Transcript Chapter 8

Chapter 8
Memory
Slide 1
What is Memory?
Often when we use the word “memory” we are referring
to the conscious recollection of some past experience.
e.g., What did you wear yesterday?
However, in Psychology, we define memory much more
generally. My definitions would go something like:
Memory influences are any influence by which past
experiences affect current performance.
Given this more broad definition, there may be a large
number of ways in which memory can influence us …
for example:
Chapter 8 – Memory
Slide 2
Alphabetic Arithmetic Example
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Chapter 8 – Memory
A+3=D
C+2=F
T+2=W
A+3=D
S+3=V
C+2=F
S+3=V
T+2=W
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C+2=F
S+3=V
A+3=D
T+2=W
A+3=D
C+2=F
S+3=V
T+2=W
Slide 3
Rough Processing Model of Memory
Stimulus
Chapter 8 – Memory
Sensory Memory
aka, iconic or
echoic memory
Working Memory
aka, short-term
memory
Long-Term Memory
aka, memory
Slide 4
Sensory Memory
Often a “sensory trace” or the stimulus remains after the
stimulus is gone.
These traces are termed sensory memory, and they tend
to be very short-lived.
Sensory memory was most extensively studies by a
cognitive psychologist named Sperling.
Sperling’s studies focused on visual sensory memory
which he termed iconic memory … here’s how they
worked.
Chapter 8 – Memory
Slide 5
Iconic Memory - Full Report Condition
Nine items will briefly be presented in the box below,
then they will disappear. How many can you remember?
Chapter 8 – Memory
Slide 6
Iconic Memory - Full Report Condition
Nine items will briefly be presented in the box below,
then they will disappear. How many can you remember?
Chapter 8 – Memory
K
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W
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P
H
J
A
Slide 7
Iconic Memory - Full Report Condition
What was your subjective impression? Did you think you
saw them all for a short while … then they faded away?
Chapter 8 – Memory
Slide 8
Iconic Memory - Partial Report Condition
This time, report only the row that is indicated by the arrow
that comes up after the letters are gone.
Chapter 8 – Memory
Slide 9
Iconic Memory - Partial Report Condition
This time, report only the row that is indicated by the arrow
that comes up after the letters are gone.
Chapter 8 – Memory
S
J
U
B
M
Q
A
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P
Slide 10
Iconic Memory - Partial Report Condition
If we multiply your number recalled here by 3, we likely
get a larger number than your full report number, right?
Chapter 8 – Memory
Slide 11
Echoic Memory
There is also an auditory version of sensory memory that
is called echoic memory.
You likely have noticed this form of memory in action.
For example, the “what? effect”.
As a further example, Steve will now do an auditory
demonstration of echoic memory … his so called
“5-3-5-7-2-stop” game.
While iconic memory disappears in approximately 1
second, echoic memory seems to last about 4 seconds.
Chapter 8 – Memory
Slide 12
Rough Processing Model of Memory
Stimulus
Chapter 8 – Memory
Sensory Memory
aka, iconic or
echoic memory
Working Memory
aka, short-term
memory
Long-Term Memory
aka, memory
Slide 13
Short-Term or Working Memory
Steve will now read out a set of numbers, try your best to
remember them.
That “process” you feel is something Cognitive Psychologists
call working memory.
As Steve will now demonstrate, this form of memory is
fairly fragile and capacity limited.
It seems to require a great deal of mental effort to keep
things in working memory and, once the leave, they are gone.
Sometimes we use this memory for short-term storage, though
it also seems necessary for transferring info to long-term mem
Chapter 8 – Memory
Slide 14
The Relation Between Working Memory
and Long-Term Memory
The purpose of Working Memory is not to simply transfer
information into long-term memory.
In fact, some would argue that working memory is what we
sometimes call “thinking” and long-term memory clearly
enters into it.
Try some of the following:
> D+6=K, true or false?
> 5 X 13 = ?
> Imagine yourself sitting on a camel, how high
could you reach?
Chapter 8 – Memory
Slide 15
Primacy and Recency Effects
Primacy Effect
Probability of Recall
If I gave you a long list of
words to remember, then
asked you to just recall all
the words you remember,
you would likely remember
words at the beginning and
end of the list best.
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Recency Effect
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Serial Position
The primacy effect is typically attributed to additional
rehearsal of items earlier in the list - Long-term Memory.
In contrast, the recency effect is typically attributed to either
short-term memory readout or even echoic memory.
Chapter 8 – Memory
Slide 16
How long do things stay in Working
Memory?
If a person is allowed to rehearse, information will stay in
working memory for as long as it is rehearsed.
In their experiment, rehearsal
was prevented by making
subjects count back from
some number by threes
while remembering letter
trios (e.g., JDK, LPD)
Chapter 8 – Memory
Probability of Re call
However, if not allowed to rehearse, Peterson & Peterson
(1959) showed that information
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decays from working memory
fairly quickly.
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Time (seconds)
Slide 17
How are things lost from Working
Memory
So, this disappear quite quickly from working memory
if they are not rehearsed … what makes them disappear?
One possibility is that the items just decay over time.
This second possibility seems
most reasonable given the data
to the right.
Chapter 8 – Memory
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Pe rce ntage Corre ctll
A second possibility is that
new items coming into
working memory actually
“push out” things currently
in it.
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Intervening Items
Slide 18
The Capacity of Working Memory
As we already discussed, working memory has a limited
capacity. Specifically, the limit seems to be 7 plus or
minus 2 chunks.
What is a chunk? Time for another memory experiment!
Hopefully the demo showed that we can greatly increase
our ability to keep things in working memory by chunking
the information.
Chapter 8 – Memory
Slide 19
Rough Processing Model of Memory
Stimulus
Chapter 8 – Memory
Sensory Memory
aka, iconic or
echoic memory
Working Memory
aka, short-term
memory
Long-Term Memory
aka, memory
Slide 20
Long-term Memory
So, a simplistic view on what we’ve said so far is that
things that are rehearsed enough end up being stored
in long-term memory.
Things that are not rehearsed are not.
This transfer of items from working memory to longterm memory is called consolidation, and the theory
of consolidation is primarily supported by concussion
studies (e.g, the football example).
However, this simplistic
view is not sufficient.
Chapter 8 – Memory
Slide 21
Depth of Processing - Shallow
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Chapter 8 – Memory
flame
patch
sonic
bless
fleet
pears
spade
bliss
forth
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peels
speed
block
freak
pints
spice
blush
frost
pluck
Slide 22
DOP - Shallow - Recall
Chapter 8 – Memory
Slide 23
Depth of Processing - Deep
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Chapter 8 – Memory
spoon
bonds
glass
ports
spray
boots
goose
prize
steam
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brand
grass
quart
stink
bride
green
queen
story
brown
Slide 24
DOP - Deep - Recall
Chapter 8 – Memory
Slide 25
Depth of Processing - Overview
Clearly then, the way that you rehearse information
effects the likelihood that the information will enter
long-term memory.
Elaborative rehearsal (i.e. deep) tends to produce superior
memory on conceptual tasks like most memory tasks.
Maintenance rehearsal (what we typically do when trying
to remember a phone number for a little while) is not
nearly as good at transfering info to long-term memory.
Thus, let us re-visit our “attractive person gives you phone
number when you do not have paper” example.
Chapter 8 – Memory
Slide 26
Learning Without Rehearsal
As the depth of processing section demonstrates, we can
learn things via elaborative rehearsal … this type of
process is sometimes referred to as an effortful process.
However, we often remember things that we did not
rehearse in an effortful manner.
The formation of memories for things we did not perform
effortful processing on is called automatic processing.
The exact processes underlying automatic transfer to longterm memory are still largely unknown but its very existence
challenges a simple consolidation view.
Chapter 8 – Memory
Slide 27
Improving Your Memory via Mnemonics
Given all these studies of memory, what have we
learned about improving memory skills?
Techniques used to improve memory are called
mnemonic strategies and, as the name implies, typical
involve some form of effortful processing.
We’ll consider three techniques:
(1) the method of loci,
(2) the peg-word method,
(3) creating a narrative, and
(4) creating acronyms
Chapter 8 – Memory
Slide 28
The Method of Loci
In a country far far away (Greece), at a time long long
ago (sixth century BC), oratory skills were prized, and
paper was rare (OK, it didn’t exist).
Orators had to come up with ways to memorize long
speeches. They devised the method of loci.
This method simply involves forming an image of some
route you are familiar with (say the drive to Scarbra),
and then “placing” images of the concepts you want to
remember along this route. Then, by retracing the route
in your head and examining the images, you can reconstruct
the concepts in order.
Chapter 8 – Memory
Slide 29
The Peg-Word Method
This method is similar to the method of loci except,
instead of putting images along a route, you associate
them (via imagery) with nouns that rhyme with the
numbers.
The typical ones:
one:
two:
three:
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Chapter 8 – Memory
bun + image representing concept 1
shoe + image representing concept 2
tree + image representing concept 3
dirty shoe + image representing concept 32
Slide 30
Other Techniques
Another way of remembering a list of items is to
create a story (or song) that links the concepts together
in some ordered manner - this is called forming a
narrative.
Yet one more method is to form an acronym that
represents the concepts you want to remember:
Roy G. Biv
The A.B.C.s of first aid.
Begin With Review And Friend
or Big Women Really Are Fun!
Chapter 8 – Memory
Slide 31
Memory, One Structure or More?
Currently, one of the debates in memory concerns whether
we have a single, or multiple long-term memory systems.
Those who believe in multiple memory systems typically
talk about things like the following:
Episodic Memory - Our memory of very specific events
in our lives … tends to contain rich detailed info.
E.g. - What did you do last night?
Semantic Memory - Our general world knowledge.
E.g. - What city is the capitol of Manitoba?
Procedural Memory - Our memory of how to do things.
E.g. - How to ride a bike, or kill without thinking.
Chapter 8 – Memory
Slide 32
Implicit vs. Explicit Memory/Tasks
Another distinction that is often made is the distinction
between implicit and explicit memory.
Implicit memory tasks are ones that test memory without
specifically directing subjects to think about the study items.
In contrast, explicit memory tasks do direct the subject to try
and use study items when completing the memory test.
Implicit and explicit memory are the memory structures
these tasks are thought to tap.
An example if you please ...
Chapter 8 – Memory
Slide 33
Implicit/Explicit Example
Graf & Mandler (1984) showed subjects lists of words and
ask them either to perform “deep processing” (how much do
you like the word) or “shallow processing” (how many letters
does the word have) on them
Chapter 8 – Memory
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Precent Recalled
The subjects were then shown
stems corresponding to the items
(e.g., spice --> spi__) and were
given either implicit (complete
with the first word that comes to
mind) or explicit (complete with
a study item) instructions.
Explicit
Implicit
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Slide 34
The Biological Basis of Memory
So how does this all relate to the brain?
Most of what we know about the biological basis of memory
comes from research in two areas:
(1) Neuropsychological studies of human braindamaged patients.
(2) Psychophysiological studies with animals
Chapter 8 – Memory
Slide 35
Neuropsychological Studies
There are generally two types of memory impairments
that can occur as a result of brain damage:
Retrograde amnesia refers to the condition where patients
cannot remember events that occurred prior to the head
trauma. Most recent events are the most likely to be lost,
and the amount of loss can be from minutes to years.
Anterograde amnesia is a condition wherein patients
can remember past events just fine, but they have an
inability to form new long-term memories … some
types at least.
Chapter 8 – Memory
Slide 36
H.M. & Alcoholics
One of the most influential cases of anterograde amnesia was
the case of H.M., a patient who underwent bi-lateral removal
of his hippocampus and amygdala to treat severe epilepsy.
The good news is, his epilepsy was cured. The bad news is,
he ended up with a very profound case of anterograde amnesia.
This condition also is a common result of a form of alcoholism
termed Korsokoff’s syndrome. Some alcoholics get all their
nourishment from the liquor, causing vitamin deficiency.
A lack of one vitamin in specific leads to profound anterograde
amnesia.
Chapter 8 – Memory
Slide 37
What is lost and what is not?
Patients with anterograde amnesia do have memory for
events that occurred prior to the trauma, so clearly they
have an intact memory retrieval system.
Thus, it seems their real
problem is in storing new
memories … but not all
kinds of new memories,
just episodic memories
it seems.
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Implicit
Thus, the hippocampus
appears critical for the formation of episodic memories
Chapter 8 – Memory
Slide 38
Psychophysiological Studies
Critters also appear to
form episodic memories
which help them to do
things like remember
locations where they
have already searched
for food.
If their hippocampus
is destroyed, they also
appear to suffer from
the loss of episodic
memory.
Chapter 8 – Memory
Slide 39
Summary of Long-Term Memory So
Far
So we know that there are a number of ways things can
get into long-term memory, and various strategies can
be used to facilitate this process.
We also know that there at least seems to be different
types of long-term memory and episodic memory seems
to be the most fragile of these.
Finally, we also know that the hippocampus appears
critical for the formation of new long-term episodic
memories, with destruction of the hippocampus leading
to anterograde amnesia.
Chapter 8 – Memory
Slide 40
Remembering
Generally, psychologists believe that the actual process
of retrieving information from memory is an automatic
process.
An automatic process is one that:
(a) is carried out very quickly
(b) is not under the control of consciousness
(c) does not interfere with other ongoing processes
Things are assumed to become automatic via a process of
overlearning … the assumption being that if some process
is performed over and over again, it will become automatic
Chapter 8 – Memory
Slide 41
Reading as an Automatic Process
As an example of an automatic process, remember the
Stroop experiment we did early in the year?
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Chapter 8 – Memory
Slide 42
The Importance of Retrieval Cues
If retrieval from memory is automatic, why does it
sometimes seem so effortful to retrieve something
from memory?
For example, the tip of the tongue phenomenon
Retrieval is automatic IF useful retrieval cues are
present in the environment.
The effortful part of retrieval is trying to come up with
effective retrieval cues that will make retrieval happen.
Chapter 8 – Memory
Slide 43
Tranfer-Appropriate Processing
The most effective retrieval cues are those that, in some
manner, re-create part of the original learning environment.
The importance of recreating the learning
environment was first shown in what may
be the only (so far) psychology
experiment with SCUBA divers.
That is why when you lose something people will often
suggest that you “retrace your steps” from some point in
time when you had that thing.
It is also related, but not identical, to the concept of statedependent learning.
Chapter 8 – Memory
Slide 44
Decay from Long-Term Memory
Often students feel like they study hard for an exam
and, as soon as the exam is complete, the information
they studied is gone! Is it?
How long does information stay in memory, and how
can we scientifically study memory decay?
This issue was first addressed by Ebbinghaus (1895)
and his results and techniques are still interesting.
Ebbinghaus taught himself thirteen nonsense syllables
(e.g., dax, wuj) and then tested his memory after various
delays.
Chapter 8 – Memory
Slide 45
Percent Recalled
Ebbinghaus’ Results and Real World
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Ebbinghaus’ work suggests we retain some of the info
for at least 30 days, even when it has no meaning.
Similar “real world” studies suggest that we can retain
information we learned over 40 years ago or more.
Chapter 8 – Memory
Slide 46
Relearning: Gone but not Forgotten
Ebbinghaus also showed that even when information feels
like it has been lost from memory, it is still there.
He demonstrated this using a relearning task in which he
had to relearn a list he had already studied a long time ago.
Even when he felt that the information had been completely
lost from memory, it took him less time to relearn that
information than it had the first time.
So, even though you think you forget stuff after you write
your exam, it is still there, and you will be able to get it
back quickly if you should ever need to.
Chapter 8 – Memory
Slide 47
Remembering: Part Fact, Part Fiction
When we remember something, some of what we
remember is fact, and some is a reconstruction that
fits with our ideas of the world and our current context.
How about an experiment?
Chapter 8 – Memory
Slide 48
Remembering: Part Fact, Part Fiction
When we remember something, some of what we
remember is fact, and some is a reconstruction that
fits with our ideas of the world and our current context.
How warm was it yesterday?
Chapter 8 – Memory
Slide 49
Remembering: Part Fact, Part Fiction
When we remember something, some of what we
remember is fact, and some is a reconstruction that
fits with our ideas of the world and our current context.
How cold was it yesterday?
Chapter 8 – Memory
Slide 50
Remembering: Part Fact, Part Fiction
What we seem to do is remember only certain details that
we experienced, then, while remembering, we create a
“story” that includes these details.
The “story” we create is biased by a number of things
including (a) the current context including the question
that lead to recounting, (b) a desire to tell a coherent,
sensical story, (c) our current mental state and beliefs.
Moreover, the confidence we have in our memories seems
largely unrelated to the accuracy of those memories, often
we are most confident in the “memories” we created.
Chapter 8 – Memory
Slide 51
A Final Experiment (for now)
SLEEP
HAMMER
CHAIR
TETINUS
STICHES
Chapter 8 – Memory
YARN
PILLOW
THIMBLE
CACTUS
DREAM
PINK
MATRESS
SHOT
SHEET
NIGHT
THREAD
TIRED
BLANKET
CANDLE
PIERCE
Slide 52
A Final Experiment (for now)
PINK?
CANDLE?
Chapter 8 – Memory
NEEDLE?
TICKET?
ROSE?
BED?
WATCH?
BOOK?
Slide 53
A Final Experiment (for now)
SLEEP
HAMMER
CHAIR
TETINUS
STICHES
YARN
PILLOW
THIMBLE
CACTUS
DREAM
PINK
MATRESS
SHOT
SHEET
NIGHT
THREAD
TIRED
BLANKET
CANDLE
PIERCE
PINK?
CANDLE?
NEEDLE?
TICKET?
ROSE?
BED?
WATCH?
BOOK?
Chapter 8 – Memory
Slide 54