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Learning
z Learning
yrelatively permanent change
in an organism’s behavior due
to experience
yexperience (nurture) is the
key to learning
Association
zWe learn by association
yOur minds naturally connect events
that occur in sequence
yAristotle 2000 years ago
yJohn Locke and David Hume 200 yrs
ago
zAssociative Learning
ylearning that two events occur together
xtwo stimuli
xa response and its consequences
Association
Event 1
Event 2
zLearning to
associate
two events
Sea snail associates splash with a tail shock
Seal learns to expect a snack for its showy antics
Classical or Pavlovian
Conditioning
Two related events:
Stimulus 1
Lightning
Stimulus 2
Thunder
Result after repetition
Stimulus
We see
lightning
Response
We wince
anticipating
thunder
zWe learn to
associate two
stimuli
Operant Conditioning
zWe learn to
associate a
response and
its
consequence
Response: Pushing
vending machine
button
Consequence:
Receiving a candy bar
Behaviorism
zJohn B. Watson
yviewed psychology as objective
science
xgenerally agreed-upon consensus
today
yrecommended study of behavior
without reference to unobservable
mental processes
xnot universally accepted by all
schools of thought today
Classical or Pavlovian
Conditioning
zIvan Pavlov
y1849-1936
yRussian physician/ neurophysiologist
yNobel Prize in 1904
ystudied digestive secretions
Pavlov’s Classic
Experiment
Before Conditioning
UCS (food
in mouth)
UCR
(salivation)
During Conditioning
Neutral
stimulus
(tone)
No
salivation
After Conditioning
UCS (food
in mouth)
Neutral
stimulus
(tone)
UCR
(salivation)
CS
(tone)
CR (salivation)
Classical or Pavlovian
Conditioning
zPavlov’s device
for recording
salivation
Classical or Pavlovian
Conditioning
zClassical Conditioning
yorganism comes to associate two stimuli
xlightning and thunder
xtone and food
ybegins with a reflex
ya neutral stimulus is paired with a stimulus
that evokes the reflex
yneutral stimulus eventually comes to evoke
the reflex
Classical or Pavlovian
Conditioning
zUnconditioned Stimulus (UCS)
yeffective stimulus that unconditionallyautomatically and naturally- triggers a
response
zUnconditioned Response (UCR)
yunlearned, naturally occurring automatic
response to the unconditioned stimulus
xsalivation when food is in the mouth
Classical or Pavlovian
Conditioning
zConditioned Stimulus (CS)
ypreviously neutral stimulus that, after
association with an unconditioned stimulus,
comes to trigger a conditioned response
zConditioned Response (CR)
ylearned response to a previously neutral
conditioned stimulus
Conditioning
zAcquisition
ythe initial stage of learning, during which a
response is established and gradually
strengthened
yin classical conditioning, the phase in which a
stimulus comes to evoke a conditioned
response
yin operant conditioning, the strengthening of
a reinforced response
Conditioning
zExtinction
ydiminishing of a CR
yin classical conditioning, when a
UCS does not follow a CS
yin operant conditioning, when a
response is no longer reinforced
Classical or Pavlovian
Conditioning
Strength
of CR
Acquisition
(CS+UCS)
Extinction
(CS alone)
Spontaneous
recovery of
CR
Extinction
(CS alone)
Pause
Classical or Pavlovian
Conditioning
zSpontaneous Recovery
yreappearance, after a rest period, of
an extinguished CR
zGeneralization
ytendency for a stimuli similar to CS to
evoke similar responses
Classical or Pavlovian
Conditioning
zDiscrimination
yin classical conditioning, the ability to
distinguish between a CS and other stimuli
that do not signal and UCS
yin operant conditioning, responding
differently to stimuli that signal a behavior
will be reinforced or will not be reinforced
Generalization
Drops of saliva
in 30 seconds
60
50
40
30
20
10
0
Hind
paw
Pelvis
Thigh
Shoulder
Trunk
Front
paw
Foreleg
Part of body stimulated
Classical or Pavlovian
Conditioning
UCS
(passionate
kiss)
CS
(onion
breath)
CS
(onion
breath)
UCR
(sexual
arousal)
UCS
(passionate
Kiss)
CR
(sexual
arousal)
UCR
(sexual
arousal)
Nausea Conditioning in
Cancer Patients
UCS
(drug)
UCR
(nausea)
CS
(waiting
room)
CS
(waiting
room)
UCS
(drug)
UCR
(nausea)
CR
(nausea)
Operant Conditioning
zOperant Conditioning
ytype of learning in which behavior is
strengthened if followed by reinforcement or
diminished if followed by punishment
zLaw of Effect
yThorndike’s principle that behaviors followed
by favorable consequences become more
likely and behaviors followed by unfavorable
consequences become less likely
Operant Conditioning
zOperant Behavior
ycomplex or voluntary behaviors
xpush button, perform complex task
yoperates (acts) on environment
yproduces consequences
zRespondent Behavior
yoccurs as an automatic response to
stimulus
ybehavior learned through classical
conditioning
Operant Conditioning
zB.F. Skinner (1904-1990)
yelaborated Thorndike’s Law of
Effect
ydeveloped behavioral technology
Operant Chamber
zSkinner Box
ysoundproof
chamber with a
bar or key that an
animal presses or
pecks to release a
food or water
reward
ycontains a device
to record
responses
Operant Conditioning
zReinforcer
yany event that strengthens the behavior it
follows
zShaping
yconditioning procedure in which
reinforcers guide behavior toward closer
approximations of a desired goal
zSuccessive Approximations
yreward behaviors that increasingly
resemble desired behavior
Principles of
Reinforcement
zPrimary Reinforcer
yinnately reinforcing stimulus
ysatisfies a biological need
zSecondary Reinforcer
yconditioned reinforcer
ylearned through association with
primary reinforcer
Schedules of
Reinforcement
zContinuous Reinforcement
yreinforcing the desired response each time it
occurs
ylearning occurs rapidly
yextinction occurs rapidly
zPartial Reinforcement
yreinforcing a response only part of the time
yresults in slower acquisition
ygreater resistance to extinction
Schedules of
Reinforcement
zFixed Ratio (FR)
yreinforces a response only after a
specified number of responses
yfaster you respond the more rewards you
get
ydifferent ratios
yvery high rate of responding
ylike piecework pay
Schedules of
Reinforcement
zVariable Ratio (VR)
yreinforces a response after an
unpredictable number of responses
yaverage ratios
ylike gambling, fishing
yvery hard to extinguish because of
unpredictability
Schedules of
Reinforcement
zFixed Interval (FI)
yreinforces a response only after a
specified time has elapsed
yresponse occurs more frequently as
the anticipated time for reward
draws near
Schedules of
Reinforcement
zVariable Interval (VI)
yreinforces a response at
unpredictable time intervals
yproduces slow steady responding
ylike pop quiz
Schedules of
Reinforcement
Number of
responses
1000
Fixed Ratio
Variable Ratio
Fixed Interval
750
Rapid responding
near time for
reinforcement
500
Variable Interval
250
Steady responding
0
10
20
30
40
50
Time (minutes)
60
70
80
Punishment
zPunishment
yaversive event that decreases
the behavior that it follows
ypowerful controller of unwanted
behavior
Problems with
Punishment
zPunished behavior is not forgotten, it's
suppressed- behavior returns when
punishment is no longer eminent
zCauses increased aggression- shows that
aggression is a way to cope with problemsExplains why aggressive delinquents and
abusive parents come from abusive homes
Problems with
Punishment
zCreates fear that can generalize to desirable
behaviors, e.g. fear of school, learned
helplessness, depression
zDoes not necessarily guide toward desired
behavior- reinforcement tells you what to do-punishment tells you what not to doCombination of punishment and reward can be
more effective than punishment alone
zPunishment teaches how to avoid it
Cognition and Operant
Conditioning
zCognitive Map
ymental representation of the layout of
one’s environment
yexample- after exploring a maze, rats act
as if they have learned a cognitive map of
it
zLatent Learning
ylearning that occurs, but is not apparent
until there is an incentive to demonstrate it
Cognition and Operant
Conditioning
zOverjustification Effect
ythe effect of promising a reward for
doing what one already likes to do
ythe person may now see the reward,
rather than intrinsic interest, as the
motivation for performing the task
Latent Learning
Average
errors
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30
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20
18
16
14
12
10
8
6
4
2
0
1
2
3
4
5
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10 11 12 13 14 15 16 17 18 19 20 21 22
Days
Operant vs Classical Conditioning
Classical
Conditioning
Operant
Conditioning
The Response
Involuntary, automatic
“Voluntary,” operates on
environment
Acquisition
Associating events;
CS announces UCS.
Associating response with a
Consequence (reinforcer or
punisher).
Extinction
CR decreases when CS is
repeatedly presented alone.
Responding decreases when
reinforcement stops.
Cognitive
processes
Subjects develop expectation
that CS signals the arrival of
UCS.
Subjects develop expectation that
a response will be reinforced or
Punished; they also exhibit latent
learning, without reinforcement
Biological
predispositions
Natural predispositions
contain what stimuli and
responses can easily be
associated.
Organisms best learn behaviors
similar to their natural behaviors;
unnatural behaviors instinctively
drift back toward natural ones.
Observational Learning
zObservational Learning
ylearning by observing and imitating others
zModeling
yprocess of observing and imitating behavior
zProsocial Behavior
ypositive, constructive, helpful behavior
yopposite of antisocial behavior