Transcript learned

Learning
Chapter 8
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ADAPTATION
• Adaptation is adjusting to a changed
environment
• Development involves adapting to
increasingly complex environments, using
knowledge gained from experience
• Instinctive behavior is adaptive
(ex:imprinting, others?)
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Definition
Learning is a relatively permanent change in an
organism’s behavior due to experience.
Learning is more flexible in comparison to the
genetically-programmed behaviors of Chinooks,
for example.
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HABITUATION
• Habituation is a type of learning: adapting
to stimuli that do not change
• It is NOT because the organism has learned
about a relationship or an association
• Opponent Process Theory by Richard
Solomon is based on habituation
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OPPONENT PROCESS
THEORY
• Habituation to repeated stimuli is the result
of two interacting processes:
– A Process = fixed automatic, emotional,
unlearned response
– B Process = initially slower reaction, triggered
by the A Process; counter effect of A Process
– Explains emotions, drug dependency
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How Do We Learn?
EXPERIENCE IS THE KEY TO
LEARNING
We learn by association. Our minds
naturally connect events that occur in
sequence.
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Stimulus-Stimulus Learning
Learning to associate one stimulus
with another (basis of Classical Conditioning).
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Stimulus-Stimulus Learning
Learning to associate one stimulus
with another.
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Response-Consequence Learning
Learning to associate a response
with a consequence (basis of Operant Conditioning).
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Classical Conditioning
Sovfoto
Ideas of classical conditioning originate from old
philosophical theories. However, it was the
Russian physiologist Ivan Pavlov who elucidated
classical conditioning. His work provided a basis
for later behaviorists like John Watson and B. F.
Skinner.
Ivan Pavlov (1849-1936)
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BEHAVIORISM
• Behaviorism is a view that Psychology
should:
– Be an objective science (currently accepted)
– Study behavior without reference to mental
processes, therefore a rejection of introspection
(currently not accepted)
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Pavlov’s Experiments
Before conditioning, food (Unconditioned
Stimulus, US) produces salivation
(Unconditioned Response, UR). However, the
tone (neutral stimulus) does not.
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Pavlov’s Experiments
During conditioning, the neutral stimulus (tone)
and the US (food) are paired, resulting in
salivation (UR). After conditioning, the neutral
stimulus (now Conditioned Stimulus, CS) elicits
salivation (now Conditioned Response, CR)
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CLASSICAL CONDITIONING
• TERMINOLOGY
–
–
–
–
Conditioned = Learned
Unconditioned = Unlearned
Stimulus = Causes a response
Response = Behavioral reaction to stimulus
• BASIC COMPONENTS:
–
–
–
–
Natural reflex (automatic, involuntary)
Neutral stimulus
Association of stimuli
Timing
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Acquisition
Acquisition is the initial stage in classical
conditioning in which an association between a
neutral stimulus and an unconditioned
stimulus takes place.
In most cases, for conditioning to occur, the
neutral stimulus needs to come before the
unconditioned stimulus.
The time in between the two stimuli should be
about half a second.
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Extinction
When the US (food) does not follow the CS
(tone), CR (salivation) begins to decrease and
eventually causes extinction. Example?
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RECONDITIONING
THE QUICK RELEARNING OF A
CONDITIONED RESPONSE AFTER
EXTINCTION Example?
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Spontaneous Recovery (NOT the
same as Reconditioning)
After a rest period, an extinguished CR (salivation)
spontaneously recovers, but if the CS (tone) persists
alone, the CR becomes extinct again. Example?
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Stimulus Generalization
Tendency to respond to
stimuli similar to the CS is
called generalization. Think
of Baby Albert.
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EXTENDING PAVLOV
• John Watson, another Behaviorist, worked with
Baby Albert (Reading and Questions)
• Video: Phobias (define) and Wolpe’s systematic
desensitization (define) treatment is based on CC
• Various Behavioral therapies –
• Some medical treatments are based on classically
conditioning immune system response (placebos)
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Stimulus Discrimination
Discrimination is the learned ability to distinguish
between a conditioned stimulus and other stimuli that
do not signal an unconditioned stimulus. Example?
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SECOND ORDER
CONDITIONING
• ALSO referred to as Higher Order Conditioning
• When a conditioned stimulus acts like an
unconditioned stimulus, creating conditioned
stimuli out of events associated with it.
• Example?
• Very important adaptive characteristic of cc in
preparing organism for life threatening events
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ACQUISITION SCHEDULES
• Delayed
• Interval
• Backward
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Extending Pavlov’s Understanding
Pavlov and Watson considered consciousness,
or mind, unfit for the scientific study of
psychology. However, they underestimated the
importance of cognitive processes and
biological constraints.
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Cognitive Processes
Early behaviorists believed that learned
behaviors of various animals could be reduced
to mindless mechanisms.
However, later behaviorists suggested that
animals learn the predictability of a stimulus,
meaning they learn expectancy or awareness of a
stimulus (Rescorla, 1988).
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Biological Predispositions
Pavlov and Watson believed that laws of
learning were similar for all animals.
Therefore, a pigeon and a person do not differ
in their learning.
However, behaviorists later suggested that
learning is constrained by an animal’s biology.
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Biological Predispositions
Courtesy of John Garcia
Garcia showed that the duration
between the CS and the US may be
long (hours), but yet result in
conditioning. A biologically adaptive
CS (taste) led to conditioning and not
to others (light or sound).
John Garcia
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Biological Predispositions
Even humans can develop classically to
conditioned nausea.
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Pavlov’s Legacy
Pavlov’s greatest contribution
to psychology is isolating
elementary behaviors from
more complex ones through
objective scientific
procedures.
Ivan Pavlov
(1849-1936)
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Operant & Classical Conditioning
1. Classical conditioning
forms associations
between stimuli (CS
and US). Operant
conditioning, on the
other hand, forms an
association between
behaviors and the
resulting events
(consequences).
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Operant & Classical Conditioning
Classical conditioning involves respondent
behavior that occurs as an automatic
response to a certain stimulus. Operant
conditioning involves operant behavior, a
behavior that operates on the environment,
producing rewarding or punishing stimuli.
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Skinner’s Experiments
Skinner’s experiments extend Thorndike’s
thinking, especially his law of effect. This law
states that rewarded behavior is likely to occur
again.
Yale University Library
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Using Thorndike's law of effect as a starting
point, Skinner developed the Operant chamber,
or the Skinner box, to study operant
conditioning.
Walter Dawn/ Photo Researchers, Inc.
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From The Essentials of Conditioning and Learning, 3rd
Edition by Michael P. Domjan, 2005. Used with permission
by Thomson Learning, Wadsworth Division
Operant Chamber
Operant Chamber
The operant chamber,
or Skinner box, comes
with a bar or key that
an animal manipulates
to obtain a reinforcer
like food or water. The
bar or key is connected
to devices that record
the animal’s response.
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Shaping
Shaping is the operant conditioning procedure
in which reinforcers guide behavior towards the
desired target behavior through successive
approximations (hot/cold activity).
Fred Bavendam/ Peter Arnold, Inc.
Khamis Ramadhan/ Panapress/ Getty Images
A rat shaped to sniff mines. A manatee shaped to discriminate
objects of different shapes, colors and sizes.
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CHAINING =
Linking a sequence of several different reinforced
behaviors
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Types of Reinforcers
Any event that strengthens the behavior it
follows is a reinforcer. A heat lamp positively
reinforces a meerkat’s behavior in the cold.
Reuters/ Corbis
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NEGATIVE REINFORCEMENT
• Remember: the behavior increases due to
the removal or the end of an aversive
stimuli
• Two types:
– Escape conditioning: organism learns to make a
response to end the negative reinforcement
– Avoidance conditioning: organism learns to
avoid the negative reinforcer.
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• Avoidance conditioning (continued):
– A powerful influence on everyday behavior
– Maintains phobias etc. because the response is
reinforced by the reduction of the fear
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Primary & Secondary Reinforcers
Primary Reinforcer: An innately reinforcing
stimulus like food or drink.
Conditioned Reinforcer (sometimes called a
secondary reinforcer): A learned reinforcer
that gets its reinforcing power through
association with the primary reinforcer.
Example?
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Reinforcement Schedules
1. Continuous Reinforcement: Reinforces the
desired response each time it occurs.
Learning is very rapid but extinction is also
rapid.
2. Partial Reinforcement: Reinforces a
response only part of the time. Though this
results in slower acquisition in the
beginning, it shows greater resistance to
extinction later on. You may need to start
with a continuous schedule.
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PARTIAL OR INTERMITTENT
REINFORCEMENT TERMS
•
•
•
•
Fixed - Never changing
Variable - Changing
Interval - Having to do with time
Ratio - Having to do with behavior or
performance
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Partial or Intermittent
Reinforcement Schedules
Fixed-ratio schedule: Reinforces a response only
after a specified number of responses. e.g.,
piecework pay.
Variable-ratio schedule: Reinforces a response
after an unpredictable number of responses.
This is hard to extinguish because of the
unpredictability. (e.g., behaviors like
gambling, fishing.)
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Interval Schedules
Fixed-interval schedule: Reinforces a response
only after a specified time has elapsed. (e.g.,
preparing for an exam only when the exam
draws close.) Produces a scalloping response
Variable-interval schedule: Reinforces a
response at unpredictable time intervals,
which produces slow, steady responses. (e.g.,
pop quiz.)
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Schedules of Reinforcement
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Punishment
An aversive event that decreases the behavior it
follows.
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PUNISHMENT
• REMEMBER:
• POSITIVE IS TO ADD
• NEGATIVE IS TO SUBTRACT
• DO NOT THINK IN TERMS OF GOOD
AND BAD!
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Punishment
Although there may be some justification for
occasional punishment (Larzelaere & Baumrind,
2002), it usually leads to negative effects.
1.
2.
3.
4.
Results in unwanted side effect such as fear.
Conveys no information to the organism.
Justifies pain to others.
Causes unwanted behaviors to reappear in its
absence.
5. Causes aggression towards the agent.
6. Causes one unwanted behavior to appear in
place of another.
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PUNISHMENT
• 7. Does not erase an undesirable habit, it
merely suppresses it
• 8. Ineffective unless applied immediately
after and each time
• 9. Does not specify correct behavior
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GUIDELINES IN USING
PUNISHMENT
• Specify why
• Concentrate on behavior not the person
• Should be immediate and strong enough
without being too strong
• Be careful of escalation (if punishment is
not given early enough, bad behavior
escalates
• Combine with other behavior
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Extending Skinner’s Understanding
Skinner believed in inner thought processes and
biological underpinnings, but many
psychologists criticize him for discounting
them.
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Cognition & Operant Conditioning
Evidence of cognitive processes during operant
learning comes from rats during a maze
exploration in which they navigate the maze
without an obvious reward. Rats seem to
develop cognitive maps, or mental
representations, of the layout of the maze
(environment).
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COGNITIVE PROCESSES
• Learned helplessness (Martin Seligman)
• Insight (Sultan’s Aha! Experience)
• Premack Principle (hierarchy of behavioral
preferences)
• Disequalibrium Hypothesis (What you’ve
been prevented from will increase as a
reinforcer) “Reverse psychology!”
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Latent Learning
Such cognitive maps are based on latent
learning, which becomes apparent when an
incentive is given (Tolman & Honzik, 1930).
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Motivation
Intrinsic Motivation:
The desire to perform a
behavior for its own
sake.
Extrinsic Motivation:
The desire to perform a
behavior due to
promised rewards or
threats of punishments.
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Biological Predisposition
Photo: Bob Bailey
Biological constraints
predispose organisms to
learn associations that
are naturally adaptive.
Breland and Breland
(1961) showed that
animals drift (instinctive
drift) towards their
biologically predisposed
instinctive behaviors.
Marian Breland Bailey
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Skinner’s Legacy
Skinner argued that behaviors were shaped by
external influences instead of inner thoughts and
feelings. Critics argued that Skinner
dehumanized people by neglecting their free will.
Falk/ Photo Researchers, Inc
.
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Applications of Operant
Conditioning
In children, reinforcing good behavior increases the
occurrence of these behaviors. Ignoring unwanted
behavior decreases their occurrence.
PARENTING:
Reinforce correct behavior, target specific behavior
Ignore whining
When behavior occurs, explain and give a time out.
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Applications of Operant
Conditioning
•
•
•
•
Culturally approved gender roles
Discriminative stimuli (insomnia)
Socialization
Others?
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Operant vs. Classical Conditioning
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Reprinted with permission from the American
Association for the Advancement of Science,
Subiaul et al., Science 305: 407-410 (2004)
© 2004 AAAS.
Mirror Neurons
Neuroscientists discovered mirror neurons in
the brains of animals and humans that are active
during observational learning.
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Learning by observation
begins early in life. This
14-month-old child
imitates the adult on TV
in pulling a toy apart.
Meltzoff, A.N. (1998). Imitation of televised models by infants.
Child Development, 59 1221-1229. Photos Courtesy of A.N. Meltzoff and M. Hanuk.
Imitation Onset
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Bandura's Bobo doll
study (1961) indicated
that individuals
(children) learn
through imitating
others who receive
rewards and
punishments.
Courtesy of Albert Bandura, Stanford University
Bandura's Experiments
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Applications of Observational
Learning
Unfortunately,
Bandura’s studies
show that antisocial
models (family,
neighborhood or TV)
may have antisocial
effects.
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Positive Observational Learning
Bob Daemmrich/ The Image Works
Fortunately, prosocial (positive, helpful) models
may have prosocial effects.
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Gentile et al., (2004)
shows that children in
elementary school
who are exposed to
violent television,
videos, and video
games express
increased aggression.
Ron Chapple/ Taxi/ Getty Images
Television and Observational
Learning
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Modeling Violence
Children modeling after pro wrestlers
Glassman/ The Image Works
Bob Daemmrich/ The Image Works
Research shows that viewing media violence
leads to an increased expression of aggression.
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iClicker Questions for
Psychology, 8th Edition
by David G. Myers
Karla Gingerich, Colorado State University
Chapter 8: Learning
68
Through direct experience with
animals, we come to anticipate that
dogs will bark and that birds will
chirp. This best illustrates:
A.
B.
C.
D.
the law of effect.
spontaneous recovery.
respondent behavior.
associative learning.
69
Ivan Pavlov noticed that dogs began
salivating at the mere sight of the
person who regularly brought food to
them. For the dogs, the sight of this
person was a(n):
A.
B.
C.
D.
primary reinforcer.
unconditional stimulus.
immediate reinforcer.
conditioned stimulus.
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Conditioning seldom occurs when a(n)
________ comes after a(n) _____.
A.
B.
C.
D.
CS; US
UR; CS
secondary reinforcer; operant behavior
negative reinforcer; operant behavior
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The predictability of an association
between a CS and a US facilitates an
organism's ability to anticipate the
occurrence of the US. This fact is most
likely to be highlighted by a(n)
________ perspective.
A.
B.
C.
D.
evolutionary
behaviorist
cognitive
neuroscience
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Researchers condition a flatworm to
contract when exposed to light by
repeatedly pairing the light with electric
shock. The electric shock is a(n):
A.
B.
C.
D.
negative reinforcer.
conditioned stimulus.
conditioned reinforcer.
unconditioned stimulus.
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If you get violently ill a couple of hours after
eating contaminated food, you will probably
develop an aversion to the taste of that food but
not to the sight of the restaurant where you ate
or to the sound of the music you heard there.
This best illustrates that associative learning is
constrained by:
A.
B.
C.
D.
intrinsic motivation.
spontaneous recovery.
biological predispositions.
conditioned reinforcers.
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After getting ill from eating her friend’s
Thanksgiving turkey, Natalia couldn’t stand
the the sight or smell of turkey. However,
when her friend baked a whole chicken,
Natalia thought it sounded good. This
illustrates:
A.
B.
C.
D.
generalization.
discrimination.
extinction.
acquisition.
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The law of effect relates most
closely to:
A.
B.
C.
D.
modeling.
operant conditioning.
classical conditioning.
latent learning.
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For some children who bite themselves or bang
their heads, squirting water into their faces
when they hurt themselves has been observed
to decrease the frequency of these self-abusive
behaviors. This best illustrates the potential
value of:
A.
B.
C.
D.
punishment.
conditioned reinforcers.
negative reinforcers.
latent learning.
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Occasional, unpredictable reinforcement
usually results in _________ rates of
responding.
A.
B.
C.
D.
unpredictable
steady
delayed
speedy
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Mirror neurons are important to the
process of learning because they:
A. enhance cognitive maps.
B. enable imitation.
C. provide a neurological basis for operant
conditioning.
D. explain aversive conditioning.
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Critical Thinking Questions
80
Martin likes to shower in the men’s locker room after
working out. During a shower he hears a toilet
flushing nearby. Suddenly boiling hot water comes
out of the showerhead, causing Martin serious
discomfort. Later on in the shower, he hears another
toilet flush and he immediately jumps out from under
the showerhead. In this scenario, what is the
unconditioned response (UR)?
A.
B.
C.
D.
jumping out of the shower
sound of the toilet flushing
pain avoidance
boiling hot water
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A child is sent to his room with no supper
because he presented a bad report card to
his parents. The parent’s intent was to:
A. punish poor academic performance.
B. negatively reinforce poor academic
performance.
C. extinguish poor academic performance.
D. partially reinforce poor academic
performance.
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Brian ate a tuna salad sandwich that had
become tainted from being in the sun too long.
Not long after eating, Brian became extremely
nauseated and felt awful. After that, even the
sight of a tuna sandwich caused Brian to feel
nauseated. In this scenario, what is the
conditioned response (CR)?
A.
B.
C.
D.
tuna
nausea
mayonnaise
sight of any sandwich
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Luke gets paid a fixed sum after
every four pianos he tunes. He is on
a _________ schedule of
reinforcement.
A.
B.
C.
D.
fixed interval
fixed ratio
variable interval
variable ratio
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Extinction occurs ___________ in
classical conditioning and ___________
in operant conditioning.
A. when the CS is presented with the US; when
reinforcement increases
B. when the CS is presented alone repeatedly;
when reinforcement increases
C. when the CS is presented alone repeatedly;
when reinforcement stops
D. when the CS is presented with the US; when
reinforcement stops
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