The answer may be in how the brain responds to rewards, according to new research.
For their study, researchers at Pennsylvania State University (or Penn State) observed the brains of nicotine-deprived smokers with functional magnetic resonance imaging (fMRI) and found that those who exhibited the weakest response to rewards were also the least willing to not smoke, even when offered money.
“We believe that our findings may help to explain why some smokers find it so difficult to quit smoking,” said Stephen J. Wilson, Ph.D., assistant professor of psychology.
“Namely, potential sources of reinforcement for giving up smoking — for example, the prospect of saving money or improving health — may hold less value for some individuals and, accordingly, have less impact on their behavior.”
The researchers examined 44 smokers’ striatal responses to monetary rewards to not smoke.
“The striatum is part of the so-called reward system in the brain,” explained Wilson. “It is the area of the brain that is important for motivation and goal-directed behavior — functions highly relevant to addiction.”
The smokers, who were between the ages of 18 and 45, all reported that they smoked at least 10 cigarettes a day for the past 12 months. The researchers told them to abstain from smoking and from using any products containing nicotine for 12 hours before arriving for the experiment.
Each smoker spent time in an fMRI scanner while playing a card-guessing game with the potential to win money. Each was informed that they would have to wait approximately two hours, until the experiment was over, to smoke a cigarette.
Partway through the card-guessing task, half of the participants were informed that there had been a mistake, and they would be allowed to smoke during a 50-minute break that would occur in another 16 minutes.
However, when the time came for the cigarette break, the participants were told that for every five minutes they did not smoke, they would receive $1, with the potential to earn up to $10.
The researchers reported that the smokers who could not resist the temptation to smoke also showed weaker responses in the ventral striatum when offered monetary rewards while in the fMRI.
“Our results suggest that it may be possible to identify individuals prospectively by measuring how their brains respond to rewards, an observation that has significant conceptual and clinical implications,” said Wilson.
“For example, particularly ‘at-risk’ smokers could potentially be identified prior to a quit attempt and be provided with special interventions designed to increase their chances for success.”
The study was published in Cognitive, Affective and Behavioral Neuroscience.
Source: Penn State