Pavlov and his dogs

Pavlov and his dogs - Pavlov studied the effect of outside stimuli on body processes. His most famous experiment involved the salivation reflex in dogs. The salivation reflex is an involuntary, natural body process that occurs when food is in someone’s or something’s mouth. In his experiment, he tried to create the salivation reflex in the dogs when they did not have food in their mouths. To accomplish this, he would turn on a metronome and then give the dogs food he was studying. Naturally, because food was in their mouths, they would salivate. However, after doing this for a while, when he would turn on the metronome, the dogs would salivate even though they were not eating and there was no food in front of them. This is an example of conditioning.

Like many great scientific advances, Pavlovian conditioning, aka classical conditioning, was discovered accidentally. Ivan Petrovich Pavlov (1849–1936) was a physiologist, not a psychologist. During the 1890s, Pavlov researched salivation in dogs in response to being fed. He inserted a small test tube into the cheek of each dog to measure saliva. When the dogs were fed with a powder made from meat, Pavlov predicted the dogs would salivate in response to the food in front of them. But he noticed that his dogs would begin to salivate whenever they heard the footsteps of his assistant who was bringing him the food.

When Pavlov discovered that any object or event that the dogs learned to associate with food, such as the lab assistant, would trigger the same response, he realized that he had made an important scientific discovery. Accordingly, he devoted the rest of his career to studying this type of learning.

Table of contents:

Pavlovian conditioning — theory of learning.

Pavlov's theory of learning, known as classical conditioning or Pavlovian conditioning, posits that behaviors can be learned through the association between different stimuli. Classical conditioning, later developed by Watson in 1913, involves learning to associate an unconditioned stimulus that already brings about a particular response—a reflex—with a new conditioned stimulus, so that the new stimulus brings about the same response.

Pavlov developed some rather technical terms to describe this process:

• Neutral Stimulus (NS): A stimulus that initially does not elicit a particular response or reflex action. In other words, before any conditioning takes place, the neutral stimulus has no effect on the behavior or physiological response of interest. For example, in Pavlov’s experiment, the sound of a metronome was a neutral stimulus initially, as it did not cause the dogs to salivate.

• Unconditioned Stimulus (UCS): This is a stimulus that naturally and automatically triggers a response without any learning needed. In Pavlov’s experiment, the food was the unconditioned stimulus, as it automatically induced salivation in the dogs.

• Conditioned Stimulus (CS): This is a previously neutral stimulus that, after being repeatedly associated with an unconditioned stimulus, comes to trigger a conditioned response. For instance, in Pavlov’s experiment, the metronome became a conditioned stimulus when the dogs learned to associate it with food.

• Conditioned Response (CR): This is a learned response to the conditioned stimulus. It typically resembles the unconditioned response but is triggered by the conditioned stimulus instead of the unconditioned stimulus. In Pavlov’s experiment, salivating in response to the metronome was the conditioned response.

• Unconditioned Response (UCR): This is an automatic, innate reaction to an unconditioned stimulus. It does not require any learning. In Pavlov’s experiment, the dog’s automatic salivation in response to the food is an example of an unconditioned response.

Pavlov's dog experiment (1902) started from the idea that there are some things a dog does not need to learn. For example, dogs don’t learn to salivate whenever they see food; this reflex is hardwired into the dog. Pavlov showed that dogs could be conditioned to salivate at the sound of a bell if that sound was repeatedly presented at the same time that they were given food.

Pavlov and his studies of classical conditioning have become famous since his early work between 1890 and 1930. Classical conditioning is “classical” in that it is the first systematic study of the basic laws of learning, also known as conditioning. So, the dog had learned an association between the metronome and the food, and a new behavior had been learned. Because this response was learned or conditioned, it is called a conditioned response, also known as a Pavlovian response. The neutral stimulus had become a conditioned stimulus.

Temporal contiguity:

Pavlov found that for associations to be made, the two stimuli had to be presented close together in time, such as a bell and food. He called this the law of temporal contiguity. If the time between the conditioned stimulus (bell) and the unconditioned stimulus (food) is too large, then learning will not occur.

Extinction:

In extinction, the conditioned stimulus (the bell) is repeatedly presented without the unconditioned stimulus (the food). Over time, the dog stops associating the sound of the bell with the food, and the conditioned response—salivation—weaken and eventually disappears. In other words, the conditioned response is unconditioned or extinguished.

Spontaneous recovery:

Pavlov noted the occurrence of spontaneous recovery, where the conditioned response can briefly reappear when the conditioned stimulus is presented after a rest period, even though the response has been extinguished. This discovery added to the understanding of conditioning and extinction, indicating that these learned associations, while they can fade, are not completely forgotten.

Generalization:

The principle of generalization suggests that after a subject has been conditioned to respond in a certain way to a specific stimulus, the subject will also respond in a similar manner to stimuli that are similar to the original one. In Pavlov’s famous experiments with dogs, he found that after conditioning dogs to salivate at the sound of a bell paired with food, the dogs would also salivate in response to similar sounds like a buzzer. This demonstrated the principle of generalization in classical conditioning.

However, the response tends to be more pronounced when the new stimulus closely resembles the original one used in conditioning. This relationship between the similarity of the stimulus and the strength of the response is known as the generalization gradient. This principle has been exemplified in research, including a study conducted by Mutas and colleagues in 2013.

Impact of Pavlov's research:

Ivan Pavlov’s key contribution to psychology was the discovery of classical conditioning, demonstrating how learned associations between stimuli can influence behavior. His work laid the foundation for behaviorism, influenced therapeutic techniques, and informed our understanding of learning and memory processes.

Behaviorism:

Pavlov’s work laid the foundation for behaviorism, a major school of thought in psychology. The principles of classical conditioning have been used to explain a wide range of behaviors, from phobias to food aversions. Therapy techniques based on classical conditioning, such as systematic desensitization and exposure therapy, have been developed to treat a variety of psychological disorders, including phobias and post-traumatic stress disorder (PTSD). In these therapies, a conditioned response such as fear can be gradually unlearned by changing the association between a specific stimulus and its response.

Little Albert experiment:

The Little Albert experiment, conducted by John B. Watson in 1920, demonstrated that emotional responses could be classically conditioned in humans. A young child, Little Albert, was conditioned to fear a white rat, which generalized to similar objects.

Educational strategies:

Educational strategies like repetitive learning and rote memorization can be seen as applications of the principles of classical conditioning. The repeated association between stimulus and response can help reinforce learning.

Marketing and advertising:

Principles from Pavlov’s conditioning experiments are often used in advertising to build brand recognition and positive associations. For instance, a brand may pair its product with appealing stimuli like enjoyable music or attractive visuals to create a positive emotional response in consumers, which then gets associated with the product.