Brain works towards getting rewards

Washington: Rewards can attract brain waves. A study reveals that brains get distracted automatically by some objects if they are once associated with rewards.

Researchers from Johns Hopkins University found that participants who were completing a visual search task were distracted when items that had been associated with small amounts of money occasionally appeared.

The findings have implications for understanding how the brain responds to rewarding stimuli, which may contribute to the development of more effective treatments for obesity
and drug addiction in which sufferers cannot resist their cravings for the pleasure, or rewards, they get from eating or taking drugs, the researchers said.

Steven Yantis, who led the study, said: "We know that not everyone who takes drugs becomes addicted to them, but we also recognise 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.

"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."

In the study, published in the Proceedings of the National Academy of Sciences, the participants first searched for red or green circles in an array of many differently coloured circles displayed on a computer screen.

One colour (for instance, red) was always followed by a monetary reward (10 cents) and the other (perhaps green) by a smaller reward (1 cent).

After doing this for more than an hour, the study subjects then were asked to search for particular shapes (for instance, a circle among diamonds) and colour was no longer relevant or rewarded.

Still, occasionally, one of the items in the display was red or green. When that happened, the study subjects' responses slowed down.

According to Yantis, this proved that an overwhelming number of people in the study became distracted by the red or green objects, even though they had been instructed to ignore those items and the items were inconspicuous and had no relevance to the task at hand.

"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," Yantis said.

"We think that this form of attentional capture may play a role in various clinical syndromes like drug addiction."