Researchers at the Montreal Neurological Institute and McGill University scanned the brain of 20 healthy smokers who were randomly divided into one of two groups: "expectant" -- they could smoke right after the test or "non-expectant" -- they could only smoke four hours after the test.
The researchers scanned the brains of each subject to pinpoint the areas that were active while the subjects were exposed to visual smoking cues through videotaped footage of people lighting cigarettes, smoking while socializing or blowing smoke rings.
In the group who expected to smoke immediately after the test, areas of the brain implicated in arousal, attention and cognitive control were activated. In the subjects who could only smoke four hours after the test, there was almost no neural response to smoking cues, even if the subject reported an equivalent craving level, according to Dr. Alain Dagher, a neurologist who specializes in functional brain imaging.
The findings were published in the journal Neuropsychopharmacology.