PowerpointOperantConditioningTheory.pptx

Powerpoint Operant Conditioning Theory

1. Operant Conditioning Theory by B.F. Skinner

2. Prof. B.F. Skinner (b. 1904) started his research work on behavior while he was a graduate in the Department of Psychology of the Harvard University. In 1931 he wrote his thesis entitled, “The concept of the reflex in the Description of the behavior”. Skinner was a Practical Psychologist who conducted several experiments on rats and pigeons . His important publications are: ‘The Behavior of Organism’ (1930), ‘Science and Human Behavior’ (1953), Verbal behavior (1957), Cumulative Record (1957), Beyond Freedom and Dignity (1971) and ‘About Behaviorism’ (1974).

3. Introduction of Operant Conditioning According to Skinner, there are two types of behaviors, namely respondent behavior and operant behavior. You blink your eye in response to a flash of light. This reflexive behavior is elicited directly by the environment. So this is respondent behavior - spontaneous response to stimuli. But most of our behaviors are not so simply generated by the environment. You are not forced by the environment to look at a book , to talk, to sing, and to eat. These behaviors are emitted by you, the individual. Through such behaviors, you operate upon the environment. These are called operant behaviors

4. The Operant Experiment Skinner designed a box named as ‘Skinner box’ and placed a hungry rat inside. There was a lever which, after being pressed, released a mechanism to deliver a pellet of food to the rat. Initially , the rat is engaged in a number of random behaviors like walking, sniffing and scratching. None of these helped to get the food. At some point of time, the rat accidentally hit the lever and the food was delivered. Of course, for the semi-starved rat, this was a big reward.

5. Skinner observed that after a few accidental manipulations of the lever, the rat started spending more time near the lever, and then deliberately pressed the lever whenever it was hungry. So, now pressing the lever became a new operant for the rat. Skinner further noted that if the pressing of the lever did not deliver food any longer, the operant behavior by the rat decreased and gradually stopped altogether. This is known as experimental extinction of operant conditioning.

6. For doing experiments with pigeons, Skinner made use of another specific apparatus called “Pigeon Box”. A Pigeon in this experiment had a peck at a lighted plastic key mounted on the wall at head height and was consequently rewarded by receiving grain.

7. Measuring Operant Behavior Quantification of operant behavior was crucial to Skinner’s work. He needed to demonstrate that through appropriate use of reward and punishment you can actually increase the probability of occurrence of a conditioned operant behavior. Therefore Skinner introduced the rate of occurrence of the target behavior as the measure of operant conditioning . He simply counted how many times the learnt behavior has taken place within a given time. In fact, he used the cumulative frequency of the operant behavior as the final indicator. If you put it in a graphical form you will readily see whether the probability of the occurrence of that behavior has actually increased over time.

8. 1. Shaping Shaping is an extremely important concept in operant conditioning. Shaping means modification of the organism’s behavior to the experimenter’s desired end. It takes place only through ‘successive approximations’. Suppose you are trying to modify a child’s behavior by selectively rewarding the response desired by you. Before the ultimate desired behavior is enacted, the child’s usually engaged in numerous other behaviors which may be considered as steps to the final behavior. They are close to the target, but not the target per se. If these approximate target behaviors are rewarded, shaping is facilitated.

9. Skinner discovered this principle of successive approximation rather accidentally. He was conditioning a pigeon to swipe a ball with its beak movement which in turn would release a food magazine. The pigeon was not lucky enough. After waiting for the accidental success to happen for a long time Skinner was bored. So, just casually, he decided to reward any behavior that might lead toward the target behavior. As these approximate behaviors were successively rewarded, to Skinner’s surprise, the total process was quickened. Very soon ‘the ball was caroming off the walls of the box as if the pigeon had been a champion squash player’ (Skinner, 1938, p. 38). Rewarding of the simpler step has automatically led to the next higher step and so on. (This is successive approximation)

10. 2. Extinction In the operant conditioning paradigm, extinction refers to the process of no longer providing the reinforcement that has been maintaining a behavior. Operant extinction differs from forgetting in that the latter refers to a decrease in the strength of a behavior over time when it has not been emitted.

11. 3. Spontaneous Recovery Spontaneous recovery is a phenomenon that involves suddenly displaying a behavior that was thought to be extinct. This can apply to responses that have been formed through both classical and operant conditioning

12. 4. The Concept of Reinforcement Reinforcement  is defined as a consequence that follows an  operant response  that increase (or attempts to increase) the likelihood of that response occurring in the future. I n operant conditioning, the concept of CS and UCS are not applicable, as we are concerned with shaping of target behavior. So here reinforcement comes separately as a consequence of desirable behavior. It simply serves to strengthen the response. The food pellet emerges only if the lever is pressed, and not otherwise. So it is contingent upon operant behavior and strengthens the same.

13. 1. Continuous Reinforcement 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 a strong association between the behavior and the response. Once the response if firmly attached, reinforcement is usually switched to a partial reinforcement schedule.

14. 2. Partial Reinforcement In partial 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.

15. A) Fixed–ratio schedules  are 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 reinforce. An example of a fixed-ratio schedule would be delivering a food pellet to a rat after it presses a bar five times . B) Variable-ratio schedules  occur when a response is reinforced after an unpredictable number of responses. This schedule creates a high steady rate of responding. Gambling and lottery games are good examples of a reward based on a variable ratio schedule. In a lab setting, this might involve delivering food pellets to a rat after one bar press, again after four bar presses, and the third pellet after two bar presses.

16. C) Fixed-interval schedules : are those 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 but much slower responding immediately after the delivery of the reinforce. D) Variable-interval  schedules  occur when a response is rewarded with an unpredictable amount of time has passed. This schedule produces a slow, steady rate of response. An example of this would be delivering a food pellet to a rat after the first bar press following a one-minute interval, another pellet for the first response following a five-minute interval, and a third food pellet for the first response following a three-minute interval.

17. Educational Implications Identification of root cause of the behavior. Eliminates Negative Behavior: The operant conditioning theory involves the use of negative reinforcement which strengthens behavior by eliminating unpleasant behavior. By building operant conditioning techniques into lesson plans, it is easily possible to teach children useful skills-as well as good behaviors. The use of reinforcement in the form of rewards motivates children to keep learning and perform better.