What is Operant Conditioning?

Operant conditioning is another approach to the study of associative learning. When tack a dog a trick, it is hard to specify the unconditioned stimuli that could produce such behaviour before conditioning. Actually, you “got him to do it” as best you could
and afterward rewarded him with either approval or food. The approval or food did not produce the behaviour.

The; word operant derives from the fact that the operant behaviour “operates” on the environment to produce some effect. Thus going to where the telephone is and raising the receiver are operant acts lead to the telephone conversation.

To demonstrate operant conditioning in the laboratory a rat is placed in a box like. (a). Skinner’s Experiment the one in, called a “skinner box.” Because the rat has been deprived of food for some specified period, it is assumed to be motivated by a hunger drive. (By drive we refer to the aroused condition of an organism that results from deprivation of some sort). The inside of the skinner box is bare, except for the protruding bar with the food dish beneath it. A small light bulb above the bar can be lighted at the (a) experimenter’s discretion.

Operant conditioning refers to increasing the probability of a response in a particular stimulus environment by following the response with reinforcement. Usually the reinforcement is something that can satisfy a basic drive, like food to satisfy hunger or water to satisfy thirst, but as we will see later it need not be.

Measures of Operant Strength:

Because the bar is always present in the skinner box, the rat can respond to it as frequently or infrequently as it chooses. Hence rate of response is a useful measure of operant strength. The more frequently the response occurs during a given interval of time, the stronger it is.

The rate of response in operant condition­ing is usually portrayed by a cumulative curve. The bar of the skinner box is attached to a recording pan that rests on a slowly moving strip of paper.

Each time the animal presses the bar the pen moves upward and then continues on its horizontal path. Because the paper moves at a fixed rate, the slope of the cumulative curve is a measure of response rate. A horizontal line indicates that the animal if not responding: a steep curve indicates a fast response rate.

Another measure of operant strength is the total number of responses during extinction. A single reinforcement can produce considerable strength according to this measure.

Food tray:

Operant Conditioning of Human Behaviour:

In the following experiment (Verplanck, 1955) a college student was unaware that an experiment was being conducted, and the experimenter thereby avoided the artificiality of many conditioning experiments. The experimenter carried on what appeared to be an informal conversation with the subject, but actually behaved according to a plan.

The experimenter determined in advance to reinforce all statements of opinion made by the subject, such as sentences beginning “I think,” “I believe,” “It seems to me,” and the like. The reinforcement was the experimenter’s saying “You’re right,” “I agree,” “That’s so” after each statement of opinion. Extinction was carried out in another portion of the experiment by mere no reinforcement-silence-following a statement of opinion.

Following verbal reinforcement, statements of opinion showed a marked increase in frequency, following extinction, they decreased.

The experimenter controlled verbal behaviour in this situation in much the same way as he controlled bar pressing by a rat. In studies of this kind the subject may on some occasions begin to realize that the experimenter is actually manipulating his verbal behaviour. There is evidence, however, that verbal conditioning can occur without the subject’s being consciously aware of the fact that his statements are being controlled by the reinforcement schedule of the experimenter (Rosenfeld and Bear, 1969).

Operant conditioning principles have also been used to modify problem behaviour in children.

In one case, nursery school teachers used social reinforcement to change the behaviour of a shy, withdrawn three-year-old girl who spent most of her time crawling about the floor and resisted all attempts to encourage her to play or to join in group activities.

On the assumption that getting the child to spend more time on her feet was the first step toward increasing participation in school activities, a reinforcement schedule was set up whereby the teachers gave attention to the child only when she was standing and ignored her completely the rest of the time.

Careful recording of the child’s minute-by-minute activity showed that she progressed from an initial rate of over 90 per cent of the day on the floor to the point where, after two weeks, her behaviour was indistinguishable from that of the other children in terms of talking, smiling, and using the school equipment.

To determine whether the reinforcement schedule was the causative factor, the procedure was reversed so that only on-the-floor activity was reinforced. Within two days the child was again spending the majority of her time on the floor.

Interestingly enough, she did not revert to her earlier behaviour in other respects, but managed to play happily while sitting or crawling and continued to initiate contacts with the other children.

A second reversal procedure (that is, again giving the child steady attention when she was on her feet and none when she was on the floor) reinstates her vigorous on-the-feet participation in school activities within a few hours, and her behaviour in the days that followed seemed adequate in every way (Harries and other, 1965).