January 19, 2011
Smoking In Films Excites Smokers Brains
Scientists have found that simply watching movie stars take a drag on a cigarette is thought to make cravings more intense for those who are trying to quit a habit that kills 5 million people worldwide each year.
The researchers scanned the brains of smokers and non-smokers while they watched film stars puff on a cigarette. The scans showed that specific parts of the brain went into action, but only if the person was a smoker. The particular brain areas were involved in planning and coordinating movements in the person's smoking hand "“ as if the brain were preparing itself for the physical actions required for smoking.
Brain circuits that dealt with urges and rewards also flickered into life when smokers saw actors light up on screen.
The work provides fresh insight into the challenge smokers face when they try to quit, but so far there is no good evidence that watching movies that contain smoking scenes actually reduces a person's chances of kicking the habit.
The finding, reported in the Journal of Neuroscience, builds on previous research that found smokers were more likely to fancy a cigarette after watching films that included smoking scenes.
"When a smoker sees someone smoking, their brain seems to simulate the movements they would make if they were having a cigarette themselves," Todd Heatherton at the Centre for Social Brain Sciences at Dartmouth College in New Hampshire told The Guardian.
At the end of the study, it was the smokers who had the most active reward circuits who said they craved a cigarette the most.
"In our daily lives we constantly get impulses to do things and often we don't know where they come from. If we can identify how something like a movie can affect us, then perhaps it will at least help us deal with it," Heatherton told the Guardian's Ian Sample.
Heatherton, along with graduate student Dylan Wagner, invited 17 smokers and 17 non-smokers to watch the first half hour of the 2003 Ridley Scott film Matchstick Men while their brains were scanned by functional magnetic resonance imaging. The researchers chose the film because it features smoking prominently, but lacks scenes of sex, violence and alcohol use.
When the subjects - who were unaware that smoking was the subject of the study - viewed smoking scenes, they showed greater brain activity in a part of the parietal lobe called the intraparietal sulcus, as well as other areas involved in the perception and coordination of actions. In the smokers' brains specifically, the activity corresponded to the hand they use to smoke.
"Smokers trying to quit are frequently advised to avoid other smokers and remove smoking paraphernalia from their homes, but they might not think to avoid a movie with smoking content," Wagner said. The US Centers for Disease Control and Prevention has warned that exposure to onscreen smoking in movies makes adolescents more likely to smoke.
According to their 2010 report, tobacco use in films has decreased in recent years, but about half of popular movies still contained tobacco imagery in 2009, including 54 percent of those rated PG-13.
Scott Huettel, PhD, of Duke University, an expert in the neuroscience of decision-making who was unaffiliated with the study, said scientists have long known that visual cues often induce drug cravings. "This finding builds upon the growing body of evidence that addiction may be reinforced not just by drugs themselves, but by images and other experiences associated with those drugs," Huettel told the Guardian.
Last year, the US Centers for Disease Control and Prevention warned that smoking scenes in movies made adolescents more likely to smoke, although smoking scenes have become less common in recent years, around half of popular movies included smoking in some form in 2009, the organization said.
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