The links produced between the drug and various environmental stimuli have been gradually learned by the brain, even without the knowledge of its owner, during the whole phase described as addictive: we then speak of conditioned reflexes.
In contrast to simple reflexes such as the patellar reflex, which do not involve the higher brain centers, these established associations between drugs and sensory experiences are related to more complex learning involving different brain structures.
In Pavlov's experience, the dog gets a workout. The effect of the sensory stimulus (1), the food, and the neutral stimulus (2), the bell, is tested separately for their effects on the animal. Once the preliminary results have been obtained, the conditioning stimulus (1) is associated with the neutral stimulus (2) in a repetitive manner. If conditioning succeeds - the animal memorizes the link between the two stimuli - the neutral stimulus alone (2) becomes conditioned and has the same physiological effects as the conditioning stimulus (1). This process of conditioning is also at work in addict addiction.
This process of conditioning happens to everyone in different areas and allows the memory of many associations more or less simple. The use of drugs, which is usually accompanied by a sense of well-being, is the perfect example: the individual feels better when he knows he has his product on hand and be able to use when he wants
