Operant Conditioning

1. Operant Conditioning

2. Operant Conditioning • Operant Conditioning – A form of learning in which voluntary responses come to be controlled by their consequences. • What does this mean? • Founded by B.F. Skinner

3. How did Skinner Study Operant Conditioning? • Skinner Box – Small enclosure in which an animal can make a specific response that is systematically recorded while consequences of response are controlled • How does the device work?

5. Operant Conditioning Principles • Reinforcement – Occurs when the event following a response increases an organisms tendency to make a response • ie.) response strengthened because of what follows • Examples • Punishment – Occurs when an event following a response weakens an organisms tendency to make response • ie.) response weakened because of what follows • Examples

6. Types of Reinforcement/Punishment • 1.) Positive Reinforcement • 2.) Negative Reinforcement • 3.) Positive Punishment • 4.) Negative Punishment How to remember: • Reinforcement- behavior increases • Punishment- behavior decreases • Positive- something is added • Negative- Something is removed

7. 1.) Positive Reinforcement • A response is strengthened because it is followed by a rewarding stimulus • In skinner box, rats press lever more if they are rewarded with food • Real World Examples:

8. 2.) Negative Reinforcement • A response is strengthened because it is followed by the removal of an unpleasant stimulus • In skinner box, rat would press lever more to avoid a shock • Real World Examples:

9. 3.) Positive Punishment • A response is weakened because it is followed by an unfavorable stimulus • In Skinner box, rats would stop pressing lever if it was followed by a shock • Real World Examples:

10. 4.) Negative Punishment • A response is weakened because it is followed by the removal of a pleasant stimulus • Equate this with “Time out” • Children stop acting out because their toys are removed • Other Real World Examples:

11. How can Operant Procedures be used? • Shaping – The reinforcement of closer and closer approximations of a desired response • Family guy clip: http://www.youtube.com/watch?v=prvSM8TlIeI Other examples:

12. Extinction • Extinction – This term refers to the gradual weakening and disappearance of a response when it is no longer followed by reinforcement • In Skinner box, rats would stop pressing lever if food was never delivered • Real World Examples:

13. Schedules of Reinforcement -Pattern of presentation of reinforcers over time • Continuous Reinforcement – Every Instance of a response is reinforced • Ex.) every time rat presses lever, he receives food • Intermittent Reinforcement- A response is only reinforced some of the time. • 4 Types: • 1. Fixed Ratio • 2. Variable Ratio • 3. Fixed Interval • 4. Variable Interval

14. 4 Types of Intermittent Reinforcement • 1. Fixed Ratio • 2. Variable Ratio • 3. Fixed Interval • 4. Variable Interval • Terminology Breakdown • Fixed – Reinforcement occurs after set # (of responses or hours) • Variable- Reinforcement occurs after a varied # (of responses or hours) • Ratio – Based on responses (# of times hit lever, for example) • Interval – Based on time (# of hours passed, for example)

15. 1.) Fixed Ratio • A reinforcer is given after a set (or fixed) number of responses • Examples: • Rat receives food every 10th lever press

16. 2.) Variable Ratio • A reinforcer is given after varied number of responses • Examples: • Rat gets food, on average, every 10th lever press

17. 3.) Fixed Interval • A reinforcer is given after a set (or fixed) time interval • Examples: • Rat given food for lever press every 2 minutes

18. 4.) Variable Interval • A reinforcer is given after a varied amount of time passes • Examples: rat given food, on average, every 2 minutes.

19. Ratio Schedules = more rapid responding • Why? • Variable Schedules = greater resistance to extinction • Why?