July 01, 2008
Brain region for adventurousness reported found
June 25, 2008
Courtesy Wellcome Trust
and World Science staff
Scientists have identified a brain region that they say encourages us to seek adventure.
Located in a primitive part of the brain, it's activated when we choose unfamiliar options, the researchers said. This suggests trying out the unknown offered advantages to our evolutionary ancestors, they added.
It may also explain, they went on, why re-branding of familiar products encourages to pick them off the supermarket shelves.
Researchers showed volunteers a selection of cards, each with an image the volunteers had already seen. Each image was associated with a specific chance of a reward.
Participants were allowed to choose some images over others in hopes of the prizes. As the game went on, the players could also figure out which choice would provide the highest rewards.
But when unfamiliar images were introduced, the researchers found volunteers were more likely to take a chance and pick one of these than go on with familiar—and arguably safer—options.
Bianca Wittmann of University College London and colleagues used brain scanners that measure blood flow in the brain to highlight which brain areas were most active during the game. They found that when the subjects chose a new option, an area of the brain known as the ventral striatum lit up.
The primitivity of this brain region suggests adventure-seeking is common to creatures ranging from humans to simpler animals, Wittman argued.
"Seeking new and unfamiliar experiences is a fundamental behavioural tendency," she said. "It makes sense to try new options as they may prove advantageous in the long run. For example, a monkey who chooses to deviate from its diet of bananas, even if this involves moving to an unfamiliar part of the forest and eating a new type of food, may find its diet enriched."
When we do something that turns out to be beneficial, we're rewarded with a flow of special neurotransmitters, or signaling chemicals, in the brain that create a good feeling. A key neurotransmitter associated with reward is known as dopamine. The feeling of satisfaction encourages us to repeat the advantageous behavior.
The ventral striatum is one of the key areas involved in processing such rewards, Wittman and colleagues said. Although the researchers couldn't tell from the scans how novelty seeking was being rewarded, Wittmann said it's probably through dopamine.
Our taste for adventure may also make us vulnerable to exploitation, Wittman warned. "I might have my own favourite choice of chocolate bar, but if I see a different bar repackaged, advertising its 'new, improved flavour,' my search for novel experiences may encourage me to move away from my usual choice," said Wittmann. This "old wine" in a new bottle syndrome, she added, "is something that marketing departments take advantage of."
Rewarding the brain for novel choices could have a grimmer side effect, argues Nathaniel Daw, now of New York University, who also worked on the study. "In humans, increased novelty-seeking may play a role in gambling and drug addiction, both of which are mediated by malfunctions in dopamine release."
The research utilized the brain-scanning technique known as functional magnetic resonance imaging, at the university's Wellcome Trust Centre for Neuroimaging. The findings appear in the June 25 issue of the research journal Neuron.
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