Download conditioning

AP Psychology Unit 7
Behavioral theory:
Classical & Operant conditioning
Mods 21, 22 (Barron’s 6)
Chamberlain 2011-2012
The behaviorist approach
1.
• Behaviorist focus on OBSERVABLE
BEHAVIORS
• Try to explain the environmental/nurture
causes of
2.
human behaviors
• Choices for 1:
A.predictable
B.observable
C.harmful
D.abnormal
Choices for 2:
A.genetic
B.environmental
C.unusual
D.universal
What kind of learning is a behaviorist
interested in?
• Cognitivists focus on how we acquire and process knowledge
• Behaviorists focus on how we LEARN behaviors
• Learning= long-lasting changes in one’s behavior due to experiences
▫ “experience” includes:
 receiving punishment or reward for a behavior
 observing and imitating a behavior
 associating stimuli with physical responses
• What kinds of experiences might lead to behavioral changes
that are NOT due to “learning”?
▫ changes in behavior due to biological changes
 illness
 hormonal changes of puberty or old age
 neural damage
Classical Conditioning: Pavlov and “Pavlovian Response” -the contiguity model
Russian Dr. Ivan Pavlov,
M.D. (1849-1936)
studies of physiology of
digestion in dogs led to
discovery of
conditioned reflexive
responses
 “Classical conditioning
focuses on the learning
of involuntary emotional
or physiological
responses such as fear,
increase heartbeat,
salivation, or sweating,
which are sometimes
called respondents or
reflexes because they
are automatic
responses to stimuli” *
video clip The Office
Your turn!! p. 1-2 of conditioning packet
Contiguity: The idea that the more times you pair 2 stimuli (CS & US, the greater the learning
4 types of classical conditioning:
•
•
•
•
Delayed: (NS/CS) first and continues when (US) is presented
Trace: Present NS/CS first, take a break, present US
Simultaneous: Present NS/CS and US at exact same time
Backward: US first, followed by NS/CS
Let’s act it out!
Delayed is
best,
backward
is least
effective!
1. Acquisition (learning)
A.Stimulus similar to CS will elicit same CR
2. Generalization:
3. Discrimination:
4. Extinction:
1.
2.
3.
4.
C, c
A,
d
Answers
D, a
B, b
B.CR will stop after repeated exposure to CS
without US
C.NS becomes CS and leads to CR (previously
neutral stimulus becomes a conditioned stimulus
able to elicit a reflexive response)
D.Animal learns to ignore stimuli that are similar
to CS
a) If similar stimuli never accompany original US or sound of different
bell NEVER paired with food
b) Original bell rung many times without exposure to food
c) Bell alone leads to salivation
d) Different bells elicit salivation
• Spontaneous recovery: Conditioned response reoccurs when
exposed to CS AFTER extinction AND without any further training
• Second-order (AKA higher-order) conditioning: Pair CS
with new US to train person/animal to have CR in response to new
US
• once dog has been trained to bite every time trainer says, “Attack!”,
owner adds a hand gesture to his command. Eventually, do will attack if
he sees the hand gesture alone.
Rober Rescorla’s revised contingency model “The
cognitive view of classical conditioning”
• the learning takes place more effectively when the US reliably
predicts the presence of the NS
• If during training stage, food only sometimes accompanies
bell, bell will not elicit desired response (salivation) US will not
become CS
• This contrasts with Pavlov’s contiguity model which suggests it is
merely the amount of times the pairings occur that matters, NOT
that they occur reliably together
• Rescorla & Wagner add expectancy/cognition to conditioning
Conditioning = association = survival?
• What would an evolutionary psychologist say about why we
learn through conditioning?
▫ Taste aversion (Garcia effect) and evolutionary theory
 rats were trained to associate a sound, sight, or taste (NS)
with the nausea (UR) crated by radiation (US)
 Would the sound NS, sight NS or taste NS become
conditioned stimuli? Would the rats associate the nausea
with the neutral stimuli?
 YES—but only with the taste stimulus!!
▫ Learning to associate smell, sound, sight, touch stimuli with
food, danger, mate promotes survival
 e.g.? Domjan’s Japanese quail studies
 red light district male quail more virile, primed for sex
Are attitudes conditioned?
• When words that elicit positive or negative
emotions are repeatedly paired with ideas or
images, do we become conditioned to have
positive or negative ‘visceral’ reaction to those
ideas or images?
▫ Pokeman study (Olson and Fazio, 2001)
 participants primed to associate negative or positive
emotions w/ specific Pokeman characters because +
or – words flashed repeatedly w/ specific characters
Practical applications of Pavlovian Response
In simple terms: you can train an animal (and a person) to respond in a
desired way (perform a behavior or extinguish a behavior!) by training
the person to associate desired (or undesired) behavior with a simple
stimulus
 stop coyote from eating sheep by poisoning sheep carcasses
(aversive conditioning)
 eliminate phobias through counter-conditioning (create positive
association feelings with negative stimulus) and systematic
desensitization –
 Behaviorist Joseph Wolpe teaches people to relax muscles while exposed to
incrementally scarier situations involving the phobia
 1920 John Watson experiment & aversive conditioning “Baby
Albert” video
Operant Conditioning
Thorndike & B.F. Skinner—Start with demonstration
 What are the major similarities and differences between  Differences
classical and operant conditioning?
 Classical=respondent
(automatic) behavioral
 Similarities:
response to
 Both involve association
events/stimuli out of
 Both involve acquisition, discrimination, extinction,
animal’s control
generalization, spontaneous recovery (Make sure
you are able to identify the processes for each type!)  Operant=behavior that
is learned due to
 Practice: (a) Discrimination or (b) generalization?
association with
(c) Operant or (d) classical?
consequences
1. a rat that has had the behavior of pressing a bar
(person’s behavior
reinforced begins pushing on other parts of his cage
“operates” on the
2. a pigeon that has been trained through reinforcement
environment and
to peck at red circles only when hearing a beep does
behavior is either
not peck the red circle in absence of beep
reinforced OR
3. a lab monkey that has learned to respond fearfully in
extinguished due to
the presence of a man in a white lab coat does NOT
punishment or reward)
respond fearfully to the man in the blue coat who
cleans his cage
1.
cb 2. ca 3. da
answers
Operant conditioning (cont.)
• Thorndike’s law of effect
▫ rewarded behavior is likely to recur (punished behavior NOT
likely to recur)
▫ instrumental learning consequence of one’s behavior is
instrumental to shaping FUTURE behaviors
• Skinner box (AKA operant chambers) studies
▫ shaping non-reflexive behaviors through rewarding successive
approximations (almost doing the task—think Hot/Cold
game)
▫ chaining: animals can be trained to do difficult, multi-step tasks
(such as navigating through a maze or operating a complex
machine) if rewarded for behaviors that are similar to desired
behavior AND rewarded for each step of process
Operant conditioning (cont.)
▫ Reward can be
 gaining something positive (positive reinforcer) OR
 losing something negative (negative reinforcer)
Reinforce=increases likelihood behavior will recur
 Video clip : Sheldon conditions Penny
 Reinforcement examples
+ reinforcement
cookie, stickers, money,
high grade, praise, positive touch,
toy, extra t.v. time, extra “free time”,
extra privileges, attention, given
AFTER behavior occurs
Subject learns to associate behavior
with receiving the desired reward
- reinforcement
•If behavior occurs, remove pain, annoying
stimulus (shock, loud noise, physical restraints,
bright lights) Subject learns to associate
behavior with eliminating an undesirable
stimulus
•escape learning: subject learns to end/escape
the yucky stimulus by behaving a certain way
•avoidance learning: subject learns to avoid a
yucky situation all together
Remember: Just because someone thinks she is punishing you or
reinforcing you doesn’t mean she actually is! Sometimes what is
intended to be a reinforcer becomes a punishment and what is intended
to be a punishment becomes a reinforcer!
Now you try: p. 3-4 of packet
Different kinds of reinforcers
• primary:
▫ something that inherently gives the recipient pleasure (you don’t have to
learn to like it)
 food, positive touch, warmth, water, rest, shelter...
• secondary
▫ something that has no inherent value in itself but grows to be seen as
valuable because society has deemed it so
 good grades, points, stickers, praise, privileges
▫ generalized reinforcer= $
 practical application seen in “token economies” used by parents,
schools, prisons...
• Premack principle—essentially bribing! I can control you IF I
allow you to do a behavior you normally would do without
reinforcement (it has instrinsic value to you) ONLY AFTER
you do the behavior you don’t really want to do e.g. you may
eat dessert only if you eat your broccoli
Skinner’s findings
Video clip: Skinner’s pigeon study and schedules of reinforcement
 Schedules of reinforcement:
1.
2.
3.
4.
5.
Continuous reinforcement—Reward every
time behavior occurs
fixed-ratio schedule—reward comes after
consistent, fixed amount of behaviors
fixed-interval schedule—reward occurs after a
fixed amount of time has passed after
behavior occurs
variable-ratio schedules—reward appears in
after random, unpredictable occurrences of
behavior
variable-interval—reward appears after
varying time intervals have passed after
behavior occurs
 Continuous vs. intermittent reinforcement—
which is better to elicit desired behavior?


continuous is better during the training
intermittent is better once the behavior has
been learned—leads to persistence
1. C 2. BAnswers
3. E 4. D 5. A
A. slow, steady responses; know reward will
eventually come, but no idea when!
B. leads to return to high rate of response
after short pause after reinforcement;
able to predict how often the behavior
must occur before reward will arrive
C. leads to low rate of response; reinforcer
loses its effectiveness
D. high rates of response, system used in slot
machines; don’t know how often you’ll
have to do behavior, but know reward will
eventually arrive!
E. produces choppy start-stop pattern which
increases as reward time draws nearer
Practical Applications of Operant Conditioning
 Gambling—slot machines used variable interval schedules
 Behavior modification (B-mod)— “Extinguish an undesirable behavior
by removing the reinforcer and replace undesirable behavior with a
desirable behavior by reinforcement. It has been used on all sorts of
psychological problems -- addictions, neuroses, shyness, autism, even
schizophrenia -- and works particularly well with children” (Boeree
2006) see reading
 Token economy (see reading)
Boeree, G. PhD. 2006. “Personality Theories. B.F. Skinner” http://webspace.ship.edu/cgboer/skinner.html
One caveat to operant conditioning...
• You can teach a dog tricks BUT you can’t make it
go against its nature no matter how sweet the
reward
• instinctive drift—the reward an animal gets from
following its instinctive behavioral drive
probably outweighs any reinforcements a trainer
tries to use
▫ pigs would rather bury the disks instead of put
them in a slot, even if given extrinsic reward for
putting in slot