Neuroanthropology

For a greater understanding of the encultured brain and body…

Archive for August, 2008

Women on tests update: response to stress

Posted by gregdowney on August 31, 2008

A while ago, I posted an overly-long discussion of recent research on the ‘math gap’ between boys and girls on standardized testing (Girls closing math gap?: Troubles with intelligence #1). That posting discussed several studies published in Science that have shown the gap in average math scores between boys and girls is not set in stone. In one paper, an increase in the test pool brought on by the No Child Left Behind program, with mandatory universal tests instead of exams only for those wishing to go to college, caused the gap in average scores to disappear; in the other paper, a decrease in the ‘math gap’ was found to correlate with other measures of greater gender equality in European states.

As I pointed out in the previous post, however, many commentators suggest that it is not the gap in average test scores that really matters; rather, these critics argue that the different variance in boys’ and girls’ scores explains the disproportionate number of boys who produce exceptional scores (as well as exceptionally bad scores), and thus the marked gap of men and women in PhD math programs, in prestigious prizes for physics and related subjects, and in related fields like engineering. In the earlier post, I argued that even if this greater variance showed up reliably across all testing populations, what exactly was being illuminated was still not clear; that is, many other explanations–other than that men had better ‘math modules’ in their brains, or greater ‘innate’ mathematics ability, or something like that–could explain even very stable differences in math performance. At the time I suggested a number of other possibilities, such as sex differences in stress response during testing, as other possible explanations for even a universal ‘math gap’ (which still had to contend with studies like the two in Science which severely undermined the assertion of universality).

As if on cue, I stumbled upon a video and accompanying article in Science Daily on differences in stress responses among men and women: Neuroscientists Find That Men And Women Respond Differently To Stress (but don’t click on that link — keep reading!). Stress is a good candidate to explain a test-taking gap because the observable physiological processes offer abundant evidence that men and women don’t respond to stress in exactly the same way (although there are underlying commonalities). For example, stress causes different diseases in men and women, and some long-term psychological disorders that demonstrate sex-linked disparities seem to emerge from stress.

Unlike the ‘black box’ explanation that boys and simply better at math or evidence greater variability in innate ability, with no observable neural correlate or plausible explanatory mechanism, in variation in stress response we have a clear candidate for male-female difference that plausibly affects their performance and even physiology (for example, in different stress-related diseases).
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Posted in Brain imaging, Education, Gender, Human variation, Inequality, Stress | Tagged: , , , , | 6 Comments »

Culture on the Teen Brain

Posted by dlende on August 30, 2008

Harvard Magazine has a short piece this month on the work of neurologists Frances Jensen and David Urion to popularize information about the “teen brain” to audiences. As Jensen says, “This is the first generation of teenagers that has access to this information, and they need to understand some of their vulnerabilities.”

That information? That, given the way their brain is maturing (both fast-growing synapses and other sections relatively unconnected), adolescents are more “easily influenced by their environment and more prone to impulsive behavior.” As expected, there follows a typical line of parental angst: the sexes are different, drugs harm brains, kids need to sleep and get exercise, they are suffering from sensory overload from all the new technology. By implication, it is all due to being in “this paradoxical period in brain development.”

Certainly there are some intriguing results about brain development in adolescent related to differential brain maturation, developmental plasticity, and the like. Some early research based on longitudinal research is summarized here in an NIMH press release, which concludes in better fashion: “the teenage brain is a very complicated and dynamic arena, one that is not easily understood,” whether for parents or for researchers. But as I covered earlier in a post on emotion and decision making, teenagers can actually be seen as rather good decision makers, just focused on differential goals and contexts than most adults.

And come on, teenagers are overwhelmed by information and multitasking in today’s “brave new world”? I wish I had half the skills that my incoming freshmen display in this arena-I’m the one who doesn’t quite know how to handle the sensory overload…

Another graphic accompanies the Harvard article (only in the pdf though), an illustration by Leslie Cober-Gentry. For me, it shows the enormous gap between the brain imaging graphic and this more cultural graphic. As with all imaging research, there can only be correlations between level of activity and a particular task at hand. But that equation leaves out all the other important correlations that exists between, say, being impulsive and a particular environmental context. The juxtaposition of the two images capture perfectly what Urion and Jensen do, project our everyday life and concerns onto our newest explanatory cause-the brain.

Posted in Brain imaging, Brain Mechanisms, Developmental psychology | Leave a Comment »

Foxy Evolution

Posted by dlende on August 28, 2008

Here’s a great video that shows how selection can work its effects–in this case artificial selection, demonstrated through the work of the Russian Dmitri Belyaev and his tame silver foxes. Still, what I find most striking about this video is the analogy to ourselves.

Jim Rilling, a neuroanthropologist at Emory, once commented to me that humans are wired to cooperate (in his latest work, he’s doing neuro-imaging on what happens when people don’t reciprocate, having researched the neural bases of cooperation earlier). The example Jim used has stuck with me ever since. Imagine 50 chimpanzees trying to sit down and watch an introductory lecture together. Pandemonium with those chimps. For us, it’s the most mundane sort of thing. People do it everyday around the world.

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Posted in Animals, Cultural theory, Evolution | 4 Comments »

Human Evolution Fun!

Posted by Paul Mason on August 28, 2008

 

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Posted in Fun and Humor | 1 Comment »

Brain School

Posted by Paul Mason on August 28, 2008

In anticipation of the lecture on the Brain in Greg’s undergraduate Human Evolution class next week, I have compiled a bunch of fun links to learn about brain structure and function. Please suggest a link to your educational blog or a brain school website that I perhaps haven’t included on the list!

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Posted in Brain imaging, Brain Mechanisms, Evolution, Links | 5 Comments »

Four Tangled Blue Banks

Posted by dlende on August 27, 2008

The new Four Stone Hearth of anthropology is up at Tangled Up in Blue Guy.

Some favorites include Oetzi the IceMan’s clothes, Neanderthals were not stupid, and the article in PLoS about life in the Sahara 7000 years ago, complete with some striking mortuary remains and grave sites.

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Wednesday Round Up #26

Posted by dlende on August 27, 2008


Anthropology

Brandon Keim, Culture Shapes How People See Faces
New research on East Asian/Western contrast in facial perception using eye tracking. Has this great graphic! And includes this important quote: “We tested some Chinese who had been in Glasgow for three or four years, and you see a clear difference between them and those who just arrived,” he said. “That really demonstrates that it’s not genetic. It’s experience.”
For more detail on the study, see Ed Yong’s piece “Westerners Focus on the Eyes, East Asians on the Nose

LL Wynn & Nikki Kuper, Annotated Bibliography on HTS, Minerva and PRISP
A comprehensive listing of resources on the US Army’s Human Terrain Systems and other efforts to engage social science (and in many minds, subvert and corrupt it). Erkan Saka offers some more links, as well as other interesting anthro stuff, in one of his round-ups.

Somatosphere, Web Gleanings 2
Another round up from the new med anthro blog – quite a collection!

Disparate, Enthused Tech
Slideshow and blog post on enthusiasm in learning, especially through technology. Another Anthro Blog provides some enthusiastic reaction.

Antropologi, Open Access: New Alliances Threaten the American Anthropological Association
Did the AAA make the wrong choice in hiding its online publications away?

Madeleine Coorey, Prehistoric Giant Animals Killed by Man, Not Climate: Study
In Tasmania, the climate was stable so recently arrived humans become the main suspects in the disappearance of giant kangaroos

Roger Cohen, News Good Enough to Be Buried
Nice op-ed: “In my lifetime, conditions have grown immeasurably better, freer and more prosperous for a majority of humanity, yet hand-wringing about the miserable remains the reflex mode for most coverage of planet earth.”

Randolph Schmid, Monkeys Reward Friends and Relatives
Better to give and receive rather than just give—the importance of building relationships and reciprocity

Brain

Arthur Shapiro, 100th Anniversary of “A New Visual Illusion of Direction”
Another great one from Illusion Sciences—clicking on the red lines really made the difference! And we get plenty of added intellectual background too!

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Posted in general | 1 Comment »

Links to Consciousness: Consciousness Links

Posted by Paul Mason on August 26, 2008

It takes around eight minutes and twenty seconds for light from the sun to reach the earth. It then takes another half a second for that light to be reflected off an object, detected by the retina, trigger signals that travel along the optic nerve, pass the optic chiasm, continue down the optic tract, go through the Lateral Geniculate Nucleus, arrive at the primary visual cortex and spread to wider areas of the cortex and to finally then somehow become part of consciousness. If we decide to move in response to that light, there is a similar time lapse. Specific neurons in the brain must activate continuously for at least half a second before we make the decision to move. To some, consciousness is divine; to others consciousness is the result of the contemporaneous firing of distributed populations of neurons feeding through a dynamical core of deep brain activity.

 

 

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Posted in Brain Mechanisms, general, Links | 3 Comments »

Role of Emotions in Brain Function

Posted by Paul Mason on August 26, 2008

Emotions can be overpowering, but they are also the driving force of life. It was long thought that emotion and thought were separate processes. Brain science has begun to realise that the brain is not an organ of thought, but that it is a feeling organ that thinks. A tiny almond shaped structure deep in the brain, the Amygdala, is the first to respond to an emotional event. It triggers a series of reactions within the brain’s emotional core and sends signals throughout the body that change body posture, facial expression, heart-rate, breathing and awareness. The emotions are important in social interaction and in forming social connections. The awareness of emotion is crucial to motivation, decision-making, memory and forethought. Learning how to manage our emotions is an important skill that we continually develop throughout our lives.

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Posted in Brain Mechanisms, general, Links, Medical anthropology, Psychological anthropology | 7 Comments »

Giving your right arm to be ambidextrous

Posted by Paul Mason on August 26, 2008

Apologies for yet another excessively long post, but I would like to ask, Would you give your right arm to be ambidextrous?

It is often thought that the left hemisphere of the brain is the logical/analytical side of the brain and that the right hemisphere is the creative/intuitive side of the brain. However, to what extent is this true? Most people are right handed, which in most cases means that the left hemisphere of their brain controls speech. Sometimes, however, the brain is symmetrical and both hemispheres contribute equally to functions like speech. Cerebral symmetry is thought to contribute to disorders like stuttering. Cerebral asymmetry, on the other hand, seems to be an important part of brain function. Laterality is also key to understanding the effects of a stroke in the brain, or a brain lesion due to an accident, or knowing which parts of the brain can be safely removed in a patient with epilepsy.

While having an asymmetrical brain does actually have some advantages, some psychologists suggest mixing it up. It may improve brain function. If you brush your teeth with your right hand, try brushing with your left; If you open doors with your left hand, try opening them with your right; If you… okay, okay, I think you get the point. I’m not sure how much this actually improves brain function, but I could possibly see how this behaviour might help you should you ever have an accident affecting one side of your body or one side of your brain. It may even help reduce neuro-degeneration in old age, but who knows…

FIELDWORK OBSERVATIONS

An interesting thing about my fieldwork in Indonesia is the extent to which the right hand is favoured in society. It is rude to offer objects with the left hand, it is also rude to accept them in the left. Pointing, waving and gesturing with the left hand can all be considered extremely rude. Even if you are forced to use your left hand because you are eating with your right, working with it or holding onto something, you still have to indicate that you understand the rudeness of using your left. By acknowledging that you would prefer to use your right hand while forced to use your left, you are considered quite polite.

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Posted in general, Links | 6 Comments »

 
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