The reflexes which we have considered so far are inborn or inherited, a particular stimulus always producing the same response. However, a great many reflexes which we carry out daily are not inborn but are acquired from past experiences or learning. For example, the sight of a pineapple may not cause salivation in a boy who sees it for the first time. But after he has tasted pineapples several times and found that they are all sour, the mere sight of a pineapple may result in the secretion of saliva. Sometimes, just the mention of the words "sour pineapples" alone may produce the same response. Such a reflex action acquired from past experience or learning with a stimulus which is originally ineffective in producing the response is called a conditioned reflex action.
A well known experiment was performed by Pavlov, a Russian physiologist, on conditioned reflexes. Normally salivation is a simple reflex; it is the response to food coming in contact with the taste buds in the tongue. Pavlov experimented with dogs. Every time the dogs were fed they salivated, and every time the food was given he rang a bell. After a certain period he found that the ringing of the bell alone caused salivation in the dogs.
A well known experiment was performed by Pavlov, a Russian physiologist, on conditioned reflexes. Normally salivation is a simple reflex; it is the response to food coming in contact with the taste buds in the tongue. Pavlov experimented with dogs. Every time the dogs were fed they salivated, and every time the food was given he rang a bell. After a certain period he found that the ringing of the bell alone caused salivation in the dogs.
