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April 28, 2009

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Enforcer of conformity: our own brains

Jan. 14, 2009
Courtesy Cell Press
and World Science staff

Although a grammatically chal­lenged ad­vert­ise­ment ex­horts us to “think dif­fer­ent,” most of us tend to look to group op­in­ion to guide our own ideas and act­ions. This tend­ency is called con­form­ity. Now, sci­en­tists say they have found the brain ac­ti­vity un­der­ly­ing this sort of herd men­tal­ity.

“We of­ten au­to­mat­ic­ally ad­just our opin­ion in line with the ma­jor­ity opin­ion,” ob­served Va­sily Klu­char­ev of the F.C. Don­ders Cen­ter for Cog­ni­tive Neu­roimag­ing in The Neth­er­lands, lead au­thor of the study pub­lished in the Jan. 15 is­sue of the re­search jour­nal Neu­ron.

Klucharev and col­leagues scanned brain ac­ti­vity in peo­ple whose in­i­tial judg­ments of the attrac­tiveness of faces were open to in­flu­ence by group opin­ion. They ex­am­ined two brain ar­eas called the the ros­tral cin­gu­late zone and the nu­cle­us ac­cum­bens. The first is thought to play a role in mon­i­tor­ing be­hav­ior­al out­co­mes, the sec­ond in the an­ti­cipa­t­ion and pro­cess­ing of re­wards and in so­cial learn­ing.

The study au­thors found that a con­flict with the group opin­ion led sub­jects to change their own rat­ing of a face. The con­flict al­so elicited a re­sponse in the brain si­m­i­lar to one found in pre­vi­ous stud­ies, and known as “pre­dic­tion er­ror” sig­nal. It comes from a dif­fer­ence be­tween ex­pected and ob­tained out­co­mes and is thought to point an or­gan­ism to a need for a be­hav­ior­al change.

Fur­ther, the mag­ni­tude of the in­di­vid­ual con­flict-related sig­nal in the nu­cle­us ac­cum­bens cor­re­lat­ed with dif­fer­ences in con­forming be­hav­ior, the group found. The re­search­ers em­ployed the widely used brain-scanning tech­nique func­tion­al mag­net­ic res­o­nance im­ag­ing.

“Our re­sults al­so show that so­cial con­form­ity is based on mech­a­nisms that comply with re­in­force­ment learn­ing,” Klu­char­ev said. Conformity “is re­in­forced by the neu­ral error-mon­i­tor­ing ac­ti­vity which sig­nals what is prob­ab­ly the most fun­da­men­tal so­cial mis­take—that of be­ing too dif­fer­ent from oth­ers.”

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New research reveals the brain activity that underlies conformity, our tendency to act like other people, scientists say. “We often automatically adjust our opinion in line with the majority opinion,” noted Vasily Klucharev of the F.C. Donders Center for Cognitive Neuroimaging in The Netherlands, lead author of the study published in the Jan. 15th issue of the research journal Neuron. Klucharev and colleagues scanned brain activity in people whose initial judgments of the attractiveness of faces were open to influence by group opinion. They examined two brain areas called the the rostral cingulate zone and the nucleus accumbens. The first is thought to play a role in monitoring behavioral outcomes, the second in the anticipation and processing of rewards and in social learning. The study authors found that a conflict with the group opinion led subjects to change their own rating of a face. The conflict also elicited a response in the brain similar to one found in previous studies, and known as “prediction error” signal. It comes from a difference between expected and obtained outcomes and is thought to point an organism to a need for a behavioral change. Further, the magnitude of the individual conflict-related signal in the nucleus accumbens correlated with differences in conforming behavior across subjects, the group found. The researchers employed the widely used brain-scanning technique functional magnetic resonance imaging. “Our results also show that social conformity is based on mechanisms that comply with reinforcement learning and is reinforced by the neural error-monitoring activity which signals what is probably the most fundamental social mistake—that of being too different from others,” Klucharev said.