2.3 Explore the characteristics of Operant Conditioning
Characteristics of Operant (Instrumental) Conditioning
There are two types of reinforcement in operant conditioning. These are positive reinforcement and negative reinforcement. Positive rein forcers are stimuli that strengthen responses that precede them for example the food given to the rat in the Skinner box is a positive rein forcer because it made the rat repeat the action that led to the appearance of food. On the other hand, negative reinforcement involves the removal of a noxious, unpleasant or aversive stimulus in order to strengthen behaviour for example, removing broken pieces of bottles from a playing field in order to encourage children to play on the field. The effect of negative reinforcement is to maintain and strengthen the correct response, while the undesired response suffers extinction.
Modes of Reinforcement or Schedules of Reinforcement
An application of operant conditioning principles is in generating a variety of behaviour patterns. Psychologists have discovered that once a given behaviour pattern has been established it is not necessary to maintain it by giving reinforcement for every occurrence. It can be arranged so that every other response is reinforced. Alternatively it can be arranged so that reinforcement comes once after a fixed time interval irrespective of how many responses may have been displayed.
The various patterns of reinforcement include:
1. Continuous reinforcement schedule
This where reinforcement is given for every response for example if a rat receives food each time it presses a lever or a small child receives a shilling each time he ties his shoe laces correctly.
2. Fixed interval schedule
Here a reward is given at fixed time intervals. When placed on schedules of this type, people generally show a pattern in which they respond at low rates immediately after delivery of a reinforcement but then gradually respond more and more as the time when the next reward can be obtained approaches. A good example of behaviour on fixed interval schedule is provided by students studying. After a big exam, little if any studying takes place. As the time for the next test approaches, the rate of studying increases dramatically.
3. Variable interval schedule
This is where reinforcement comes after random time intervals. An example of behaviour on a variable interval schedule of reinforcement is provided by employees whose supervisor checks their work at irregular intervals. Since the employees never know when such checks will occur, they must perform in a consistent manner in order to obtain positive outcomes, such as praise, or avoid negative ones such as criticism.
4. Fixed ratio schedule
Here reinforcement occurs only after a fixed number of responses. Individuals who are paid on a piecework basis, in which a fixed amount is paid for each item produced are operating according to a fixed ratio schedule. People who are paid for every kilo of tea or coffee they pick are behaving according to a fixed ratio schedule. Another example is children who are rewarded for every piece of paper they collect from the ground in the school compound.
5. Variable ratio schedule
This is where reinforcement comes after a random number of responses have been displayed. Organisms usually respond at high and steady rates when confronted with a variable ratio schedule since they cannot predict how many responses are required before reinforcement will occur. The effect of such schedules on human behaviour is apparent in gambling casinos, where high rates of responding occur in front of slot machines and other games of chance.