Researchers have shown that damage to a small but very specific brain area can wipe out an addiction to smoking.
The insular cortex is a relatively primitive part of the brain whose functions include providing an emotional context for experiences, such as drug taking, along with some higher-level, decision-making functions involved, for example, in forming memories.
Bechera's experience with these patients supports his hypothesis that addiction is caused by an imbalance between two neuronal systems -- the impulsive system controlled by a brain area (the amygdala) that helps to process emotions and a reflective system controlled by the forebrain. The reflective system anticipates and assesses the consequences, good or bad, that any action will have for the future. Most addiction research focuses on the impulsive system.