Month: January 2008

Mice brains on stress

Blogging on Peer-Reviewed ResearchIn February 2006, a research team at University of Texas and Tufts University published a piece in Science on how experience could modify the structures in the brain that affect the production of dopamine through brain-derived neurotrophic factor (BDNF) (abstract here). The research team used ‘social defeat’ to explore ‘the neurobiological mechanisms through which psychosocial experience alters the activity of the mesolimbic dopamine pathway’; in other words, the malleable system that can induce structural changes in the brains of mice in response to persistent patterns of social interaction.The abstract, while a little thick, suggests all sorts of intriguing possibilities:

Mice experiencing repeated aggression develop a long-lasting aversion to social contact, which can be normalized by chronic, but not acute, administration of antidepressant. Using viral-mediated, mesolimbic dopamine pathway–specific knockdown of brain-derived neurotrophic factor (BDNF), we showed that BDNF is required for the development of this experience-dependent social aversion. Gene profiling in the nucleus accumbens indicates that local knockdown of BDNF obliterates most of the effects of repeated aggression on gene expression within this circuit, with similar effects being produced by chronic treatment with antidepressant. These results establish an essential role for BDNF in mediating long-term neural and behavioral plasticity in response to aversive social experiences.  

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Beyond Bourdieu’s ‘body’ — giving too much credit?

Blogging on Peer-Reviewed ResearchA while back, Daniel recommended to me that I check out an article by Mauro Adenzato and Francesca Garbarini in Theory & Psychology. It’s a great piece, and there’s a lot of positive things I could say about it. For example, Adenzato and Garbarini’s principal point is that the model of ‘mind’ as the workings of organic brain systems is inconsistent with much social theory, built instead on a treatment of mind as a kind of dis-embodied amalgamation of logical and cognitive processes. This recognition that phenomenological and cognitive mind and biological brain are inextricably linked is part of what makes neuroanthropology possible, or rather, necessary. As they write:

The embodied cognition perspective views the mind no longer as a set of logical/abstract functions, but as a biological system, which is rooted in body experience and interwoven with action and interaction with other individuals. Action and representation are no longer interpreted in terms of the classic physical–mental dichotomy, but have proven to be closely interlinked. Specifically, embodied cognition means that acting in the world, interacting with the objects and individuals in it, representing the world, perceiving it, categorizing it and understanding its meaning are merely different levels of the same relationship that exists between an organism and its environment. (Adenzato and Garbarini 2006:748) 

Adenzato and Garbarini point out that cognitive science has become increasingly concerned with grounding theories about thought and the mind in observable workings of the organic brain. Although I agree, following Clark (1997), I would refer to this movement as ‘third generation,’ rather than ‘second generation’ (as the authors do), as the first two over-arching waves in cognitive science might be termed the ‘logic machine’ and ‘connectionist’ models.I have some niggling problems with their argument, such as the ‘merely different levels’ off-handed comment, which I would dispute, and the tired technique later in the article of dragging a folk term from an ethnographic case study and showing how it’s like one’s new theoretical term, as if the natives having a word for a phenomenon is proof you’re on to something. Nevertheless, this passage is a very coherent statement, as is the whole article, of the need to incorporate more sophisticated models of the brain’s working into cultural theory.

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Puzzles and Cultural Differences

Blogging on Peer-Reviewed ResearchHere’s some interesting research where neuroscientists are using brain scans to show that cultural differences reach down to the level of functional activation in the brain.  Americans had a harder time with visual puzzles that required manipulating objects in context than “East Asians.”  Here a quote from the news article:

 

Neuroscientists Trey Hedden and John Gabrieli of MIT’s McGovern Institute for Brain Research asked Americans and East Asians to solve basic shape puzzles while in a functional magnetic resonance imaging (fMRI) scanner. They found that both groups could successfully complete the tasks, but American brains had to work harder at relative judgments, while East Asian brains found absolute judgments more challenging. Previous psychology research has shown that American culture focuses on the individual and values independence, while East Asian culture is more community-focused and emphasizes seeing people and objects in context. This study provides the first neurological evidence that these cultural differences extend to brain activity patterns.

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Why We Love, The Time Magazine Version

Too bad Jeffrey Kluger didn’t pay closer attention to Hannibal Lecter.  He might have written a better article on “Why We Love,” out this week in Time Magazine, instead of giving us a flawed view of evolution and brain research.  Still, in furtive glimpses of data, rather than quick quotes and pop theories, another way to think about love glides onto stage. 

As I told my anthropology students yesterday, the initial assumptions we make so often dictate our ideas and our results.  But those assumptions are generally presented as “facts” or assertions of truth, part of an unassailable background.  So here are the ones packed into Kluger’s piece, right there at the beginning: (1) that humans rely on our wits, so “losing our faculties over a matter like sex” needs explaining (in other words, humans are rational, why have primitive passions); (2) that we evolved in a “savanna full of predators,” so getting distracted by love could be potentially dangerous, (3) that our genes have “concerns,” primary among them to make us reproduce as much as possible (“breed now and breed plenty gets that job done”), and (4) that we can extend these sorts of explanations to all “the rituals surrounding” sex, love and relationships (like a bunch of scientists drunk on their own ideas—explanatory expansion gone wild!). 
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Monkey Makes Robot Walk!

Where does this leave the evolution of human bipedalism?  Is there some mystery “bipedal instinct”?  A bipedal “organ” in the brain?  I’ll let you decide… 😉 

Here’s the article.  It’s a great piece about the importance of training, the relevance of a body (build it and the brain will come…), and the management of different tasks by different areas of the brain that work in conjunction.  For the culturally inclined, the study authors argue that for Idoya, the monkey in question, her “motor cortex, where the electrodes were implanted, had started to absorb the representation of the robot’s legs — as if they belonged to Idoya herself.”

Re-training the damaged brain

There’s a good article today, “Coaching the Comeback,” about an occupational therapist working with patients recovering from traumatic brain injuries.  From physical training, nerve stimulation and direct social interaction (e.g., maintaining eye contact, talking to them), the therapist helps her patients along.  It’s a nice summary of several themes that we’ve said in different ways about brains.  And, the therapist with her collection of skills, her education of families, her moral views on recovery also shows the importance of culture in interaction.  It’s also a nice story in itself…