Unformatted text preview: Classical Conditioning I. Definition The simplest mechanism whereby organisms learn about relations between stimuli and alter their behavior accordingly. prediction of events new responses to stimuli new emotional reactions examples? II. Historical Beginnings
Ivan Pavlov (18491936) and his dogs 1. Originally studied to learn about digestion 2. Technicians noticed increase in stomach juice secretion at sight of food or even person who fed them III. Basic Terms Unconditioned stimulus (US) – a stimulus that naturally triggers a response. Conditioned stimulus (CS) – an originally irrelevant stimulus that after association with the US, comes to trigger a conditioned response. Basic Terms Unconditioned response (UR) – the naturally occurring response to the US Conditioned response (CR) – the learned response to the previously neutral CS Cont.
US produces a UR CS US CS produces a CR Food produces Excitement Can Opener Food Can Opener produces Excitement III. Control Groups for Classical Conditioning
Paired vs. Unpaired A. Paired: CS US Measure CR after x number of trials B. Unpaired: CS No US Measure same CR as Paired after x number of trials Note: There shouldn’t be a CR for the unpaired group IV. Paradigm Examples
Fear conditioning – shock used as US; tone or light as CS CS US Tone Shock Light Shock
A. Fast to acquire – 10 trials or less Cont.
how does the animal react to the CS? – conditioned emotional response (CER) measured by freezing, or suppression of bar pressing, or lick suppression Cont.
Suppression Ratio = CS responding (CS responding + preCS responding) A decrease in ratio = increase in animal fearfulness If no suppression (no fear) = .5 Total suppression = 0 Cont.
CS Tone US Shock = Conditioning Tone Tone = Initial Response = Nothing Initial Response Freezing Shock Freezing Cont.
Human Examples:? Cont.
Eyeblink Conditioning CS US Tone Puff of air to eye Light “ Vibration “ UR – eyeblink to puff of air CR – eyeblink to tone, light, etc, (CS)
Slow to acquire – hundred trials? CR does not always happen (inconsistent) Conditioning of natural reflex
c. Sign Tracking (autoshaping) – approaching stimuli that signal food, water, conspecifics, etc. CS generally has to be discrete, localized, and visual CS = ?, US = ? CR = ?, UR = ? Cont.
Stimulus Key light (CS) = Food (US) Conditioning Key light Key light = Initial Response ? = ? Food (10 trials) ? Cont. after several pairings animal will approach CS despite this NOT being required to obtain food Cont.
Human Examples? Cont.
D. TasteAversion Learning – learning an aversion to a novel CS (food or water) that is followed by a US that makes the organism sick Why would an aversion develop? Why is it important for the CS to be novel? Cont.
CS Novel taste (i.e. cherry flavoring in water) US Something that makes animal sick (injection, irradiation) Cont.
Novel taste Injection (animal sick) Novel taste = aversion (won’t eat or drink it) Happens in one trial Why would this be important? Human examples? How could you improve quality of life for a chemotherapy patient based on taste aversion? 1. 2. A nursing mother responds to her crying infant by putting the infant to her breast, which stimulates the delivery of milk.After several times the crying baby stimulates the milk letdown reflex. A child has a routine of having his teddy bear with him when his parents tuck him in. When his parents are away the teddy bear comforts him. 1. 2. A song continues to evoke arousal and nervousness in a person who heard the song during her first kiss with a person to whom she was wildly attracted. A stuntman has a terrible accident causing immense pain while performing a stunt on a motorcycle. Thereafter motorcycles elicit fear. 5. A cyclist was attacked by a dog while riding down “country road 5”. On subsequent trips down that road the cyclist’s heart pumps extra fast and he experiences heightened anxiety. ...
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- Spring '10
- Classical Conditioning, CS gas, CR gas