Classical Conditioning

Since Pavlov's time in the beginning of this century, research on classical conditioning has increased to a complexity level that is hardly comprehensible but to a few experts in the various fields this science has spawned. On the neurobiological side, research has come to a point where the molecular events can be traced that lead to the long lasting modification of the synapses responsible for the learning behavior in the animal. On the systemic side, psychologists have devised a plethora of behavioral experiments, the sophistication of which has steadily increased over the decades.

Pavlov's Discovery Of Classical Conditioning

Ivan P. Pavlov(1849-1936) is generally creditied with the discovery of classical conditioning(also called Pavlovian conditioning). This great Russian scientist was awarded the Nobel prize in 1904 for his work on the physiology of digestion. 
In his laboratory he used dogs as subjects. Pavlov develped a research program to investigate the parameters of the salivary reflex in dogs. He planned a number of experiments to try to understand the stimulus-response relationship between food and salivation. 

Work with new dogs went as expected at first. The animal was confined in a harness. Food was presented, and the salivation response was measured. However, with experience, dogs salivated at the sight of the harness apparatus. Sometimes in their home cage they salivated at the sight of a laboratory assistant. Pavlov realized that these salivary responses had been been learned. He proceeded to study this type of learning, and in 1927 reported his findings in a lengthy book entitled Conditioned Reflexes.