
can see that new dendritic spines have either grown stronger
or emerged and grown
in the first place to make synaptic connections. So this
indeed is an important
reason why sleep is such a very valuable aspect of learning
because sleep is when
those neuro connections are strengthened. Hundreds of times
while you're sleeping,
these little electrical signals will run across the
dendrites and the dendritic spines
that you are using to remember important information. So,
this is why for example
when you are going to sleep at night, it's a good idea to
just try to bring back to
mind the most important things that you are really trying to
learn or remember.
04:49
So study during the day, but just before you go to sleep
those last few minutes
put it in mind these last little tidbits that you want to
learn and that will remind your
brain what you wanted to be practicing with while you're
sleeping. Now, sometimes
we have a tendency to cram information. So if we might have
5 hours to study,
we might cram it 5 hours all in 1 day, say a Sunday. But
researches shown if
you are trying to learn new information, it is far more
important for you to space
that learning out. So instead of 5 hours in 1 day, you want
5 hours spaced out
1 hour each day because not only are you learning during the
day but at night
when you go to sleep, it's like you're getting a double
strengthening of those links
that you're creating. Now, if you don't do that, if you cram
all 5 hours in 1 day,
your little synaptic janitor can go and sweep those rather
weak links away much
more easily. Now, I love metaphors, a good metaphor to help
you remember this is
that when you're laying a brick wall, as you lay a layer of
bricks you put in the mortar,
layer of bricks. Before you go too high, let that
mortar dry. But if you don't do
that, if you don't take time in building a structure, you
get this wall of learning that
looks like this, it's a very very poor foundation for
learning. So again, spacing out
your learning with retrieval practice over a number of days,
spaced retrieval is a
valuable technique for learning. Now, there is also
something that people will
occasionally refer to irreverently as the meathead theory
of learning. And this is
something along the lines of when you're building muscular
tissue, it takes time to
build that muscular tissue. People can't really get their
head wrapped around the
fact that it actually also takes time to learn in your
brain, I mean it takes time to build
that neural tissue. So actually, neural tissue and muscular
tissue are both excitable
tissues and that's why the meathead theory of learning is a
valid theory to think
about. Now last of all, since we're looking at our
weightlifter here, you should be
aware that one of the best ways to help build your ability
to learn and remember as
we now know is through exercise. And the reason this is
important is because of a
wonderful substance produced in the brain when you exercise.
It's called
brain-derived neurotrophic factor, BDNF. And if you look
here, you can see another
image of a living dendrite and then this sprinkle BDNF on
this dendrite. What
happens? You can see here all of these dendritic spines just
sprout out, they emerged
and that is almost like leaving extra lumber around when you
want to build
something. It gives a very good sort of set of foundational
dendritic spines that
you can learn more easily from. So this is why it can be so
valuable to include exercise
in your learning program. Barb, that was so helpful to
understand the neurologic
basis and the cellular physiology that's involved in this
process. Many of the things
you mentioned we've heard about for years such as get sleep
at night and get plenty
of exercise, but now we know why those are so important. The
spacing concept,
however, is probably new to most of us. That was certainly
not part of my school
and clearly so important now that we understand the
neurobiology behind it.
09:33
In fact, we're going to spend a future session focused
specifically on spaced
retrieval. And it's particularly important because I have to
admit certainly I stayed
up late some nights and cram for exams and even so generally
did okay in those
exams but then when I went on to study for a final on my
boards I realized that I
remember little of the material I had crammed for. And now
we know why you have
to apply these strategies you described to avoid this
problem. So it's really helpful
getting these practical tips. And please remember it's
really important you get
sleep and give your brains time to recover and let those
dendritic spines grow.
10:23
So, Barb I also really liked your weightlifting analogy. I
tell my students all the time
work your brain just like an athlete works their muscles.
Train hard but train smart.
10:38
And now we have a better understanding of why that is so
important as well.
10:43
So thank you. Thank you and remember when you stop this
video, retrieve the
key ideas, I'll do it tomorrow too.