purepedantry | July 12, 2006What is the deal with the stories showing brain lesions that end addiction? First, there was this one. Then, today in Nature there was another one:
Strokes often change a person's character, depending on where the damage hits. Some may become more impulsive, others depressed. Now researchers have shown that damage to a small but very specific brain area can wipe out an addiction to smoking.
Antoine Bechera, of the University of Iowa in Iowa City, has identified 14 patients who all stopped smoking immediately after having a stroke that damaged their insular cortex. This seems to be not…
purepedantry | July 12, 2006Parents can rest easy. If your child is a late-talker, it is because your kid is a late-talker, not because you didn't show them enough baby Einstein videos:
New research findings from the world's largest study predicting children's late language emergence has revealed that parents are not to blame for late talking toddlers.
The LOOKING at Language project has analysed the speech development of 1766 children in Western Australia from infancy to seven years of age, with particular focus on environmental, neuro-developmental and genetic risk factors. It is the first study to look at predictors…
purepedantry | July 11, 2006I was listening to the Leonard Lopate Show yesterday on WNYC (my local NPR affiliate), and I heard this great interview with Sharon Weinberger, a defense reporter, about her new book Imaginary Weapons.
In the book, she details all the crazy, fringe science ideas that they come up with at the Pentagon, and how these things are still getting funded. And these ideas are truly crazy, like research into how we can telepathically beam voices into enemy soldiers brains.
If you are pissed about how your last grant didn't get funded, you should listen to this. We are all in the wrong business.…
purepedantry | July 10, 2006There has been a big debate over the last couple years about whether the adult human brain is capable of generating new neurons.
A new study in Neuroscience by Larsen et al. provides some relevant new evidence to that debate. It used rigorous stereological measurement -- a technique called the optical fractionator -- to show that in newborn humans there are the same number of neurons as in the adult brain. This result would lend credibility to the notion that large numbers of new neurons are not being produced in the postnatal human brain.
This is the first time the total number of…
purepedantry | July 10, 2006Misha at Mind Hacks has a great update on brain-computer interface advances.
purepedantry | July 10, 2006The next steak you eat could be grown in the lab:
Edible, lab-grown ground chuck that smells and tastes just like the real thing might take a place next to Quorn at supermarkets in just a few years, thanks to some determined meat researchers. Scientists routinely grow small quantities of muscle cells in petri dishes for experiments, but now for the first time a concentrated effort is under way to mass-produce meat in this manner.
Henk Haagsman, a professor of meat sciences at Utrecht University, and his Dutch colleagues are working on growing artificial pork meat out of pig stem cells. They…
purepedantry | July 10, 2006I haven't had time to read it all yet (it is sort of long and technical), but a new model by Grossberg and Seidman purports to explain how normal cognitive processes go wrong in autism -- a pretty tall order but it looks like they deliver. Here is a description from the press release:
A new model of the brain developed by Dr. Stephen Grossberg, professor and chairman of the Department of Cognitive and Neural Systems at Boston University, and Dr. Don Seidman, a pediatrician with the DuPage Medical Group in Elmhurst, IL, sheds light on the triggers of behaviors commonly associated with autism…
purepedantry | July 10, 2006That will teach 'em:
Social contact helped the Ebola virus virtually wipe out a population of gorillas in the Democratic Republic of Congo, French researchers reported on Monday.
A 2004 outbreak of the virus, which also kills people, killed 97 percent of gorillas who lived in groups and 77 percent of solitary males, Damien Caillaud and colleagues from the University of Montpellier and the University of Rennes in France reported.
Overall, it wiped out 95 percent of the gorilla population within a year, they reported in the journal Current Biology.
"Thousands of gorillas have probably…
purepedantry | July 10, 2006A study in the newest PNAS seeks to quantify the efficiency and resource utilization for various types of biofuels:
The first comprehensive analysis of the full life cycles of soybean biodiesel and corn grain ethanol shows that biodiesel has much less of an impact on the environment and a much higher net energy benefit than corn ethanol, but that neither can do much to meet U.S. energy demand.
The study will be published in the July 11 Proceedings of the National Academy of Sciences.
The researchers tracked all the energy used for growing corn and soybeans and converting the crops into…
purepedantry | July 9, 2006"Why would I ever care about heart attack screening, Jake?" This is a reasonable question so let me put it this way:
The ACS [American Cancer Society] recommends the following screening ages: 20 for breast cancer with mammography from age 40 (at least annually), 21 for cervical cancer (Pap test), 50 for colorectal cancer (several options), and 50 for prostate cancer (prostate-specific antigen test and digital rectal examination annually).
What do we recommend for heart attacks? Well, basically we recommend that, unless you have some very serious risk factors, you wait until you have a heart…
purepedantry | July 9, 2006That's not good:
A new analysis that compares two common inhalers for patients suffering from chronic obstructive pulmonary disease (COPD) finds that one reduces respiratory-related hospitalizations and respiratory deaths, but the other -- which is prescribed in the majority of cases -- increases respiratory deaths.
The Cornell and Stanford universities' statistical analysis of 22 trials with 15,276 participants found that common bronchodilators known as anticholinergics (generically named tiotropium and ipratropium) reduced severe respiratory events by 33 percent and respiratory-related…
purepedantry | July 9, 2006This study from the University of Michigan used eBay to determine whether a seller's reputation helped them get higher prices:
"People with good reputations are rewarded and people with no reputations are not trusted as well as people who have established reputations," said Paul Resnick, professor in the U-M School of Information and the study's principal author.
The study is the first known randomized controlled look at the value of eBay reputations in the natural setting of actual eBay auctions. The findings showed that eBay's feedback system--the cornerstone of the online auction site--…
purepedantry | July 9, 2006On July 5, 1996, Dolly the sheep became the first successfully cloned mammal. Ten years on, has cloning developed the way you expected it to?
Yes and no.
Yes, cloning has developed the way I thought it would in terms of it continuing to develop. There was much ado in our culture about whether we should have cloning at all and if so what kind. All the fuss always struck me as somewhat self-defeating considering how tremendously difficult it is to clone anything. When you can clone a complex animal without 80 tries come back and talk to me about the issues. We need to know so much more…
purepedantry | July 9, 2006I think this paper sounds fascinating but we don't have access to NBER papers here. Anyway, check out this abstract:
Cultures of Corruption: Evidence From Diplomatic Parking Tickets
Corruption is believed to be a major factor impeding economic development, but the importance of legal enforcement versus cultural norms in controlling corruption is poorly understood. To disentangle these two factors, we exploit a natural experiment, the stationing of thousands of diplomats from around the world in New York City. Diplomatic immunity means there was essentially zero legal enforcement of…
purepedantry | July 9, 2006Jonah at The Frontal Cortex posted a great article exposing the limits of genetic determinism. Sometimes a genetic explanation seems so obvious, but further study shows that environment also plays a prominent role. Definitely read the whole thing.
purepedantry | July 9, 2006The American Journal of Psychiatry has this very interesting case, but first you should know some background. There is a pathway in the brain that is commonly referred to as the reward pathway. It is referred to as the reward pathway because if I were to -- for instance -- implant an electrode into parts of it and train a rat to press a lever to zap himself there, he would do so more or less in perpetuity. This ability to very rapidly train self-stimulatory behavior (keep your mind out of the gutter) suggests that these areas of the brain are involved in learning reward.
Here is a diagram…
purepedantry | July 9, 2006This paper in Proceedings of Royal Society Biology purports to show that there is an investment trade-off between immunocompetence and animal growth. In cases where parasitism is high, the trade-off tends to tilt towards investment in immunocompetence.
I love this article for two reasons.
1) It was conducted on a species that -- I &%^@ you not -- is called the Great Tit:
The study was performed in 2004 in a population of great tits breeding in nest boxes in a mixed forest near Bern, Switzerland. The great tit is a small (16-20 g) hole-nesting passerine that produces one or two broods…
purepedantry | July 9, 2006Several bloggers and columnists have been expressing skepticism as to the concept of energy independence, and I think they make some good arguments.
John Fialka in the WSJ:
The allure of energy independence is easy to see. It reinforces the belief that Americans can control their own economic destiny and appeals to a "deep-seated cultural feeling that we are Fortress America and we will not be vulnerable to unstable regimes," says David Jhirad, a former Clinton administration energy official who is vice president at World Resources Institute, an environmental-research group.
In fact, experts…
purepedantry | July 8, 2006The Synapse #2 is up at A Blog Around the Clock.
The next Synapse is to be hosted by The Neurophilosopher's Blog on July 23rd. Submission guidelines are here.
purepedantry | July 7, 2006Prosopagnosia is a rare disorder that can result from strokes where the individual is unable to recognize faces but maintains the ability to recognize other non-face objects. Disorders like prosopagnosia suggest to neuroscientists that the machinery for processing faces in the brain is in part special and segregated from the machinery for processing other objects.
It turns out that there is also a wildly underreported and surprisingly prevalent form of hereditary prosopagnosia (HPA), as shown in a new paper in American Journal of Medical Genetics. HPA has a prevalence of almost 2.5% and…