- [Narrator] We are going to start out with a test.
I'm going to give you a list of words to learn.
And later, I'll ask you to remember them.
So don't write them down.
Just listen.
You ready?
Alright, ladybug, television,
stork, book,
airplane, hamburger,
garden, pillow,
window, stove,
planet, car, fork.
Okay, so we'll go back to those later.
Now let's talk about retrieval.
Anytime you pull something out of your long-term memory
and bring it into working memory,
or your conscious awareness,
you are engaging in an act of retrieval.
And as you've probably experienced in your lifetime
of trying to retrieve names, birthdays,
directions, and other things,
there are a variety of factors that can influence
your ability to retrieve information.
First, let's walk through some of the main methods
of retrieval in order from hardest to easiest:
free recall, cued recall, and recognition.
So, back to that list of words.
Now, try to write down or say out loud
as many of them as you can.
I'll draw some stuff over here while you're retrieving.
Okay, so what you just did,
or maybe what you're still doing
a little bit is free recall.
Without any cues and not in any particular order,
you are producing the words that you learned a minute ago.
Free recall tends to have some interesting patterns.
For example, did you remember ladybug?
How about television and road?
Those were the first three words on the list,
and people tend to remember the first things in a sequence,
especially if they know there's a memory test coming.
This pattern, where you have a high probability of recall
for the first items on the list,
is called the primacy effect.
What about planet, car, or fork?
Did you remember those?
Those were the last three words on the list,
and people also tend to remember
the last few things in a sequence.
And that's called the recency effect.
But since I distracted you for a short time
after the list, the recency effect might not be
so pronounced here as it would be
if we had done an immediate test.
But although we remember the first few items
and the last few items pretty well,
we often get fuzzy on the items in the middle.
So it might have been harder for you
to remember tennis ball, garden, and pillow, say,
which were in the middle of the list.
The difficulty you have in the middle
doesn't have a special name.
What really happens is that primacy and recency
cause the first and last items respectively
to have an increased probability of being remembered.
And this whole curve is called the serial position curve.
And the overall tendency for us to remember
the first list items really well,
the middle list items not so well,
and then the last list items really well again
is called the serial position effect.
So that's free recall.
But what if I gave you some extra clues
to help you remember those words?
If I were to ask you to complete the following words
based on what you learned earlier, it might be easier.
So for example, I might give you pl-
and have you try to retrieve planet.
This type of test is called a cued recall test
because you still have to produce an answer
but you get more retrieval cues to help you.
You tend to do better on cued recall tests
than on free recall tests because the added cues
make it more likely that you can successfully access
the information in your long-term memory.
Finally, we come to a recognition test.
Out of these three types of tests,
people tend to do best on recognition tests.
On a recognition test, I would present two words,
say fork and knife, and ask you which one
you heard earlier.
Here, you have even more cues
than in the cued recall test.
You have the entire word instead of just part of it
which makes your ability to retrieve
the correct word even more likely.