Brain imaging demonstrates that former smokers have greater willpower

(Press-News.org) London - 26 April, 2011 – A study, completed by researchers from Trinity College and the Research Institute for a Tobacco Free Society, Dublin, Ireland, compares former smokers to current smokers, and obtains insight into how to quit smoking might be discovered by studying the brains of those who have successfully managed to do so.

Functional MRI images were obtained while current smokers, former smokers and never smokers performed tasks designed to assess specific cognitive skills that were reasoned to be important for smoking abstinence. These included a response inhibition task to assess impulse control and the ability to monitor one's behavior and an attention task which assessed the ability to avoid distraction from smoking-related images, which tend to elicit an automatic attention response in smokers.

The investigators found that when doing these tasks, the current smokers compared to the never-smokers showed reduced functioning in prefrontal regions that are related to controlling behavior. In addition, the current smokers showed elevated activity in sub-cortical regions such as the nucleus accumbens that respond to the reward value or salience of the nicotine stimuli. However, in marked contrast, the former smokers did not show this sub-cortical activity, but instead showed increased activity in the frontal lobes – the areas that are critically involved in controlling behavior. Moreover, the former smokers were "super-normal", showing greater levels of activity in these prefrontal regions than the never-smokers.

The implication is that the brain regions responsible for what might be considered "willpower" show more activity in those who have quit smoking. This type of willpower can be measured, can be related to specific brain regions, and would appear to be related to being able to quit cigarettes. These results reinforce the value of smoking cessation therapies that stress the importance of, or that help to train, the cognitive skills involved in exercising control over drug desires.

### "Differences in "bottom-up" and "top-down" neural activity in current and former cigarette smokers: Evidence for neural substrates which may promote nicotine abstinence through increased cognitive control" (Liam Nestor, Ella McCabe, Jennifer Jones, Luke Clancy, & Hugh Garavan) is published in NeuroImage http://dx.doi.org/10.1016/j.neuroimage.2011.03.054

Notes to Editors The research, published in NeuroImage, was completed by Professor Hugh Garavan, Dr. Liam Nestor and colleagues at Trinity College, Dublin, Ireland and the Research Institute for a Tobacco Free Society, Dublin, Ireland.

The work was funded by the Royal City of Dublin Hospital Trust, Dublin, Ireland.

About Trinity College (TCIN) - Dublin TCIN, founded in 2002, is based in Trinity College's Lloyd Institute where it operates in over 3,300 m2 of state-of-the-art research facilities that allow it to realise its 'molecules to mind' research mission. TCIN hosts approximately 45 Principal Investigators and their research groups from the disciplines of genetics, physiology, biochemistry, immunology, pharmacology, neurology, psychiatry, gerontology, psychology, engineering and physics, thereby enabling a novel multidisciplinary approach. Established in 1592, Trinity College Dublin is ranked in 52nd position in the top 100 world universities and 14th position in the top 200 European universities by the QS World University Rankings 2010. In the Times Higher Education World University Rankings for 2010 TCD is ranked 76th in the top 200 world universities and 15th in the top European universities.

About NeuroImage NeuroImage, A Journal of Brain Function, provides a vehicle for communicating important advances, using imaging and modelling techniques to study structure-function relationships in the brain. The focus of NeuroImage is on brain systems; however, we are happy to consider papers dealing with structure and function at the microscopic level; if they inform the systems level. The main criterion, on which papers are judged, is to what extent does the scientific contribution advance our understanding of the mechanisms of brain function and how this function depends upon its structure and architecture. These mechanisms may operate in health and disease; therefore, NeuroImage welcomes clinical neuroscience papers that are framed to address mechanisms explicitly. The journal publishes original research articles, papers on methods or modelling, theory and position papers that describe the use of imaging approaches to studying the brain.

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