Transcript Unit 6 - Learning PP

Learning
• Not learning intellectually but learning behaviors
– Remember psychology:
• study of behavior and mental processes
• 3 Ways we acquire behavior
– Classical Conditioning (CC) – Pavlov and Watson
– Operant Conditioning (OC) - Skinner
– Observational Learning – Bandura
– Behaviorists – focus on observable, measurable
behavior – very objective
• Height of influence in 1920s
• NURTURE - environment
CLASSICAL CONDITIONING
Classical Conditioning
• Turn of the 20th
century, Russian
Psychologist,
Ivan Pavlov
discovered CC
while studying
digestion in dogs
• Classical Conditioning = learning by
association - people and animals
learn to associate neutral stimuli w/
stimuli that produce reflexive,
involuntary responses and will learn to
respond similarly to the new stimulus
as they did the natural one
CC
• 1. US (unconditioned stimulus)
– Original stimulus that elicits natural response
• (ex. Food)
• 2. UR (unconditioned response)
– The natural response
• (ex. Salivation)
• 3. CS (Conditioned stimulus)
– Neutral stimulus paired with US that eventually elicits response
alone
• (ex. Bell)
• 4. CR (Conditioned Response)
– UCR solicited by CS
• (ex. Salivation)
• Learning has taken place
once the animals respond
to the CS without the US =
Acquisition because
animals have acquired a
new behavior – CS
produces CR without US
Pavlov’s Dogs
Factors that affect acquisition
• 1. Repeated pairings of CS & US ; more times paired = stronger CR
• 2. Order and timing of CS & US affect the strength of conditioning
– Most effective = present CS first and then introduce the US
while CS is still evident . . . Called delayed conditioning
(ex. Bell rung, while still ringing food is presented)
A break of time in between CS and US weakens the response
• 3. Less effective methods . . .
– a. trace conditioning
• Present CS, short break, present US
– b. simultaneous conditioning
• CS & US at same time
– c. backward conditioning – worst kind – doesn’t work
• US followed by CS
CC – Important Terms
• Acquisition – behavior is learned. CS
produces CR without US
• Extinction – behavior is unlearned. CS no
longer produces CR
• Spontaneous Recovery – acquisition,
extinction and period of no training. CS
briefly produces CR but response is weak
and will disappear quickly unless repeated
training/pairing.
CC – Important Terms
• Generalization – organism responds to
stimuli similar to CS. i.e. a buzzer
produces the CR
• Discrimination – the organism is trained to
ONLY respond to the CS. Bell,
food….buzzer, no food.
• Second/Higher Order Conditioning – once
CS produces CR. It’s possible to use CS
as a US to condition a new stimulus
CC – John Watson
• Baby Albert Experiment – conditioned fear
(many phobias are the result of CC)
– US – loud noise
– UR – fear/cry
– CS – white rat
– CR – fear/cry
http://www.learner.org/series/discoveringpsychology/08/e08expand.html
Aversive Conditioning
• Any time in CC that the response is
undesirable
– Garcia affect – taste aversion
– Can be used to get you to stop an unhealthy
behavior (nail biting, shock therapy)
Biology and CC
• Can animals be conditioned to do any
response?
– Equipotentiality – many behaviorists believed
yes. All organisms have equal potential.
– Instinctive Drift – research says
equipotentiality is false. Animals will drift
towards their natural instincts and cannot be
conditioned to do things that go against their
nature.
http://www.youtube.com/watch?v=WfZfMIHwSkU
“The Office” CC clip
OPERANT CONDITIONING
Operant Conditioning
• Learning by association – associate a
behavior with its consequences
• Edward Thorndike – predecessor
– Law of effect – if consequences of a
behavior are pleasant, the stimulus response
connection is strengthened and the behavior
increases. If consequence is unpleasant, the
connection will weaken and behavior will
decrease. Thorndike called this instrumental
learning – the consequence is instrumental to
you learning the behavior
Father of Operant
Conditioning…. BF Skinner
Skinner
• Skinner created the Skinner box with
pigeons
• Reinforcer = food; reinforcers are always
positive consequences
• Punishment is always a negative
consequence
• + addition, - subtraction
Reinforcements – makes
behavior more likely
• + reinforcement: the addition of a
desirable consequence; Johnny gets all
As and his parents give him $100
• - reinforcement: the subtraction of
something unpleasant as a desirable
consequence; Johnny gets all As and his
parents say he doesn’t have to do his
chores.
Punishments make behavior
less likely
• Punishment: the addition of an unpleasant
result; Johnny gets an F and gets a
spanking or extra chores
• Omission Training: the removal of a
pleasant stimulus; Johnny gets an F and
loses his car privileges
OC Terms
• Escape Learning – terminating an aversive
stimulus. Johnny comes to class and
hears there is an exam and he asks to go
to the clinic (- reinforcement)
• Avoidance Learning – enables one to
avoid unpleasant stimulus all together.
Johnny remembers there is a test and he
skips school. (- reinforcement)
OC Terms
• Shaping – reinforcing gradual steps of improvement as
one gets closer to desired behavior.
• Chaining – reinforcement after subject performs a series
of behaviors. Little Johnny cleans his room, brushes his
teeth, says his prayers and then gets a bed time story
• Premack Principle – what works as a reinforcer for one
person may not work for another. If I don’t like
chocolate, than a candy bar will not work as a reinforcer
for me
OC Terms
• Acquisition – behavior learned. Rat
presses lever to get food
• Extinction – behavior is unlearned. Rat no
longer gets good and therefore stops
pressing lever
• Generalization – do similar behavior to get
reinforcer – rat presses other button
hoping for food
• Discrimination – only get reinforcer for
specific behavior
Types of Reinforcers
• Primary – innately rewarding – food,
water, rest
• Secondary – things we learn to value –
praise, games, material objects
• Generalized Reinforcer – can be traded in
for something else – money
– Token Economy – desired behavior gets
tickets or tokens to be traded for reinforcers
(arcade)
Reinforcement Schedules
2 critical questions
• 1.) Do I know EXACTLY when the
reinforcer is coming?
– Yes = fixed
– No = variable
2.) Is the reinforcer contingent on me
completing a task?
- Yes = Ration
- No = Interval
4 Schedules
• Fixed Ratio (FR) – I get a water break
after running 5 suicides
• Variable Ratio (VR) – I’m going to play the
slot machine and hope I win
• Fixed Interval (FI) – spring break is 4
weeks away
• Variable Interval (VI) – my car is in the
shop and I am not sure when it will be
ready
Variable schedules are more resistant to
extinction that fixed schedules. Once an
animal becomes accustomed to a fixed
schedule, a break in the pattern will
quickly lead to extinction
• When learning a behavior, continuous
reinforcement is best. Once behavior
learned, variable reinforcement is better.
• VR most resistant to extinction – why
gambling is addictive
Observational Learning
Social Modeling
Albert Bandura’s Bobo Doll
Experiment
Observational Learning
• Modeling has two basic components –
– Observation
– Imitation
– Kids who observed models play violently with
the Bobo doll were more likely to interact
violently with the Bobo doll themselves
– We can model prosocial or antisocial
behaviors
– Do violent TV shows and video games make
people more likely to act in violent ways???
http://www.youtube.com/watch?v=jWsxfoJEwQQ
Bobo Doll footage
Other Types of learning
• Latent Learning – Edward Tolman –
hidden learning Ex: rats and maze – they
don’t show knowledge until there is an
incentive
• Insight Learning – Wolfgang Kohler –
when one suddenly realizes how to solve
a problem. The answer comes in a flash
or insight. Ex: apes and bananas