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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.

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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.

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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.

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Fred Bavendam

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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.

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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

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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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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

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©H

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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.

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Modeling Violence

Research shows that viewing media violence leads to an increased expression of aggression.

Children modeling after pro wrestlers

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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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