5 important features that determines the effectiveness of operant conditioning in controlling behavior

The important features that determine the effectiveness of operant conditioning in controlling behavior are:

1. Time Interval, 2. Shaping and Chaining, 3. Primary and secondary Reinforcement, 4. Schedules of Reinforcement, and 5. Phenomena of Extinction, Generalization and Discrimination.

1. Time Interval:

As with classical conditioning, the time interval between the response and the stimulus should be short rather than long. Shorter the interval between the response and its consequence (the stimulus event), the more efficient is operant learning. If the reinforcement/punishment immediately follows the response, learning is more quick and efficient. Delayed reinforcement/punishment retards learning. But, why? Because delay in consequence allows other responses to occur during the same period and are likely to be reinforced at the cost of our target experience.

2. Shaping and Chaining

The lever-pressing response by the rat and the pecking response by the pigeons are very simple responses that these animals naturally emit. But how can behaviors (e.g., the monkey riding a bicycle in the circus), that are not spontaneously emitted be learned ? They are learned by a process termed ‘shaping’. Shaping is based on the principle that a little learning can lead to final mastery. In shaping, each small step that the organism makes to reach the goal is reinforced, rather than only the final response. This is done by the method of successive approximations. At first, actions that are faintly similar to the target behavior are reinforced. The organism learns to show responses that closely approximate the target behavior. When a baby child emits the sound ‘Mmmuuhh’, the parents immediately pour out affection on the child. Initially, the family attends enthusiastically to any sound that the child makes. Gradually, they only respond to and reinforce the child’s utterances that closely resemble the actual words. Shaping involves constructing a complex behavior by the method of successive approximations.

To reach a complex sequence of behaviors, shaping is combined with chaining. In chaining, the trainer establishes a chain of responses, the last of which leads to reward. After the last response is learned, the next-to-last one is reinforced and so on. Shaping and chaining have important implications for human behavior. Animal trainers use both shaping and chaining to teach complex chains of behavior to animals. Two psychologists, Keller and Breland used shaping and chaining to teach pigs deposit silver coins into a ‘piggy’ bank, and chickens to distribute prizes to waiting customers. But how long these tricks work? There are biological constraints on instrumental conditioning. For Keller and Breland, as time went on, the pigs began to throw coins into the ground instead of making deposits in the ‘piggy’ bank. The animals returned to their natural form of behavior, which Breland termed as instinctive drift. While the power of reinforcers and punishers are great, natural tendencies are also important in influencing the course of operant conditioning.

3. Primary and Secondary Reinforcement:

Positive reinforcement can be primary or secondary (conditioned) reinforcement. The primary reinforcers satisfy our innate biological need. The organism does not require training to respond to them. Examples are food for the hungry, water for the thirsty, sexual satisfaction for the adolescent.

Secondary reinforcers acquire their capacity to work as positive reinforcers by being associated with the primary reinforcer. They are also called conditioned reinforcers as their reinforcing status is established through conditioning. Examples are social reinforcers such as praise, smiles, welcome message, money etc. When a dancer is praised or given Rs.1000 for her excellent performance, the probability that she will dance well in future is increased. Money often is referred to as a token reinforcer, because money can be exchanged for food, which has biologically reinforcing value.

Both primary and secondary reinforcers for one person in one situation may not act as a reinforcer for another person in another context. For example, food will serve as positive reinforcer when you are hungry, but not when you are sick or have taken a large meal. Rupees 1000 for an amateur dancer may serve as a secondary reinforcer, but not for an accomplished artist. Thus, the reinforcing value of a stimulus has to be judged with reference to the individual and the context of its application. Stimuli, in and of them do not carry reinforcing.

4. Schedules of Reinforcement:

In most of life’s experiences, we are not reinforced every time we make the response. For example, a smile may not evoke a smile in the other always; a footballer does not win every tournament he enters into; a student is not patted at the back every time he receives Grade A. In many real life instances, reinforcement comes on and goes off unpredictably. In many other instances, reinforcements are delivered according to rules. We receive salary every month and the new vehicles receive free service according to rules. How do these rules – known as schedules of reinforcing – affect behavior?

The reinforcement may be continuous, in which every occurrence of behavior is reinforced. This simplest form of reinforcement delivery is termed a continuous reinforcement schedule or CRF. If a rat receives a food pellet every time it presses the lever, it is on a continuous reinforcement schedule.

Other type of schedule is called partial reinforcement (intermittent reinforcement) schedule. In partial reinforcement, response is not rewarded every time it occurs. This schedule is more important in maintaining learnt behaviours. Once a response is learned under partial reinforcement schedules, it takes longer to be extinguished. The four types of partial reinforcement schedules are fixed-interval, variable-interval, fixed-ratio and variable-ratio.

5. Extinction, Generalization and Discrimination:

As with classical conditioning, the operant response also undergoes extinction, when reinforcement no longer follows the response. If reinforcement is no longer given after the rat has learnt the lever pressing response, the tendency to press the lever gradually weakens. Over a period of time, the response extinguishes and is not shown. Following a rest period after extinction, spontaneous recovery takes place.

Once the response is acquired to a particular stimulus, the organism shows a similar response to a similar stimulus. Pigeons were reinforced for pecking at the disc of a particular color. These pigeons also pecked at discs that are close in color to the original disc, This phenomenon is known as generalization. In operant conditioning, discrimination is the process of responding in the presence of one stimulus and not responding in its absence or in the presence of another stimulus. After the rat has learnt to press the lever, suppose a light is turned on. The rat is rewarded when it presses the lever in the presence of light and the lever pressing response is not rewarded in the absence of light. Here light is the signal that tells whether lever pressing will bring reward or not. Light is the discriminative stimulus. The situational cues are the conditioned stimuli (CS), which occur in the presence of food (UCS). The organism is conditioned to exhibit the lever pressing response (CR) in the presence of these stimuli (CS). This procedure parallels that of a classical conditioning. Hence, in each operant conditioning experiment, there is also an arrangement for classical conditioning to take place.