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COURSE NOTES: Introductory Psychology

Psych101 graphic

Chapter 7:

Learning

Notes for Psychology 101: based on Myers's text, Exploring Psychology, with supplements and modifications by the instructor, Prof. Cloninger.

denotes a term that you should know how to define, and to recognize and give examples.

denotes an important person. You should remember this person's name and what (s)he has done.

denotes an important research finding.

denotes an issue that you should be able to discuss or explain.

learning: "a relatively permanent change in an organism's behavior due to experience"
examples: learning to be proud of winning; learning to do a difficult gymnastic routine

associative learning: linking two events that occur close together

Major types of learning

classical conditioning
operant conditioning

CLASSICAL CONDITIONING

classical conditioning: "learning to associate events; learning that a previously neutral stimulus signals the onset of a stimulus that produces a reflex action"
example: Pavlov's dogs (classically conditioned salivation)

Pavlov's Experiments

[graphics presented in lecture; see also the Myers text]

Learning in Aplysia (sea slug)

(a simple animal to study)
learning to withdraw more efficiently (to avoid being eaten by lobsters and other scary critters in the sea)
[graphics of classical conditioning in Aplysia will be presented in class; see the diagrams on page 229 of the text for classical conditioning in Pavlov's dogs]

unconditioned response (UCR)

unconditioned stimulus (UCS)

conditioned response (CR)

conditioned stimulus (CS)

sensitization

By learning to withdraw quickly to painful stimuli, Aplysia may be saving his or her life.
But lots of touches, even for Aplysia, are "good touch" (or at least not harmful). No need to withdraw from every touch.

habituation

By not withdrawing any more than is necessary, Aplysia conserves his precious supply of ink. He must eat a great deal of red seaweed to make ink, and excessive withdrawal from innocuous touches would leave little time for other pursuits...

examples of UCR: anxiety; salivation; allergic reactions

DESENSITIZATION OF CLASSICAL RESPONSE

before: CS -- CR (which is undesirable)
example: fear of speaking
strategy: EXTINCTION
present CS in circumstances where CR won't occur

S-R relationships
stimulus substitution
HOW?
build up a competing CR ("counterconditioning")
example: relaxation
establish a hierarchy of CS conditions
example: assignment, preparation, waiting, giving speech
Relax progressively to each step. Stop if anxious.
RESULTS: extinction of the fear

other important terms in classical conditioning:

acquisition

extinction

spontaneous recovery

generalization

discrimination

Updating Pavlov's Understanding

Cognitive Processes

such as predictability

such as awareness that nausea is drug-induced (when used to treat alcoholism)

Biological Predispositions

John Garcia's work on taste aversion

coyotes learn to avoid sheep
cancer patients (unfortunately) develop nausea

Pavlov's Legacy

Applications of Classical Conditioning

The effect of drugs, such as heroin, is influenced by classical conditioning. Sometimes the results are fatal...
Taking heroin can be deadly.... [graphic presentation of this material will be given in class]
especially in a new setting.
(And that doesn't even take into account such factors as drug impurities.)

Classical conditioning is the mechanism behind many irrational fears (phobias). It can be used to treat them, too.

"Little Albert" is a classic example of a conditioned fear, reported by John B. Watson, a famous behaviorist.

Classical conditioning involves "respondent behavior."

OPERANT CONDITIONING

operant conditioning: learning because of consequences
example: rat learning to press a bar in a Skinner box because it is reinforced with food

Skinner's experiments

law of effect
operant chamber

REINFORCER
example: any event that increases the frequency of the preceding response

PRIMARY REINFORCER
reinforcer that is unlearned (innate)
example: food, and other innately satisfying reinforcers

SECONDARY REINFORCER
reinforcer that is learned
example: praise, approval, money

POSITIVE REINFORCER
any event that, when added to a situation contingent on a response, increases the frequency of the preceding response
example: feeding a rat after it presses a bar

NEGATIVE REINFORCER
any event that, when subtracted from a situation contingent on a response, increases the frequency of the preceding response
example: ending an annoying buzzer by fastening your car seatbelt

Negative reinforcement is NOT the same as punishment! Negative reinforcers, like all reinforcers, increase the frequency of the responses that they follow. (Punishment, in contrast, decreases the frequency of responses.)

Why is this a negative reinforcer?

taking aspirin to relieve a headache

hurrying home in the winter to get out of the cold

giving in to an argument, or to a dog's begging

fanning oneself to escape the heat

leaving a movie theater if the movie is bad

smoking in order to relieve anxiety

following prison rules in order to be released from confinement

feigning a stomach ache in order to avoid school

putting on a car safety belt to stop an irritating buzz

turning down the volume of a very loud radio

putting up an umbrella to escape the rain

saying "uncle" to stop being beaten

Reinforcers that don't occur immediately are often less effective than immediate reinforcers.

SCHEDULES OF REINFORCEMENT

contingencies between response and reinforcement

continuous reinforcement
partial reinforcement
fixed-ratio schedule
variable-ratio schedule
fixed-interval schedule
variable-interval schedule

Examples of reinforcement schedules:

fixed-ratio schedule: piece work or commission
variable-ratio schedule: slot machines
fixed-interval schedule: weekly quizzes; daily delivery of mail
variable-interval schedule: pop quizzes; fishing

Notice, on the next slide, how different the cumulative record of responding looks for each schedule. [graphic in class...]

Advantages of Continuous Schedules

rapid increase in rate of responding
(but at the cost of rapid extinction)

Advantages of Partial Reinforcement Schedules

greater resistance to extinction (especially with variable schedules)

Advantages of Ratio Schedules

produce a rapid rate of responding

TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
buying state lottery tickets and winning
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
A hotel maid may take a 15-minute break only after having cleaned three rooms.
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
watching and seeing shooting stars on a dark night
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
A teenager receive an allowance every Saturday.
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
checking the front porch for a newspaper when the delivery person is extremely unpredictable
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
A professional baseball player get a hit approximately every third time at bat.
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
checking the oven to see if chocolate chip cookies are done, when baking time is known
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
A blueberry picker receives $1 after filling 3 pint boxes.
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
A charitable organization makes an average of ten phone calls for every donation it receives.
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
calling a garage mechanic to see if your car is fixed yet
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
A student's final grade improves one level for every three book reviews submitted.
TEST YOURSELF: What schedule is each of these? (FR, VR, FI, or VI)
going to the cafeteria to see if the next meal is available
TEST YOURSELF:
How did we do?

shaping: learning by (reinforcement for) successive approximations (of the desired behavior)

PUNISHMENT

a consequence (aversive) that decreases the rate of the behavior it follows
example: spanking (assuming it works), or putting a child in a corner

Punishment can be used to reduce or eliminate undesirable behavior.

Caution: we must punish the behavior, not simply what annoys the parent.
For example, the boy should be punished for playing with the hammer, not for breaking the vase.

Punishment that is certain and immediate is most effective.

Generalization can occur in both classical and operant conditioning.
see next slide [graphic presented in class]

Behavior Modification is the planned application of operant conditioning techniques

OPERANT CONDITIONING: BEHAVIOR MODIFICATION
STEPS IN BEHAVIOR MODIFICATION

Select a target behavior.
Analyze the current situation. (base rate of responding; reinforcers)
Can you control the reinforcers? Decide on a plan to change contingencies of behavior (reinforcer).
Do it.
Evaluate it: Does the behavior change as intended?
Test the reinforcer by eliminating it to see whether the rate of responding decreases.
Reinstate the reinforcer.

ACQUISITION
to increase behavior frequency
add reinforcers contingent on response
use appropriate schedule: continuous, fixed, variable

EXTINCTION
to eliminate or reduce response
Studies show that the rate of responding rises during periods of reinforcement, and falls during periods of extinction.
[graphic in class:] notice the rise in responding during periods of reinforcement

Operant conditioning can be used to reduce self-injurious behavior (e.g., head-banging in autistic children) [graphic in class]
electric shock is the punishment
reductions from 300 head-bangings per hour, down to 0, have been reported
What are the ethics of this punishment?
Perhaps positive reinforcers, such as food, would also work. (Some success has been reported.)

Skinner thought that we could create a Utopian community using operant conditioning techniques
Skinner's Walden Two

superstitious behavior [Skinner's interpretation, presented in class]