Chapter 6
Memory
Chapter 6 Overview
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The structure of human memory
The nature of remembering
How reliable is memory?
Biology and memory
Forgetting
Improving memory
The Structure of Human
Memory
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Memory is the process of encoding,
storage, consolidation, and retrieval of
information
Processes required for
remembering
Three memory systems
What are the characteristics of the
sensory memory?
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Briefly holds information from the
senses
– Visual information: for a fraction of a
second
– Auditory information: up to 2 seconds
What happens to information in
short-term memory?
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Holds about seven (plus or minus two)
items for less than 30 seconds without
rehearsal
Also called working memory
– STM acts as a workspace for carrying out
mental activity
What happens to information in
short-term memory?
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Displacement
– When STM is full, each new, incoming item
pushes out an existing item
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Chunking
– Grouping bits of information into larger units,
which are easier to remember
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Rehearsal
– Repeating information to maintain it in STM
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Maintenance rehearsal
Elaborative rehearsal
What kinds of information are
stored in the subsystems of longterm memory?
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Long-term memory has a virtually
unlimited capacity that contains vast stores
of a person’s permanent or relatively
permanent memories
What kinds of information are
stored in the subsystems of longterm memory?
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Declarative memory
– Stores facts and information, and life events
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Episodic memory
Semantic memory
Nondeclarative memory
– Stores motor skills, habits, simple conditioned responses
What kinds of information are
stored in the subsystems of longterm memory?
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Declarative memory
– Stores facts and information, and life events
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Episodic memory
Semantic memory
Nondeclarative memory
– Stores motor skills, habits, simple conditioned responses
The Nature of Remembering
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The processes that cause apparent
memory lapses, such as being unable
to recall a person’s name or a
telephone number, represent two of
the various principles that govern how
we go about remembering things.
What are the three methods used
by psychologists to measure
memory?
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Recall
– Task in which a person must search memory to
produce required information
– Recall tasks are easier when retrieval cues are
provided
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Recognition
– Task in which a person must identify information
as having been encountered before
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Relearning
– Measures retention in terms of time saved when
relearning material compared to learning it
originally
What happens when information
must be recalled in the order in
which it was presented?
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In the serial position effect recall is
better for the beginning and ending items
than for the middle items in the sequence
– Primacy effect
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Tendency to recall the first items in a sequence more
easily than the middle items
– Recency effect
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Tendency to recall the last items in a sequence more
easily than the middle items
How do environmental conditions
and emotional states affect
memory?
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People recall material more
easily in the same
environment in which they
learned it
Godden and Baddeley
(1975)
– Participants memorized
words underwater or on land
– Words learned underwater
were best recalled
underwater
– Words learned on land were
best recalled on land
How do environmental conditions
and emotional states affect
memory?
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State-dependent memory effect
– People tend to recall information better if they
are in the same emotional state as when the
information was encoded
– e.g., when feeling anxious while exposed to
snakes and spiders
What does research evidence say
about flashbulb memory?
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Extremely vivid memory of an event that is
surprising, shocking, or highly emotional
– These memories are not as accurate as people
believe them to be
– But, about 5% of children are capable of eidetic
imagery
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Ability to retain an image of a visual stimulus for
several minutes
How does culture influence
memory?
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Culture may influence the ability to
remember certain kinds of material
– Elders of the Iatmul people of New Guinea
exhibit impressive memory for the oral history of
their people
– The Asur people of India, who do not use
artificial lighting, have exceptional memory for
locations
How Reliable is Memory?
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Contrary to Canadian neurosurgeon,
Wilder Penfield, the human memory
does not really function like a tape
recorder or video recorder
What is meant by the statement
“Memory is reconstructive in
nature”?
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People reconstruct memories, piecing them
together from a few highlights, using
information that may or may not be
accurate
Frederick Bartlett
– Reconstructive memory processes are influenced
by schemas
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Integrated frameworks of prior knowledge and
assumptions
What conditions reduce the
reliability of eyewitness testimony?
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Viewing photograph of a suspect before
seeing a lineup
When members of a lineup are viewed at
the same time, rather than one at a time
When the perpetrator’s race is different
from that of the witness
When a weapon has been used in the crime
When leading questions are used
What is the controversy regarding
the therapy used to recover
repressed memories of childhood
sexual abuse?
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Repression
– Process in which traumatic memories are buried
in the unconscious
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Some therapists use hypnosis and guided
imagery to help clients recover repressed
memories of childhood sexual abuse
Critics argue that these therapists
sometimes implant false memories in their
clients
– Research indicates that imagining a fictitious
event can lead to false memory of the event
Biology and Memory
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A person’s store of memories must exist
physically somewhere in the brain. Neuronal
processes are also involved in the storage of
information in the brain. Trauma and
disorders that affect brain structures,
neuronal health, or both can seriously
impair memory function.
What roles do the hippocampus and
the hippocampal region play in
memory?
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The hippocampus plays an important role
in forming episodic memories
Formation of semantic memories involves
the hippocampus and other parts of the
hippocampal region
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The hippocampus is also involved in
navigational skills
– Posterior of hippocampus is larger in taxi drivers
than in general population
Why is long-term potentiation
important?
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Long-term potentiation (LTP)
– An increase in the efficiency of neural
transmission at the synapse that lasts for hours
of longer
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LTP may be the basis for learning and
memory at the level of neurons
When LTP is disrupted, long-term memories
are not formed
– Consolidation failure
How do hormones influence
memory?
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The strongest and most lasting memories
are usually fueled by emotion
Presence of epinephrine (adrenalin) and
norepinephrine (noradrenalin) in the
bloodstream activate the amygdala and help
imprint powerful, enduring memories for
threatening events
Excessive levels of cortisol can interfere
with memory
Estrogen appears to improve working
memory efficiency
– But post-menopausal estrogen replacement may
increase risk of dementia
What kinds of memory loss are
experienced by those who have
amnesia or dementia?
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Amnesia
– Partial or complete loss of memory due to loss of
consciousness, brain damage, or some
psychological cause
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Anterograde amnesia
– Inability to form new long-term memories
– Case of H. M.
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Retrograde amnesia
– Loss of memory for experiences that occurred
shortly before a loss of consciousness
What kinds of memory loss are
experienced by those who have
amnesia or dementia?
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Dementia
– Mental deterioration characterized by impaired
memory and intellect and by altered personality
and behavior
– Individuals with dementia can lose episodic and
semantic memories
– Can result from cerebral arteriosclerosis, chronic
alcoholism, strokes
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Alzheimer disease
– A form of dementia caused by degeneration of
brain cells
– A high IQ plus lifelong intellectual activity may
delay or lessen Alzheimer symptoms
Forgetting
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Most people think of forgetting as a
problem to be overcome, but it’s
actually not always unwelcome. Still,
when you need to remember
particular information, forgetting can
be very frustrating.
What did Ebbinghaus discover
about forgetting?
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Ebbinghaus found
that the largest
amount of forgetting
occurs very quickly,
then it tapers off
This relationship
between time and
forgetting is called
the curve of
forgetting
What causes forgetting?
Source: Nickerson & Adams, 1979)
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Can you recognize the real penny?
Encoding failure occurs when information was
never put into long-term memory
Decay theory holds that memories, if not used,
fade with time and eventually disappear
What causes forgetting?
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Proactive interference
– Information already stored in memory interferes with
remembering newer information
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Retroactive interference
– New learning interferes with remembering previously learned
information
What causes forgetting?
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Proactive interference
– Information already stored in memory interferes with
remembering newer information
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Retroactive interference
– New learning interferes with remembering previously learned
information
What causes forgetting?
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Motivated forgetting
– Forgetting through suppression or repression to
protect self from painful or unpleasant
information
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Sometimes we forget because we don’t want to
remember something
Prospective forgetting
– Not remembering to carry out some intended
action
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Retrieval failure
– Not remembering something one is certain of
knowing
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Tip-of-the-tongue phenomenon
Improving Memory
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There are no magic formulas for
improving your memory.
Remembering is a skill that like any
other requires knowledge and
practice.
How can organization,
overlearning, spaced practice and
recitation improve memory?
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Organization
– Putting information in categories, sequences, sizes, or
shapes to make retrieval easier
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Overlearning
– Practicing or studying material beyond the point where it
can be repeated once without error
– Overlearned material is remembered better and longer
and is more resistant to interference
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Spaced practice
– Learning in short practice sessions with rest periods in
between
– A better study technique than massed practice
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Recitation
– Reciting, or practicing, what you have learned
– Students recall more if they use more recitation