cortex | August 2, 2006A fascinating study on the psychological effects of war just came out in JAMA. Researchers measured the cognitive abilities of soldiers after serving in Iraq. What they found is consistent with our current models of stress, which predict that chronic stress (of the sort found in Baghdad) will damage the hippocampus, a part of the brain essential for learning and memory. But the news wasn't all bad. After returning from battle, soldiers had faster reaction times.
A large study of Army troops found that soldiers recently returned from duty in Iraq were highly likely to show subtle lapses in…
cortex | August 1, 2006Bruce Reed observes in Slate today that hot states tend to vote Republican. Does this mean that global warming will inevitably increase the spread of red states? Do sweltering summers cause conservative politics?
21 of the 27 states with an average temperature over the last half century of more than 50 degrees Fahrenheit voted for Bush in 2004, providing 241 of his 286 electoral votes. In the 23 states with an average temperature below 50 degrees, by contrast, Democrats cleaned up in the electoral vote, 141 to 45.
The political climate is the same in the House of Representatives. Democrats…
cortex | August 1, 2006The wonder of a good novel is the way it uncovers universals through particulars. Having just read Allegra Goodman's Intuition, I was struck by the way her descriptions of a fictional molecular biology lab seemed to describe every molecular biology lab. Or is it just that every lab really looks the same?
"Two to a bench, like cooks crammed into a restaurant kitchen, the postdocs were extracting DNA in solution, examing cells, washing cells with chemicals, bursting cells open, changing cells forever by inserting new genetic material. There was scarcely an inch of counter space. Lab benches…
cortex | August 1, 2006After reading articles like this (or this or this or this), I can't help but wonder what's happening to the brains of Iraqis, Palestinians, Israelis and Lebanese. After all, neuroscience now knows that chronic stress is toxic. When your brain is constantly suffused with stress hormones (usually glucocorticoids), neurons die and aren't replaced. Dendritic growth slows down. You have fewer synaptic proteins. Your hippocampus begins to wither and shrink. Even if you are just a baby in your mother's belly during the war, you are still born with reduced levels of neurogenesis.
The worst part of…
cortex | July 31, 2006I'm still puzzled over why Floyd Landis might have taken testosterone. After all, bicyclists are supposed to be svelte, and injecting yourself with a little hormone the night after a tough ride probably wouldn't lead to increased muscle recovery in time for the next day's race. So why do bicylists (like this guy) do it? Well, it seems that the only immediate effect testosterone has is psychological. The former cyclist Jesús Manzano put it bluntly: "Testosterone gives you a euphoria." Lab experiments with hamsters seem to confirm this. As researchers at USC note, "Testosterone overdose…
cortex | July 29, 2006Well, sort of. A well-timed insult by Materazzi also helped. But the WSJ reports today that several members of the Italian team used neurofeedback earlier this year to help hone their powers of concentration:
In February, months before the tournament started, some of Italy's best soccer players, including a handful who would later play in the Cup, began spending much of their practice time in a small room in Milan furnished with six luxury leather recliners facing a glass wall.
On the other side of the glass Bruno De Michelis, head of the sports science lab for AC Milan, one of the country's…
cortex | July 27, 2006After my last post on the frustrating inefficiencies of experimental failure, I recieved an interesting comment:
I discovered in the late stages of graduate school that my extremely long hours (upwards of 80/week) were extraordinarily unproductive. I was doing cell culture and electrophysiology and while I had reams of data, it wasn't going anywhere. Only when I switched to a lab doing slice electrophysiology, where the length of the day is limited by the survival of the slice (~6hrs after cutting, making for a 8-9 hr day), did I discover that I could get more work done in less time by…
cortex | July 26, 2006The NY Times Magazine described an interesting study that I'd never heard about before:
A study of French youngsters adopted between the ages of 4 and 6 shows the continuing interplay of nature and nurture. Those children had little going for them. Their I.Q.'s averaged 77, putting them near retardation. Most were abused or neglected as infants, then shunted from one foster home or institution to the next.
Nine years later, they retook the I.Q. tests, and contrary to the conventional belief that I.Q. is essentially stable, all of them did better. The amount they improved was directly related…
cortex | July 26, 2006Small Gray Matters has an insightful post on the recent mirror neuron debate here at Scienceblogs. While I think a dose of skepticism is always helpful (especially when big mysteries like "empathy" and "theory of mind" are being tossed around), Small Gray Matters offers a persuasive defense of this circuit in the motor cortex:
Mirror neurons offer what is clearly the most plausible current model of imitative behavior, which isn't a trivial matter, since imitation turns out to be pretty rare in the animal kingdom. For another, it wasn't all that long ago that people were pretty skeptical about…
cortex | July 25, 2006Scienceblogs is abuzz with discussion over the difficulty of melding family life and an academic career in science. Having worked for several years as a tech in an ambitious neuroscience lab, I'm amazed that post-docs even contemplate a family life. Most post-docs and grad-students I knew worked 60 hours a week (or more) for piss-poor wages. They came in on the weekend, and would often find themselves in the lab at odd hours of the night, feeding cultured neurons or Aplysia spawn or monitoring some other experimental variable that doesn't have to sleep.
I now realize that today's post-docs…
cortex | July 24, 2006Mixing Memory tosses a helpful bucket of cold water on the mirror neuron frenzy. The post focuses on the hypothesis that mirror neurons were a crucial ingredient in the development of human language. While I think much of the skepticism is well deserved - mirror neurons remain a mysterious bunch of cells - I think Mixing Memory neglects to mention one important bit of evidence that supports the mirror neuron-language connection.
Specifically, Giacomo Rizzolatti (the godfather of mirror neuron research) has shown that mirror neurons can be activated by fragments of language that are about…
cortex | July 22, 2006So we lost the stem cell battle this year. Moral self-righteousness once again defeated pragmatic common sense. Of course, important political progress was made: Congress supported science, and Bush was forced to veto a popular bill.
So what should we do next year? I think one important argument for the pro-stem cell side was missing from this debate. If Bush and Brownback are really serious about preventing "immoral" embryo research, then it's now clear that the federal government must become involved. Back in August 2001, when Bush originally proposed his stem cell "compromise," he assumed…
cortex | July 20, 2006The new Tesla has officially been unveiled. Wired has already taken it for a test drive:
He releases the brake and my head snaps back. One-one-thousand: I get a floating feeling, like going over the falls in a roller coaster. Two-one-thousand: The world tunnels, the trees blur. Three-one-thousand: We hit 60 miles per hour. Eberhard brakes. We're at a standstill again -- elapsed time, nine seconds. When potential buyers get a look at the vehicle this summer, it will be among the quickest production cars in the world. And, compared to other supercars like the Bugatti Veyron, Ferrari Enzo, and…
cortex | July 20, 2006The Wellcome Trust just announced the winners of the 2006 Biomedical Image Awards. The pictures are absolutely stunning:
Here is a goblet cell, which line the inside of the intestine and respiratory system.
And here is a cerebellar granule cell, growing in culture.
cortex | July 19, 2006I can't believe this man is a senator. Listen to his speech on stem cells yesterday in the Senate: it's scary.
[Hat tip: Mimms]
cortex | July 19, 2006My new Seed article is now online. I wanted to use the neuroscience of learning to draw some connections between a lot of different things, from mirror neurons to Algebra teachers to Toyota factories. Take a look, and tell me what you think.
cortex | July 19, 2006In response to my blog yesterday about America's continued love affair with horsepower and V8 engines, I recieved an excellent comment. It's worth a read:
If you ask people why they drive 4WD SUVs you get a number of answers, usually associated with safety, or power and control. While many early SUV models were available in 2WD versions, people overwhelmingly prefered 4WD. Yet repeated usage surveys in the 90s showed only about 10% of SUV drivers ever used 4WD. What gives? Why are people buying the extra design, precision engineering, and transmission weight and buying the extra gas to haul…
cortex | July 18, 2006So dumb that we're still buying SUV's. Despite the fact that gas is now almost $3 a gallon, the average fuel economy of new 2006 models was virtually flat with a year ago at 21 miles per gallon, according to a new EPA report. In fact, this is lower than the average fuel economy of new cars in 1987 (22.1 mpg).
Why the lack of progress? Because people are more interested in horsepower than fuel economy. While new cars in 1987 had an average of 117 horspower, new cars in 2006 averaged 219 horsepower. This is depressing news: even when the marketplace should encourage people to buy more fuel…
cortex | July 18, 2006We should all move to Greenland. From the WSJ:
Greenland represents one of the largely unrecognized paradoxes of global warming. In former Vice President Al Gore's recent film "An Inconvenient Truth," the melting of Greenland's ice cap, along with a similar cap in the Antarctic, is portrayed as one of the greatest threats of global warming. If the layers of ice and snow holding billions of tons of water were to melt, scientists warn that global sea levels would rise by 40 feet, submerging lower Manhattan, the Netherlands and much of California.
But to many of the people who live here in…
cortex | July 18, 2006Judge Richard Posner has stepped into the tedious debate over innate cognitive differences between men and women. While I'm usually a fan of Posner's contrarian streak, he indulges here in some terrible evolutionary psychology. He manages to justify a blatant inequality - women have lower average earnings than men - by constructing a silly, trite and untestable hypothesis about our "ancestral human environment":
the mean performance of women in college and university is superior to that of the men, but the variance of male performance is greater and as a result there are more male geniuses.…