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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.

A di­a­gram of a cross-sec­tion through the mid­dle of the hu­man brain, as shown from the per­spec­tive of some­one who would be look­ing at the right side of a per­son's head. The pur­ple and green lines mark ma­jor path­ways where the neu­ro­trans­mitter dopamine flows. The pur­ple lines, in par­tic­u­lar, show where dopamine is be­lieved to have a reward-related func­tions. One of the stops along these path­ways is the ven­tral stria­tum, point­ed out with a straight black line com­ing from the right side of the im­age. (Cour­tesy Open Uni­ver­sity, U.K.)
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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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, which suggests trying out the unknown offered advantages to our evolutionary ancestors. It may also explain, they added, why re-branding of familiar products encourages to pick them off the supermarket shelves. Researchers showed volunteers a selection of cards with images they had already seen. Each was associated with a specific chance of a reward. Participants were allowed to choose some images in hopes of 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. Using brain scanners that measure blood flow in the brain to highlight which areas are most active, Bianca Wittmann of University College London and colleagues found that when the subjects selected an unfamiliar option, an area of the brain known as the ventral striatum lit up. The primitivity of this brain region suggests adventure-seeking is a common to animals 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 that 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 cannot say definitively from the scans how novelty seeking is being rewarded, Wittmann said it’s probably through dopamine release. 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 said. 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, which utilized the brain-scanning technique known as functional magnetic resonance imaging, is reported in the June 25 issue of the research journal Neuron.