Neuroanthropology

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Archive for the ‘Stress’ Category

Gravlee et al: Race, Genetics, Social Inequality, and Health

Posted by dlende on September 11, 2009

Color SES SBP
Clarence Gravlee, Amy Non and Connie Mulligan have just published an outstanding article in PLoS ONE, Genetic Ancestry, Social Classification, and Racial Inequalities in Blood Pressure in Southeastern Puerto Rico. The abstract opens:

The role of race in human genetics and biomedical research is among the most contested issues in science. Much debate centers on the relative importance of genetic versus sociocultural factors in explaining racial inequalities in health. However, few studies integrate genetic and sociocultural data to test competing explanations directly.

Note how that fits so well into the points just made in Nature/Nurture: Slash to the Rescue. But Gravlee, Non and Mulligan don’t just say we need to overcome the nature vs. nurture dichotomy, they do research that bridges it and even better, test ideas on both sides: “We draw on ethnographic, epidemiologic, and genetic data collected in southeastern Puerto Rico to isolate two distinct variables for which race is often used as a proxy: genetic ancestry versus social classification.”

This type of collaborative research can be crucial to getting the data to answer complicated questions. Connie Mulligan and Lance Gravlee deserve credit for taking the time to discuss how to bring together their respective approaches before going out to do research. In this case, the data come down more on the nurture (or social) side. As they write:

Our preliminary results provide the most direct evidence to date that previously reported associations between genetic ancestry and health may be attributable to sociocultural factors related to race and racism, rather than to functional genetic differences between racially defined groups.

Before someone gets all hot and bothered, Lance has also shown how to bring nurture back to nature. In Gravlee’s recent paper, How Race Becomes Biology: Embodiment of Social Inequality (pdf), he gives us following: “Drawing on recent developments in neighboring disciplines, I present a model for explaining how racial inequality becomes embodied – literally – in the biological well-being of racialized groups and individuals. This model requires a shift in the way we articulate the critique of race as bad biology.”

In the PLoS paper, Lance, Amy and Connie are aiming squarely at the use of race in medicine, where it has become common in some circles to use racial classification as a proxy for genetics. Basically this research destroys the proxy notion, since social classification turns out to be a better predictor of blood pressure than genetic ancestry.

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Posted in Cognitive anthropology, Embodiment, Human variation, Inequality, Medical anthropology, Methods, Stress | 5 Comments »

Poverty and the Brain: Becoming Critical

Posted by dlende on April 10, 2009

poverty-race-opportunity
Poverty Poisons the Brain was one of our most popular posts last year. Recent research has brought that topic back into public light. It’s good research, but today I will get critical about what really matters in our emerging realization that social disadvantage results in neurological disadvantage.

Gary Evans and Michelle Shamberg recently published a PNAS paper, Childhood Poverty, Chronic Stress and Working Memory (pdf). Here’s the abstract:

The income–achievement gap is a formidable societal problem, but little is known about either neurocognitive or biological mechanisms that might account for income-related deficits in academic achievement. We show that childhood poverty is inversely related to working memory in young adults. Furthermore, this prospective relationship is mediated by elevated chronic stress during childhood. Chronic stress is measured by allostatic load, a biological marker of cumulative wear and tear on the body that is caused by the mobilization of multiple physiological systems in response to chronic environmental demands.

The Evans and Shamberg paper has gotten prominent media attention. Over at Wired, Poverty Goes Straight to the Brain got an enormous number of diggs. Brandon Keim’s opening lines are, “Growing up poor isn’t merely hard on kids. It might also be bad for their brains. A long-term study of cognitive development in lower- and middle-class students found strong links between childhood poverty, physiological stress and adult memory.”

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Posted in Brain Mechanisms, Developmental psychology, Embodiment, Inequality, Stress | 9 Comments »

Measuring Process Not Belief: Shane Battier and Stress

Posted by dlende on February 20, 2009

The Wrong Box Score

The Wrong Box Score

Besides being a great read about Shane Battier and success in professional basketball, The No-Stats All-Star article by Michael Lewis in last Sunday’s New York Times Magazine carries a larger lesson about how our understanding of the world is shifting. One of its main points is that we are becoming increasingly statistics driven, with sports at the leading edge of this transformation. We can spend lots of money on stars, like the New York Yankees, or we look more closely at what actually leads to success and how we can achieve that with less money. Shane Battier epitomizes this change because his individual stats are rather mediocre, his physical skills rather normal for an NBA player. But he makes his team win.

The key question becomes, how does he do this? That is where Michael Lewis mixes qualitative research (interviews) and ethnographic insight (coming from Battier’s own experience) with an examination of new ways of measuring everything that might count about a basketball game. It’s a powerful mix.

For me it illustrates two important points about how we can develop better measures, ones that are closer to what actually determine outcomes and that don’t fall into so easily into measuring our own beliefs about the world. And yes, by “our own” I mean the researchers who come up with the measures. Here’s a relevant section describing Daryl Morey, the man behind the Houston Rockets new approach to figuring out what works:

What [Morey] will say, however, is that the big challenge on any basketball court is to measure the right things. The five players on any basketball team are far more than the sum of their parts; the Rockets devote a lot of energy to untangling subtle interactions among the team’s elements. To get at this they need something that basketball hasn’t historically supplied: meaningful statistics. For most of its history basketball has measured not so much what is important as what is easy to measure — points, rebounds, assists, steals, blocked shots — and these measurements have warped perceptions of the game. (“Someone created the box score,” Morey says, “and he should be shot.”) How many points a player scores, for example, is no true indication of how much he has helped his team.

Here is how it makes a difference. Battier doesn’t get great traditional stats – points scored, shots blocked, and so forth. But he does things that, on aggregate, make a bigger difference.

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Posted in Cognitive anthropology, Methods, Sport, Stress | 3 Comments »

Forever at War: Veterans’ Everyday Battles with Post-traumatic Stress Disorder

Posted by dlende on January 26, 2009

ptsd-iwo-jima“To this day, every time I smell firecrackers or fire arms being shot, I feel like I am right back there. All I have to do is close my eyes and I see the whole scenario over and over again. I can’t erase it.”

Hundreds of thousands of US veterans are not able to leave the horrors of war on the battlefield. They bring the combat home and re-experience it in their minds each and every day, no matter how much time has passed.

“I don’t like people. I just live my life.”

Many PTSD veterans live a life riddled with divorce, unemployment, and loneliness because they are unable to form lasting social networks within civilian life. It is not uncommon for a war veteran plagued with PTSD to desire a solitary life in the mountains. One informant described Montana as the ideal locale – far away and quiet.

“I should have buried him.”

This veteran is still tormented by the fact he did not give an honorable burial to a fellow soldier. He knows he would have met a similar fate if he tried to leave his foxhole; yet his inability to act haunts his memory. He asks himself everyday why he didn’t even try to honor his fallen comrade. He also has never been able to justify why he wasn’t the soldier left unburied on that remote Pacific island.

“I didn’t even have the motivation to kill myself.”

Many of these men and women believe their situation will never improve. Some contemplate suicide as their only relief from the symptoms of PTSD. A number of the veterans we spoke with had thought about or even tried to end their own lives. They also participate in risky activities, threatening their life in a deliberate yet indirect way.

“I always feel like there is someone behind me – following me.”

Being on edge is the only way to survive in combat. Unfortunately, many PTSD veterans are unable to readjust within the civilian world. Everyday life becomes a battlefield.

Something as mundane as walking through a crowded grocery store aisle can be a source of intense anxiety for a veteran suffering from PTSD. Overwhelmed by a feeling that the shoppers behind them are enemies, PTSD veterans always feel as if they are under attack. A trigger as simple as the clashing of shopping carts can make them jump in fear of an imminent explosion. They are forever at war.

OUTREACH

Over the course of 4 months, South Bend veterans with Posttraumatic Stress Disorder (PTSD) have revealed their daily realities to us, five undergraduates at the University of Notre Dame. In conjunction with a course taught by Dr. Daniel Lende entitled Researching Disease: Methods in Medical Anthropology, we have engaged in community-based research with members and supporters of PTSD, Vets, Inc. Here, with the approval and encouragement of these vets, we seek to give their experiences a well-deserved voice.

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Posted in Applied Anthropology, Medical anthropology, Mental Illness, Stress, Violence | Tagged: , , | 24 Comments »

Mental Health and Global Warming

Posted by Paul Mason on December 15, 2008

Two hot topics for more than a decade:
Mental Health
and Global Warming.
Two issues connected in the most profound of ways… Read the rest of this entry »

Posted in Brain Mechanisms, Cognitive anthropology, Ethnography, Evolution, Philosophy, Stress | 12 Comments »

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 »

Relax your genes

Posted by gregdowney on July 5, 2008

Image from Good Karma Flags

Image from Good Karma Flags

Relax — it can affect your genes.

A recent article on PLoS One by a research team from the Benson-Henry Institute for Mind/Body Medicine at Massachusetts General Hospital (MGH) and the Genomics Center at Beth Israel Deaconess Medical Center (BIDMC) discusses the genetic effects of the relaxation response, a widespread bodily state induced by different mind-body techniques (such as meditation).

The original piece, Genomic Counter-Stress Changes Induced by the Relaxation Response, was published at PLoS One, and the findings are also discussed on ScienceDaily, Relaxation Response Can Influence Expression Of Stress-related Genes. It’s starting to be a bit of a refrain from genetics research, but it still bears repeating: the team is exploring a way that ‘changing the activity of the mind can alter the way basic genetic instructions are implemented,’ as Dr. Herbert Benson explained (in ScienceDaily).

The relaxation response is a bodily state, found in a variety of contexts, characterized by ‘decreased oxygen consumption, increased exhaled nitric oxide, and reduced psychological distress.’ Long-term effects of relaxation exercises include decreased oxygen intake and carbon dioxide elimination; reductions in blood pressure, heart and respiration rate; prominent low frequency heart rate oscillations; and some changes in cortical and subcortical brain regions, including increased thickness of the cortex (see NeuroReport and here also on the effect of meditation on aging).

For about three decades, dependable clinical studies have shown that relaxation response-producing exercises have a range of positive health benefits. What makes the current research distinctive (at least in my reading) is that the team traced this metabolic process to its genetic effects. As the authors write:

This study provides the first compelling evidence that the RR elicits specific gene expression changes in short-term and long-term practitioners. Our results suggest consistent and constitutive changes in gene expression resulting from RR may relate to long term physiological effects. Our study may stimulate new investigations into applying transcriptional profiling for accurately measuring RR and stress related responses in multiple disease settings.

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Posted in Genetics, Meditation, Psychological anthropology, Stress | Tagged: , , , , | 4 Comments »

Cultural Aspects of PTSD, Part II: Narrative and Healing

Posted by epfinley on June 22, 2008

Bremner et al. 2000.  MRI showing decreased hippocampal volume in Vietnam veterans diagnosed with PTSD.

Narrative and memory are interwoven in our consciousness, and thus explorations into trauma from both humanities and social science perspectives almost invariably discuss narrative in one form or another. An ongoing debate within psychological research, for example, ponders whether the coherence of trauma stories is correlated to the amount of emotional distress associated with a given traumatic memory. It is hypothesized that the greater the distress, the less organized the narrative. If this were the case, we might expect that the coherence with which an individual is able to talk about the trauma would increase as the memory is processed and resolved, a finding for which we have some evidence.

We do know – when it comes to Post-Traumatic Stress Disorder (PTSD) – that narrative matters. As I wrote in an earlier post, the most effective therapies yet proven for reducing PTSD symptoms are the exposure therapies, particularly Prolonged Exposure (PE) therapy. These therapies are more effective for reducing the full range of PTSD symptoms than any pharmaceutical yet identified. And the crux of these therapies rests on telling the story of the trauma, sometimes over and over again. This simple practice, this process of speaking, has been reliably demonstrated to result in an improvement of PTSD symptoms for many patients.

But for all its clinical benefit, this extraordinary observation tells us very little about the mechanisms of psychic healing after trauma. Instead, it points to a growing body of evidence that suggests it is not just narrative that matters in PTSD, but, more intriguingly, that it is the type of narrative that matters. Unstructured psychodynamic therapies, for example, have not been demonstrated to lessen the severity of PTSD, even among patients who continue in therapy for years. And yet certain ways of narrating memory do make a difference, and this phenomenon once again points to a role for anthropologists and other culturally-minded researchers in exploring the cultural-emotional-physiological-environmental interactions at play in post-traumatic processing.

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Posted in Neural plasticity, Brain imaging, Psychological anthropology, general, Stress, Language | 9 Comments »

Cultural Aspects of Post-Traumatic Stress Disorder: Thinking on Meaning and Risk

Posted by epfinley on June 4, 2008

Over the past year and a half, I have been conducting research among male U.S. veterans who have served combat tours in Iraq and Afghanistan, most of whom have been diagnosed with Post-Traumatic Stress Disorder (PTSD). An anthropologist myself, I planned to follow the trail originally blazed by Victor Frankl and Robert Jay Lifton, psychotherapists who wrote a great deal about meaning in their descriptions of trauma and PTSD.

Early on, however, a psychiatrist whose work on trauma I admire opined to me that crises of meaning belong to the realm of depression rather than PTSD. He suggested that combat PTSD was best thought of as the physiological effects of living under conditions of extreme stress, while more meaning-related struggles were best understood as a symptom of depression. Given the frequency of comorbidity between PTSD and depression, I was for some time inclined to go along with his analysis.

Then two things happened. First, I began the work of talking with veterans themselves about their stories of trauma and PTSD, listening to how they describe their own experiences. And second, I began to explore the increasingly dominant Prolonged Exposure model of PTSD, which views the disorder as a pathology that develops when individuals fail to process their traumatic memories in the normal way.

Some background is important here. A recent RAND report suggests that as many as 18.5% of combat troops have gone on to develop PTSD after serving in Iraq or Afghanistan; alarming as that number is, it nonetheless demonstrates that the vast majority of combat-exposed individuals do not develop PTSD. However, most of the veterans I’ve spoken with – even those without a formal PTSD diagnosis – report experiencing some PTSD symptoms for a period of time following their combat deployment. Many of them dealt with such symptoms for a while – a month, three months, a year – before passing through this period of processing their memories and going on with their lives. They may be changed by their experiences in the war zone, but they are not broken by them, and may even describe them as resulting in personal growth and other positive effects.

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Posted in Mental Illness, Psychological anthropology, Stress, Violence | 29 Comments »

‘Psychological kevlar’ and the burden of remembering war

Posted by gregdowney on May 4, 2008

I just read a fascinating piece by Clayton Dach, America’s Chemically Modified 21st Century Soldiers, on Alternet. Although there’s a sense in which Mr. Dach jumps to some of the worst possible outcomes when he looks at technology in the pipeline, on the whole, it’s a pretty well thought and concerned-but-not-hysterical account of some of the technology being brought to bear on soldiers, including the possibility of removing humans further from the ‘loop’ in combat decisions. I’m less interested with the latter — the robot warriors angle — not only because I think it’s been done better in science fiction movies, but also because I think it’s simply a more remote technology than some of the pharmaceutical work he discusses.

In particular, I found the discussion of ‘psychological kevlar’ to be interesting for neuroanthropology:

In the U.S., where roughly two-fifths of troops returning from combat deployments are presenting serious mental health problems, PTSD has gone political in form of the Psychological Kevlar Act, which would direct the Secretary of Defense to implement “preventive and early-intervention measures” to protect troops against “stress-related psychopathologies.”

Proponents of the “Psychological Kevlar” approach to PTSD may have found a silver bullet in the form of propranolol, a 50-year-old beta-blocker used on-label to treat high blood pressure, and off-label as a stress-buster for performers and exam-takers. Ongoing psychiatric research has intriguingly suggested that a dose of propranolol, taken soon after a harrowing event, can suppress the victim’s stress response and effectively block the physiological process that makes certain memories intense and intrusive. That the drug is cheap and well tolerated is icing on the cake.

With PTSD so prevalent among soldiers, can it be better treated, even if that means blocking the formation of traumatic memories? Daniel did a piece on PTSD rates in soldiers in April, Invisible Wounds of War, and he discussed a RAND Corporation estimate that treatment of soldiers with PTSD would cost ’6.2 billion dollars in the first two years after returning from deployment.’ (Daniel also provided links to a number of articles on Iraq and its psychological effects in Wednesday Round Up #7.) The potential to use drugs to stop the development of PTSD, even if it also blocks normal memory formation, raises a number of ethical and moral questions as well as some interesting neuroanthropological ones.

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Posted in Medical anthropology, Mental Illness, Stress | 3 Comments »

 
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