Griggs Chapter 5: Memory

A Concise Introduction
2nd Edition
Richard Griggs
Chapter 5
Prepared by
J. W. Taylor V
The Journey…
 Three-Stage
 Encoding
Model of Memory
Information into
 Retrieving
Information from
Model of Memory
Sensory Memory
Short-Term Memory
Long-Term Memory
The Three-Stage Model
Has guided research in memory since the
late 1960s
Views memory as composed of three
relatively distinct stages
The Three-Stage Model
Sensory Memory
Consists of a set of five registers (temporary
storage places, one from each sense) for
incoming sensory information from the
physical environment until we attend to it,
interpret it, and it proceeds to the next stage
of memory (short-term memory)
Iconic Memory
Is an exact copy of visual information
Less than a second in duration
Very large capacity
Consider the example of a
cartoon movie, which is nothing
more than a series of still
drawings flashed in rapid
Iconic memory allows us to
perceive motion in the drawings
Testing Iconic Memory
The temporal integration procedure
involves giving two random meaningless dot
patterns sequentially at the same visual
location with a brief time delay between the
two presentations
When the two patterns
are integrated, a
meaningful pattern is
An Example of the
Temporal Integration Procedure
Testing Iconic Memory
For a meaningful pattern to be perceived,
the two patterns must be integrated
somewhere in the memory system
However, if the time delay between the two
presentations is greater than one second, no
meaningful pattern can be perceived because
the image from the first pattern has faded from
iconic memory
Testing Iconic Memory
Sperling’s full- and partial-report
procedures present participants with a
different 3 x 3 matrix of unrelated consonants
(a total of 9) for 50 ms across numerous
experimental trials
Here is an example:
Testing Iconic Memory
In the full-report procedure participants had
to report the entire matrix
Participants said they sensed the entire matrix but
that it had faded from memory before they could
report all 9 letters
Testing Iconic Memory
In the partial-report procedure, the
participants had to report only one row
of the matrix, a row indicated by an
auditory cue on each trial
When the auditory cue was given
immediately after the brief presentation of
the letter matrix, participants recalled the
indicated row 100% of the time
When there was a one second delay
between presentation of the matrix and
the auditory cue, participants’ recall of
the cued row worsened
Short-Term Memory
Is the memory stage in which the recognized information from sensory memory enters consciousness
It is where you are doing your present conscious
cognitive processing
Serves as a place to rehearse
information so it can be transferred
to long-term memory and as a place
to bring information from long-term
memory when asked to recall it
Must concentrate on information in
short-term memory or it will be lost in
30 seconds
Capacity of Short-Term Memory
The memory span task tests for the capacity of shortterm memory by giving a series of items one at a time
Memory span is the average number of items you can
remember across a series of memory span trials
The person has to remember the items in the order in which they
were presented
Humans have a memory span of
7+/- 2 (5 to 9) chunks of information
A chunk is a meaningful
unit of information
Experts in a given domain tend
to have larger chunks for
information in their area of
Duration of Short-Term Memory
Measured using the distractor task, in which
people are given a small amount of information
(e.g., three unrelated consonants such as CWZ)
Then the participant is immediately distracted from
concentrating on the information for a brief time period
(by counting backwards aloud by 3’s), and then asked to
recall the information
To keep information in short-term memory, we use
maintenance rehearsal (i.e., repeating
information in short-term memory to keep in from
fading from short-term memory)
Results for the Short-Term
Memory Distractor Task
Long-Term Memory
Allows storage of
information for a long
period of time
(perhaps permanently)
and its capacity is
essentially unlimited
Types of Long-Term Memory
Explicit memory (also called declarative
memory) is long-term memory for factual
knowledge and personal experiences and
requires conscious recall
Two types of explicit memories:
Semantic memories are memories for factual
knowledge that is true of everyone (e.g., the current
President of the United States)
Episodic memories are memories for personal life
experiences (e.g., your senior prom night)
Types of Long-Term Memory
Implicit memory (also called non-declarative memory)
is long-term memory that influences our behavior, but
does not require conscious awareness or declarative
statements (e.g., for most adults, driving a car; walking)
Some implicit memories are procedural memories
because they have a physical procedural aspect to them
For a tennis expert, such as Serena Williams,
the movements to play the game are implicit,
procedural memories, whereas for the average
person, such movements require conscious
recall, and are more semantic memories
Other implicit memories have become
automatic responses to certain stimuli (e.g.,
feeling tense when police car lights are
flashing behind us)
Types of Long-Term Memory
Amnesia, the Loss
of Long-Term Memories
Amnesics are people with severe memory deficits following
brain surgery or injury
H. M. had his hippocampus and surrounding temporal lobe
area removed at age 27 (to reduce epileptic seizures)
Before the operation, both his short- and long-term memories
were normal
After the operation, he didn’t seem to be able to store any new
information in long-term memory
H.M. suffered from anterograde amnesia – the inability to
form long-term memories for events following brain surgery
or trauma
By contrast, retrograde amnesia is the inability to remember
events before, especially just before, the surgery or trauma
Infantile Amnesia
The cerebellum seems to be important for
formation of implicit memories, whereas the
hippocampus seems to be important for
formation of explicit memories
Because the hippocampus does not fully develop
until about the age of 3, this explains why we
cannot remember as adults events that occurred
prior to this age (i.e., infantile/ child amnesia)
Evidence for the Short-Term
vs. Long-Term Distinction
H. M.’s short-term memory did not suffer any
substantial damage after the operation
The free recall task is an experimental procedure in
which participants are given a list of words one at a
time, then asked to recall them in any order they wish
Compared with the middle of such lists, the recall
of the items at the start of the list is superior
(the primacy effect)
Compared with the middle of such lists, the recall
of the items at the end of the list is superior
(the recency effect)
Serial Position Effects
for the Free Recall Task
Evidence for the Short-Term
vs. Long-Term Distinction
The recency effect is caused by recall from short-term
memory, whereas the primacy effect is the result of
superior recall from long-term memory of the first few
words in the list
The first few words enter an empty long-term memory and get
proportionately more attention than the words in the middle of
the list and can thus be transferred into long-term memory
The last few words are still in short-term memory at the time of
If recall is delayed by having participants count rapidly
backward by 3’s for 30 seconds, the recency effect is
eliminated, but the primacy effect remains
To eliminate the primacy effect, simply rehearse each of the
items on the list equally
Encoding Information
into Memory
How We Encode Information
How to Improve Encoding
Memory System Processes
The process of
information from
one memory
stage to the next
The process of
information in a
The process of
bringing stored
information from
memory to the
conscious level
in short-term
How We Encode Information
Automatic processing is processing that
occurs subconsciously and does not require
Effortful processing is
processing that occurs
consciously and requires
For a particular type of
processing, much
practice is needed
Levels-of-Processing Theory
Describes what types of
encoding lead to better
Three levels of processing
Physical: How information
Acoustic: How the information sounds
Semantic: What the information means
Long-term memory is best for information encoded
semantically, next best for information encoded
acoustically, and worst of information encoded
Elaborative Rehearsal
Rehearsing information by relating new information
to information already in long-term memory
Contrasts with maintenance rehearsal (i.e., the
repetitive cycling of information in short-term memory)
Elaborative rehearsal provides more retrieval cues to
facilitate retrieval
A good way to elaborate on new material is to relate
the material to yourself
The self-reference effect says it is easier to remember
information that you have related to yourself because
such connections provide more retrieval cues and lend
more meaning to the new information
Effects on Encoding
Encoding specificity principle proposed
that the cues present during encoding serve
as the best cues for retrieval
This is why the various concepts and examples
that you relate to a new concept during
elaborative rehearsal help you remember the
State-dependent memory is memory that
depends upon the relationship of one’s
physiological state at the time of encoding
and at the time of retrieval
Effects on Encoding
Mood-dependent memory effects attest to the fact
that memory is better when a person’s mood is the
same during encoding and retrieval
For example, if you are happy during encoding
information, it is easier to retrieve that information if you
are happy at the time of retrieval
Mood-congruence effect is the fact that memory is
better for experiences that are congruent with a
person’s current mood
For example, when we are sad it is easier to retrieve
negative events in our lives
How to Improve Encoding
Mnemonics are memory aids that require elaborative
In the method of loci, the sequential pieces of
information to be remembered are first associated
with sequential locations in a very familiar room or
 When retrieving the information, you merely
mentally go around the room (or location) and
retrieve the item stored at each sequential
location; uses elaborative mental imagery
In the peg-word system, you visually associate
the items to be remembered in a jingle that you
first memorize
The Peg-Word Method
Keyword Meaning
heart rate,
and blood
Mental Picture
Imagine the winner of a
race (i.e., heart pounding
and breathing heavily),
while a medal is hung
round the winner’s neck.
Imagine a young child
down in a pit. The child
grows and grows until
he’s finally big enough to
climb out!
The Peg-Word Method
Keyword Meaning
Mental Picture
Calms the Imagine the peace and
calming effect of
watching a parachute
drift slowly downward.
the body
Imagine a symphony
playing loudly in the
room next door! The
music excites you and
you can’t sit still.
The Peg-Word Method
Keyword Meaning
Reticular Retickle Attention
Mental Picture
Imagine tickling
someone to get her
attention. Then, she
loses interest so you
have to retickle her!
Facilitates Imagine hearing the
movement cereal bell. That’s the
signal to move to the
table and begin
spooning cereal.
Other Tips for
Improving Encoding
The spacing effect (or distributed study effect)
contends that your memory will improve if you
study for an exam over an extended time interval
rather than just a few days before the exam
Overlearning is studying material past the point
of initial learning, and has been demonstrated to
aid in retrieval of that information
Retrieving Information
from Memory
How to Measure Retrieval
Why We Forget
The Reconstructive
Nature of Retrieval
How to Measure Retrieval
Recall is a measure of retrieval that requires the
reproduction of the information with essentially
no retrieval cues
Recognition is a measure of retrieval that only
requires the identification of the information in
the presence of retrieval cues
Relearning, also called the savings method, is
a measure of the amount of time saved when
learning the information for a second time
An Early Study
Ebbinhaus conducted the first experimental
studies on human memory more than 100 years
ago using the relearning method.
He would study a list of nonsense syllables until
he could correctly recite the complete list
without any hesitations. He then put the list
aside and waited some period of time and then
relearned the list to the same criterion.
To get a measure of learning, he computed a
savings score – the reduction in the number of
trials it took him to reach criterion.
Result? The “forgetting curve” reveals that most
forgetting occurs in the first two days after
learning material.
Forgetting Curve for
Long-Term Memory
Why We Forget
Encoding failure theory says that sometimes
forgetting is not really forgetting, but rather that the
information never entered long-term memory in the
first place
Storage decay theory suggests that forgetting
occurs because of a problem in the storage of the
The biological trace of the memory gradually decays over
time and the periodic usage of the information will help to
maintain it in storage
An Example of
Encoding Failure
Why We Forget
Cue-dependent theory says we
forget because the cues necessary for
retrieval are not available
The information is in memory, but we
cannot access it
This theory is analogous to knowing a book
is in the library but you cannot access it
because the library lacks call numbers
Interference theory proposes that
other similar information interferes and
makes the forgotten information
Types of Interference
Proactive interference occurs when
information you already know makes it hard to
retrieve newly learned information
Retroactive interference occurs when
information you just learned makes it hard to
retrieve old information
Types of Interference
Types of Interference
Think about changing phone numbers after having a
certain number for many years. When asked for your
new phone number, remembering the old one
interferes with retrieving the new one.
This is proactive interference
Now think about being at a party with many people you
don’t know. You meet someone whom you want to talk
to later, but after meeting her, you are introduced to
many more people. Now, you cannot remember her
This is retroactive interference
The Reconstructive
Nature of Retrieval
When reading a newspaper article, for instance, we
usually code the gist or main theme of the story, along
with some of the some of the story’s highlights
Then, when we retrieve the information from our memory,
we re-construct a memory of the story using the theme and
Retrieval re-construction is guided by schemas –
organized frameworks of knowledge about people,
objects, and events that tell us what normally happens
in a given situation
They allow us to encode and retrieve information more
The Reconstructive
Nature of Retrieval
Schemas, however, can lead us to
“misremember” information so that it is
more consistent with our schemas
Frederick Bartlett (1932) had people read
unusual stories and subsequently recall details
from the stories
When the participants recalled the stories, they
made them more consist with their schemas
about the world
Source Misattribution
Occurs when we do not remember the true source
of a memory and attribute the memory to the
wrong source
Source misattribution results in false memories,
which are inaccurate memories that feel as real as
accurate memories.
False memories can also occur because of the
misinformation effect, which occurs when a
memory is distorted by subsequent exposure to
misleading information
A Study of False Memories
Loftus and Palmer (1974) showed people film of a traffic
accident and later tested their memory for the accident
Some people were asked “How fast were the cars going
when they smashed into each other?”
and others were asked “How fast were
the cars going when they hit each other?”
Participants asked the first
question estimated a higher
speed at impact and
reported seeing broken
glass when in fact there
was none
Memory and Testimony
False memories suggest that eyewitness
testimony is subject to error and manipulated
by misleading information
Likewise, false memories
suggest that recovered
memories are not
necessarily accurate

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