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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.
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How experience changes an organism Learning Perspective EVENTChange in Behavior Memory (Cognitive) Perspective EVENTChange in what organism knows
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Learning vs Cognitive (Memory) Perspectives Learning focuses on simple tasks Pavlovian Conditioning built-infoodsalivation reflex USUR CStonefoodsalivation tonesalivation new learned association
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Operant Conditioning Animal makes random response then accidentally presses bar RRe (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)
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Word Completion S M T O What’s the word? Question answering What is the red pigment that carries oxygen in the blood called? The Learning Perspective uses Animals as Subjects can control environment belief that laws of learning apply to all animals
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The memory perspective uses humans we care more about humans language stimuli The learning perspective takes an Associationistic Approach Mind is a collection of innate reflexes and learned associations stored in the brain Complex behavior is gradually built up out of simple associations
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Memory perspective adopts the 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)
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NID Experiment Learning “It’s a conditioning study!” 42 unconditioned stimulus (US) “forty-two” unconditioned response (UR) NID42“forty-two” conditioned stimulus (CS) after learningNID “forty-two” Memory “It’s a memory experiment” cueitem-to-be-recalled studyNID42 testNID? cued recall
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Pavlovian Conditioning Definitions food US air in eye shock... salivation UR blink “ouch!” US is paired with CS CS US tonefoodsalivation tonesalivation CR conditioned response Sometimes the CR is like the UR Sometimes the CR tries to compensate for US Example:If US is shock, CR is fear and behavior that compensates for pain
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Forgetting Conditioning Strength of CR Acquisition Extinction US is paired with CS CS never paired with US Extinction Is it because conditioning is gone? OR because conditioning is inhibited?
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Inhibition Hypothesis + CSUSCSUS acquisitioninhibition extinction Loss Hypothesis + CSUS CS US CS US acquisition extinction Evidence Favors Inhibition Hypothesis 1.Spontaneous Recovery prob. of CR Suggests that the original learning was not lost time wait a while
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2. Disinhibition Effect External Inhibition light foodsalivation lightsalivation lightsali … TONE! (salivation stops) light foodsalivation lightsalivation lightsali extinctionlightsa lightnothing lightTONE! salivation starts again Tone inhibits the inhibition from extinction Shows extinction is due to inhibition, not loss
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3. Stimulus-compounding experiments (Rescorla, 1979) ExperimentalControlGroup Phase 1ToneShock(same) Tone Fear Phase 2Tone + Light - 0Tone - 0 Extinction no shockLight - 0 stimulus compound Phase 3Light + Buzzer - Shock Test to seeExperimental group develops if lightfear more slowly is inhibited The light became a conditioned inhibitor of fear Extinction leads to inhibition
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What is learned in Pavlovian Conditioning? S-R viewORS-S viewtone CS food salivationfood salivation US R US R Which one is right?
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Sensory Pre-conditioning Experiment Phase 1Buzzer... Light CS 2 CS 1 Phase 2Light... FoodSalivation US LightSalivation Phase 3 (test)Buzzer...? What happens? S-R view predicts no salivation S-S view predicts salivation Results show salivation supporting S-S view
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Sensory pre-conditioning shows S-S association is learned BuzzerLightFood predicts buzzerS-SSalivation causes salivation BuzzerLightFood predicts buzzerS-RSalivation does not cause salivation Conclude: at least some of the learning is S-S
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Konorski’s (1948) second-order conditioning experiment Phase 1light... food salivation Phase 2buzzer... light salivation buzzersalivation This is second-order conditioning Phase 3light... shock leg withdrawal Test phasebuzzer... What happens? salivation or leg withdrawal
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S-S view lightfoodsalivation buzzer S-S
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buzzer S-S
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shockleg withdrawal Buzzer should lead to leg withdrawal S-S
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S-R view foodsalivation light S-R
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buzzer S-R
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shock leg withdrawal Buzzer should lead to salivation S-R
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Conclude: Both S-S and S-R learning occur
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Conclude: Both S-S and S-R learning occur But why didn’t leg withdrawal occur in Konorski’s experiment? Phase 1 lightfood salivation S-R S-S
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When do you get conditioning? Pavlov“If CS and US occur at around the same time” Temporal Contiguity View Modern View (Rescorla) “If the CS predicts whether the US will happen” Contingency View
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Contingency Perfect positive contingency thunder no thunder lightning 200 no lightning 0 345 prob (thunder lightning) = 1.0 prob (thunder no lightning) = 0 Strong negative contingency sun no sun stars 1 200 no stars 200 60
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Contiguity without Contingency 10 20 20 40 airplane no plane no Stim 2 a b c d Stim 1 No Stim 1 bird and plane are paired A quick test for contingency a·d > c·b then positive a·d = c·b zero contingency a·d < c·b then negative no bird prob. (bird plane) =.33 prob. (bird no plane) =.33
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You can have a positive contingency even when pairing is the least frequent possibility Example: can you learn that and “cat” are associated? “cat” no “cat” 100 900 1,000 200 9,80010,000 see no prob (“cat” ) =.10 prob (“cat” no ) =.02 hear positive contingency
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shock no shock tone no tone 04 4 0 perfect negative contingency tone becomes a conditioned inhibitor of fear shock no shock tone no tone 4 0 0 3 perfect positive contingency tone leads to fear Unpaired Experiment Contingency and Conditioning Standard Experiment time tone shock
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shock no shock tone no tone 2 1 1 2 conditioning occurs shock no shock tone no tone 2 2 2 2 zero contingency Conclude: contingency, not contiguity matters Partial positive contingency No conditioning occurs even though tone and shock are occasionally paired Random Pairing SS T S TT S T
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Random Pairing Experiment shock no shock tone no tone 20 zero contingency no conditioning occurs Shows that there must be some contingency between CS and US to get conditioning. Contiguity is not enough.
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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)
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Blocking Effect phase 1toneshock 16 times phase 2tone+lightshock 8 times phase 3light alone NO FEAR IS ELICITED! Shows that contingency alone doesn’t produce conditioning Get conditioning when (a) CS predicts US AND (b) CS tells something we didn’t already know
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Explaining the Blocking Effect trial 1CSUS toneshock CS is surprising US is surprising Process CS and US Create association between CS & US trial 2tonestock trial 3 trial 8 CS memory of fear US tone shock shock Shock is not surprising any more so no additional strengthening of association occurs
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trial 3 trial 8 CS memory of shock CR fear toneUS-shock Tone fully activates memory of US shock, so when shock comes it is not at all surprising. No additional learning occurs. Strength of CS-US Association 1 2 3 4 5 6 7 8 rapid learning no more learning
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Phase 2 trial 9 CS 1 CS 2 memory tone +lightof shock fear The light is surprising, so it is processed. But the tone completely predicts the shock US shock 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.
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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.
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