innate knowledge (what an organism is born with) experience leads to changes in knowledge
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Innate Knowledge (what an organism is born with) Experience leads to changes in knowledge and behavior Learning refers to the process of adaptation Of behavior to experience. Memory refers to the permanent records that Underlie this adaptation. How experience changes an organism - PowerPoint PPT PresentationTRANSCRIPT
Innate Knowledge
(what an organism is born with)
Experience leads to changes in knowledge
and behavior
Learning refers to the process of adaptation
Of behavior to experience.
Memory refers to the permanent records that
Underlie this adaptation.
How experience changes an organism
Learning Perspective
EVENT Change inBehavior
Memory (Cognitive) Perspective
EVENT Change in whatorganism knows
Learning vs Cognitive (Memory) Perspectives
Learning focuses on simple tasks
Pavlovian Conditioning
built-in food salivationreflex
US UR
CS tone food salivation
tone salivation
new learnedassociation
Operant Conditioning
Animal makes random responsethen accidentally presses bar
R Re(response) (reward or
reinforcement)
Animal is more likely to press bar
Memory perspective focuses on complex tasks
Recall
Present a list of words (STUDY)
(wait)
Write down all the words (TEST)
Word Completion
S M T O
What’s the word?
Question answering
What is the red pigment that carriesoxygen in the blood called?
The Learning Perspective uses Animals as Subjects
can control environment
belief that laws of learning apply to all
animals
The memory perspective uses humans
•we care more about humans
•language stimuli
The learning perspective takes an AssociationisticApproach
Mind is a collection of innate reflexes and learnedassociations stored in the brain
Complex behavior is gradually built up out ofsimple associations
Memory perspective adoptsthe information processing approach
The brain is a computer
•It has software or programming called the mind
•It has a “programming language”
Experience constantly adds to the program
It has a “central processor”(innate knowledge)
It has a large “hard disk”(long-term store)
NID Experiment
Learning “It’s a conditioning study!”
42unconditioned
stimulus(US)
“forty-two”unconditioned
response(UR)
NID 42 “forty-two”
conditionedstimulus
(CS)
after learning NID “forty-two”
Memory “It’s a memory experiment”
cue item-to-be-recalledstudy NID 42test NID ?cued recall
Pavlovian Conditioning
Definitions
foodUS
air in eyeshock
. . .. . . . . .. . .
salivationUR
blink“ouch!”
US is paired with CS
CS UStone food salivation
tone salivationCRconditionedresponse
Sometimes the CR is like the URSometimes the CR tries to compensate for US
Example: If US is shock, CR is fearand behavior that compensatesfor pain
Forgetting Conditioning
Strengthof CR
AcquisitionExtinction
US ispaired
with CS
CS neverpaired
with US
Extinction
Is it because conditioning is gone?
OR
because conditioning is inhibited?
Inhibition Hypothesis
+CS US CS USacquisition inhibition
extinction
Loss Hypothesis
+CS US CS US CS USacquisition extinction
Evidence Favors Inhibition Hypothesis
1. Spontaneous Recovery
prob.of
CR
Suggests that the original learning was not lost
time
wait a while
2. Disinhibition Effect
External Inhibition
light food salivation
light salivation
light sali … TONE!
(salivation stops)
light food salivation
light salivation
light sali
extinction light sa
light nothing
light TONE!
salivation startsagain
Tone inhibits the inhibition from extinction
Shows extinction is due to inhibition, not loss
3. Stimulus-compounding experiments(Rescorla, 1979)
Experimental ControlGroup Group
Phase 1 Tone Shock (same)Tone Fear
Phase 2 Tone + Light - 0 Tone - 0Extinction
no shock Light - 0
stimuluscompound
Phase 3 Light + Buzzer - Shock
Test to see Experimental group developsif light fear more slowlyis inhibited
The light became a conditioned inhibitor of fear
Extinction leads to inhibition
What is learned in Pavlovian Conditioning?
S-R view OR S-S view
tone CS tone CS
food salivation food salivation US R US R
Which one is right?
Sensory Pre-conditioning Experiment
Phase 1 Buzzer . . . Light
CS2 CS1
Phase 2 Light . . . Food Salivation US
Light Salivation
Phase 3 (test) Buzzer . . . ?
What happens?
S-R view predicts no salivation
S-S view predicts salivation
Results show salivation supporting S-S view
Sensory pre-conditioning shows S-S association is learned
Buzzer Light Food
predictsbuzzer S-S Salivationcausessalivation
Buzzer Light Food
predictsbuzzer S-R Salivationdoes notcause salivation
Conclude: at least some of the learning is S-S
Konorski’s (1948) second-order conditioning experiment
Phase 1 light . . . food salivation
Phase 2 buzzer . . . light salivation
buzzer salivation
This is second-order conditioning
Phase 3 light . . . shock leg withdrawal
Test phase buzzer . . .
What happens?salivation or leg withdrawal
S-S view
light food salivation
buzzer
S-S
S-S
buzzer
S-S
S-S
shock leg withdrawal
Buzzer should lead to leg withdrawalS-S
S-R view
food salivation
light
S-R
buzzer
S-R
shock
leg withdrawal
Buzzer should lead to salivation
S-R
Conclude:
Both S-S and S-R learning occur
Conclude:
Both S-S and S-R learning occur
But why didn’t leg withdrawal occur inKonorski’s experiment?
Phase 1
light food
salivation
S-R
S-S
When do you get conditioning?
Pavlov “If CS and US occurat around the same time”
Temporal Contiguity View
Modern View (Rescorla)
“If the CS predicts whetherthe US will happen”
Contingency View
Contingency
Perfect positive contingency
thunder no thunder lightning 20 0
no lightning 0 345
prob (thunderlightning) = 1.0
prob (thunderno lightning) = 0
Strong negative contingency
sun no sun stars 1 200
no stars 200 60
Contiguity without Contingency
10 20
20 40
airplane
no plane
no
Stim 2 Stim 2 a b
c d
Stim 1
No Stim 1
bird andplane are paired
A quick test for contingency
a·d > c·bthen positive
a·d = c·bzero contingency
a·d < c·bthen negative
no bird bird
prob.(birdplane) = .33prob.(birdno plane) = .33
You can have a positive contingency even whenpairing is the least frequent possibility
Example: can you learn that
and “cat” are associated?
“cat” no “cat”
100 900 1,000
200 9,800 10,000
see
no
prob (“cat” ) = .10
prob (“cat”no ) = .02
hear
positive contingency
shock no shock
tone
no tone
0 4
4 0
perfect negativecontingency
tone becomes a conditioned inhibitorof fear
shock no shock
tone
no tone
4 0
0 3
perfect positivecontingency
tone leads to fear
Unpaired Experiment
Contingency and Conditioning
Standard Experiment
timetone tone tone tone
shockshock shockshock
shock no shock
tone
no tone
2 1
1 2
conditioningoccurs
shock no shock
tone
no tone
2 2
2 2
zerocontingency
Conclude: contingency, not contiguity matters
Partial positive contingency
No conditioning occurs even though tone and shockare occasionally paired
Random Pairing
S S
T
S
T T
S
T
Random Pairing Experiment
shock no shock
tone
no tone
20 20
20 20
zerocontingency
no conditioningoccurs
Shows that there must be some contingency
between CS and US to get conditioning.
Contiguity is not enough.
Fear vs Anxiety
•if tone predicts shock then animal becomes
afraid after tone
(like a phobia)
•if tone does not predict shock (random pairing)
animal ignores the tone and experiences
something like anxiety (unfocused fear)
Blocking Effect
phase 1 tone shock
16 times
phase 2 tone+light shock
8 times
phase 3 light alone
NO FEAR IS ELICITED!
Shows that contingency alone doesn’t produceconditioning
Get conditioning when
(a) CS predicts USAND
(b) CS tells something we didn’t already know
Explaining the Blocking Effect
trial 1 CS UStone shock
•CS is surprising US is surprising•Process CS and US•Create association between CS & US
trial 2 tone stock
trial 3
trial 8 CS memory of fear UStone shock shock
Shock is not surprising any more so no additional strengthening of association occurs
trial 3
trial 8
CS memory of shock CR fear tone US-shock
Tone fully activates memory of US shock, so when shock comes it is not at all surprising.No additional learning occurs.
Str
engt
h o
f C
S-U
S A
ssoc
iati
on
1 2 3 4 5 6 7 8
rapidlearning
no morelearning
Phase 2trial 9
CS1 CS2 memory
tone + light of shock fear
The light is surprising, so it is processed. But the tone completely predicts the shock
USshock
So the US shock is not processed, so no association is formed between light and shock.
Explains blocking effect
General Conclusion
Stimuli are associated when they provide information that the organism doesn’t already know.
Modern view of conditioning and the blocking effect
(1) Form association between stimuli only if they
are actively processed or “rehearsed” together.
(2) Stimuli are processed only if they are
unexpected
(3) As conditioning proceeds both the CS and US
become less surprising. So they are processed less
and, hence, less additional learning occurs.