Month: April 2008

How well do we know our brains?

Blogging on Peer-Reviewed ResearchMaking the rounds of neuro-related sites on the web is a recent story from Wired, Brain Scanners Can See Your Decisions Before You Make Them, by Brandon Keim. It’s an interesting short piece on an even more interesting research paper by Chun Siong Soon, Marcel Brass, Hans-Jochen Heinze and John-Dylan Haynes forthcoming in Nature Neuroscience (abstract here). But like so much in the science writing about neurosciences, the piece leaves me feeling like either I don’t get it or science writers really don’t understand the significance of basic brain research. I won’t dwell too much on my issues though with the science writer because I want to really consider the relationship between brain activity and experience, or what role phenomenology might serve in neuroanthropology (besides, I’ve been railing at science writers a bit too much of late…).

Brain areas that predict decisions. By John-Dylan Haynes. Wired.
From Keim’s article, we have this explanation of Haynes’ work:

Haynes updated a classic experiment by the late Benjamin Libet, who showed that a brain region involved in coordinating motor activity fired a fraction of a second before test subjects chose to push a button. Later studies supported Libet’s theory that subconscious activity preceded and determined conscious choice [I have a problem with that phrase, especially ‘determined’] — but none found such a vast gap between a decision and the experience of making it as Haynes’ study has….
Taken together, the patterns [in frontopolar cortex and then parietal cortex] consistently predicted whether test subjects eventually pushed a button with their left or right hand — a choice that, to them, felt like the outcome of conscious deliberation. For those accustomed to thinking of themselves as having free will, the implications are far more unsettling than learning about the physiological basis of other brain functions.

The Libet research is a classic piece (I don’t know if it makes any top 100 lists, but it’s especially important to those of us interested in motor action). The problem seems to be forcing Haynes’ data — which confirms Libet’s older research about the subconscious activity that precedes conscious awareness of ‘choice’ — through a folk theory about ‘free will’ being a necessarily conscious activity setting in motion a chain of mind events leading up to action. Folk understandings posit the existence of ‘The Decider’ in the brain, a kind of uncaused cause, the prime neural mover, which is conscious.

Bottom line, as far as I’m concerned: the research can’t be proving whether or not we have ‘free will’ because ‘free will’ is fundamentally about constraints on ‘will’ (itself a fuzzy concept when you’re looking at brain imaging). That is, the research would have to examine not what the brain does when it makes a choice, but whether that brain activity was constrained by something external to the person. After all, if we say that a person’s ‘free will’ is limited by their brain, that doesn’t really make sense now, does it? Presumably, acts of a ‘free will’ would also be determined by the brain, wouldn’t they? For the brain to ‘constrain’ our own ‘free will,’ it would have to be a thing separate from us.

What the research is showing, however, is something fascinating about the relationship of phenomenology and native categories of mind and how they might intersect with brain science research.
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Jeff Lichtman’s Brainbows

Take a genetically-engineered mouse and add color. That is what Jeffrey Lichtman, Jean Livet, and Joshua Sanes have done. Start by inserting genes that turn neurons fluorescent hues of yellow, red and cyan. Then add some more DNA that randomly expresses those three genes. Presto, rainbow brains.

As a Harvard Science piece reports, “By activating multiple fluorescent proteins in neurons, neuroscientists at Harvard University are imaging the brain and nervous system as never before, rendering their cells in a riotous spray of colors dubbed a ‘Brainbow.’ This technique… allows researchers to tag neurons with roughly 90 distinct colors, a huge leap over the mere handful of shades possible with current fluorescent labeling.”

So many colors in something as complex and elegant as a neuron produces striking images, and I have included many here. These images also permit the study of fields of neurons, from the life course of one neuron to the patterns of connections between neurons. Hence the emerging field of “Connectomics” which “attempts to physically map the tangle of neural circuits that collect, process, and archive information in the nervous system.”

I stumbled across Lichtman’s images in two publications recently. Harvard Magazine features his work, along with five other Harvard scientists, in this month’s feature article, Shedding Light on Life: Advances in Optical Microscopy Reveal Biological Processes as They Unfold. The magazine also provides an online collection of short video clips called Lights! Microscopes! Action! Across the Charles River, MIT’s Technology Review features Lichtman’s work as one of its Ten Emerging Technologies of 2008, complete with an accompanying video featuring Lichtman.

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Savage Minds & Department of Defense’s Plan for Academia

Savage Minds, the blog of “notes and queries in anthropology,” has an important post on “Camelot Revisited: The Department of Defense’s New Plan for Academia.” Robert Gates, Secretary of Defense and former university professor, wants to buy our research and shape it to military uses.

As the post says, “His goal is not to further the overall body of knowledge within academic disciplines, but to increase the military’s stock of knowledge about ‘the countries or cultures we [are] dealing with.’ And by ‘dealing with’, he doesn’t mean tourism.”

Why object? Besides the pernicious skewing of free inquiry (funding matters to researchers and university administrators alike), there is a more important argument: “it treats humans—their lives, their culture, their behavior—as means to an end. This is not knowledge for knowledge’s sake, not by a long stretch. It’s not knowledge for the betterment of humanity. It’s not even knowledge for the satisfaction of human curiosity. It’s knowledge for the achievement of strategic goals—goals that are set and grow out of particular political interests, not the priorities of anthropology and the other social sciences. Goals that take a particular status quo—US imperialism, to put a blunt point on it—as desirable, necessary, and even natural.”

Don’t think the military will do such a thing? They certainly are learning how to work the media, as the New York Times reports in Behind TV Analysts, Pentagon’s Hidden Hand. Now they have a plan for academia too.

A Times Trifecta

Well, actually a double trifecta. The Science and the Health sections online (Tuesday publication) are all neuroanthropolicious.

John Schwartz’s article The Body in Depth covers the work of David Bassett, professor of anatomy and dissection. Even better, we get an online sampling of his dissections on human cadavers, Body Works but without the hype. eHuman will have the entire Bassett collection online (pay to download), with a sample and some accompanying audio here.

Christine Kenneally writes When Language Can Hold the Answer, describing a new way to the old Sapir-Whorf debate: “In stark form, the debate was: Does language shape what we perceive, a position associated with the late Benjamin Lee Whorf, or are our perceptions pure sensory impressions, immune to the arbitrary ways that language carves up the world?” Kenneally points to the role of objects, to brain function and color perception, and spatial processing as new ways to attack the old debate. One nice quote: “By giving us a framework for marshaling our thoughts, language does a lot for us,” Professor Gentner said. “Because spatial language gives us symbols for spatial patterns, it helps us carve up the world in specific ways.”

John Tierney’s piece This Time He’ll Be Breathless covers the magician David Blaine’s physical and mental training in his soon-to-be-successful attempt to break the world record for holding one’s breath. Even without moving and having breathed pure oxygen, 16 minutes sounds like a lot to me! Tierney describes well the mental approach and the embodied expertise, familiar themes for this blog, in accomplishing such a feat.

At 60, He Learned to Sing So He Could Talk is a great story by Karen Barrow on Harvey Atler’s recovery from a stroke. Using “melodic intonation therapy,” Atler learned to draw on the language/musical parts of his right brain after damage to the Broca area in his left hemisphere. In other words, singing helps the brain adapt after a stroke, recapturing language skills.

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Craving money, chocolate and… justice

Image by Lou Beach of The New York Times.A while back, I got really hacked off about a piece of really pathetic science reporting about some brain-related research in the post, Bad brain science: Boobs caused subprime crisis. And now, as if sent from heaven (or the Benevolent Goddess That Pokes Holes in Bad Evolutionary Psychology), this news release from UCLA, Brain reacts to fairness as it does to money and chocolate, study shows, by Stuart Wolpert. All caveats in place — including that I haven’t seen the reviewed piece that backs this up — we have some nifty data with which I can continue to pile scorn on those who think images of women’s cleavage dancing before them is what made the ‘financial titans’ leverage the US economy into subprime disaster.

The human brain responds to being treated fairly the same way it responds to winning money and eating chocolate, UCLA scientists report. Being treated fairly turns on the brain’s reward circuitry.

“We may be hard-wired to treat fairness as a reward,” said study co-author Matthew D. Lieberman, UCLA associate professor of psychology and a founder of social cognitive neuroscience.

That’s right — if you recall the sex-money-chocolate ‘hub’ in the brain that we discussed (well, snickered at) in the ‘Bad Brain Science’ post, now it also looks like this part of the brain is also involved in being treated fairly. So now it’s the ‘sex-money-chocolate-justice hub’ (they’re sure beer and pizza isn’t in there, too?).
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The Sugar Made Me Do It

Neuroscientifically Challenged had a great post awhile back, Every Sweet Hath Its Sour, reporting on research that basically equates modern, processed food with drugs.

Why? As the Duke Health news release tells us, “Researchers at Duke University Medical Center have discovered that the brain can respond to the calorie content of food, even in the absence of taste.” An even better title summarizing this research is “Tasteless Food Reward.”

This March 2008 Neuron paper “Food Reward in the Absence of Taste Receptor Signaling” by Ivan de Araujo, Albino Oliveira-Maia and colleagues shows that high-calorie food can directly reinforce the mesolimbic dopamine system. This result overturns that common assumption that what we eat relies on conditioned preference, pairing taste with the ingestion of a particular substance, say, cops and their donuts. This assumption has been used to great effect in evolutionary medicine research—we evolved in a fat-, sugar- and salt-limited environment, and today our evolved tastes drive our excessive consumptions of fast food in the modern world.

Now the modern situation appears even more dire, for calories alone can also reinforce food consumption, at least in mice “which lack the cellular machinery required for sweet taste transduction.” The Tasteless Food Reward editorial by Zane Andrews and Tamas Horvath tells us that “de Araujo et al. show that mice lacking functional ‘sweet’ taste receptors (trpm5−/−) develop a preference for sucrose by activating the mesolimbic dopamine-accumbal pathway, solely based on calorie load.”

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