Transcript Lecture - ClassTools.Info

Memory: A strange brew
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Doctor: Good morning, I’m doctor X, I’m here to test your memory
H.M. Hi, nice to meet you. Anybody ever tell you that you look just like Frank Sinatra?
Doctor: I get that a lot. I’m going to start by showing you some pictures and I want to you to name them as fast as you can
and then try and remember them because I will ask you later about them. OK?
H.M. OK.
H.M. Slowly - Rhinoceros, Camel, Anchor,, lamp
Doctor: good -- can you repeat those back to me:
H.M. Sure, Rhinoceros, Camel, anchor, and lamp
Doctor: that’s very good (pager rings), I’m sorry, I’ll be right back
H.M. No problem.
Doctor leaves room for 3 minutes and comes back.
Doctor: I’m going to ask you now if you remember any of the words I asked you to remember before.
H.M. What words? Anybody ever tell you that you look just like Frank Sinatra?
Doctor: I get that a lot. Do you remember any of the words I told you before?
H.M. What are you talking about? I’ve never met you before in my life,
Doctor: OK, I’m doctor X. I’m going to start by showing you some pictures and I want to you to name them as fast as you
can OK?
H.M. No problem. - quickly. (F)Rhinoceros, (S)car, (F) camel, (S) horse, (F) anchor.
Doctor: do you remember naming these pictures for me before?
H.M. Huh? I told you, I just met you,, I’ve never seen these pictures before.
Doctor: Why do you think you named some of the pictures (like the rhinoceros) more quickly?
H.M. They’re were easier to recognize
Doctor: Does it make sense that a rhinoceros would be easier to recognize than a car given that you see cars a lot more
often than rhinoceroses?
H.M. No, not really -- something weird is going on.
Memory Systems: Explicit and
Implicit
• Memory is divided into two systems
• Neurally separate
• Behaviorally dissociable to some
degree
Explicit (related to
“declarative” memory)
• “Conscious recollection”
• Episodes (e.g. The trip I took to mars
last year)
• Facts (e.g. Paris is the capital of
France)
• Behavioral measure usually used Recall
Explicit Memory: Neural
Architecture
• Related to “Hippocampal formation
(HF)” in medial temporal lobe can
cause of explicit memory deficits
• Korsakoff’s syndrome damages
mammillary bodies with alcohol abuse
• Amnesics have deficits in explicit
memory
Amnesia
• Retrograde: Can’t remember things in
past
– Go on trip to mars for 1 year (return trip
was 1 month)
– Hit head on capsule when landing in
ocean
– Temporally graded (events just before
accident are forgotten)
• (e.g.Forget return trip but remember being
on mars)
Why is Amnesia temporally
graded?
• HF holds info for a while and
“teaches” information to rest of cortex
• This “teaching” is part of consolidation
• After new info has been “taught”, then
it is stored in rest of cortex
– Time on mars has already been “taught”
(OK!)
– Return trip not completely “taught” yet
(GONE!)
Amnesia
• Anterograde: New information cannot
be learned
– H.M cannot learn new information (e.g.
who doctor “X” is)
Implicit Memory: Everything
that’s not Explicit
• Repetition priming (e.g. object
recognition priming)
• Savings upon relearning (relearning the
psych 120 material 10 years from now)
• Motor and skill learning (e.g. riding a
bike)
Implicit Memory: Example
Explicit vs. Implicit Memory
Experiments
• Study phase - subjects look at words
that have common stems (e.g. market)
• Test phase - cued recall:
– Given “mar”, say which word on
previous list
• Test phase - completion:
– Given “mar”, say any word on which
comes to mind
Explicit vs. Implicit: Results
Cued Recall
Completion
80
% Correct
60
40
20
0
Controls
Amnesics
Impaired Implicit Memory
with Intact Explicit
• Right occipital lobe removed at age 14
• Normal functioning (owner of
computer software company)
• Recognition Task: OK
• Priming (perceptual identification):
Impaired
• Priming impairment specific to vision:
Normal auditory priming
Explicit vs. Implicit in
Normals
• Study phase - subjects look at words in 3
condition
– Generate (hot - ????)
– Context (hot - cold)
– No context (xxx - cold)
• Test phase - recognition - say if on old list
• Test phase - perceptual identification
(detect word very briefly presented)
Explicit vs. Implicit in
Normals: Results
Rec ognition (Explicit)
Priming (Implicit)
0.8
Performance
0.6
0.4
0.2
0.0
Generate
hot - ????
Context
hot - cold
No Context
xxx - cold
Memory: How Reliable Is It?
• Memory is like a tape recorder: NOT!!
• Memory is Reconstructive
Eyewitness Testimony:
Leading the Witness
• Loftus, Burns and Miller 1978
• Subjects shown series of slides
depicting accident
• One group fed misleading questions
like
• “Did any car pass the red sports car
when it was stopped at the stop sign?”
(if yield sign was actually present)
Results:
• No misleading info: 85% correct
• Misleading info: 38% correct
• Called “the misinformation effect”
Flashbulb Memories
• Supposedly very good memory for
huge events (e.g. JFK assassination)
• But are they correct?
Test of Flashbulb memory:
Challenger
• Students recorded info at time of
disaster: Tested 2 years later
• Many had vivid memories
• Scored 0 to 7, (2 - where, 1 -who they
were with, 1- time of day etc.)
• 3/ 44 scored 7, mean =2.9, 50% <2.
• Almost no correlation of accuracy and
confidence
Learning: Acquiring New
Knowledge
• Associations: (e.g.) The smell of coffee
means that you will get some Folger’s
• Structures: (e.g. how U.S. government
is put together)
Learning Associations:
Classical Conditioning
• Every time I play mozart, my dog
salivates
• Unconditioned Stimulus (US) (meat)
• Unconditioned Response
(UR)(salivates)
• Conditioned stimuli (CS) (Mozart)
• Conditioned response (CR) (salivating
to mozart)
Classical Conditioning:
Timing
• CS comes on a little before US
• Adaptive: CR prepares the organism
for the US
• Some pairings take longer
Classical conditioning one one
trial
• Danger pairings can happen very fast
– E.g. conditioning dog to fear the mailperson
(shock him once after showing him mailperson)
– Conditioned taster aversion
•
•
•
•
•
US can follow a long time after
Give rats flavored water
Make them sick with a drug
They will avoid flavored water in future
Associate flavor with getting ill
Constraints of Conditioning
• Not all things get associated equally as
well
– Flavor with sickness - good association
– Loud noise and sickness - not as well
– Hard-wired pathways that affect ability
for things to associate
Stages of Classical Conditioning
• Acquisition (training): pair CS and US
(e.g. playing mozart and giving dog
food)
• Extinction (testing): don’t pair CS and
US, but still get some response for a
while
• Spontaneous Recovery: wait a while
after extinction trials and try CS again
and get UR, but then goes away again
Stimulus Specificity and
Stimulus Generalization
• What gets paired with US?
• CS is middle “C’ and is paired with meat
• Dog learns that middle “C” means meat
and salivation
• What if tested with “D above middle “C”?
• If he salivates he is showing stimulus
generalization
Instrumental Conditioning
• How do you train your dog to bark
jingle bells?
• Get her to bark and then slowly shape
her behavior with reinforcement
• “Law of Effect”
• Can reinforce with positive (good dog)
or negative (bad dog)
• Learnability of responses varies
Non-associative Learning
• Habituation - less response with experience
– Construction noise outside my window every
day
• Day 1 - I want a bb gun, Day 20 - I sleep blissfully
– Major way of studying cognitive processes in
babies
• Sensitization - more response with
experience
– Often associated with strongly aversive stimuli
Long-Term Memory: Overview
• Encoding (study)
• Storage
• Retrieval (test)
Encoding Specificity
• Retrieving is easier when retrieval
conditions match study conditions
Example: Study and test on land
and under water
60
50
Percent Correct
40
Studied Underwater
30
Studied on Land
20
10
0
Recalled on Land
Recalled underwater
Test condition
Context and Mood
• Subjects learned words either inside (I) or
outside (O)
• Recall was better when study and test
matched
• But (I) was dreary office and (O) was nice
sunny place outside
• Maybe outside caused a good mood and
inside caused a bad mood
Context and Mood
•
•
•
•
•
•
Same experiment, but mood manipulated
I+ (Inside with good mood)
I- (Inside with bad mood)
0+ (Outside with good mood)
0- (Outside with bad mood)
Results: mood mattered, Inside/Outside
didn’t
Assessing Memory: Recall and
Recognition
• High-Frequency words recalled better than
Low-frequency
• Low-Frequency words recognized better
than High-frequency
Context-dependent learning
• A double edged sword
– If you study only in one context and reproduce
all conditions at test, then similar context is
good
– But there are contextual elements you can’t
control (state of your brain fluctuates)
– You can’t always reproduce study conditions
(can’t study in 2278 all the time)
Context-Independent Learning
• You want to take your knowledge on
the road
• You want to retrieve this information
anywhere, anytime
• Vary study contexts so that memory
traces are encoded with variability
Memory: Finding the Way
• Even information is stored somewhere in
your head, you still have to access that
information
– Many “failures” of memory are really failures
to access
– Things you thought you forgot can often be
relearned easily (savings upon relearning)
• Encoding with variability sets up accessible
memory traces
Encoding Variability: Spacing
• Massed practice: Large blocks of practice
– Performance during training is often better
– Long-term performance is crummy
• Spaced (distributed) practice: Smaller
blocks of practice separated by time
– Performance during training is sometimes not
as good as massed
– Long-term learning is much better than massed
Spacing Effects Example
• Baddeley (1990) taught subjects typing
• 4 training schedules
– (1) 1 hour sessions/day
– (2) 1 hour sessions/day
– (1) 2 hour sessions/day
– (2) 2 hour sessions/day
Spacing Effects: Results
90
(1) 1-ho ur s es sion
(2) 1-ho ur s es sions
(1) 2-ho ur s es sion
Correct Keystrokes
80
(2) - 2 hour se ss ions
70
60
50
35
45
55
65
75
Hours of practice
85
Spacing Effects
• Applies to almost all kinds of learning
– Skill learning (motor)
– Fact learning (explicit learning)
Spacing Effects: Short Time
Frames
60
4.3 Sec
50
Percent Correct
2.3 Sec
40
1.3 Sec
30
20
0
10
20
30
Events Between the 2 presentations
40
50
Spacing Effects: Long Time
Frames
80
Percent Correct
70
60
56 day
50
28 day
40
14 day
30
0
1
2
3
Years
4
5
6
Encoding Variability: Context
• Studying in different contexts will help you
generalize the information
– Example: Study in more than one place if you
cannot take the test in the place where you
study
• One exception: If you have a hard time getting
focused except in one place
• Better to learn to have a few places where you can
study
Encoding Variability: Motor
Skills
Kids had to throw a bean bag at a post 4 feet
away
– Group A: Practice at 4 feet only
– Group B: Practice at 3 and 5 feet
– Wait a while then test
– Group B did better at 4 foot toss!
Encoding Variability: Motor
Skills
Practical advice for Shaq’s free throw
problem
– Don’t shoot 40 free throws in a row
– Do shoot 14 ft, 15 ft, 16 ft, 15 ft, hook
shot, 15 ft, etc…
Mental Imagery Experiment
–
–
–
–
–
–
–
–
–
–
–
–
Custard-Lumber
Jail-clown
Envelope-slipper
Sheepskin-candle
Freckles-apple
Hammer-star
Ivy-mother
Lizard-paper
Scissors-bear
Candy-mountain
Book-paint
Tree-ocean
Using Imagery to Enhance
Memory
• Interaction between elements is
especially useful
– Example: Dollar Bill and Elephant
• Imagine elephant paying with a dollar bill at
a checkout line
• Bizarreness is not especially important
The Method of Loci
• Associate each item on a list with a
place
• Take a “Mental Walk” and associate
each place with an item
Loci: Does it Really Work?
100
90
LOCI
80
Percent Correct
70
60
50
Control
40
30
20
10
0
1 Week
5 Weeks
Retention Interval
Enhancing Memory:
Organization Demonstration
Enhancing Memory: Depth of
Processing
• Processing at deeper levels lead to better
memory
– Example (meaning>rhyming>case judgments)
• Try to connect new material with old
material in as as many ways as possible
Enhancing Memory: Interaction
• Interact with material as much as possible
• Read (less than 50%)
• Organize, Summarize and Test (>50%)
Enhancing Memory: Testing
• Testing is powerful learning event
• Also reveals what you really know and what
you really don’t know
Enhancing Memory: Expanding
Retrieval Practice
• Bob Bjork invented this to facilitate learning
• Practice retrieving the information
• Slowly expand the delay interval between study
and test
– E.g. (Job interview - remember names)
•
•
•
•
Retrieve all names immediately after you leave
Retrieve again in 5 minutes
Retrieve again in 20 minutes
Retrieve again 60 minutes
Learning vs. Performance
• Not the same thing
• Sometimes performance and learning
trade off
• Massed vs spaced practice
• Massed - better for performance
• Spaces - better for learning
False Intuitions
• During learning:
– Hey - I really know this stuff (massed practice)
– I’m not so sure about this stuff (spaced
practice)
• Later when it counts:
– Hey - I actually remember that stuff (spaced
practice)
– Huh? (massed practice)
Testing: A Great Way to
Assess Learning
• Test yourself
– Assessed what you really know
– Testing is itself a powerful learning event
•Memory Enhancement
– “Seven Tigers Invade Indiana Mall”
– Space out study periods
– Test yourself often (expanding retrieval if
possible)
– Interact with material, process as deeply as
possible by connecting to existing knowledge
– Imagery (method of loci)
– Match study and test conditions when possible