MEMORY
Chapter 6
WHAT IS MEMORY?
Memory is the system by which we
retain information and bring it to
mind.
Without memory, experience would
leave no mark on our behavior; we
would be unable to retain the
information and skills we acquire
through experience.
HUMAN MEMORY AS AN INFORMATION
PROCESSING SYSTEM
3 basic processes of human memory;
Encoding
Storage
Retrieval
These processes allow us to take
information, encode it in a form that can
be stored in memory, and later retrieve it
when it is needed.
Three Basic Processes of Memory
Encoding
Converting
information into a
form usable in
memory
Storage
Retaining
Information in
memory
Retrieval
Bringing to mind
information
stored in
memory
MEMORY ENCODING: TAKING IN
INFORMATION
Information about the outside world comes to
us through our senses, but for this information
to enter memory, it must undergo a process of
memory encoding, or conversion into a form
we can store in memory.
Ways we encode information;
Acoustically (coded by sound)
Visually (coded by forming a mental picture)
Semantically (coded by meaning)
MEMORY STORAGE: RETAINING
INFORMATION IN MEMORY
Memory storage is the process of
retaining information in memory.
Not all information becomes an
enduring or long-term memory.
Some information is retained for
only a fraction of a second.
MEMORY RETRIEVAL: ACCESSING
STORED INFORMATION
Memory retrieval is the process of accessing
stored information to make it available to
consciousness.
Retrieving long-held information is one of the
marvels of the human brain.
Some memories seem to be retrieved
effortlessly, others depend on the availability
of retrieval cues, cues associated with the
original learning, to jog them into awareness.
MEMORY STAGES
Some memories are fleeting; others are
more enduring.
The three-stage model of memory
proposes three distinct stages of
memory that vary with the length of time
information is stored;
Sensory memory
Short-term memory
Long-term memory
SENSORY MEMORY: GETTING TO KNOW
WHAT’S OUT THERE
Sensory memory is a storage system that
holds sensory information in memory for
a very short time.
Stimuli that you bring in constantly strike
your sensory receptors, forming
impressions that are briefly held in
sensory memory in a kind of temporary
storage device called sensory register.
SENSORY MEMORY: GETTING TO KNOW
WHAT’S OUT THERE
 This information lasts in memory for perhaps a
fraction of a second to as long as 3-4 seconds.
 The sensory impression disappears and is
replaced by the next one.
 Iconic memory- A sensory store for holding
mental representation of a visual image for a
fraction of a second.
 A visual held in iconic memory is so clear and
accurate that people can report exact details of
the image.
SENSORY MEMORY: GETTING TO KNOW
WHAT’S OUT THERE
Some people can recall a visual image they
have previously seen as accurately as if
they are still looking at it. This is known as
eidetic memory
This is also known as photographic memory
(eidetic comes from the Greek eidos,
meaning “image”).
Eidetic imagery is rare in adults, but it
occurs in about 5% of young children.
SENSORY MEMORY: GETTING TO KNOW
WHAT’S OUT THERE
Echoic memory is a sensory store for
holding a mental representation of a
sound for a few seconds after it
registers in the ears.
Although sounds held in echoic
memory fade quickly, they last about
two or three seconds longer than
visual images.
SHORT-TERM, OR WORKING, MEMORY:
THE MIND’S BLACKBOARD
Many sensory impressions don’t just
fade away into oblivion; they are
transferred into short-term memory for
further processing.
Short-term memory is the memory
subsystem that allows for retention and
processing of newly acquired information
for a maximum of about 30 seconds.
SHORT-TERM, OR WORKING, MEMORY:
THE MIND’S BLACKBOARD
Short-term memory relies on both acoustic
and visual coding, but mostly on acoustic (ex.
Repeating a phone number to yourself until
you dial it).
In the 1950s psychologist George Miller did
studies to determine the storage capacity if
short-term memory.
Professor Miller determined that people can
retain 7 items (plus or minus 2), referred to as
the “Magic 7”.
ROW 1
6293
ROW 2
73932
ROW 3
835405
ROW 4
3820961
ROW 5
18294624
ROW 6
9284619384
ROW 7
1992199319941995
SHORT-TERM, OR WORKING, MEMORY:
THE MIND’S BLACKBOARD
Did you do better remembering the 7 th row
than the 5 th or 6 th ?
If you did, it is because of chunking- the
process of breaking a large amount of
information into smaller chunks to make it
easier to recall.
Children learn the alphabet by chunking a
series if letters (that’s why they often say the
letters lmnop as if they are one word)
LONG-TERM MEMORY: PRESERVING THE
PAST
Long-term memory is a storage system that
allows you to retain information for periods
of time beyond the capacity of short-term
memory.
Some info can remain for days or weeks,
whereas other info can last a lifetime.
Short-term memory storage is limited, but
long-term storage is virtually limitless.
LONG-TERM MEMORY: PRESERVING THE
PAST
Consolidation is the process by which the
brain converts unstable, fresh memories into
stable, long-term memories.
The first 24 hours after information is
acquired are critical for consolidation to occur.
REM sleep plays an important role in
consolidating daily experiences, so if you have
a test the next day, make sure you get a good
night’s sleep.
DECLARATIVE MEMORY: “KNOWING THAT”
 Declarative Memory: Memory of facts and personal
info that requires a conscious effort to bring to mind.
 Ex. There are 50 states, what street we live on.
 Semantic Memory: Memory of facts.
 Ex. Which film won Best Picture last year, who wrote
Grapes of Wrath.
 Episodic Memory: Memory of personal experiences
that constitute the story of your life.
 Ex. What you had for dinner last night, when you fell
out of a tree when you were 10.
FLASHBULB MEMORY: WHAT WERE YOU
DOING WHEN…?
Extremely stressful or emotionally arousing
personal or historical events may leave vivid,
lasting, and highly detailed memories called
flashbulb memories.
Flashbulb memories are enduring memories
of emotionally charged events that seem
permanently seared into the brain.
Some flashbulb memories are accurate, but
others are prone to the kinds of distortion we
see in other forms of long-term memory.
EYEWITNESS TESTIMONY: :WHAT DID YOU
SEE ON THE DAY IN QUESTION?”
In reaching a verdict, juries give considerable
weight to eyewitness testimony. Yet memory
researchers find that eyewitness testimony
can be as flawed and strewn with error as
other forms of memory.
Psychologist Elizabeth Loftus describes how a
misinformation effect may lead to distortions
in eyewitness testimony from when the event
happened to when the events are recalled (in
court).
EYEWITNESS TESTIMONY: :WHAT DID YOU
SEE ON THE DAY IN QUESTION?”
The accuracy of eyewitness testimony involves
the following factors.
Ease of recall- People who take longer to
answer questions are less likely to be
accurate in their recall.
Degree of Confidence- People who say with
certainty, “That’s the person who did it, “ may
not be any more accurate than those who
admit they could be mistaken.
EYEWITNESS TESTIMONY: :WHAT DID YOU
SEE ON THE DAY IN QUESTION?”
General knowledge about a subjectPeople who know more about a subject
are more likely than those who know less
about the subject to be reliable
witnesses.
Racial identification- People are
generally better able to recognize faces
of people of their own race than the face
of people of other races.
EYEWITNESS TESTIMONY: :WHAT DID YOU
SEE ON THE DAY IN QUESTION?”
Types of questions- Leading or suggestive
questions by investigators can result in the
misidentification of perpetrators, whereas
open-ended questions, tend to increase the
accuracy of eyewitness testimony.
Facial characteristics- Faces with
distinctive features are much more likely to
be accurately recognized than
nondistinctive faces.