From Science:
Cigarette smokers who suffer damage to a particular brain region often lose the urge to smoke, according to a new study. Although brain damage is hardly a recommended treatment for smokers who want to quit, researchers say the findings provide important insight into the biological basis of addictive behaviors.
Previous research on addiction has implicated the insula, a brain region tucked into a deep fold in the cerebral cortex. In brain scans of cocaine addicts, for example, the insula lights up in response to images of drug paraphernalia. Those kinds of images also tend to give addicts an urge to take more drugs. Similarly, videos of people smoking stimulate the insula in smokers’ brains. Such work suggests that the insula helps generate addicts’ drug-related urges. So what would happen if the insula suddenly went offline?
Antoine Bechara, a neuroscientist at the University Southern California in Los Angeles, and colleagues investigated this question in 19 cigarette smokers who had suffered insula damage as a result of a stroke or other neurological problem. Twelve of these people stopped smoking immediately after their brain injury and reported feeling no urges to smoke and no relapses since they quit. “My body forgot the urge to smoke,” one man told the researchers. Before his stroke he was smoking 40 unfiltered cigarettes a day and had no intention of quitting.
More here.