Chapter 7Learning

Classical ConditioningClassical Conditioning• Learning: a relatively permanent change in

behavior that is brought about by experience

• Ivan Pavlov: – Noticed that dogs were responding to learning

which he called classical conditioning– Classical Conditioning: a type of learning in

which a neutral stimulus (such as the experimenter’s footsteps) comes to elicit a response after being paired with a stimulus (such as food) that naturally brings about that response

Pavlov’s ExperimentPavlov’s Experiment• Attached a tube to the dog’s mouth to

measure salivation. Rang a bell and gave the dog a piece of meat. Did this several times. At first the dog would only salivate when it would see the meat, but after several tries the dog starts to salivate when it hears the bell. Even when Pavlov did not give the dog the meat, it would still salivate when it would hear the sound. The dog had been classically conditioned to salivate when it would hear the bell.

How Does it Work?How Does it Work?• Neutral Stimulus: a stimulus that, before conditioning,

does not naturally bring about the response of interest (example: bell)

• Unconditioned Stimulus: a stimulus that naturally brings about a particular response without having been learned (example: meat)

• Unconditioned Response: a response that is natural and needs to no training (example: salivation)

• Conditioned Stimulus: a once-neutral stimulus that has been paired with an unconditioned stimulus to bring about a response formerly caused only by the unconditioned stimulus (bell after the conditioning)

• Conditioned Response: a response that, after conditioning, follows a previously neutral stimulus (example: salivation after ringing of bell)

Examples in HumansExamples in Humans In the past a big yellow “M” would not elicit

any kind of response. However, if we see the golden arches of McDonalds we (like Pavlov’s dogs) may salivate.

Phobias: seeing something you are scared of elicits a response

ExtinctionExtinction Extinction: a basic phenomenon of learning

that occurs when a previously conditioned response decreases in frequency and eventually disappears. If you ring the bell and don’t give the meat,

eventually the salivation will stop

Spontaneous RecoverySpontaneous Recovery The reemergence of an extinguished

conditioned response after a period of rest and with no further conditioning Example: You may “cure” someone of a drug

addiction, yet something may trigger an irresistible impulse to use again (example: see a white powder, or some other associated thing which causes this reaction)

Generalization Generalization DiscriminationDiscrimination

Stimulus Generalization: occurs when a conditioned response follows a stimulus that is similar to the original conditioned stimulus; the more similar two stimuli are the more likely a generalization is to occur Example: Little Albert was conditioned to be

fearful of white rats. However, he developed a fear of all white, soft, furry things.

Generalization & Generalization & DiscriminationDiscrimination

• Stimulus Discrimination: the process that occurs if two stimuli are sufficiently distinct from one another that one evokes a conditioned response, but the other does not. This is the ability to differentiate between stimuli– Example: dog runs into the kitchen when it

hears the sound of the can opener which is used to open the can of dog food, but does not come when it hears the food processor

Pavlov’s View of Pavlov’s View of LearningLearning

Learning is just a bunch of unconditioned responses

Operant ConditioningOperant Conditioning Operant Conditioning: Learning in which a

voluntary response is strengthened or weakened, depending on its favorable or unfavorable consequences

Thorndike’s Law of Thorndike’s Law of EffectEffect

If you place a cat in a cage and put food outside the cat will try to get it. If the cat accidentally steps on a lever which opens the door, next time you put the cat in the cage it will take less time to step on the paddle.

Conclusion: responses that lead to satisfying consequences are repeated.

SkinnerSkinner Skinner Box: placed a rat in a box with a

lever. At first the lever is accidentally pressed by the rat and it releases a pellet. The first time this happens the rat does not learn that pressing the lever will release a pellet. However, after a few times the rat will learn that pressing the lever gives it food and will press it repeatedly until it satisfies it’s hunger.

Operant ConditioningOperant Conditioning Reinforcement: the process by which a

stimulus increases the probability that a preceding behavior will be repeated

Reinforcer: Any stimulus that increases the probability that a preceding behavior will occur again

Operant ConditioningOperant Conditioning Positive Reinforcer: a stimulus added to the

environment that brings about an increase in a preceding response

Negative Reinforcer: an unpleasant stimulus whose removal leads to an increase in the probability that a preceding response will be repeated in the future

Punishment: a stimulus that decreases the probability that a previous behavior will occur again

The Pro’s and Con’s of The Pro’s and Con’s of PunishmentPunishment

Pro’s Quickest route to changing behavior Provides a way to temporarily reinforce

behavior

Con’s Can be frequently ineffective if not delivered

right after the behavior Physical punishmentidea that physical

aggression is okay Doesn’t convey alternatives

Schedules of Schedules of ReinforcementReinforcement

Schedules of Reinforcement: different patterns of frequency of timing of reinforcement following desired behavior

Continuous reinforcement schedule: reinforcing of a behavior every time it occurs Learning occurs more rapidly

Partial reinforcement schedule: reinforcing of a behavior some but not all the time Results in stronger, longer lasting learning

(example, slot machine)

Fixed & Variable Ratio Fixed & Variable Ratio SchedulesSchedules

Fixed-Ratio Schedule: reinforcement is given after a fixed number of responses are made Example: you get paid for every blouse you

make

Variable-Ratio Schedule: reinforcement is given after a varying number of responses Example: a sale person’s job- you may get

paid on the first, seventh, or tenth person you attend

Motivation Intrinsic Motivation: the desire to perform a

behavior for its own sake A Dr. who likes to help people

Extrinsic Motivation: the desire to perform in a certain way to get an external reward or avoid punishment A Dr. who does it for the money

Biological ConstraintsBiological Constraints You can’t teach an old dog new tricks

Thoughts?

Cognitive Approaches Cognitive Approaches to Learningto Learning

Cognitive Learning Theory: An approach to the study of learning that focuses on the thought processes that underlie learning

Latent LearningLatent Learning Learning in which a new behavior is

acquired but is not demonstrated until some incentive is provided for displaying it Rats are put in a maze for days and wonder

around. However, when food is given at the end of the maze they learn to run quickly through the maze

Observational Observational LearningLearning

Learning by watching the behavior of another person

Bandura conducted an experiment with children and a Bobo doll

MediaMedia Does the media’s message matter?