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.

Tightening your belt on your mind

The New York Times has an opinion piece by Sandra Aamodt and Sam Wang, Tighten Your Belt, Strengthen Your Mind, on the implications of new research on ‘willpower.’ Daniel already noted this research in his post, Glucose, Self Control and Evolution, and linked to the original research paper, Self-Control Relies on Glucose as a Limited Energy Source: Willpower Is More Than a Metaphor.

The New York Times‘ piece discusses the possibility that spending discipline necessitated by economic hard times might lead to less ‘willpower’ when confronting weight control issues. The authors write:

The brain has a limited capacity for self-regulation, so exerting willpower in one area often leads to backsliding in others. The good news, however, is that practice increases willpower capacity, so that in the long run, buying less now may improve our ability to achieve future goals — like losing those 10 pounds we gained when we weren’t out shopping.

Specifically, the research team ‘found that people who successfully accomplish one task requiring self-control are less persistent on a second, seemingly unrelated task.’ In one study, subjects were either given radishes or freshly baked chocolate chip cookies before doing a puzzle (how did they get human ethics clearance for the cookies?!). The folks who ate the radishes lasted longer and were more persistent in experimental tasks than the cookie eaters, or those who were allowed to pass on the radish appetizer.

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‘Blind to change’ or just ‘mostly blind’?

The New York Times Science section has a recent article, Blind to Change, Even as It Stares Us in the Face, by Natalie Angier (you can access it without charge by signing up to their site). The article follows along some of the lines laid out by Jeremy Wolfe of Harvard Medical School, at a symposium on Art and Neuroscience.

Angier discusses Wolfe’s use of Ellsworth Kelly’s ‘Study for Colors for a Large Wall’ to illustrate what is typically called ‘change blindness’: ‘the frequent inability of our visual system to detect alterations to something staring us straight in the face.’ Kelly’s painting is an 8×8 grid of coloured squares, and Wolfe apparently showed repeatedly slides of the picture, sometimes with the colours of squares altered. When he first showed the slide, Angier writes: ‘We drank it in greedily, we scanned every part of it, we loved it, we owned it, and, whoops, time for a test.’ After the test, when the audience was thoroughly uncertain about its ability to recall even the basic patterns of colours; ‘By the end of the series only one thing was clear: We had gazed on Ellsworth Kelly’s masterpiece, but we hadn’t really seen it at all,’ Angier reports.

Change blindness is a fun phenomenon to put into research design. Researchers get away with some really amazing manipulations without their subjects recognizing them. Some experiments report that subjects fail to notice, as Angier details, whole stories of buildings disappearing or that ‘one poor chicken in a field of dancing cartoon hens had suddenly exploded.’

Dr. Wolfe also recalled a series of experiments in which pedestrians giving directions to a Cornell researcher posing as a lost tourist didn’t notice when, midway through the exchange, the sham tourist was replaced by another person altogether.

I’ve also seen discussions of experiments in which subjects watched a videotape and failed to notice a guy in a gorilla suit walking through the middle of the video because they were asked to pay attention to other details.

But is it that we’re blind to change, or that we just trust the world to remember for us, and we’re really good at getting the information we need?
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Encephalon at Of Two Minds

The most recent edition of the brain sciences blog carnival, Encephalon, is being hosted on the blog, Of Two Minds. Encephalon Goes to Paris (Hilton) includes a couple of references to work here on Neuroanthropology, but we do get called out on our severe reservations about twin studies (ooooo… don’t get me started…).

This won’t be news to many of you. In fact, a fair few of the visits we’ll get over the next few days will probably come from Encephalon-related browsers, but if you don’t already know about it, there’s a pile of interesting material in this edition. I won’t even attempt to summarize all the interesting stuff that you’ll find links to on everything from video games to synesthesia to the history of lithium to olfaction and sensing danger. If you’re not visiting here from there, you may want to pay a visit.

Meditating makes the brain more compassionate

Blogging on Peer-Reviewed ResearchScientific American‘s Mind & Brain website has a discussion of a recent study of meditation, Meditate on This: You Can Learn to Be More Compassionate. The original research article that this piece is discussing, ‘Regulation of the Neural Circuitry of Emotion by Compassion Meditation: Effects of Meditative Expertise’ by Antoine Lutz, Julie Brefczynski-Lewis, Tom Johnstone, and Richard J. Davidson, is available on-line at the Public Library of Science (here).

The research team investigated the activity of the insula and anterior cingulate cortices, areas implicated in empathetic reactions to others’ suffering, when people voluntarily sought to feel compassion. In other words, the research team looked at whether a set of brain areas which are active when people see other people suffering and feel empathy might be intentionally activated in situations where subjects imagined compassion; could will or conscious thought be used to summon up brain activity that looks like a reaction to suffering that is almost automatic in most people? (Lots of caveats here, but you get the gist.)

In particular, the team was looking at whether compassion meditation might make people more likely to have strong reactions to hearing the signals of another person’s distress; from the abstract, ‘Our main hypothesis was that the concern for others cultivated during this form of meditation enhances affective processing, in particular in response to sounds of distress, and that this response to emotional sounds is modulated by the degree of meditation training.’ Specifically, the research team compared novice meditators to ’16 long-term Buddhist meditators, whom we classified as experts’: ‘Experts had previously completed from 10,000 to 50,000 hours of meditative training in a variety of practices, including compassion meditation, in similar Tibetan traditions (Nyingmapa and Kagyupa).’

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New neuroscience podcasts and Brazilian racial genomics

Vaughn at Mind Hacks points out several sites with good neurosciences lectures to download on a recent post, Lancet and MNI neuroscience podcasts. The ones from Lancet Neurology can be found here; and the ones from the Montreal Neurological Institute are here. In a post in February, Neurology podcasts – the shocking truth, Vaughn offers still more lectures available online from a number of sources (maybe we should try to do this at Neuroanthropology, especially if we can match Vaughn’s description of one podcast as an ‘excessively thorough lecture given by a voice synthesiser’ — now there’s something for which I can strive!).

On the Lancet Neurology site, there’s a number of good-looking lectures, but many are discussions of the whole volume by editor Helen Frankish. This might be an easy way to get a grip on a wide variety of current research, but they are more likely to be kind of technical for the non-specialist.

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Smell, fear and sensory learning

Blogging on Peer-Reviewed ResearchWen Li, James D. Howard, Todd B. Parrish, and Jay A. Gottfried have a fascinating article in the most recent edition of Science, ‘Aversive Learning Enhances Perceptual and Cortical Discrimination of Indiscriminable Odor Cues.’ The researchers trained subjects to discern between the aroma of chemicals that initially were indistinguishable using electric shocks (!) coupled with one of the two aromas. The research is a great example of perceptual learning, a form of neural enculturation that I think is absolutely essential to understanding cultural difference but little appreciated in anthropology.

Subjects in the experiment were given a test of their ability to discern between very closely related chemicals: ‘On each trial, subjects smelled sets of three bottles (two containing one odorant, the third containing its chiral opposite) and selected the odd stimulus.’ Before the training, subjects selected the odd odor out 33% of the time — no better than random. After the repeated association of one chemical with shocks, subjects’ ability to discriminate the smells improved markedly, showing that negative reinforcement training could ‘enhance perceptual discriminability between initially indistinguishable odors.’ Moreover, the neural representation of the smells changed, as found with fMRI.

From their abstract:

We combined multivariate functional magnetic resonance imaging with olfactory psychophysics to show that initially indistinguishable odor enantiomers (mirror-image molecules) become discriminable after aversive conditioning, paralleling the spatial divergence of ensemble activity patterns in primary olfactory (piriform) cortex. Our findings indicate that aversive learning induces piriform plasticity with corresponding gains in odor enantiomer discrimination, underscoring the capacity of fear conditioning to update perceptual representation of predictive cues, over and above its well-recognized role in the acquisition of conditioned responses. That completely indiscriminable sensations can be transformed into discriminable percepts further accentuates the potency of associative learning to enhance sensory cue perception and support adaptive behavior.

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