Friday 17 February 2017

What is “Classical Conditioning”?

Classical Conditioning
Classical Conditioning
When you are pinched, you feel pain; you react in some way that is unlearned. For example, someone flashes a light and then he/she pinches you; if he/she does this for several times, you come to feel a facsimile of the pain when the light is flashed before you are pinched or even you are not pinched. This latter reaction is a learned reaction. Psychologists explain this (learned reaction) in terms of conditioning a simple form of learning.

Conditioning is of two types:

1. Classical Conditioning
2. Instrumental Conditioning or Operant Conditioning.

Classical Conditioning:

Classical conditioning is a form of learning in which two stimuli are presented together and the response originally elicited by one of them comes to be elicited by the other stimulus. It has its origin in the experiments of Russian Psychologist I. P. Pavlov who is known primarily for his work in classical conditioning.
Pavlov, who was born on 26th September 1849, encountered the phenomenon of conditioning during his studies on the digestive process for which he was awarded the Nobel Prize in 1904. Thus, Pavlov became the first Russian Nobel laureate. After the completion of his doctorate, Pavlov went to Germany to study at Leipzig.
The food causes a particular reaction, the salivation. A stimulus can be defined as any object, event or experience that causes a response. Food is a natural stimulus to evoke salivation in dog; for example, in the case of Pavlov’s dogs, the food is the stimulus and salivation is the response.
At the beginning of his experiments, Pavlov began by a sound of bell and recording a dog’s response. As expected, there was no salivation. At this point, the bell was a “Neutral Response” because it brought forth no salivation.
Then, Pavlov fed the dog, the response was salivation. The food was an “Unconditioned Stimulus” (US) because no prior training or conditioning was needed to establish the connection between food and salivation. In this case, the salivation was an “Unconditioned Response”, because it occurred automatically without any conditioning.
Using these three—the food, the salivation, and the bell, Pavlov demonstrated that a dog could be conditioned to salivate after hearing the bell. He did this by pairing of sound of bell with the food. At the beginning of the experiments, he sounded the bell and then quickly fed the dog. After Pavlov repeated this several times, the dog began to salivate after hearing the sound of bell, but before receiving the food. Here, the sound became a “Conditioned Stimulus” (CS) that could bring forth salivation by itself. The response of salivating was called a “Conditioned Response” (CR).

Elements of Classical Conditioning:

Pavlov identified several key elements that must be present for conditioning to take place. Following are the key elements:
Unconditioned Stimulus (US): It is the original naturally occurring stimulus which leads to reflex or involuntary response. In case of Pavlov’s dogs, food is the unconditioned stimulus.
Unconditioned Response (UR): It is the reflex response to the unconditioned stimulus. In case of Pavlov’s experiment, salivation to food is the unconditioned response.
Conditioned Stimulus (CS): Pavlov determined that almost any kind of stimulus could get associated with the unconditioned stimulus. In case of Pavlov’s experiment, bell was the neutral stimulus because it had no effect on salivation. After being paired with food, so many times, the bell came to produce the same salivation response. The neutral stimulus can now be called conditioned stimulus.
Conditioned Response: It is a learned response to the previously neutral stimulus that has changed into conditioned stimulus. In case of Pavlov’s experiment, the salivation on hearing the sound of bell is conditioned response.

Other Processes in Classical Conditioning:

Generalization: Pavlov discovered that if an animal is conditioned to salivate at the sound of a bell, it would salivate at the sound of a buzzer. The dog tended to generalize the conditioned response to other stimuli that were somewhat similar to the original conditioned stimulus. This process is called generalization, because the conditioned response of salivation generalized or occurred in the presence of similar stimuli.
Discrimination: It is the process of learning to make one response to one stimulus and a different response or no response to another stimulus. Pavlov could also teach the dogs discrimination; Pavlov trained the dogs to respond to one tone, but not to respond to other tones that are similar. Pavlov did so by making sure that food always followed only one tone, and not any others.
Extinction: It occurs when a conditioned stimulus (for example, bell) is presented repeatedly, but is not followed by the unconditional stimulus (such as, food). Then, the conditioned response (salivation) gradually fades away and finally it extinguished and disappears altogether. A response is set to be forgotten over time when there is no explicit procedure involved.