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Learning

Learning
 relatively
permanent
change in an
organism’s
behavior due
to experience
To Gain Knowledge,
Understanding or Skill
by Study, Instruction or
Experience
2
Association
 We learn by association
 Our minds naturally connect events that
occur in sequence
 Aristotle 2000 years ago
 John Locke and David Hume 200 years ago
 Associative Learning
 learning that two events occur together
 two stimuli
 a response and its consequences
Association
Event 1
Event 2
 Learning 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
 We learn
to
associate
two
stimuli
Frasier Clip
http://www.youtube.com/watch?v=2c4_l2
oe22U
2 min
6
Operant Conditioning
 We learn to
associate a
response and
its
consequence
Classical
Conditioning
 Classical Conditioning
Ivan Pavlov
 organism comes to associate two
stimuli
 a neutral stimulus that signals an
unconditioned stimulus begins to
produce a response that anticipates and
prepares for the unconditioned stimulus
Classical
Conditioning
 Ivan Pavlov
 1849-1936
 Russian
physician/
neurophysiologist
 Nobel Prize in
1904
 studied digestive
secretions
Classical
Conditioning
 Pavlov’s device
for recording
salivation
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 Conditioning
NEUTRAL STIMULUS
will
elicit
NO REACTION
UNCONDITIONED STIMULUS
will
elicit a
REFLEX ACTION
will
elicit a
REFLEX ACTION
will
elicit a
CONDITIONED
RESPONSE
UNCONDITIONED STIMULUS
NEUTRAL STIMULUS
CONDITIONEDSTIMULUS
STIMULUS
CONDITIONED
The Office Clip
http://www.youtube.com/watch?v=nE8pFWP
5QDM
2 min
Classical
Conditioning
 Unconditioned Stimulus (UCS)
 stimulus that unconditionally--automatically
and naturally--triggers a response
 Unconditioned Response (UCR)
 unlearned, naturally occurring response to
the unconditioned stimulus
 salivation when food is in the mouth
Classical
Conditioning
 Conditioned Stimulus (CS)
 originally irrelevant stimulus that, after
association with an unconditioned stimulus,
comes to trigger a conditioned response
 Conditioned Response (CR)
 learned response to a previously neutral
conditioned stimulus
Classical
Conditioning
 Acquisition
 the initial stage in classical conditioning
 the phase associating a neutral stimulus with
an unconditioned stimulus so that the neutral
stimulus comes to elicit a conditioned
response
 in operant conditioning, the strengthening of
a reinforced response
Classical
Conditioning
 Extinction
 diminishing of a CR
 in classical conditioning, when a
UCS does not follow a CS
 in operant conditioning, when a
response is no longer reinforced
Classical
Conditioning
Strength
of CR
Acquisition
(CS+UCS)
Extinction
(CS alone)
Spontaneous
recovery of
CR
Extinction
(CS alone)
Pause
Variations Within
Classical Conditioning
Extinction
If a stimulus is never reinforced, then the response will go away.
Spontaneous Recovery
After extinction, a response will suddenly reappear.
Generalization
A response can be generalized to other like stimuli.
Generalization is a behavior
that spreads from one situation
to a similar one.
(A baby will call Daddy
“Dada.” When the baby sees
any man, the baby calls out
“Dada.”)
Discrimination is the reverse of generalization.
Some stimuli have pleasant consequences and
some do not.
(A baby gradually learns that only one person
responds with a smile when called “Dada.”)
Cognitive Processes
Conditioning occurs best when the CS and
UCS have just the sort of relationship that
would lead a scientist to conclude that the
CS causes the UCS. — even in classical
conditioning, it is not only the simple
stimulus-response association but also the
thought that counts.
 Conditioning in advertising
Behaviorism
 John B. Watson
 viewed psychology as
objective science
 generally agreed-upon
consensus today
 recommended study of
behavior without reference
to unobservable mental
processes
 not universally accepted by
all schools of thought today
Watson took a a baby named Albert and conditioned him to be
afraid of white furry objects using Pavlov’s techniques.
Watson & Raynor with Little Albert
Little Albert Experiment
http://www.youtube.com/watch?v=9hBfn
XACsOI
7 min
24
Conditional Training:
Albert and Peter
Conditioned fear
experiments such as
Albert’s experience
would never occur
today because of the
existing ethical
standards.
Mary Cover Jones
Mary Cover Jones used an
early form of desensitization
to prove that fears (phobias)
could be unlearned.
Peter, a young boy, had an extreme fear of
rabbits. Jones gave Peter his favorite food
while slowly bringing the rabbit closer and
closer. Eventually Peter no longer panicked
around rabbits.
Operant Conditioning
 Operant Conditioning
 type of learning in which behavior is
strengthened if followed by reinforcement or
diminished if followed by punishment
 Law of Effect
 Thorndike’s principle that behaviors followed
by favorable consequences become more
likely, and behaviors followed by unfavorable
consequences become less likely
Operant Conditioning
 Operant Behavior
 operates (acts) on environment
 produces consequences
 Respondent Behavior
 occurs as an automatic response to
stimulus
 behavior learned through classical
conditioning
Early Operant Conditioning
E. L. Thorndike (1898)
Puzzle boxes and cats
First Trial
in Box
Situation:
stimuli
inside of
puzzle box
Scratch at bars
Push at ceiling
Dig at floor
Howl
Etc.
After Many
Trials in Box
Situation:
stimuli
inside of
puzzle box
Scratch at bars
Push at ceiling
Dig at floor
Howl
Etc.
Etc.
Etc.
Press lever
Press lever
Edward L. Thorndike ( 1874–1949)
Operant Conditioning
 B.F. Skinner
(1904-1990)
 elaborated
Thorndike’s Law
of Effect
 developed
behavioral
technology
B. F. Skinner (1904–1990)
Operant Chamber
 Skinner Box
 chamber with a
bar or key that an
animal
manipulates to
obtain a food or
water reinforcer
 contains devices
to record
responses
Operant Conditioning
In shaping, successively closer
versions of a desired response are
reinforced (as in learning to play
tennis).
In chaining, each part of a sequence is reinforced; the
different parts are put together into a whole (as in
learning the steps to a dance).
Operant Conditioning
 Positive Reinforcement
 any event that strengthens the
behavior it follows
 Negative Reinforcement
 The removal of a punishment or an
aversive stimulus
 It STRENGTHENS behavior
Operant Conditioning Processes
Primary Reinforcement is unlearned and usually
necessary for survival. Food is the best example
of a primary reinforcer.
Secondary Reinforcement is anything that comes to
represent a primary reinforcer such as praise from a
friend or a gold star on a homework assignment.
Also called conditioned reinforcer.
Schedules of
Reinforcement
 Immediate Reinforcers
 To our detriment, small but immediate
reinforcements are sometimes more alluring than
big, but delayed reinforcements
 Continuous Reinforcement
 reinforcing the desired response each time it occurs
 Partial (Intermittent) Reinforcement
 reinforcing a response only part of the time
 results in slower acquisition
 greater resistance to extinction
Schedules of
Reinforcement
 Fixed Ratio (FR)
 reinforces a response only after a
specified number of responses
 faster you respond the more rewards you
get
 different ratios
 very high rate of responding
 like piecework pay
Schedules of
Reinforcement
 Variable Ratio (VR)
 reinforces a response after an
unpredictable number of responses
 average ratios
 like gambling, fishing
 very hard to extinguish because of
unpredictability
Schedules of
Reinforcement
 Fixed Interval (FI)
 reinforces a response only after a
specified time has elapsed
 response occurs more frequently as
the anticipated time for reward
draws near
Schedules of
Reinforcement
 Variable Interval (VI)
 reinforces a response at unpredictable
time intervals
 produces slow steady responding
 like pop quiz
Big Bang theory-positive
reinforcement
http://www.youtube.com/watch?v=teLoN
YvOf90
7 min
42
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
 Punishment
 aversive event that decreases the
behavior that it follows
 powerful controller of unwanted
behavior
Punishment
Problems with Punishment
Does not teach or promote alternative,
acceptable behavior
May produce undesirable results such as
hostility, passivity, fear
Likely to be temporary
May model aggression
Updating Skinner’s
Understanding
Skinner’s emphasis on external control of
behavior made him an influential, but
controversial figure. Many psychologists
criticized Skinner for underestimating the
importance of cognitive and biological
constraints.
Cognition and Operant
Conditioning
 Overjustification Effect
 the effect of promising a reward for
doing what one already likes to do
 the person may now see the reward,
rather than intrinsic interest, as the
motivation for performing the task
Cognition and Operant
Conditioning
 Intrinsic Motivation
 Desire to perform a behavior for its
own sake and to be effective
 Extrinsic Motivation
 Desire to perform a behavior due to
promised rewards or threats of
punishments
Observational Learning
 Observational Learning (Albert Bandura)
 learning by observing and imitating others
 Modeling
 process of observing and imitating a
specific behavior
 Prosocial Behavior
 positive, constructive, helpful behavior
 opposite of antisocial behavior
Crash Course Psych #12
http://www.youtube.com/watch?v=128Ts
5r9NRE
10 min
51