Transcript File

Retrieving & Forgetting
Memories
Short-Term Memory
• Maintenance
rehearsal: shallow
processing
• 20 seconds
• “Rule of 7” (7 +/- 2)
• Try to remember as
many of the
following letters as
possible.
FABCPBSNBCCNNMTV
F ABC PBS NBC CNN MTV
Chunking: the process of
grouping items to make them
easier to remember.
Social Security Numbers
Phone Numbers
Put Your Pens/Pencils Down and
Listen to the List of Words I Read.
5
Dream
Night
Toss
Turn
Sound
Rest
Snore
Night
Slumber
Artichoke
Comfort
Tired
Clock
Fatigue
Silence
Dark
Quilt
Night
Bed
Sleep
10
15
20
Short-Term Memory
• The Serial Position
Effect: we are better
able to recall
information presented
at the beginning and
end of a list.
• Primacy Effect
• Recency Effect
Long Term Memory (LTM) Storing
Implicit & Explicit Memories
Explicit Memory refers to facts and experiences that one can
consciously know and declare. Implicit memory involves learning an
action while the individual does not know or declare what she knows.
Retrieval Cues
Memories are held in storage by a web of
associations. These associations are like anchors
that help retrieve memory.
water
smell
fire
smoke
Fire Truck
heat
truck
red
hose
Priming
To retrieve a specific memory from the web of
associations, you must first activate one of the
strands that leads to it. This process is called
priming.
Déja Vu
Déja Vu means “I've experienced this before.”
Cues from the current situation may
unconsciously trigger retrieval of an earlier
similar experience.
© The New Yorker Collection, 1990. Leo Cullum from
cartoonbank.com. All Rights Reserved
Telephone Game (Psych Style)
Memory Construction
• Leveling
• Sharpening
• Assimilation: Changing details to better fit the
subject’s own background, knowledge, or
schemas.
• Semantically encoded: because many parts of
the story are encoded this way (basic gist rather
than exact words), they are likely to be altered in
line with the teller’s schemas.
• Expectations, Experiences, Biases,
Stereotypes
Elizabeth Loftus and
John Palmer: Memory
Experiment and Hypothesis
• Hypothesis: People will remember a car accident
differently if given different language cues (words)
about the accident
Loftus and Palmer:
Methodology
• Students watched a film of two cars colliding
• Collision was moderate with no broken glass
• Different students asked different questions: hit,
smashed, collided, bumped, contacted
Loftus and Palmer: Results
VERB
MEAN ESTIMATE OF SPEED (MPH)
Smashed
40.8
Collided
39.3
Bumped
38.1
Hit
34.0
Contacted
31.8
• People reported the fastest speeds if the researchers
had used the word “smashed” in the question
• From fastest to slowest reported speeds: smashed,
collided, bumped, hit, and contacted groups
Loftus and Palmer: Results
• One week later, subjects were asked if they had seen
broken glass
• 32% of subjects asked the “smashed” question said
yes; 14% of subjects asked the “hit” question said yes
Loftus and Palmer: Results
and Implications
• People remember things differently depending on
the language used to describe an event (e.g.,
“smashed” versus “hit”)
• Misinformation effect – memories can become
skewed when presented with misinformation (Eye
Witness Test) 60 Minutes- Eyewitness
Factors that influence
reconstructive memory
• Leading questions“Did you see a broken headlight?”
“Did you see the broken headlight?”
• Lawyer-speak- “Is it not true that . . .”
• Schema-Mental framework of an object or
event based on previous experience.
Cue Dependence
• Available cues affect which
memories are retrievable
– Emotional
• Mood congruence
• Adult memory is emotionally
laden
• Current cues determine what is
retrievable
• Using our memories shapes
them over time
– Social/contextual
• State dependence
• Context effects
(Godden & Baddeley, 1975)
Forgetting
An inability to retrieve information due to
poor encoding, storage, or retrieval.
Which penny is real?
Encoding Failure
We cannot remember what we do not
encode.
Storage Decay
Poor durability of stored memories leads to
their decay. Ebbinghaus showed this with
his forgetting curve.
Unfamiliar &
Uninteresting =
more forgetting
Forgot 80%
after 1 week
Retaining Spanish
Bahrick (1984) showed a similar pattern of
forgetting and retaining over 50 years.
Andrew Holbrooke/ Corbis
Retrieval Failure
Although the information is retained in the
memory store, it cannot be accessed.
Tip-of-the-tongue (TOT) is a retrieval failure
phenomenon. Given a cue (What makes blood cells
red?) the subject says the word begins with an H
(hemoglobin).
Mnemonics – video clip
Volunteers Anyone?
Who
wants
To
Stroop?
Interference
Learning some new information may disrupt
retrieval of other information.
Retroactive Interference
Sleep prevents retroactive interference. Therefore, it
leads to better recall.
Motivated Forgetting
Motivated Forgetting:
People unknowingly
revise their memories.
Culver Pictures
Repression: A defense
mechanism that banishes
anxiety-arousing
thoughts, feelings, and
memories from
consciousness.
Sigmund Freud
Why do we forget?
Forgetting can occur at
any memory stage. We
filter, alter, or lose
much information
during these stages.
Hippocampus
• Hippocampus – a neural center in the limbic
system that processes explicit memories.
• Amnesia – loss of memory
Cerebellum
Cerebellum – a neural center in the hindbrain
that processes implicit memories. “muscle memory”
Storing Implicit & Explicit Memories
Explicit Memory refers to facts and experiences that one
can consciously know and declare. Implicit memory
involves learning an action while the individual does not
know or declare what she knows.