Transcript Ch06a

Clear cases of Damaged LTM
• Korsakoff’s Syndrome (Vit B1)
• Traumatic loss (H.M.)
LTM covers 30 seconds ago and beyond.
LTM is always working with STM.
There is an interesting story about the
telescope. In Holland, a man named
Lippershey was an eyeglass maker. One day
his children were playing with some lenses.
They discovered that things seemed very
close if two lenses were about a foot apart.
Lippershey began experiments and his
"spyglass" attracted much attention. He sent
a letter about it to Galileo, the great Italian
scientist. Galileo at once realized the
importance of the discovery, and set out to
build an instrument of his own.
Count the Vowels in Each Word
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Worm
Sunglasses
Water
Drink
Carrot
Baby
Backpack
Church
Airforce
Pepper
Make a sentence including each
word and the word “puppy.”
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Leg
Solid
Garden
Pocket
Aeroplane
Fruit
Explosive
Money
Tiger
Printer
•Serial-position curve (Murdoch, 1962).
Specific changes can affect one without the other.
More time between words: Rehearsal and improves LTM arm
Thirty-second delay before report: eliminates recency effect
Coding in LTM
• Like the phonological loop and
visuospatial sketchpad in WM, LTM
probably has different components and
coding mechanisms but semantic
coding seems to be the predominant
mechanism.
Which Sentence is from the Text?
1. He sent a letter about it to Galileo, the
great Italian scientist.
2. He sent Galileo, the great Italian scientist,
a letter about it.
3. A letter about it was sent to Galileo, the
great Italian scientist.
4. Galileo, the great Italian scientist, sent him
a letter about it.
Semantic Coding is Central to LTM
1. Identical: He sent a letter about it to Galileo, the
great Italian scientist.
2. Formal: syntactic change, but kept meaning "He
sent Galileo, the great Italian scientist, a letter
about it."
3. Voice: Changed from active to passive "A letter
about it was sent to Galileo, the great Italian
scientist."
4. Semantic: A difference in meaning " Galileo, the
great Italian scientist, sent him a letter about it."
Endel Tulving (1972) proposed two types of
Declarative memory. Evidence of these two?
- Maybe it’s better to say HM lost the ability to
create Declarative memories
Implicit Memory
Q: Are unknown forces controlling your life?
A: Probably
• Repetition Priming in the case of Korsakoff’s
Syndrome (Affects LTM – But how, exactly?)
– Shows implicit memories can still be created.
– Incomplete image task (Figure 6.11)
Amnesia After Brain Damage
• “H.M.”
– He experienced massive anterograde
amnesia. He was unable to store any new
memories. (It was 1953 forever)
– He had moderate retrograde amnesia for
many events that occurred between 1 and 3
years before his surgery.
– Normal short-term memory functions.
– His procedural memory was retained intact!
Procedural Memory Task
Encoding and Retrieval
• Rehearsal facilitates encoding
– Maintenance rehearsal
• Repeating a phone number until you make
the call
• You probably won’t transfer it to LTM
– Elaborative Rehearsal
• Think of meaning (semantics) and make a
connection
Levels of Processing Theory
• Fergus Craik and Robert Lockhart (1972)
– Shallow processing - Read and memorize
– Deep processing - Read, think about it, and
memorize.
• Recall words from the vowel and “puppy”
tasks.
Just because
you can’t get it
out doesn’t
mean it’s not in
there!!!
Craik and Tulving’s (1975) experiment.
Circumstances of Encoding
and Retrieval
• Transfer-Appropriate Processing
– Does the recall task match the acquisition task?
• Encoding Specificity
– Does the recall environment match the
acquisition environment (external state)?
• State Dependent Learning
– Does your internal state during recall match
the state during acquisition?
Transfer-Appropriate Processing
Recall is enhanced when the testing task matched the
acquisition task. NOT what LOP theory would predict!
(Morris et al., 1977).
How are memories made?
LTP (Long-term potentiation) = LTM
• This change is a “neural record” of an
experience!
Storage and Retrieval
• We’ve described how consolidation begins
(Donald Hebb, 1948)
– It may take up to three years to completely
consolidate memories (evidence?).
• We know that the hippocampus is vital to
the formation of new LTMs
• Kandel (2001) and others have shown that
LTP is easiest to demonstrate in brain areas
associated with LTM (esp. hippocampus)
So how are memories Lost?
• Traumatic disruption of the consolidation
process or “storage vaults”
– Can be chemically or physically induced
• The initial changes are probably fragile
• Consolidation period is long - maybe
years.
So how are memories Lost?
• Squire (1975, 1986): ECT studies show
dramatic loss of memories for events
immediately preceding the therapy and
subtler loss for memories that are several
years old.
Ventral Surface of the Brain showing structures
in the medial temporal lobe
Later brain scan data demonstrated that HM
lost more than his hippocampus (MTL).
Hippocampus Review
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Not needed for STM/WM
Needed for forming conscious LTMs
NOT where LTMs are stored
NOT needed for forming implicit
memory
Getting memories out.
• What about the ones that are there, but
hard to find?
• Retrieval cues bring us back to the
organizational nature of memory.
• LOP Theory tells us that memory
storage is like a graded pool
– Easy to get the stuff in the shallow end
– Tougher to get stuff in the deep end
Transfer-Appropriate Processing
Recall is enhanced when
the acquisition task.
the testing task matched
NOT what LOP theory would
predict! (Morris et al., 1977).
Retrieval is Active
• Getting memories out is not simply a
matter of dipping a bucket in a pool
Cued Recall: Tulving and Pearlstone (1966).
Other Cue
Your Cue
Results of Mantyla’s (1986) experiment.
Circumstances of Encoding
and Retrieval
• Transfer-Appropriate Processing
– Does the recall task match the acquisition task?
• Encoding Specificity
– Does the recall environment match the
acquisition environment (external state)?
• State Dependent Learning
– Does your internal state during recall match
the state during acquisition?
Godden and Baddeley (1975) - Author says were
matching “place.” Is this a matter of LOCATION
or INTERNAL STATE?
Environment: Grant et al.’s (1998) “studying”
experiment. Is it OK to study while the
television is on?
Mood (internal state): Eich and Metcalfe’s
(1989) experiment.
Functional Significance of
Memory
• Consider the importance of remembering
things under similar conditions
• What are the implications for
– Recall in a courtroom?
• Different environment
– Recall under hypnosis?
• Different physical state
Do you remember events or
memories of events?
Sure, Now you tell me!
• How will you study for the exam?
• Will you employ any of the
information you have acquired?