Transcript Chapter 8: Learning - rcook

Chapter 8: Learning
Tiffany Amaya, Mandee Caulfield, Jeffrey Taboada,
Peta Kalokola, Rashaan Williams, and Xena Nguyen
How Do We Learn?
• Learning is a relatively permanent change in an organism's
behavior due to experience
• In associative learning, we learn to associate two stimuli (as in
classical conditioning) or a response and its consequences (as in
operant conditioning)
o Ex: When disturbed the sea snail will withdraw its gill but if the
squirts continue its withdrawal response diminishes. However
if the sea snail repeatedly receives an electric shock just after
being squirted its withdrawal response becomes stronger
because it relates the squirt to the shock.
• In observational learning, we learn by watching others'
experiences and examples.
How Do We Learn?
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We learn by association, our minds naturally connect
events that occur in sequence
Simpler animals can learn simple associations (the
snail) and complex animals can learn more responseoutcome associations (seals in an aquarium)
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In both cases the animals learned
something important to their survival: to
predict the immediate future
Successful adaptation requires both
nature and nurture
Classical Conditioning
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Also called Pavlovian or Respondent Conditioning
(Defn.) A type of learning in which an organism comes to
associate stimuli.
This phenomenon was explored by Ivan Pavlov(1849-1936)
What occurs?
o A neutral stimulus that signals an unconditioned stimulus (US) begins to
produce a response that anticipates and prepares for the unconditioned
stimulus
Pavlov's work laid a foundation for John B. Watson's ideas
o Believed that psychology should study how organisms respond to stimuli in
their environment, it should be based on observable behavior.
Behaviorism
o The view that psychology should be an objective science that studies behavior
without reference to mental processes.
Classical Conditioning
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Pavlov's Experiment
o Pavlov presented the dog with food and so it had an unconditioned
response, an unlearned natural response ( Ex. salivation). Then a neutral
stimulus ( Ex. a tone) was present before an unconditioned stimulus,
stimulus that naturally triggers a response ( Ex. food in mouth). The neutral
stimulus then became a conditioned stimulus, an originally irrelevant
stimulus that, after association with an unconditioned stimulus trigger a
conditioned
response. This is a
learned response to
a previously neutral
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stimulus.
Generalization
o The tendency, once a response has been conditioned, for stimuli similar to the
conditioned stimulus to evoke similar responses.
Classical Conditioning
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Acquisition
o The initial stage in classical conditioning. the phase associating a neutral
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stimulus with an unconditioned stimulus so that the neutral stimulus comes to
evoke a conditioned response.
A very unusual conditioned stimulus!
Classical Conditioning
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Extinction and Spontaneous Recovery
o The diminishing of a conditioned response. This occurs in classical
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conditioning when an unconditioned stimulus does not follow a
conditioned stimulus.
When the conditioned stimulus (tone) no longer sends signals for the
unconditioned stimulus (food).
Spontaneous Recovery
 The reappearance of a weakened conditioned after a pause, of an
extinguished conditioned response.
Discrimination
o The learned ability to distinguish between a conditioned stimulus and
a stimuli that do not signal an unconditioned stimulus.
Extending Pavlov's
Understanding
• Cognitive Processes
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The early behaviorists' optimism that learning principles would generalize from
one response to another and from one species to another has given way to the
understanding that conditioning principles are influenced by our thoughts,
perceptions, and expectations.
In classical conditioning, humans and other animals learn when to expect a
Unconditional Stimulus, and their awareness of the link between stimuli and
responses can weaken associations.
Biological Predispositions
o Early behaviorists believed that any natural response could be conditioned to
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any neutral stimulus in any living organisms. Learning theorists have
abandoned this belief.
Each species is biologically prepared to learn associations-such as humans' fear
of spiders and snakes, or rats' aversion to tastes associated with nausea-that
enhance its survival.
Outside the laboratory, a Conditioned Stimulus tends to have a neutral
association with the Unconditioned Stimulus it predicts
Pavlov's Legacy
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A great deal of his ideas about conditioning
remain
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HOWEVER if they were to be judged by today's
information on cognitive processes and biological
predispositions his ideas would be incomplete
Classical conditioning is one way that
virtually all organisms learn to adapt to their
environment (apply across species)
Pavlov also showed us how a process such as
learning can be studied objectively
Pavlov's Legacy (continued)
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Conditioning principles have important
applications
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Suggesting how some fears are learned and can be
treated
His success suggested a scientific model for
how the young discipline of psychology
might proceed by isolating the building
blocks of complex behaviors and studying
them with objective lab procedures
Close-Up: Trauma as classical
conditioning
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Experiments reveal that if a painful stimulus
is sufficiently powerful a single event is
sometimes enough to traumatize the
animal/person when it again faces the
situation
Eleven years later she reported (as many
trauma victims do) that her conditioned
fears had mostly extinguished
Operant Conditioning
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A type of learning in
which behavior is
strengthened if followed
by a reinforcer or
diminished if followed
by a punisher.
Organisms associate
their own actions with
consequences.
Behaviors followed by
reinforcers increase;
those followed by
punishers decrease.
Similarities & Differences of Classical
Conditioning and Operant Conditioning
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Both involve acquisition, extinction,
spontaneous recovery, generalization, and
discrimination.
In Classical Conditioning:
o The organism forms associations between behaviors it does not
control; this form of conditioning is called respondent
behavior(automatic responses to some stimulus)
In Operant Conditioning:
o The organism learns associations between its own behavior and
resulting events; this form of conditioning involves operant
behavior(behavior that operates on the environment, producing
consequences.
Skinner's Experiments
Edward L. Thorndike's Law of
Effect:
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asserts that rewarded
behavior is likely to
reiterate.
Skinner designed an operant
chamber( Skinner
Box)
o The box has a bar
or key that an
animal presses or
pecks to release a
reward of food or
water, and a
device that records
these responses.
Shaping Behavior
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In shaping, we use reinforcers to guide a
person's or an animal's behavior toward a
desired goal.
Building on existing behaviors, we reward
successive approximations to some desired
behavior.
Since nonverbal animals and babies can
respond only to what they perceive, their
reactions demonstrate which events they can
discriminate.
Positive vs. Negative
Reinforcement
Positive Reinforcement:
adds something desirable to increase the
frequency of behavior.
Negative Reinforcement:
removes something undesirable to
increase the frequency of behavior.
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Types of Reinforcers
Primary Reinforcers:
an innately reinforcing stimulus, such as one that
satisfies a biological need.
o ex's: getting food when hungry or being relieved
of electric shock
Conditioned Reinforcers(secondary reinforcer):
a stimulus that gains its reinforcing power through
its association with a primary reinforcer.
o ex's: the food or medicine we buy
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Strengths & Weaknesses of
Continuous and Partial Reinforcement
Schedules
In Continuous Reinforcement:
reinforcing the desired response every
time it occurs; learning is rapid.
In Partial Reinforcement:
initial learning is slower, but the behavior
is much more resistant to extinction.
Reinforcement schedules may vary according to
the number of responses rewarded or the
time gap between responses.
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Reinforcement Schedules
Fixed- Ratio Schedules:
offers rewards after a set number of responses.
Variable- Ratio Schedules:
provide reinforcers after an unpredictable number of
responses
Fixed-Interval Schedules:
reinforce the first response after a fixed period of
time
Variable-Interval Schedules:
reinforce the first response after varying time
intervals
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Ways Negative Punishment, Positive
Punishment, and Negative Reinforcement
Differ
Both positive punishment and negative
punishment attempt to decrease the
frequency of a behavior.
Positive Punishment:
administering an undesirable consequence,
such as spanking
Negative Punishment:
withdrawing from something desirable, such
as taking away a child's favorite toy
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Ways Negative Punishment, Positive
Punishment, and Negative Reinforcement
Differ(continued)
Negative Reinforcement
removes something undesirable to increase
the frequency of a behavior.
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Ex: Taking Aspirin calms down a headache
Punishment's undesirable side effects may
include suppressing rather than changing
unwanted behaviors, teaching aggression,
creating fear, etc.
Latent Learning Effects
Latent Learning indicates that we can learn
from experience, without apparent
reinforcement. An external rewards ability to
undermine our interest and pleasure in an
activity weakens the idea that behaviors are
rewarded will increase in frequency.
Intrinsic & Extrinsic Motivation
• An external reward’s ability to undermine our
interest and pleasure in an activity weakens
the idea that behaviors that are rewarded will
increase in frequency.
Intrinsic Motivation:
o A desire to perform a behavior for its own sake.
Extrinsic Motivation:
o A desire to perform a behavior due to promised
rewards or threats or punishments.
Biological Predispositions
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Biological constraints predispose organisms
to learn associations that are naturally
adaptive. Training that attempts to override
these tendencies will probably not endure
because the animals will revert to their
biologically predisposed patterns.
Learning by Observation: Overview
Observation Learning:
learning by observing
others
Modeling: the process of
observing and imitating a
specific behavior
Mirror neurons: frontal lobe neurons that fire
when performing certain actions or when
observing another doing so; may enable imitation,
language learning, and empathy
Learning by Observation
Bandura's Experiments
Likely to imitate actions that go unpunished;
imitate those whom we view as similar,
successful or admirable
Ex: Peers, Celebrities, Parents
Applications of Observation Learning
Helps to understand actions of others
Ex: Abusive parents
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Learning by Observation
Television and Observational
Learning
Correlations demonstrate
relationships but not the
direction of influence (Violent
shows, experiment)
Imitation and Desensitization
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Positive Observational Learning
Prosocial behavior: positive, constructive, helpful
behavior; opposite of antisocial behavior
Children imitate regardless of good or bad;
conformity (Parents)
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Skinner's Legacy
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Skinner was one of the most controversial
figures because people opposed his ideas of
ignoring personal freedom and trying to
control humans’ actions
We still continue to use his ideas today
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Applications of Operant
Conditioning
School: Skinner advocated the use of teaching machine and textbooks
because it would free teachers to concentrate on their students’
special needs
o Good instruction demands two things:
 Students must be told immediately whether what they do is right or
wrong and,
 When right, they must be directed to the next step
Sports: The key is to shape behavior, by first reinforcing small
successes and then gradually increasing the challenge.
o Golfers learn putting by starting with very short putts. As they build
mastery they step back
o Baseball players begin with half swings at an oversized ball pitched 10 ft.
away. As they achieve mastery they move back -15,20,30,40.5 feet- and
then introduce a standard baseball.
Applications of Operant
Conditioning (continued)
• Work: Managers on the floor should affirm good
wok with positive encouragement and, if need
be, criticism. Material objects are not condoned.
• Home:
o Give children attention and other reinforcers when
they are behaving well. Target a specific behavior,
reward it, and watch it increase.
o Ignore whining.
o When children misbehave or are defiant, do not yell
or hit them. Explain the misbehavior and give them a
timeout.
Using Operant Conditioning
on Yourself
• State your goal- to stop smoking, exercise,
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eat less- in measurable terms, and make your
intention public to people close to you.
Monitor- how often you engage in the
behavior you wish to promote
Reinforce- the desired behavior
Reduce the incentives