Author: gregdowney

Trained as a cultural anthropologist at the University of Chicago, I have gone on to do fieldwork in Brazil and the United States. I have written one book, Learning Capoeira: Lessons in Cunning from an Afro-Brazilian Art (Oxford, 2005). I have also co-authored and co-edited several, including, with Dr. Daniel Lende, The Encultured Brain: An Introduction to Neuroanthropology (MIT, 2012), and with Dr. Melissa Fisher, Frontiers of Capital: Ethnographic Reflections on the New Economy (Duke, 2006). My research interests include neuroanthropology, psychological anthropology, sport, dance, human rights, neuroscience, phenomenology, economic anthropology, and just about anything else that catches my attention.

Parents’ stress, children’s health

Blogging on Peer-Reviewed ResearchTo all the stressed-out parents out there, here, let me just hand you a bit more to worry about. A research team led by Dr. Mary T. Caserta at the University of Rochester (more on her research here) have an article in press at Brain, Behavior, and Immunity entitled, ‘The associations between psychosocial stress and the frequency of illness, and innate and adaptive immune function in children’ (abstract here, unfortunately, I couldn’t find a downloadable version of the whole article). 169 school-aged children and their parents were studied through health diaries and over seven sequential visits, each separated by six months (three years total, by my quick calculation). At these visits, children were tested for human herpesvirus 6 reactivation and general measures of immune function were examined, such as ‘natural killer (NK) cell function and the percentage of CD4 and CD8 cells associated with immune control of cytomegalovirus (CMV).’

The study was to test the relation between parental stress and children’s immune systems:

Family processes have a substantial impact on children’s social and emotional well-being, but little is known about the effects of family stress on children’s physical health. To begin to identify potential links between family stress and health in children, we examined associations between specific aspects of family psychosocial stress and the frequency of illnesses in children, measures of innate and adaptive immune function, and human herpesvirus 6 (HHV-6) reactivation.

The researchers found that parental stress was associated with the illness rates in their children. Although HHV6 activation rates did not increase, the rate of illness in the children (according to the diaries, presumably) and the activation of the children’s immune systems were both elevated. It’s not entirely clear to me from the abstract, so I’ll have to wait for the full write-up to get a sense for the mechanisms involved. The researchers concluded, ‘There is an association between specific psychosocial stress exposure and rates of illness and immune function in normally developing children.’

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How your brain is not like a computer

At the end of my last post, or the one before that, I had a late-night ‘inspiration’ that must have sounded a bit like an outburst about how our brains are not like computers. There’s lots of good reasons for making that assertion, whether or not it’s an outburst. But one of the key issues is concern about ’embodiment’ in cognitive science and the discussion of embodied cognition. Daniel, in his comments, put a link to the posting by Chris Chatham, 10 Important Differences Between Brains and Computers, which is excellent. There’s also an interesting discussion of this going on at Dr. Ginger Campbell’s blog on her Brain Science Podcasts, both of which (discussion and podcasts) I strongly recommend. See the first two topics on the list you can find here on ‘Artificial Intelligence.’

For the anthropologists in our audience, however, the term ’embodied cognition’ is a bit unfortunate, not because it’s not a great term, but because an earlier intellectual movement in anthropology already snagged the adjective ’embodied’ and then didn’t push the issue far enough to actually deal with physiological and biological dimensions of being embodied. That is, in anthropology, the term ’embodiment’ has not been allowed to really stretch its wings, and has instead been more narrowly constrained to dealing with phenomenological, interactional, and theoretical issues deriving primarily from feminism, Foucauldian post-structuralism, and Bourdieu-ian sociology. All of these streams are important, but they do not yet engage with the sort of material that cognitive scientists mean when they use the term ’embodied.’ The danger is that anthropologists will see the term, ’embodied cognition,’ and it will not seem quite as disruptive to anthropology-as-usual as it should be.

Chatham’s posting makes this key issue clearer in his tenth reason that brains are not like computers: brains have bodies:

This is not as trivial as it might seem: it turns out that the brain takes surprising advantage of the fact that it has a body at its disposal. For example, despite your intuitive feeling that you could close your eyes and know the locations of objects around you, a series of experiments in the field of change blindness has shown that our visual memories are actually quite sparse. In this case, the brain is “offloading” its memory requirements to the environment in which it exists: why bother remembering the location of objects when a quick glance will suffice? A surprising set of experiments by Jeremy Wolfe has shown that even after being asked hundreds of times which simple geometrical shapes are displayed on a computer screen, human subjects continue to answer those questions by gaze rather than rote memory. A wide variety of evidence from other domains suggests that we are only beginning to understand the importance of embodiment in information processing.

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The history of mind-altering mechanisms

Katherine MacKinnon of St. Louis University just dropped me a line to point out a recent book review in The New York Times, I Feel Good, by Alexander Star. Star reviews the book, On Deep History and the Brain, by Daniel Lord Smail (University of California Press). Amazon raters are giving it 4.5 stars at the moment, if you want to check it out through the bookseller. Normally, I’d trust Daniel to write our best stuff about ‘mind-altering’ chemicals of all sorts, but this book review just set me to thinking, so I thought I’d put my own two cents in.

Smail wants to tell the story of humanity as a series of ‘self-modifications of our mental states,’ according to the reviewer Star:

We want to alter our own moods and feelings, and the rise of man from hunter-gatherer and farmer to office worker and video-game adept is the story of the ever proliferating devices — from coffee and tobacco to religious rites and romance novels — we’ve acquired to do so. Humans, Smail writes, have invented “a dizzying array of practices that stimulate the production and circulation of our own chemical messengers,” and those devices have become more plentiful with time. We make our own history, albeit with neurotransmitters not of our choosing.

Smail is really a historian, but his venture into a kind of neuro-history shows the robustness of the emerging awareness that the brain is shaped by what humans do. Star points out that most ‘macro-history’ these days — long, sweeping accounts of human evolution and what is sometimes called something prosaic like the ‘rise and fall of civilizations’ — is not being written by historians, but rather by folks like Jared Diamond. In contrast, Smail is a medieval historian.

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More on persuasive, irrelevant ‘neuroscience’

Continuing on the subject from my previous post, Mark Liberman has a nifty little post on ‘The Functional Neuroanatomy of Science Journalism’ on the blog, Language Log (tip of the hat to Coturnix at A Blog Around the Clock for alerting me to this one). Liberman points out some of the same things that I argued in the previous post, but he also brings in a very careful reading of a number of recent pieces in the press that attracted quite a bit of attention while really offering very little in the way of something new, except for the Unexpected Flavor of Neuroscience to spice things up!

One of the pieces that Liberman discusses is an article on the ‘hard-wiring’ of maternal instincts that Daniel explored in an earlier post, ‘Headline: Maternal Instinct Is Wired Into The Brain.’ Liberman nominates the original article by Tara Parker-Pope of The New York Times as an example of what he believes is a leading candidate for the ‘Most Pernicious Science Narrative of the Decade’:

1. Consider the hypothesis that (Stereotypical-Observation-X-About-People).
2. Brain Researcher Y used fMRI to show that (some experimental proxy for) X is (somewhat) true. Now we know!
3a. Optional bonus #1: Now we know why! It happens (somewhere) in the brain!
3b: Optional bonus #2: This shows that X is hard-wired and biological, not all soft and socially constructed.

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‘Neuroscience’ persuasive, even when irrelevant

Cognitive Daily, one of my favorite websites, has a great piece on a study that examined whether or not people find references to brain areas ‘lighting up’ in neuroimaging (one of my least favorite expressions) and other neuro-speak more persuasive than plain old psychology articles. The piece is titled, ‘When we see a brain “light up,” [most of] our brains shut off.’ Author Dave Munger reports that he originally found out about the research through an online article in Seed Magazine (available here) (I hope I’m not inadvertently misrepresenting anything Munger has written…). The newly published study, ‘The Seductive Allure of Neuroscience Explanations,’ has appeared in the Journal of Cognitive Science (abstract here).

The study set out to find whether or not a bit of neuroscience-speak can persuade people, even when explanations are bad: ‘Explanations of psychological phenomena seem to generate more public interest when they contain neuroscientific information. Even irrelevant neuroscience information in an explanation of a psychological phenomenon may interfere with people’s abilities to critically consider the underlying logic of this explanation’ (from the abstract). The crucial part of this is that, according to experts, the neuroscience in the experimental passages was irrelevant to whether or not the argument being advanced was valid or not.

Munger describes the original study as finding, not that neuroscience is always more persuasive than psychological explanation, but that neuroscience makes bad explanations more persuasive. He explains:

While there was no significant difference in the results for good explanations, people rated the bad explanations significantly better when they included irrelevant neuroscience. The team repeated the experiment on college undergraduates who were enrolled in an introductory neuroscience class, and the results were similar, both at the beginning and the end of the semester. The students actually rated all the explanations significantly better when neuroscience was included, whether or not the explanations themselves were good.

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Trust your hand, not your eyes

Blogging on Peer-Reviewed ResearchDaniel forwarded me a link to the story, The Hand Can’t Be Fooled, Study Shows, from Science Daily. The story is a short piece about research by Ben-Gurion University of the Negev Psychologist Tzvi Ganel and his colleagues on how the “Ponzo” illusion affects visual perception. The “Ponzo” illusion occurs when two equal line segments appear to be of different lengths because they are superimposed on a pair of converging lines; like two lines hovering over train-tracks disappearing into the distance appear to be of different lengths, as you can see from this illustration I took from the BBC. Ponzo illusion

Ganel and his colleagues ‘hooked participants’ index finger and thumb to computerized position tracking equipment and asked them to grasp the objects with their fingers. Even thought the object appeared to be larger (or smaller) than it really was, the size of their grasp reflected the object’s real rather than apparent size. For good measure, the researchers arranged the illusion so that the object that appeared to be the smaller of the two was actually the larger of the two.’

Ganel argues that the experiment provides compelling support for the ‘two visual systems’ hypothesis put forward by Mel Goodale and David Milner about a decade ago (see Goodale and Milner 1992; Milner and Goodale 1995; for an overview, see Goodale and Humphrey 2001). According to Goodale and Milner, one visual system processes input for object and color recognition, recognizes objects no matter what the perspective of the viewer, and uses conscious parts of the brain; another visual system judges spaces, movement and object trajectories in egocentric space in order to control body movement, and does not necessarily access conscious thought. I’ve written about the two visual systems hypothesis elsewhere in a book chapter that just came out (Downey 2008), so Daniel probably recognized that I’m a bit of a fan of the ‘tectopulvinar’ (motion control) visual system. (For a quick overview of the two systems, this is a good set of diagrams and explanation.)

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