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Operant Conditioning
Thorndike’s Theory of Connectionism
Law of Effect
If Situation + Response is followed by a positive consequence then the connection between the Situation + Response is strengthened.
If Situation + Response is followed by a negative consequence then the connection between the Situation + Response is weakened.
In Thorndike’s words:
“When a modifiable connection between an situation and a response is made and is accompanied or followed by a satisfying state of affairs, that connection’s strength is increased: When made or accompanied or followed by an annoying state of affairs, the strength is decreased.” (Thorndike, 1913) Note: Thorndike(1932) later modified the Law of Effect when research showed that while positive consequences strengthened connections, negative consequences did not necessarily weaken them.
“Spare the reward, spoil the child” by E.L. Thorndike
The Big IdeaConsequences of behavior effect behavior, responses resulting in satisfying consequences are learned.
Behavioral theories explain learning in terms of environmental events.
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Skinner’s ExperimentsSkinner’s experiments extend Thorndike’s
thinking, especially his law of effect. This law states that rewarded behavior is likely to
occur again.
Yale U
niversity Library
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Operant Chamber
Using Thorndike's law of effect as a starting point, Skinner developed the
Operant chamber, or the Skinner box, to study operant conditioning.
Walter D
awn/ Photo R
esearchers, Inc.
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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.
A rat shaped to sniff mines. A manatee shaped to discriminateobjects of different shapes, colors and sizes.
Kham
is Ram
adhan/ Panapress/ Getty Im
ages
Fred Bavendam
/ Peter Arnold, Inc.
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Types of Reinforcers
Reinforcement: Any event that strengthens the behavior it follows. A heat lamp positively reinforces a meerkat’s behavior in the cold.
Reuters/ C
orbis
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1. Primary Reinforcer: An innately reinforcing stimulus like food or drink. Satisfies a biological need.
2. Conditioned Reinforcer: A learned reinforcer that gets its reinforcing power through association with the primary reinforcer.
Primary & Secondary Reinforcers
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Reinforcement Schedules
1. Continuous Reinforcement: Reinforces the desired response each time it occurs.
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.
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Ratio Schedules
1. Fixed-ratio schedule: Reinforces a response only after a specified number of responses. e.g., Quiz at end of chapter
2. Variable-ratio schedule: Reinforces a response after an unpredictable number of responses. This is hard to extinguish because of the unpredictability. (e.g., pop quiz once a chapter)
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Interval Schedules
1. Fixed-interval schedule: Reinforces a response only after a specified time has elapsed. (e.g., quiz every friday.)
2. Variable-interval schedule: Reinforces a response at unpredictable time intervals, which produces slow, steady responses. (e.g., pop quiz once a week.)
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Punishment
An aversive event that decreases the behavior it follows.
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Punishment
1. Results in unwanted fears.2. Conveys no information to the organism.3. Justifies pain to others.4. 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.
Although there may be some justification for occasional punishment (Larzelaere &
Baumrind, 2002), it usually leads to negative effects.
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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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Latent Learning
Such cognitive maps are based on latent learning, which becomes apparent only when an incentive is given (Tolman &
Honzik, 1930).
Learning that is not immediately reflected in a behavior change
We learn lots of stuff without having to demonstrate it immediately
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Biological Predisposition
Biological constraints predispose organisms to learn associations
that are naturally adaptive.
Breland and Breland (1961) showed that
animals drift towards their biologically
predisposed instinctive behaviors. Marian Breland Bailey
Ph
oto
: Bob
Baile
y
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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
Skinner introduced the concept of teaching machines that shape learning in small steps and provide reinforcements
for correct rewards.
In School
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A-JD
L/ C
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Operant vs. Classical Conditioning
Table 6.1 Comparison of Basic Processes in Classical and Operant Conditioning
Learning from observation
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Learning by Observation
Higher animals, especially humans,
learn through observing and
imitating others.
The monkey on the right imitates the
monkey on the left in touching the pictures in a certain order to
obtain a reward.
© H
erb Terrace
©H
erb Terrace
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Imitation Onset
Learning by observation begins early in life. This
14-month-old child imitates the adult on TV
in pulling a toy apart.
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Bandura's Experiments
Bandura's Bobo doll study (1961)
indicated that individuals
(children) learn through imitating
others who receive rewards and punishments.
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Applications of Observational Learning
Unfortunately, Bandura’s studies
show that antisocial models (family,
neighborhood or TV) may have
antisocial effects.
Observational Learning and theMedia Violence Controversy
• Studies demonstrate that exposure to TV and movie violence increases the likelihood of physical aggression, verbal aggression, aggressive thoughts, and aggressive emotions
• The association between media violence and aggression is nearly as great as the correlation between smoking and cancer
Figure 6.27. Comparison of the relationship between media violence and aggression to other correlations.
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Television and Observational Learning
Gentile et al., (2004) shows that children
in elementary school who are
exposed to violent television, videos, and video games express increased
aggression.
Ron
Cha
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/ Tax
i/ G
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Im
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Modeling Violence
Research shows that viewing media violence leads to an increased expression of aggression.
Children modeling after pro wrestlers
Bob
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Observational Learning
• Vicarious Reinforcement / Punishment– Watching someone else rewarded or punished
for a behavior and being more or less likely to exhibit the same behavior
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