00:01
So memory decay can result in failure
to retain stored information as well.
00:05
So,
So as things decay over time
if you’re not accessing them,
you’re not going to be
able to retain them.
00:13
You’re not going to be
able to recall them.
00:15
Okay?
So, retention interval is the time since the information was learned.
00:19
So,
So, when you learn something to --
as long as it lasts in your memory,
would be retention interval
and this can be variable.
00:28
So the longer this interval is, the more
likely this info will be forgotten.
00:31
So if you don’t access something
often, you’re going to lose it.
00:35
That makes sense, right?
And the more often
you do access it,
the better because it’s getting
reinforced and it’s staying.
00:42
The more you access something,
the better its retention.
00:45
So the most rapid loss of info
occurs within the first few days.
00:48
So if you learn something and then
you don’t revisit it, it’s gone.
00:51
And the moment where you’re trying to
remember, you’re like, “Oh, I got this.”
And then it’s gone.
00:55
Now, you, right now,
sitting at your desk,
trying to remember all the stuff that
you’ve been studying here for the MCAT,
it’s great that in the
moment when you’re studying,
you say, “Yup, I totally understand
social behavior. I got it.”
And then you don’t access it
again until you write the exam,
you’re not going to remember as
much as opposed to revisiting it.
01:15
And by revisiting, it doesn’t
mean necessarily relearning
the whole thing but just
simply reading passages over
or reintroducing yourself to a
concept that you’ve learned prior
will strengthen its retention.
01:26
Okay?
Proposed mechanisms behind
decay and loss include
the loss of memory specific
brain cells which can happen.
01:35
But more specifically, for us and kind
of what we’re talking about today,
it’s more around the weakening of
the associations between nodes.
01:41
So,
if we don’t access and if we don’t
strengthen the connections between nodes,
the chances are
that you will lose and it will decay, and
then that memory is no longer there.
01:54
So here’s
some what we call
forgetting curves.
01:58
And what you see is, we’re looking at
percentage of data remembered on the Y axis.
02:02
And on the bottom, we’re just
looking at the times that you have
repeated or access yourself
to the information.
02:09
So very first time you see it.
02:11
Your percentage of data remembered
right away will be very, very high,
but very quickly that decays.
02:17
Okay?
So that’s where you see the dash
line and that’s the memory loss.
02:22
It’s being decayed.
02:24
Now, if you move over, if you move over
one point, you have second repetition.
02:29
It goes right back
up to 100% memory.
02:32
You’re recalling it.
02:34
And then that also
quickly decays.
02:36
A third repetition
and then a fourth.
02:39
Now, what you notice is,
a couple of things, one,
the amount of decay that
happens is a lot less.
02:45
So, by the time you get to the
transition between third and fourth,
even at its worst case scenario,
it’s still at roughly 85%, 90%
versus the very, very first time
at that same time interval,
you would have decayed down
to, you know, 50%, 40%.
03:01
So, the take home message
here is, repetition is key.
03:04
So the more you access something,
the more you activate a node,
the more likely that you
remember something.
03:10
So, down to the MCAT.
03:12
Don’t just read or memorize
something once, revisit, revisit.
03:16
Have study notes or
re-read chapters,
re-watches video over and
over because it’s so amazing.
03:22
And you’ll remember everything.
03:23
So that comes time to the exam,
you will ace this section.
03:27
Okay. Now,
interference from new
learning may interfere
with retrieval of older
learning from memory.
03:32
So this is a unique
concept is that
sometimes you learn new things.
03:37
And whether it’s commonality or
whether it’s a complete difference,
it actually impacts
older memories.
03:45
So I’m trying to piece together an
example here, but you may have learned,
say, capitals of a country
when you’re in grade school.
03:53
And now, all of a sudden, you’ve taken
up geography again and you’re learning
all this new stuff around maps
and you’re learning a whole bunch of new
things around different cities and countries.
04:05
That may actually impact some of the
older stuff that you’ve learned
and you’re going
to have to either
revisit the old stuff to reintegrate
that with the new stuff.
04:13
Or you’re going to end up decay and losing
the old stuff and just have the new stuff.
04:17
Okay?
So proactive interference
happens when
previous information interferes with
the ability to recall new information.
04:23
So, let’s take a look an example
where you park your car.
04:26
So, you park your car in
the exact same spot --
sorry, in exact same garage every day,
but it’s a different spot every day.
04:34
So, on Monday, you
park in spot B,
but then on Tuesday, Wednesday,
Thursday, let’s say, Friday,
you are like, “Geez,
where did I park again?”
because on Monday it was at A,
then I parked at B on Tuesday,
Wednesday was here,
Thursday is there.
04:51
And you now mix up where
you parked today.
04:55
So, you have difficulty
in either recalling
where you parked and where
you parked your today
because there’s all this information
that’s interfering with one another.
05:03
So we call that
proactive interference.
05:06
Retroactive interference happens
when the newly learned information
interferes with the ability
to recall older information.
05:11
So, do you remember your old phone number
and you have your new phone number?
Your new phone number
is interfering with what
your old number was.
05:22
So, you know, if I
ask you right now,
“Can you remember your very
first phone number as a child
compared to what
you have today?”
Your new mobile cellphone
number is probably
interfering and blocking all
the old numbers that you have.
05:35
You might be able to remember like
the one before the one you had now,
but do you remember phone number
that you had 10 times ago?
Probably not.
05:44
Positive transfer is when older info
facilitates the learning of new information.
05:49
So this is really good.
05:49
This is building on
your previous learning.
05:51
That’s a good thing.
05:52
So learning a related language.
05:54
So, if you know something already like
English and you’re trying to learn,
you know, Latin, there’s a
lot of words that, you know,
the original underlying definition
of an English word comes from Latin.
06:07
So when you’re trying
to learn Latin
because you understand
English, it’s a lot easier.
06:11
Okay? So that helps a lot.
06:12
Or say for example, if you
play American football,
there’s basic rules
that you’ve learned,
how to throw the ball, how to
hold the ball, the basic rules.
06:20
And then rugby, which is a different
thing, has a lot of similarities.
06:24
And so some of that learnings that
you had from American football
will translate into rugby which makes
acquisition rugby a lot easier.
06:32
Which is why after you’ve learned a
couple of core languages, for example,
it’s easier to stock on another that
slightly somewhat related because
you’ve already learned a lot of the basic
rules and how that encoded and stored.