Classical Conditioning

What is Classical conditioning

Classical conditioning (古典的條件形成, also known as respondent conditioning or Pavlovian conditioning) is a theory in behaviorist psychology. It describes the process where a previously neutral stimulus (conditioned stimulus) becomes able to evoke a response that was originally evoked only by another stimulus (unconditioned stimulus) through repeated association.

 

In particular, it explains how a new conditioned reflex response can be formed through learning, even though the response and corresponding stimulus are not innate instincts. This was first demonstrated by Russian physiologist Ivan Pavlov through experiments involving dogs. His research challenged the predominant late 19th-century academic view that the mind cannot be a scientific subject because it is not material, and contributed to the differentiation of psychology from philosophy, aiding the establishment of an independent academic discipline. This had an influence on behaviorist psychology.

 

 

Conditioning and Response

The innate responses an organism naturally possesses are termed the unconditioned response (UR), while the stimulus that elicits this response is termed the unconditioned stimulus (US). A stimulus that does not elicit an unconditioned response is called a neutral stimulus (NS), and the response elicited by the neutral stimulus is referred to as the conditioned response (CR). When a neutral stimulus is repeatedly paired with an unconditioned stimulus, the neutral stimulus alone can eventually elicit the conditioned response. This process is known as "classical conditioning."

 

Procedure

According to Ivan Pavlov, conditioning allows for modification of behavior. Conditioning refers to the process by which a neutral stimulus that typically would not cause a specific response (a neutral stimulus or NS) is made to do so by pairing it with a stimulus that already produces the response (an unconditioned stimulus or US). Once conditioning has occurred, the neutral stimulus becomes a conditioned stimulus (CS), and the response evoked by the conditioned stimulus is called a conditioned response (CR).

 

 

For example, a dog may naturally salivate when presented with food (US), a response called the unconditioned response (UR). A bell may be rung without causing any reaction. However, if the bell is repeatedly rung just before the dog is presented with food, the dog may learn to associate the bell with food and begin to salivate in response to the bell alone. In this case, the bell becomes a conditioned stimulus (CS), and salivating in response to the bell becomes a conditioned response (CR). This is also considered classical conditioning.

 

The reason classical conditioning occurs is that an organism comes to expect that a conditioned stimulus (CS) will soon be followed by an unconditioned stimulus (US). In other words, it interprets the conditioned stimulus as a signal that an unconditioned stimulus is about to be presented. This is the basic principle behind classical conditioning.

 

Second-order Conditioning

Secondary Conditioning A conditioned stimulus was originally a neutral stimulus that could not elicit a response. However, after conditioning has taken place, it is able to elicit a response in the same way as an unconditioned stimulus. This is known as secondary conditioning. In secondary conditioning, a conditioned stimulus that has undergone conditioning can itself serve as a stimulus in further conditioning processes. For example, in Ivan Pavlov's experiments with dogs, once conditioning has occurred, showing a blue light along with the conditioned tone may cause the dog to salivate in response to the blue light alone.

 

Such a phenomenon is called secondary conditioning, and conditioning beyond this level is called higher-order conditioning, such as tertiary conditioning or quaternary conditioning. However, it is difficult for higher-order conditioning to occur realistically. In such high-order conditioning, conditioned stimuli are provided one after another, and extinction occurs because food is not provided.