LEARNING | NATURE AND PARADIGMS OF LEARNING | CLASSICAL CONDITIONING

Learning preserves errors of the past as well as its wisdom. – A.N. Whitehead

INTRODUCTION:

At the time of birth every human baby is equipped with the capacity to make a limited number of responses. These responses occur reflexively whenever appropriate stimuli are present in the environment. 

As the child grows and matures, s/he becomes capable of making diverse types of responses. These include identifying the images of some persons as one’s mother, father or grandfather, using a spoon when eating food, and learning how to identify alphabets, to write, and to combine them into words. S/he also observes others doing things in specific environmental conditions, and imitates them.

Learning names of objects such as book, orange, mango, cow, boy, and girl, and retaining them is another important task. As one grows older, one observes many events or objects, and learns their distinct features. 

Objects are categorised as ‘furniture’, ‘fruits’, and so on. One also learns to drive a scooter or a car, to communicate with others effectively, and to interact with others. It is all due to learning that a person becomes hard working or indolent, socially knowledgeable, skilled, and professionally competent. Each individual manages her or his life and solves all kinds of problems because of the capacity to learn and adapt.

Learning is defined and characterised as a psychological process. 

Nature of Learning:

Learning is a key process in human behaviour. It refers to a spectrum of changes that take place as a result of one’s experience. Learning may be defined as “any relatively permanent change in behaviour or behavioural potential produced by experience”.

One must remember that some behavioural changes occur due to the use of drugs, or fatigue. Such changes are temporary. They are not considered learning. Changes due to practice and experience, which are relatively permanent, are illustrative of learning.

Features of Learning:

The process of learning has certain distinctive characteristics. 

• The first feature is that learning always involves some kinds of experience. 
• Repeated experience of satisfaction after doing something in a specified manner leads to the formation of habit. 
• Sometimes a single experience can lead to learning. A child strikes a matchstick on the side of a matchbox, and gets her/his fingers burnt. Such an experience makes the child learn to be careful in handling the matchbox in future.

Behavioural changes that occur due to learning are relatively permanent. They must be distinguished from the behavioural changes that are neither permanent nor learned.

Behavioural change due to fatigue , habituation and drugs is temporary and it is not considered learning. People who are on sedatives or drugs or alcohol, their behaviour changes as it affects physiological functions. Such changes are temporary in nature and disappear, as the effect wears out. 

Learning involves a sequence of psychological events. A typical learning experiment can be expressed in following sequence :-

1. Do a pre-test to know how much the person knows before learning, 
2. Present the list of words to be remembered for a fixed time, 
3. During this time the list of words is processed towards acquiring new knowledge,
4. After processing is complete, new knowledge is acquired (this is LEARNING), and
5. After some time elapses, the processed information is recalled by the person. 

By comparing the number of words which a person now knows as compared to what s/he knew in the pre-test, one infers that learning did take place. Thus, learning is an inferred process and is different from performance. Performance is a person’s observed behaviour or response or action. 

Let us understand what is meant by the term inference. Suppose a child is asked by his teacher to memorise a poem. He read that poem a number of times. Then he say that he has learned the poem. Child is asked to recite the poem and he is able to recite it. The recitation of the poem by child is his performance. On the basis of his performance, the teacher infers that he has learned the poem.

Paradigms of Learning

Learning takes place in many ways. There are some methods that are used in acquisition of simple responses while other methods are used in the acquisition of complex responses.

The simplest kind of learning is called conditioning. Two types of conditioning have been identified. The first one is called classical conditioning, and the second instrumental/operant conditioning. In

addition, we have observational learning, cognitive learning, verbal learning, concept learning, and skill learning.

Classical Condition:

This type of learning was first investigated by Ivan P. Pavlov. We may have noticed that all dogs salivate when they are presented with food. Food is thus an Unconditioned Stimulus (US) and salivation which follows it, an Unconditioned Response (UR). 

After conditioning, salivation started to occur in the presence of the sound of the bell. (Actually Ivan P. Pavlov had performed an experiment where he gives food to dog after a bell sound.)

The bell becomes a Conditioned Stimulus (CS) and saliva secretion a Conditioned Response (CR). This kind of conditioning is called classical conditioning. The procedure is illustrated in Table below.

It is obvious that the learning situation in classical conditioning is one of S–S learning in which one stimulus (e.g., sound of bell) becomes a signal of another stimulus (e.g., food). Here one stimulus signifies the possible occurrence of another stimulus.

Examples of classical conditioning abound in everyday life. Imagine you have just finished your lunch and feel satisfied. Then you see some sweet dish served on the adjoining table. This signals its taste in your mouth, and triggers the secretion of saliva. We feel like eating it. This is a conditioned response (CR).

Determinants of Classical Conditioning

How quickly and strongly acquisition of a response occurs in classical conditioning depends on several factors. Some of the major factors influencing learning a CR are described below:

1. Time Relations between Stimuli : 

The classical conditioning procedures, discussed below, are basically of four types based on the time relations between the onset of conditioned stimulus (CS) and unconditioned stimulus (US). The first three are called forward conditioning procedures, and the fourth one is called backward conditioning procedure. 

The basic experimental arrangements of these procedures are as follows:

• When the CS and US are presented together, it is called simultaneous conditioning.
• In delayed conditioning, the onset of CS precedes the onset of US. The CS ends before the end of the US.
• In trace conditioning, the onset and end of the CS precedes the onset of US with some time gap between the two.
• In backward conditioning, the US precedes the onset of CS.

It is now well established that delayed conditioning procedure is the most effective way of acquiring a CR. 

Simultaneous and trace conditioning procedures do lead to acquisition of a CR, but they require greater number of acquisition trials in comparison to the delayed conditioning procedure. It may be noted that the acquisition of response under backward conditioning procedure is very rare.

2. Type of Unconditioned Stimuli :

The unconditioned stimuli used in studies of classical conditioning are basically of two types, i.e. appetitive and aversive. 

a). Appetitive unconditioned stimuli automatically elicits approach responses, such as eating, drinking, caressing, etc. These responses give satisfaction and pleasure. 

b). Aversive: On the other hand, aversive US, such as noise, bitter taste, electric shock, painful injections, etc. are painful, harmful, and elicit avoidance and escape responses.

It has been found that appetitive classical conditioning is slower and requires greater number of acquisition trials, but aversive classical conditioning is established in one, two or three trials depending on the intensity of the aversive US.

3. Intensity of Conditioned Stimuli : 

This influences the course of both appetitive and aversive classical conditioning. More intense conditioned stimuli are more effective in accelerating the acquisition of conditioned responses. It means that the more intense the conditioned stimulus, the fewer are the number of acquisition trials needed for conditioning.