1. Operant conditioning (Skinner – 1938, 1956)

2. Skinner box
A small soundproof chamber in which an experimental animal learns to make a particular response for which the consequences are controlled.

3. Skinner’s original experiments
When a hungry rat was placed in a Skinner box, it scurried around the box and randomly touched parts of the floor and walls.
Eventually, it accidentally pressed a lever and a food pellet appeared.
The rat continued random movement and pressed the lever again. Another food pellet appeared.
With additional repetitions of lever pressing followed by food, the rat’s random movements were replaced by consistent lever pressing.
The rat “learned” that particular behaviours resulted in a desirable consequence.

5. Skinner’s original experiments

6. Operant conditioning
The learning process by which the likelihood of a particular behaviour occurring is determined by the consequences of that behaviour, and the environment (antecedent).
The organism will tend to be repeat behaviour which has a desirable consequence (reinforcement) and tend not to repeat behaviour which has an undesirable consequence (punishment).
Also called instrumental conditioning.

7. A B C Antecedent Behaviour Consequence Environment or context
Voluntary behaviours made by organism
Consequence
Positive (reinforcement) or negative (punishment)

8. Types of consequences Reinforcement Positive reinforcement
ADD positive to INCREASE behaviour
Negative reinforcement
REMOVE negative to INCREASE behaviour
Punishment
ADD negative to DECREASE behaviour
Response cost
REMOVE positive to DECREASE behaviour

9. Reinforcement
Any event which strengthens, increases the frequency, or increases the likelihood of a particular response occurring.
Reinforcer: The stimulus that provides reinforcement. Often used interchangeably with the term reward.

10. Types of reinforcement
Positive reinforcement
The application of a pleasant stimulus following a response. The behaviour (response) is strengthened (more likely to occur again).
Negative reinforcement
The removal or avoidance of an unpleasant stimulus. Because the outcome is a pleasant one, the behaviour that removes or avoids the unpleasant stimulus is strengthened (more likely to occur again).

11. Punishment
When a response is followed by a negative consequence (an unpleasant event or taking away something that is pleasant) which decreases the likelihood of that response occurring again over time.
The weakening of a response by following it with negative consequences is not negative reinforcement – it is punishment.

12. Punishment considerations
Order of presentation
Consequence (punishment) must be presented after undesired behaviour, never before
Timing
Punishment most effective when given immediately after the behaviour has occurred (without delay)
Appropriateness
Consequence (reinforcer) must be satisfying, punishment must be unpleasant

13. Are speeding fines enough of a deterrent
Are speeding fines enough of a deterrent? What else can be done to stop speeding?

15. Types of reinforcement
Continuous reinforcement: When a correct response is reinforced every time it occurs.
Partial reinforcement: Reinforcing only some correct responses.
Schedule of reinforcement: The frequency and manner in which a correct response is reinforced.

16. Types of reinforcement

17. Fixed and variable schedules
Fixed-ratio schedule: reinforcer given after a fixed number of correct responses
eg, every 10 times
Variable-ratio schedule: reinforcer given after a variable number of correct responses
eg, almost random – certain number of correct responses must be made
Fixed-interval schedule: reinforcer given after a fixed amount of time since last reinforcer (eg, every 10 seconds).
Variable-interval schedule: reinforcer given after a variable amount of time
Eg, almost random – certain number of correct responses must be made

18. Which schedule does gambling use and why?

20. Shaping
Shaping: An operant conditioning procedure in which a reinforcer is given for any response that successively approximates and ultimately leads to the final response, or target behaviour. Also called method of successive approximations.

21. Shaping

23. Acquisition
The overall learning process in which a specific response, or pattern of responses is established, through reinforcement.
A pigeon receives a food pellet every time it pecks a disk, until the behaviour is established.

24. Extinction
The gradual decrease in the strength or rate of a conditioned response following consistent non-reinforcement of the response.
When a pigeon is no longer reinforced for pecking a disk, the behaviour will diminish over time and eventually extinguish.

25. Spontaneous recovery
After the apparent extinction of a conditioned response, the organism again shows the response in the absence of any reinforcement.
A pigeon that was trained 6 months previously to peck a disk for food and then had that response extinguished, pecks the disk when returned to the Skinner box, without reinforcement.

26. Stimulus generalisation
The correct response occurs to another stimulus that is similar to the stimulus that was presented when the response was reinforced.
A pigeon pecks at a disk that is a different shape from the one it was trained to peck.

27. Stimulus discrimination
The organism makes the correct response to a stimulus and is reinforced, but does not respond to any other stimulus, even when they are similar.
The pigeon will only peck the round disk in the Skinner box, and not any other shaped disk.

28. Real-life applications
Animal training
Behaviour modification in therapy, schools, workplace, etc
Treat addictive behaviour, eg gambling
“Loyalty” programs such as coffee clubs, frequent flyer programs, etc