Operant Conditioning - Skinner

Skinner is regarded as the father of Operant Conditioning, but his work was based on Thorndike’s (1905) law of effect. Skinner introduced a new term into the Law of Effect - Reinforcement. Behavior which is reinforced tends to be repeated (i.e., strengthened); behavior which is not reinforced tends to die out-or be extinguished (i.e., weakened).

Skinner (1948) studied operant conditioning by conducting experiments using animals which he placed in a '*Skinner Box*' which was similar to Thorndike’s puzzle box.

B.F. Skinner (1938) coined the term operant conditioning; it means roughly changing of behavior by the use of reinforcement which is given after the desired response. Skinner identified three types of responses or operant that can follow behavior.

### Operants

* Neutral operants: responses from the environment that neither increase nor decrease the probability of a behavior being repeated.
* Reinforcers: Responses from the environment that increase the probability of a behavior being repeated. Reinforcers can be either positive or negative.
* Punishers: Responses from the environment that decrease the likelihood of a behavior being repeated. Punishment weakens behavior.

### Reinforcement

#### Positive Reinforcement

Positive reinforcement occurs when a pleasant or desirable event follows a response, and will generally increase or strengthen the likeliness of the response occurring again.

#### Negative Reinforcement

Negative reinforcement occurs when an unpleasant stimulus is removed, reduced or prevented from occurring in order to create a positive consequence, and this in turn strengthens the likelihood of the response occurring again.

### Punishment

Punishment can be positive or negative, but the result of punishment is the opposite to that of reinforcement; rather than increasing a particular behaviour, punishment decreases the likelihood that the behaviour will occur again.

### Determining Positive or Negative Reinforcement/Punishment

#### Reinforcement/Punishment

* Increase or decrease in behaviour?
	+ Increase = Reinforcement
	+ Decrease = Punishment

#### Positive/Negative

* Pleasantness added or unpleasantness removed?
	+ Added = Positive
	+ Negative = Removed

### Primary and Secondary Reinforcers

Primary reinforcers are biological. Food, drink, and pleasure are the principal examples of primary reinforcers. But, most human reinforcers are secondary, or conditioned. Examples include money, grades in schools, and tokens.

Secondary reinforcers acquire their power via a history of association with primary reinforcers or other secondary reinforcers. For example, if I told you that dollars were no longer going to be used as money, then dollars would lose their power as a secondary reinforcer.

### Primary vs Secondary Reinforcers

Primary reinforcers are those that are biologically connected to us; food, water, sleep, etc. They are viewed as positive stimulus that can motivate our actions. Secondary reinforcers are those that are, over time, conditioned to act as reinforcers through association with primary reinforcers. Money is a secondary reinforcer, as we associate it with comfort, food, and luxury.

### Examples of:

#### Positive Reinforcement

Give the dog a treat every time the bring the newspaper in.

#### Negative Reinforcement

Don’t feed the dog every time he doesn't bring the newspaper in.

#### Positive Punishment

A driver is speeding and gets pulled over and given a ticket: ticket added, speeding decreased

#### NegativePunishment

A driver is speeding and gets pulled over and his license is taken away: license removed, speeding decreased

### Influencers of Effectiveness

#### Timing

Timing of reinforcement/punishment must be enacted during or quickly after the behaviour has been shown, otherwise the reinforcement/punishment will not have an effect as the stimulus will not be associated with the behaviour.

#### Appropriateness

Appropriateness is a factor of effectiveness because if the individual does not associate the stimulus as positive/negative, the stimulus will have no effect on coercing the individual or reinforcing/punishing the behaviour.

#### Satiation

Satiation is the phenomenon in which an individual is no longer affected and desensitized to the stimulus because the individual has been over-stimulated and the stimulus no longer affects them.

### Reinforcement Schedules

#### Continuous Reinforcement Schedule

In continuous reinforcement, the desired behavior is reinforced *every single time* it occurs. This schedule is best used during the initial stages of learning in order to create a strong association between the behavior and the response.

Partial Reinforcement Schedules

In partial or intermittent reinforcement, the response is reinforced only *part of the time*. Learned behaviors are acquired more slowly with partial reinforcement, but the response is more resistant to extinction.

#### Fixed Ratio Schedule

Fixed-ratio schedulesare those where a response is reinforced only after a specified number of responses. This schedule produces a high, steady rate of responding with only a brief pause after the delivery of the reinforcer.

#### Fixed Interval Schedule

Fixed Interval Schedules are where the first response is rewarded only after a specified amount of time has elapsed. This schedule causes high amounts of responding near the end of the interval. Creates a post-reinforcement pause.

#### Variable Ratio Schedule

when a response is reinforced after an unpredictable number of responses. This schedule creates a high steady rate of responding.

#### Variable Interval Schedule

Variable-interval schedules occur when a response is rewarded after an unpredictable amount of time has passed. This schedule produces a slow, steady rate of response.