Brain: Our Culture Influences How Our Brains Function

From Denny: This is the first time a brain imaging study about this question of culture has been done. It was reported in the Psychological Science January 2008 issue.

What did the MIT researchers find?

People from different cultures around the world actually use their brains differently to solve the same visual perceptual tasks.

What are the differences in the cultures?

American culture values greatly the individual which in turn “emphasizes the independence of objects from their contexts.”

Asian cultures “emphasize the collective and the contextual interdependence of objects.”

Studying an impersonal brain scan is far different than behavioral studies researchers have done. Behavioral studies learned that memory and perception can be influenced by cultural differences. What scientists wanted to know: But can this be proven in brain activity patterns?

The Study

Organizing the team was John Gabrieli, professor at the McGovern Institute for Brain Research at MIT. It was a very small study of 10 East Asians recently arrived in the USA (I guess so they would not be tainted by their now new culture) and 10 Americans. Researchers asked the subjects to make quick perceptual judgments while they were being scanned in an fMRI (Magnetic Resonance Imaging). An fMRI is a new technology that while a person’s brain is responding to a test, this machine starts mapping the blood flow changes in the brain, corresponding to the brain’s responses.

What were those mental tasks?

They were abstract stimuli like lines within squares. People were shown a progression of this kind of stimuli and then asked to compare to the last one given. In some of these trials, people were being asked for an absolute judgment of individual objects that were independent of context. Researchers accomplished this by asking if the lines were the same length regardless of the surrounding squares.

In other trials, researchers were looking for relative judgment of interdependent objects. They accomplished this by asking people to decide whether the lines were in the same proportion to the squares, regardless of absolute size.

What happened during these tests?

Different brain activation patterns were present for these two groups when performing these tasks. Apparently, Americans find it more difficult to make relative judgments. What happened to them is that these tasks activated the brain regions involved in attention-demanding mental tasks. Americans fared better in more culturally familiar absolute judgments and there was less activation of these regions.

East Asians proved to show the opposite tendency. They had to engage the attention-demanding part of their brains more so for making absolute judgments. Relative judgments were easier for them.

Trey Hedden was a lead author of the paper and also a researcher scientist at McGovern. Hedden remarked, “We were surprised at the magnitude of the difference between the two cultural groups, and also at how widespread the engagement of the brain’s attention system became when making judgments outside the cultural comfort zone.”

What else did they find that was significant?

The effect was greater in individuals who identified more closely with their culture. It was shown that a stronger cultural association presented a culture-specific pattern of brain-activation. A bit of how researchers went about being able to identify this was by the use of questionnaires. They asked about preferences and values in social relations – like do you think an individual is responsible for the failure of a family member? This helped gauge cultural identification.

Researchers have long wondered how these differences came to be

Gabrieli thinks, “Everyone uses the same attention machinery for more difficult cognitive tasks. They are trained to use it in different ways. It’s the culture that does the training. It’s fascinating the way the brain responds to these simple drawings, reflects, in a predictable way, how the individual thinks about independent or interdependent social relationships.”

Summary

Society does affect our brains; that much is established both in behavioral and now brain scan studies. Perhaps we need to be careful what we teach…

Brain: The Technology of Mind Reading

Animation of an MRI Brain Scan Image via Wikipedia

From Denny: Published last fall in Nature - and their academic snooze writing decoded by Psychology Today - come most curious findings from an fMRI study of human brain activity. It seems science is on the outside edges of being able to read your mind!

Right now researchers have been able to learn what a subject is looking at as long as it is a photo of a scene in nature. "Using fMRI, the investigators acquired a template response from each subject's visual cortex and then used this template to "decode" the brain's response to novel images," says Psychology Today.

How were the investigators able to decipher to a high degree of accuracy what the subjects were viewing? Using a computer algorithm they scanned the visual cortex of the subject. Basically, it came close to mind reading with a 92% accuracy.

In the experiment all the algorithm was required to do was look at the known brain activity and then proceed to choose from a known set of images to determine which one was the best match. The algorithm did not take the brain activity and then reconstruct what the subject was actually seeing - there is a difference here. If there was a large image library maybe some day the computer just might be able to do this reconstruction process and practically "read minds."

Written by Denny Lyon

Brain: Brain Scanners Know Where You've Been

"The brain's center of memory and navigation, once considered too disorganized to decode, may soon be unlocked. Using a brain scanner, researchers were able to determine the location of people standing in a virtual room from the activity in their brains.

"We could read their spatial memories, so to speak," said study co-author Eleanor Maguire, a University College, London, cognitive neuroscientist. "There must be a structure to how this is coded in the neurons. Otherwise we couldn't have predicted this."

Maguire's team focused on the hippocampus, a region of the forebrain responsible for processing spatial relationships and short-term memories. As people move, hippocampal activation helps them know where they are. In Alzheimer's patients, disorientation and memory loss go hand in hand...

Maguire's study, published Thursday in Current Biology, challenges that notion. And though it's far too soon to pull memories directly from a brain, the findings suggest future avenues of research on Alzheimer's and other forms of dementia.

"How these millions of hippocampal neurons work is a fundamental question in neuroscience," said Maguire. "We still don't know how the hippocampal neural code is organized to support memory and activation."

The researchers used an fMRI machine to measure hippocampal blood flow in four subjects who navigated a room in virtual reality. They focused on groups of neurons identified by Maguire in an earlier study of London taxi drivers, whose hippocampi were hyperdeveloped by years of mental navigation through the city's mazelike streets.

After analyzing activation patterns and correlating them with a record of test subjects' movements, Maguire's team found that patterns could actually be used to predict location."

By Brandon Keim

From Denny: Pretty wild stuff! While they are still a long way from fully understanding the complete process of laying down memory or even how memory deteriorates, this small study is an intriguing first step.