Sensitization is a learning process wherein we become sensitive to pain, sound, smell, and other senses. It is a basic type of non-associative learning (i.e. learning that some events are irrelevant or not connected to one another). While sensitization is a good adaptive learning process of an organism, it can also lead to maladaptive process when the organism is “sensitized” with harmful stimuli.
When you rub your arms continuously, you will feel a warm sensation due to the repeated stimulation of the peripheral nerves located in your arms. However, after some time this warm sensation would turn into a painful feeling, so your brain would warn you that rubbing your arms vigorously for a long time would be harmful and painful for you. This is scenario is an example of sensitization.
The concept of sensitization holds that there is a particular cellular receptor that is expected to respond to a stimulus. Once stimulation occurs, that cellular receptor is to transmit information to and from the brain via the peripheral nerves, resulting to sensitization.
In the year 2000, Eric Kandle won the Nobel Prize in Physiology because he was the first researcher to study the neuronal learning process involving sensitization from 1960 to 1970s.
Sensitization is a useful model in studying the underlying causes of pathologies such as asthma, substance dependence, allergies, pain-related illnesses, psychological disorders, etc. Now, there are different types of sensitization therapies not only utilized for medical purposes (allergies, cancer and other tumors) but also for marriage counseling and family psychotherapy.