Transcript EXPLORING PSYCHOLOGY (7th Edition in Modules) David Myers

Psychology in Everyday
Life
David Myers
PowerPoint Slides
Aneeq Ahmad
Henderson State University
Worth Publishers, © 2011
Memory
Chapter 7
Memory
Studying Memory
 An Information-Processing Model
 Two Memory Tracks
Building Memories
 Encoding: Getting Information In
 Storage: Retaining Information
 Retrieval: Getting Information Out
Memory
Forgetting
 Encoding Failure
 Storage Decay
 Retrieval Failure
Memory
Memory Construction
 Misinformation and Imagination Effects
 Source Amnesia
 Children’s Eyewitness Recall
 Repressed or Constructed Memories of
Abuse?
Improving Memory
Memory is the persistence of learning
over time through the encoding,
storage and retrieval of information
Building a Memory
To remember any information or
experience requires:
• Encoding: getting information into our
brain
• Storage: retaining the encoded
information
• Retrieval: getting the information back out
of memory storage
An Information-Processing Model
A model of memory based on a computer
(Atkinson & Shiffrin, 1968)
1. Experience is first recorded, for just a moment,
as a sensory memory
2. Information is processed into short-term
memory, encoded through rehearsal
–
Holds a few items briefly
3. Information moves to long-term memory for
later retrieval
Updates to the I-P Model
• Some memories are formed through
unconscious processing, without our
awareness
• Working memory: a view of short-term
memory that stresses conscious, active
processes
– Working memory is not just a storage shelf,
but an active desktop for linking new and old
information
An Information-Processing Model
Two-Track Processing:
Automatic vs. Effortful
• We automatically
process vast amounts
of everyday
information
• We remember new
and important
information through
effortful processing
Automatic Processing
• We automatically process information
about
– Space
• “The definition was at the top of the right page”
– Time
• “I went to the store before lunch”
– Frequency
• “This is the third time I’ve seen her today!”
Effortful Processing
• Requires close attention and effort
• Memory can be improved through
rehearsal, the conscious repetition of
information
• Rehearsal was the subject of one of many
studies of memory by Hermann
Ebbinghaus (next slide)
Ebbinghaus’s Experiment
• Studied his own learning and
forgetting
• Used lists of nonsense
syllables
– JIH, BAZ, FUB, YOX, SUJ,
DAX, VUM, etc.
• Tested his memory for the
list every day.
• The more he practiced out
loud on day 1, the less time
needed to relearn it on day 2
Effortful Processing
• Spacing effect: we remember better if
study or practice is spread over time
– Cramming is less effective!
• Testing effect: repeated quizzing of
previously studied material also helps
Serial Position
• Serial position
effect: We
remember the
first and last
items in a list
best
• After a delay,
we only
remember the
first items best
Facts vs. Skills
• H.M. and others with certain traumatic
brain injuries cannot form new explicit
memories
– Cannot learn new facts
• However, they can learn new skills, and be
classical conditioned
– E.g., mirror-writing, jigsaw puzzles, navigation
– Won’t remember learning these skills
Two-Track Memory
• Implicit memory: retaining skills or conditioning,
often without conscious awareness
• Explicit memory: memories of facts and
personal events that can be consciously
retrieved
• Separate brain regions:
– Encoding of new explicit memories requires the
hippocampus, though they are consolidated
elsewhere
– Implicit memory formation requires the cerebellum
Two-Track Memory
Sleep and Memory
• Sleep supports memory consolidation
• During sleep, the hippocampus and cortex
display rhythmic patterns of activity, as if
communicating with each other
• The brain may be “replaying” the day’s
experiences as it transfers them to the
cortex for long-term storage
Building Memories
• Encoding: Getting Information In
• Storage: Retaining Information
• Retrieval: Getting Information Out
Encoding Meaning
• We may encode meaning rather than raw
information
• When asked to recall text, we often report the
meaning, or gist, rather than the raw text
• It can be difficult to remember things without a
meaningful context
– You will more easily remember what you read and
hear if you translate it into personally meaningful
information
Encoding Images
• We can more easily remember things we
can process visually as well as
meaningfully
• Memorable sentences often evoke
powerful imagery, or mental pictures
– High-imagery words are more easily
remembered than low-imagery words
Sensory Memory
• Storage is extremely short, especially for visual
sensory memory
• Study: Sperling (1960) flashed nine letters for
1/20th of a second.
• Sensory memory made the letters momentarily
available for encoding.
Short-Term Memory: Duration
• Short-term memories (or
“STMs” as on the slide, but
then insert the abbreviation
into the title in parentheses)
disappear quickly.
• Study: Peterson (1959)
presented 3-letter strings
(CHJ, DPZ), and prevented
rehearsal by having people
count backward.
• Result: letters 50% gone at
3 seconds, 90% gone at 12
seconds.
Storage Capacities
• Short-term memory capacity is limited
– The Magical Number Seven, plus or minus
two (George Miller, 1956)
• Long-term memory seems to have no limit
and can endure for a lifetime
How Does the Brain Store
Memory?
• Memory is not stored like books in a
library, in neat, precise locations.
• Rather, different aspects of a memory are
assigned to various groups of neurons.
• Thus, to understand how memory works,
we must study the brain
Synaptic Changes
• Synapses are the sites where the signal
from one neuron is received by another
• Experience modifies the brain’s neural
network: increased activity in a pathway
strenghtens connections between the
neurons involved
Synaptic Changes
• Kandel and Schwartz (1982) classically
conditioned sea slugs to withdraw their tail when
squirted with water (with electric shock).
• As the slug learned, serotonin was released into
certain synapses. These synapses then become
more sensitive and able to transmit signals more
effectively.
Synaptic Changes
• Long-Term Potentiation
(LTP): An increase in a
synapse’s firing potential. A
neural basis for learning and
memory
Stress-Related Memories
• Excitement of stress can enhance memories.
• Stress  hormones  more available glucose
to fuel brain activity  signals brain “something
important has happened”
• Meanwhile, emotion-processing clusters in the
brain boost activity in memory-forming areas
• The persistence of such memories is adaptive
Flashbulb Memories
• Emotion-triggered hormone changes help
explain flashbulb memories, unusually
clear memories of an emotionally
significant moment or event
E.g., many people remember exactly
where they were on September 11, 2001
Retrieval: Getting Information Out
Evidence that something has been
remembered:
• The item can be recalled, as on a fill-in-theblank test
• The item can be recognized, as on a multiplechoice test
– Recognition memory is quick and vast
• Relearning the item may be easier than it was
the first time
Retrieval Cues
• Memories are linked together in the brain,
in a storage web of associations.
• These associations can serve as retrieval
cues, any stimuli (events, feelings, places,
etc.) linked to a specific memory
• The more retrieval cues you’ve encoded,
the better chance of finding a path to
retrieve the memory
Context Effects
• Returning to the context
where you experienced
something can prime your
memory of it
• Godden and Baddeley
(1975) had scuba divers
learn lists of words on land
or underwater, and then
attempt to recall them in
the same or different
context
Context Effects
• Sometimes being in a similar context to
one previously experienced can trigger the
eerie feeling of déjà vu (I’ve seen this
before)
• This can happen when the current
situation is loaded with retrieval cues that
remind us of earlier, similar experiences
Moods and Memories
• Mood-congruent
memory: we more easily
recall experiences that
are consistent with the
current (good or bad)
mood
• Teen ratings of their
parents are tightly linked
to the teen’s current
mood
Forgetting
• Jill Price (A.J.) is unable to forget anything.
• Why might this be a problem?
Seven Sins of Memory
(Daniel Schacter, 1999)
• “Sins” of forgetting and retrieval, problems
with the way memory works
– Absent-mindedness – inattention to detail
leads to encoding failure
– Transience – memory loss as unused
informaiton fades
– Blocking – inability to access stored
information
Seven Sins of Memory
(Daniel Schacter, 1999)
• Sins of distortion
– Misattribution – confusing the source of
information
– Suggestibility – e.g., asking a leading question
influences answer and subsequent memory
– Bias – belief-colored recollections. Current
feelings may alter a memory.
• Sin of intrusion
– Persistence – unwanted memories (e.g., PTSD)
Encoding Failure
• We cannot remember what we have not
encoded
Storage Decay
• Forgetting is initially rapid, and then levels off
• People who had studied Spanish in high school but not
after were tested on vocabulary recall
• One explanation may be a gradual fading of the
memory trace, the physical changes in the brain as a
memory forms
Retrieval Failure
• We can sometimes fail to retrieve a
memory because we don’t have enough
information to access the pathway to it
Interference
• Interference: the blocking of recall as old or new
learning disrupts the recall of other memories
– Learning new passwords may interfere with remembering older
ones
• Learning an hour before sleep can be good because of
less interference (but still need rehearsal)
Forgetting
Forgetting, the
loss of
information in
between
sensation and
retrieval, can
occur at any
stage
Repressed Memories
• Freud argued that we self-censor, or
repress, painful or unacceptable
memories to minimize anxiety
• He argued that these repressed memories
linger, and can be retrieved by some later
cue or therapy
• Today, many memory researchers think
repression rarely, if ever, occurs
Memory Construction
• Every time we “replay” a memory, we
replace the original with a slightly modifed
version
– Often called reconsolidation
• What implications does this have for
everyday life?
Misinformation
• Misinformation effect: a memory that has
been corrupted by misleading information
• Loftus and Palmer (1974) has subjects
watch a film of a traffic accident.
“How fast were the cars going when they
smashed into each other?”
or
“How fast were the cars going when they hit
each other?”
Misinformation
• People who were asked “smashed”
version reported higher speeds
• A week later, they were more likely to
(falsely) recall seeing broken glass
False Memory and Eyewitness
Testimony
• Even hearing a vivid retelling of an event
can implant false memories
• Sample of 200 convicts later proven
innocent by DNA testing
– 79% misjudged based on faulty eyewitness
identification
– Leading questions (“Did you hear loud
noises”) can lead to false memories
Imagination and Memories
• Even imagining fake actions and events can
create false memories
• College students were asked to imaging specific
childhood events (like breaking a window with
their hand). 25% later recalled the event as
actually having happened.
• Possible cause: visualizing something and
actually perceiving it activate similar brain areas
Source Amnesia
Source Amnesia
• Source amnesia: faulty memory for how,
when, or where information was learned or
imagined
• Sometimes experienced by songwriters
and authors, who may unintentially
plagiarized something
Children’s Eyewitness Recall
• How can jurors decide cases in which children’s
memories of sexual abuse are the only
evidence?
• When 3 year-olds were asked to show on a doll
where a pediatrician had touched them, 55%
pointed to the genitals or anus, even though the
doctor had not touched them there
• Use nonleading questions soon after the event,
in language the child can understand
Repressed or Constructed
Memories of Abuse
Two tragedies concerning adult
recollections of childhood abuse:
1.When people don’t believe abuse
survivors who share their secret
2.When truly innocent people are falsely
accused
What about clinicians who help people
“recover” memories of abuse?
Guidelines for Thinking about
Recovered Memories of Sexual Abuse
•
•
•
•
•
Sexual abuse happens
Injustice happens
Forgetting happens
Recovered memories are commonplace
Memories of things happening before age 3 are
unreliable (Infantile amnesia)
• Memories “recovered” under hypnosis of under the
influence of drugs are especially unreliable
• Memories, whether real or false, can be emotionally
upsetting
Horror Carves a Memory
• The most common response to a
traumatic experience is not to banish the
experience into the unconscious.
• Rather, such experiences are typically
etched on the mind as vivid, persistent,
haunting memories.
Tips for Improving Memory
• Study repeatedly
• Space study sessions apart
• Spend more time rehearsing or actively thinking
about the material
• Make the material personally meaningful
• Activate retrieval cues
• Minimize interference
• Sleep more
• Test your knowledge, both to rehearse it and to
find out what you don’t know