FRIDAY, June 10, 2011 (HealthDay News) -- People have a difficult time ignoring objects that seem rewarding but really aren't important, a finding that could help lead to new treatments for addiction, obesity and attention deficit hyperactivity disorder (ADHD), according to researchers.
A team of neuroscientists at Johns Hopkins University found that people who were asked to complete a visual search task were distracted when they saw items that had previously been associated with small amounts of money.
The results, published this week in the journal Proceedings of the National Academy of Sciences, may help improve understanding about how the brain responds to rewarding stimuli.
In the study, participants were asked to search for red or green circles on a computer screen that showed circles in multiple colors. One color (for example, red) was always followed by a monetary reward (10 cents) while the other (green) was associated with a smaller reward.
After searching for one hour, participants were asked to hunt instead for certain shapes instead of colors.
When the screen showed a red or green object while participants did this task, they weren't as quick at identifying the correct shape because they were distracted by the red or green object previously associated with reward, researchers said.
"It was clear to us that those red or green items had become valuable to the study subjects, because they were linked in their minds with a reward," study team leader Steven Yantis, a professor and chair of psychological and brain sciences, said in a Hopkins news release.
Participants also completed a questionnaire measuring impulsivity. Those who were more impulsive were also more easily distracted, the study found.
"We know that not everyone who takes drugs becomes addicted to them, but we also recognize that there is some connection between the euphoria that the drugs cause and how that sensation 'rewires' the brain in ways that make it difficult to suppress the craving to experience that again," Yantis said.
"One aspect of this scenario is how reward-related objects capture attention automatically in the way that a sign advertising happy hour at a bar might snag the attention of a recovering alcoholic driving by. Understanding the psychological and brain mechanisms of that reward-object pairing and why some people are more susceptible to it than others could lead to more effective treatments," he explained.
The U.S. National Institutes of Health has more about the science of addiction.