Tuesday, February 23, 2010

Culture and the brain

There's a fascinating article in Newsweek discussing how cultural differences appear to affect how individuals use their brains and cognitive facilities. Here's an extract.

... scientists have been surprised at how deeply culture—the language we speak, the values we absorb—shapes the brain, and are rethinking findings derived from studies of Westerners. To take one recent example, a region behind the forehead called the medial prefrontal cortex supposedly represents the self: it is active when we ("we" being the Americans in the study) think of our own identity and traits. But with Chinese volunteers, the results were strikingly different. The "me" circuit hummed not only when they thought whether a particular adjective described themselves, but also when they considered whether it described their mother. The Westerners showed no such overlap between self and mom. Depending whether one lives in a culture that views the self as autonomous and unique or as connected to and part of a larger whole, this neural circuit takes on quite different functions.

"Cultural neuroscience," as this new field is called, is about discovering such differences. Some of the findings, as with the "me/mom" circuit, buttress longstanding notions of cultural differences. For instance, it is a cultural cliché that Westerners focus on individual objects while East Asians pay attention to context and background (another manifestation of the individualism-collectivism split). Sure enough, when shown complex, busy scenes, Asian-Americans and non-Asian--Americans recruited different brain regions. The Asians showed more activity in areas that process figure-ground relations—holistic context—while the Americans showed more activity in regions that recognize objects.

Psychologist Nalini Ambady of Tufts found something similar when she and colleagues showed drawings of people in a submissive pose (head down, shoulders hunched) or a dominant one (arms crossed, face forward) to Japanese and Americans. The brain's dopamine-fueled reward circuit became most active at the sight of the stance—dominant for Americans, submissive for Japanese—that each volunteer's culture most values, they reported in 2009. This raises an obvious chicken-and-egg question, but the smart money is on culture shaping the brain, not vice versa.

Cultural neuroscience wouldn't be making waves if it found neurobiological bases only for well-known cultural differences. It is also uncovering the unexpected. For instance, a 2006 study found that native Chinese speakers use a different region of the brain to do simple arithmetic (3 + 4) or decide which number is larger than native English speakers do, even though both use Arabic numerals. The Chinese use the circuits that process visual and spatial information and plan movements (the latter may be related to the use of the abacus). But English speakers use language circuits. It is as if the West conceives numbers as just words, but the East imbues them with symbolic, spatial freight. (Insert cliché about Asian math geniuses.) "One would think that neural processes involving basic mathematical computations are universal," says Ambady, but they "seem to be culture-specific."

. . .

Ambady thinks cultural neuro-science does advance understanding. Take the me/mom finding, which, she argues, "attests to the strength of the overlap between self and [people close to you] in collectivistic cultures and the separation in individualistic cultures. It is important to push the analysis to the level of the brain." Especially when it shows how fundamental cultural differences are—so fundamental, perhaps, that "universal" notions such as human rights, democracy, and the like may be no such thing.

There's more at the link. Highly recommended reading.

I note Professor Ambady's last comment with particular interest. It's fascinating to note that what are described as 'self-evident truths' in the US Declaration of Independence (see the second paragraph of that document) may, in fact, not be 'self-evident' to those of other cultures. As Shakespeare said in Hamlet:

"There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy."

Sobering thought, that . . .


1 comment:

Jon said...

I've felt, for years, that the unique experience of the United States is much more than just a political experiment. It's looking like there's some hard wiring involved, which is good. I like to think of freedom and Democracy as the advantagious aspects of evolution.

Maybe that's why the United States is such a melting pot. As a hunter/gatherer species, the ultimate environment is one that allows the most advantages for survival and health. The ability to migrate to that environment may involve a yearning that is at the cellular level, and transcends ethnic differences.