In 2009, the journal Experimental and Clinical Psychopharmacology published a study that investigated changes in brain activity in response to smoking-related images immediately before quitting smoking and after an extended period of smoking abstinence.
The authors of this study recruited 13 tobacco addicted participants. While they were shown smoking-related and neutral images, the participants brain activity was measured with a fMRI. There brain activity was measured twice: at one session immediately before quitting smoking and again after an average of 52 days of tobacco abstinence.
According to the authors, during the first brain scan,
Smokers exhibited significantly greater fMRI reactivity to smoking-related versus neutral images in a number of brain areas. These included the frontal, anterior cingulate, posterior cingulate, temporal, parietal, and occipital cortex, and cerebellum.
These areas of the brain are associated with emotional processing, decision-making, and motor behavior.
After abstaining from tobacco from an extended period of time, brain activity in this regions did not decrease in response to smoking-related images. In fact, as the authors explain, in some areas of the brain, there was increased activity,
During extended smoking abstinence subjects exhibited significantly greater fMRI activation to smoking versus neutral images in prefrontal, anterior and posterior cingulate, temporal, and parietal cortex, as well as in caudate nucleus. Those regions are known to be involved in action planning, habit learning, and craving.
Reference:
Janes, A.C., Frederick, B.D., Richardt, S., Burbridge, C., Merlo-Pich, E. Renshaw, P.F., Evins, A.E., Fava, M. & Kaufman, M.J. (2009). Brain fMRI reactivity to smoking-related images before and during extended smoking abstinence. Experimental and Clinical Psychopharmacology, Vol. 17, No 6: 365–373.