Ivan Pavlov and Classical Conditioning
Ivan Pavlov (1849 – 1936) was a Russian scientist whose work with dogs has been influential in understanding how learning occurs (Figure 1). Through his research, he established the theory of classical conditioning.
The most well-known of his experiments involves the study of the salivation of dogs. Pavlov was originally studying the saliva of dogs as it related to digestion, but as he conducted his research, he noticed that the dogs would begin to salivate every time he entered the room - even if he had no food. The dogs were associating his entrance into the room with being fed. This led Pavlov to design a series of experiments in which he used various sound objects, such as a buzzer, to condition the salivation response in dogs.
He started by sounding a buzzer, or stimulus, each time food was given to the dogs, and found that the dogs would start salivating immediately after hearing the buzzer even before seeing the food. After a period of time, Pavlov began sounding the buzzer without giving any food at all, and found that the dogs continued to salivate at the sound of the buzzer even in the absence of food. They had learned to associate the sound of the buzzer with being fed. Pavlov has successfully associated an unconditioned response (salivation in response to food) - which had originally been linked to an unconditioned stimulus (food) - with a conditioned stimulus (a buzzer), eventually creating a conditioned response (salivation in response to a buzzer). With these results, Pavlov established his theory of classical conditioning.
Behaviorism and other research
Pavlov's research led to a large number of other studies and theories in behaviorism, which is an approach to psychology interested in observable behaviors rather than the inner workings of the mind. The philosopher Bertrand Russell argued that Pavlov's work was an important contribution to a philosophy of mind. His research also contributed to Hans Eysench’s personality theory of introversion and extroversion. Eysench built upon Pavlov’s research on dogs, hypothesizing that the differences in arousal that the dogs displayed was due to inborn genetic differences. Eysench then extended the research to human personality traits.
Pavlov’s research further led to the development of important behavior therapy techniques, such as flooding and desensitizing, for individuals who have fear and anxiety. Desensitizing is a kind of reverse conditioning, where an individual is repeatedly exposed to the thing that is causing the anxiety. Flooding is similar in that it exposes an individual to the thing causing the anxiety, but in a more intense and prolonged way.