Economists in the last few years have been shifting toward testing their theoretical models, whether through the experiments of behavioral economics, or, “natural experiments.” The reason economists have had issues with testing their models is that experimentation on humans has some natural constraints. Macroeconomists have an even greater problem, as experimentation on whole societies not only presents ethical conundrums, but there’s no way to fund or implement experiments on this scale. Macroeconomists turn out to be the paleontologists of economics.

Of course economists aren’t the only ones who’ve had this sort of problem with humans. The reason that geneticists focused on organisms such as flies, mice and fish is partly that these taxa breed fast and are easy to maintain in laboratories. But obviously there are things you can do, such as mutagenesis, with model organisms which you can not do with humans. Human genetics has traditionally relied on “natural experiments” of a sort, inbred lineages, recurrent recessive diseases, etc. Genetics has been a supplementary handmaid to medicine by and large. But sometimes history can load the die in genetics’ favor as well.

During the “Columbian Exchange” the New and Old World engaged in a massive transfer of ideas and individuals. The Old World received potatoes, maize, and tomatoes (to name a few). The New World…well, the New World received black people and white people. As documented in works such as 1491 the indigenous populations of the New World collapsed with the introduction of Old World diseases. Native peoples disappeared from the Caribbean, and were marginalized on the mainland excepting ecologically remote (e.g., the Guatemalan highlands) or forbidding (e.g., the Peruvian highlands) regions. But of course despite the obliteration of indigenous cultural self-consciousness and identity, the native populations did not totally disappear, they persisted genetically in the numerically dominant mestizo populations of much of Latin America. You don’t need genetics to understand what happened, books like Mestizaje in Ibero-America outline in detail using conventional historical archives how Spanish men arrived in New World and entered into relationships with indigenous women. Often several at a time, in contravention of the Catholic Church’s requirement of monogamy.

But in the post-genomic era we have more to go on than impressions, we can quantitize the extent and nature of the admixture, something of importance when considering medical research. A new paper in PNAS adds some more to the growing body of results on Latin American genomics by including populations which have traditionally been overlooked, and also putting a spotlight on the long term impact of sex-biased admixture. Genome-wide patterns of population structure and admixture among Hispanic/Latino populations:

Hispanic/Latino populations possess a complex genetic structure that reflects recent admixture among and potentially ancient substructure within Native American, European, and West African source populations. Here, we quantify genome-wide patterns of SNP and haplotype variation among 100 individuals with ancestry from Ecuador, Colombia, Puerto Rico, and the Dominican Republic genotyped on the Illumina 610-Quad arrays and 112 Mexicans genotyped on Affymetrix 500K platform. Intersecting these data with previously collected high-density SNP data from 4,305 individuals, we use principal component analysis and clustering methods FRAPPE and STRUCTURE to investigate genome-wide patterns of African, European, and Native American population structure within and among Hispanic/Latino populations. Comparing autosomal, X and Y chromosome, and mtDNA variation, we find evidence of a significant sex bias in admixture proportions consistent with disproportionate contribution of European male and Native American female ancestry to present-day populations. We also find that patterns of linkage-disequilibria in admixed Hispanic/Latino populations are largely affected by the admixture dynamics of the populations, with faster decay of LD in populations of higher African ancestry. Finally, using the locus-specific ancestry inference method LAMP, we reconstruct fine-scale chromosomal patterns of admixture. We document moderate power to differentiate among potential subcontinental source populations within the Native American, European, and African segments of the admixed Hispanic/Latino genomes. Our results suggest future genome-wide association scans in Hispanic/Latino populations may require correction for local genomic ancestry at a subcontinental scale when associating differences in the genome with disease risk, progression, and drug efficacy, as well as for admixture mapping.

The issue here is that “Hispanic” and/or “Latino” is not a race. In fact, as American readers may be aware the category emerged in 1970 as a way of organizing ethnic and racial identity for the Census. Despite a real pan-American consciousness there is obviously a great deal of cultural and genetic variation in Latin America. Caribbean nations which a large African component have a different identity from Mexico, where the non-Spanish segment is indigenous. Conversely, Argentina has a self conception as a white nation, despite some ambiguity in genetics.

In this paper they focused on 100 individuals from Mexico, Columbia, Ecuador, Dominican Republic and Puerto Rico. This gives them a good coverage of different regions of Latin America, and also looks into populations which are not often included in these studies, such as Dominicans. A series of figures highlights the primary results.

I’ve rotated this figure to maintain its resolution. It’s a Frappe analysis of the ancestry of individuals within various populations assuming K ancestral populations. With Latin Americans the idea of ancestral populations makes a bit more sense, since we know what the ancestral populations are! They use the HGDP populations as a reference for points of comparison.

Since we’re focused on native, Africa and white ancestry, K = 3 is probably more important. No surprise that the Latin America populations exhibit variation in ancestral quanta within them. Some Mexicans look like Europeans. Some Mexicans look like Native Americans. And some Mexicans look mixed. I assume that most readers are aware of this, assuming that they encounter Mexicans at all in their daily life.

Of course the ancestry came in through different avenues. The sexual exploitation of black females by white males in the United States is well known, but it does seem that the same dynamic, at least in terms of the genetic combination, existed in Latin America for much of its history, with black females being complemented by indigenous females. Figure 5 illustrates this well. You see the various Latin American populations (the abbreviations should be obvious). The boxes span the 1st to 3rd quartile in ancestry within each subpopulation from each respective ancestral group (the whiskers represent the ranges). Note the differences between the X chromosome, which spends 2/3 of its time in females, and the autosome, which is not sex biased.

Ah, but we can get more precise than that. They typed these individuals on their mtDNA, which is passed purely through women, and their Y chromosomes, which is passed purely through men. These loci do not recombine, and so are transmitted in such a manner that it is relatively easy to reconstruct their phylogenies. There has been a great deal of phylogeographic exploration of these two loci. In the next figure what you see are the position of the individuals in this study in terms of total genome content distance from the three ancestral populations, but, the color of their positions is dictated by the origin of their mtDNA and Y lineages.

The top panel are male lineages, and the bottom panel are female lineages. The preponderance of European ancestry, in relation to native and African ancestry, seems rather clear on the autosomal genome. There is admixture, but you have more people concentrating at the European vertex than at the other two. Most of the Y lineages, presumably men, are European. Some are African, and a few are native. Interestingly they note in the text that several lineages associated with North Africa and the Middle East are found in these populations. Why? The answer seems relatively simple: they were brought by the Muslim invaders, or were Jews, who later became Christian. There have been many phylogeographic analyses of Y lineage distributions, and believe it or not Iberia and North Africa are actually strongly differentiated. The Middle Eastern lineages I’m betting are from Sephardic Jews; most of the “Moors” who settled in Spain are likely to have had more Berber than Arab ancestry.

The maternal lineages show a really interesting pattern. There are a preponderance of native mtDNA lineages, and a significant number of African ones. But notice that most people of overwhelming European ancestry nevertheless retain a native maternal lineage! We saw this in Argentina, a population which identifies as white, seems to be highly admixed on the mtDNA. I suspect that what you’re seeing is the long reach of the first mothers, whose descendants intermarried with Spanish men who relocated to the New World. The Aztec and Inca nobility gave their daughters to the Spaniards who arrived, and I suspect that the predominantly European elites of Latin America still carry those lineages with them, despite their overwhelming limpieza de sangre. Another important point is that both Dominicans, and especially Puerto Ricans, carry signatures of these first mothers (as well as total genome content). 20 of 27 Puerto Ricans carry native mtDNA. This is somewhat shocking, as these Caribbean islands were reputed to have been nearly devoid of indigenous populations only a generation after First Contact, in large part due to disease.

Which brings me back to Neandertals. Non-African humans may carry somewhat less than 5% of their ancestry from this population. But to my knowledge there is no cultural continuity, and we do conceive of ourselves as fundamentally different from the Neander-kind. And yet genetically the Neandertals are highly successful through us The chaos, havoc, and population collapse wrecked by the Europeans when they encountered native New World populations may be somewhat analogous to what happened to archaic groups who had to face the oncoming demographic blast of African humans. And yet some of the genetic material of the locals was absorbed just before their extinction. The half-Taino children whose fathers were Spanish may have had the genetic defenses of European diseases which allowed them to survive the hardships of their lives. Granted, these children lost a genuine connection with their Taino ancestors, but the descent of those native peoples still persists onward. Interestingly, some readers of this weblog have had the same reaction to the idea that Neandertals persist in our own genome. Ultimately the reaction and response to this is not a scientific issue, but a normative one. Dare I even say, a spiritual one?

Citation: Bryc K, Velez C, Karafet T, Moreno-Estrada A, Reynolds A, Auton A, Hammer M, Bustamante CD, & Ostrer H (2010). In the Light of Evolution IV: The Human Condition Sackler Colloquium: Genome-wide patterns of population structure and admixture among Hispanic/Latino populations. Proceedings of the National Academy of Sciences of the United States of America PMID: 20445096

Image Credit: Cristiano Del Riccio

Like the CEOs of failing car companies and steroid-suspected baseball players before them, the leaders of BP, Transocean, and Halliburton had to trek up to Capitol Hill today to stand before Congress. The three company executives played circle-of-blame in front of the Senate Energy and Natural Resources Committee. To sum up their statements:

BP: It was Transocean’s fault.

Transocean: It was Halliburton’s fault.

Halliburton: It was BP’s fault.

Since we may not know the whole story about the Deepwater Horizon’s explosion and sinking that resulted in the current environmental disaster in the Gulf, let’s recap the technical failures.

1. Blowout preventer

This piece of equipment, previously anonymous to most of the public, is now notorious for its failure to do its job—closing off the well automatically in response to a sudden emergency. Lamar McKay, president and chairman of BP America, used that fact to deflect blame:

Since Transocean owned the rig’s safety equipment, Mr. McKay said that Transocean was responsible; he added that there were “anomalous pressure test readings” before the explosion that “could have raised concerns” [The New York Times].

However, just after the accident, BP’s CEO Tony Heyward said that a blowout preventer’s failure was “unprecedented.” Not exactly, according to the AP’s investigation, which found many examples of accidents this decade in which failed blowout preventers played a role. Transocean knew about the issues, the AP says, but so did the federal government.

In the late 1990s, the industry appealed for fewer required pressure tests on these valves. The federal [Minerals Management Service] did two studies, each finding that failures were more common than the industry said. But the agency, known as MMS, then did its turnaround and required tests half as often. It estimated that the rule would yield an annual savings of up to $340,000 per rig. An industry executive praised the “flexibility” of regulators, long plagued with accusations that it has been too cozy with the industry it supervises [AP].

2. Cementing

OK, Transocean chief executive Steve Newman said, there was a blowout preventer failure, but that was not the root cause of the explosion or the leak.

“The one thing we know with certainty is that on the evening of April 20 there was a sudden, catastrophic failure of the cement, the casing, or both,” Newman said. The cementing job was done by Halliburton [The Washington Post].

In fact, Halliburton was still working on its cementing job 20 hours before the explosion.

There was already a pipe in the well for the oil to flow through, but no oil was supposed to flow yet. Cementing, one of the last steps in well construction, seals the crack between the pipe and the wall of rock. Crews pump the cement through the pipe, but it ends up on the outside of the pipe, in the space between the pipe and the rock wall. The cement also caps the bottom of the pipe [NPR].

Cementing could go bad if the material isn’t mixed to the correct consistency. If any oil and gas leaks out early, NPR reports, it can cause a pocket in the cement that doesn’t seal up. And if cement doesn’t set properly, oil and gas could escape the well and even explode.

3. Oversight, and response failures

While Transocean owned the rig and Halliburton poured the concrete, this was BP’s show. And, so, the other two companies also employed the “just following orders” defense.

Halliburton was “contractually bound,” to follow BP’s instructions, Tim Probert, president of global business lines for the Houston-based energy services company, will tell the panel.

“All offshore oil and gas production projects begin and end with the operator,” Stephen Newman, chief executive officer of Swiss drilling company Transocean said in his prepared remarks. BP, the London-based oil company, decided “where and how” its well was to be drilled, Newman said [BusinessWeek].

Whatever BP’s failures were in administering the the drilling operation and preventing an accident (and those will most likely continue to leak out, like oil into the Gulf), the company’s attempts to mitigate the spill have met with limited success. BP’s initial attempt to shut of the flow, using robot submersibles to close of the valves, has failed. After the company built its 100-ton containment dome to try to capture the flow and pump it to a tanker on the surface, icy buildup of methane and water at the depth of 5,000 feet prevented the dome from getting a seal.

The methane that caused the original explosion remains gaseous down to -161°C. The “ice” that’s forming is actually a solidified mixture of methane and water called a clathrate [Ars Technica].

Faced with dwindling options and still two months before a relief well could be completed, BP is even considering throwing garbage at the leak in the form of a “junk shot” in a last-ditch effort to stem the flow.

“They have horribly underestimated the likelihood of a spill and therefore horribly underestimated the consequences of something going wrong,” said Robert Bea, a professor at the University of California, Berkeley, who studies offshore drilling. “So what we have now is some equivalent of a fire drill with paper towels and buckets for cleanup” [Dallas Morning News].

Previous posts on the BP oil spill:
80beats: 5 Offshore Oil Hotspots Beyond the Gulf That Could Boom—Or Go Boom
80beats: Gulf Oil Spill: Do Chemical Dispersants Pose Their Own Environmental Risk?
80beats: Gulf Oil Spill: Fisheries Closed; Louisiana Wetlands Now in Jeopardy
80beats: Gulf Oil Spill Reaches U.S. Coast; New Orleans Reeks of “Pungent Fuel Smell”
80beats: Uh-Oh: Gulf Oil Spill May Be 5 Times Worse Than Previously Thought

Image: U.S. Coast Guard

Sadly, this is probably good politics.....

Click here to view the embedded video.

NASA just tested an emergency escape system in the event of an aborted launch attempt.  In light of the current end to human space flight, you might be asking yourself, why?

For one thing, they put a lot of work into the project, I’d want to see it work too. Eventually the private space industry WILL be doing human spaceflight.  I’m sure they will be able to use some of the technology. Besides I think NASA should act as enablers to the private industry, because in the end private industry will be more efficient.  There is 1.2 billion in NASA’s budget to greatly help in that regard.

While I’ll make no bones about my displeasure of us becoming dependent on others to continue just getting a ride to the ISS — to the tune of a half billion dollars.  Not everything about the NASA budget is (IMO) bad, sure there are a couple big ticket items I’d toss, still it sounds we could end up with a couple pretty good Mars missions and a moon mission.  The James Webb telescope appears still to be funded, plus an increase in the budget to look for asteroids potentially hazardous to Earth.

There is also hope for getting some of our bright students employment in the aerospace field, certainly a positive idea.

We’ll just have to wait and see what actually transpires.  I keep hearing “transparency” bandied about where the government is concerned.  Let’s just hope the meaning of transparency starts to be defined as open, and not invisible like it currently seems to be.

I’ll get off my soapbox now. Be sure the have a look at some of the comments posted to the video at YouTube, I got a kick out of them.

AND FINALLY (!!)  Happy Mother’s Day to all the mom’s out there.

Happy Mother’s Day! If you’re a mother, then I suggest you take a tip from this mom here:

Go take a nap!

[Click to enhootenate. Touching back story that all mothers will relate to here.]

An anonymous reader writes, “I am a computer programmer and amateur herpetologist. On my leg is Henry, a North Brazilian Boa constrictor — rare in captivity at the time. I brought him in for photos before we began, and again after it was completely healed. As you can see in this photo, his colors were altered in the tattoo to stand out better. It took 20 hours over the course of 14 months to complete and was done completely freehand. Each scale was drawn individually. This photo is so special, since he’s posed very much the way he came out on my leg, tongue and all. It’s not like I could give him instructions on what to do.”

Click here to go to the full Science Tattoo Emporium.

Photographed at Perth Zoo

It’s Mother’s Day here in the States, so…

I know, I just did a Star Wars metaphor, but this made me LOL.

It’s been floating around teh tubez for a few days now. Sometimes these viral things really are pretty cool. In a dorky way. And congrats to the happy couple; two more for the Rebel Alliance coming up!

Tip o’ the R2 unit to Fark.

Universe Today is reporting that a recent landslide on Mars looks to be triggered by a small (under 1 meter) rock hitting the surface of the planet. The landslide is less than three years old, and a new impact crater near the top appears to be the culprit.

Go to the UT article to get details. And look at the bigger version there of the image taken by the HiRISE camera; there’s a much larger crater near the bottom of the slide, and you can see where the dust rolled into it and up the far slope of the crater wall, but only partway! It’s yet another amazing shot of the dynamic surface of this nearby world.

Bill Gates is getting serious about geoengineering. Back in January, after the failure of governments at the Copenhagen Climate Change summit to do anything serious, the billionaire former head of Microsoft announced he’s give nearly $5 million of his fortune to fund research into geoengineering projects. Recently he announced his first concrete foray into the field: giving $300,000 to project that would spray seawater into the sky, seeding clouds that would hopefully block some of the sun’s UV rays.

The machines, developed by a San Francisco-based research group called Silver Lining, turn seawater into tiny particles that can be shot up over 3,000 feet in the air. The particles increase the density of clouds by increasing the amount of nuclei contained within. Silver Lining’s floating machines can suck up ten tons of water per second. If all goes well, Silver Lining plans to test the process with 10 ships spread throughout 3800 square miles of ocean [Inhabitat].

Most of the major geoengineering ideas that have been proposed—launching a reflective shield into space, artificial trees to pull carbon dioxide out of the air—are extremely expensive and difficult.

However, a study last year calculated that a fleet of 1,900 ships costing £5 billion (about $7.5 billion) could arrest the rise in temperature by criss-crossing the oceans and spraying seawater from tall funnels to whiten clouds and increase their reflectivity [The Times].

Unlike, say, seeding the sea with iron, seawater spraying doesn’t involve dumping additional material into the environment, so it would require less arduous permit-getting to test. And as opposed to the plans to put particulates in the clouds, seawater spraying would be easier to shut down and wouldn’t affect weather patters for quite as long.

Armand Neukermanns, who is leading the research, said that whitening clouds was “the most benign form of engineering” because, while it might alter rainfall, the effects would cease soon after the machines were switched off [The Times].

Related Content:
80beats: With $4.5 Million of Pocket Change, Bill Gates Funds Geoengineering Research
80beats: Bill Gates Patents a Device Aimed at Halting Hurricanes
80beats: Iron-Dumping Experiment Is a Bust: It Feeds Crustaceans, Doesn’t Trap Carbon
DISCOVER: 5 Most Radical Ways to Squelch a Climate Crisis (photo gallery)

Image: John McNeill

"Kenrick et al.'s experiments demonstrate that men who view photographs of physically attractive women or Playboy centerfolds subsequently find their current mates less physically attractive and become less satisfied with their current relationships. What then would be the cumulative effect of being exposed to young, attractive women on a daily basis? Would there be any real consequences to the men's dissatisfaction with their relationships? Secondary school teachers and college professors come in contact with more young women at the peak of their reproductive value than others do. The analysis of a large, representative data set from the United States indicates that, while men in general are less likely to be divorced than women, and secondary school teachers and college professors in general are less likely to be divorced than others, simultaneously being male and being a secondary school teacher or college professor statistically increases the likelihood of being divorced (p <.05)." Photo: flickr/anyjazz65 Related content:
Discoblog: NCBI ROFL: Boys and girls, please open your textbooks to page 69…
Discoblog: NCBI ROFL: Why Facebook is ruining your marriage.
Discoblog: NCBI ROFL: An ecological study of glee in small groups of preschool children. WTF is NCBI ROFL? Read our FAQ!

Nearly 150 years after scientists discovered the first specimen of the dino-bird archaeopteryx, we get to see what it was made of. Researchers who scanned one of the fossils with x-rays say the specimen contains not just impressions of fossils, but actually the remains of soft tissue with some of the chemical components intact. They published their findings (in press) today in the Proceedings of the National Academy of Sciences.

The team led by Roy Wogelius scanned a 150-million-year-old Archaeopteryx fossil using a synchrotron-type particle accelerator located at the Stanford Synchrotron Radiation Lightsource in California.

The synchrotron excites atoms in target materials to emit X rays at characteristic wavelengths. The scan reveals the distribution of elements throughout the fossil. The green glow of the bones in this false-colour image shows that Archaeopteryx, like modern birds, concentrated zinc in its bones. The red of the rocks comes from calcium in the limestone that had encased the fossil since the animal died [New Scientist].

That distinct difference you can see between the bird remains and the surrounding ground, made clear by the false-color image, made Wogelius confident that the elements he found came from the Archaeopteryx remains and not from contamination. To him, then, it was clear:

“We talk about the physical link between birds and dinosaurs, and now we have found a chemical link between them. In the fields of palaeontology and geology, people have studied bones for decades. But this whole idea of the preservation of trace metals and the chemical remains of soft tissue is quite exciting” [Sydney Morning Herald].

While this Archaeopteryx finding adds to our knowledge of this strange creature, the real importance of this study could lie in the method.

Other methods to analyse fossil specimens such as x-ray fluorescence and electron microscopy can only analyse samples on microscope slide scale and therefore to study Archaeopteryx by these methods, it would have to be destroyed. Breaking up the specimen was not an option, says Wogelius [Chemistry World].

Thus, he argues, this tool—which goes by “synchrotron rapid scanning x-ray fluorescence” (SRS-XRF)—could prove invaluable to paleontologists who want to know what a specimen is made of without tearing it apart.

“We’re able to read so much more into these organisms now using this technology – we’re literally touching ghosts” [Sydney Morning Herald].

Related Content:
DISCOVER: Birds May Have Used Big Brains To Outlast the Dinosaurs
The Loom: A Hairy Archaeopteryx?
80beats: “Bizarre” And Fluffy Dino May Have Used Feathers To Attract Mates
Science Tattoo Emporium: Archaeopteryx

Image: W.I. Sellers/ PNAS

I missed the NECSS meeting last month, but my pal (and JREF President) D.J. Grothe was there, and gave a great talk about the meaning of skepticism, and how it relates to humanism. And, wonderfully, the whole thing is online!

I agree with pretty much everything he said there. The idea of why we do what we do in the skeptical movement has come up a lot in my life (online and IRL) lately, and I have been doing a lot of thinking about it. I may write a post (or more likely a series of them) outlining my thoughts on this. It’s important, and the movement itself has been debating it internally recently as well. Certainly D.J.’s calm, rational discourse on this can only help.

As I've said, there is much that is surprising or unexpected about Elaine Ecklund's findings on religion among scientists. I'm going to be blogging on this all week, but again, as background, if you haven't yet you should first check out our Point of Inquiry episode (show website here; listen here; download/subscribe here). The second point that arises from Ecklund's research that I find intriguing is this. There's a cliche out there, particularly among some conservative religious folks, that there is something nasty about science (and particularly evolutionary science), such that studying it will kill off your belief system. However, Ecklund's research seems to give the lie to this idea--and our discussion of this topic begins around minute 17:55-19:10. First, among scientists who are atheists, Ecklund found that they tended to come from irreligious or not very observant family backgrounds. In other words, their atheism or lack of religion was in place long before their scientific training began. Meanwhile, for scientists who retained religious beliefs, they tended to have started out with them to begin with, and then held on to them after a struggle or crisis of faith. But once again, if I understand Ecklund right, the struggle tended to happen before one's ...

How should teachers use the media to teach students about evolution? Carefully! That’s my advice in a paper I was asked to write for the journal Evolution: Education and Outreach, where I take a look at the history of journalists writing about evolution.

I start way back, at the beginning:

Evolution has been news from the start. On March 28, 1860, The New York Times ran a massive article on a newly published book called On the Origin of Species (Anonymous 1860). The article explained how the dominant explanation for life’s staggering diversity was the independent creation of every species on Earth. “Meanwhile,” the anonymous author wrote, “Mr. DARWIN, as the fruit of a quarter of a century of patient observation and experiment, throws out, in a book whose title has by this time become familiar to the reading public, a series of arguments and inferences so revolutionary as, if established, to necessitate a radical reconstruction of the fundamental doctrines of natural history.”

If you want to read the rest of that 1860 article, you can find it here. And if you want to read the rest of my paper, check out the pdf I’ve posted over at my web site.

For the definition of mistake, look no further than the Oxford English Dictionary. A physics professor from Australia's Queensland University of Technology discovered that the go-to source has carried a mistake for nearly a century: an error in the definition of the word "siphon." The dictionary erroneously stated that a siphon's ability to move liquids from one location to another is due to atmospheric pressure. In fact, it's really thanks to the force of gravity, according to an article in Physorg.com:
"Senior lecturer [Stephen Hughes]... discovered the error after viewing an enormous siphon in South Australia, which was transferring the equivalent of 4000 Olympic swimming pools from the Murray River system into depleted Lake Bonney"... "It is gravity that moves the fluid in a siphon, with the water in the longer downward arm pulling the water up the shorter arm," he said."
Conveniently, when the team in charge of revising the Oxford English Dictionary received Hughes' email pointing out the error, they were working on words starting with the letter "R:"
"I thought, 'oh good, just in time', because S is next," Dr Hughes said.
The de facto dictionary-of-record is planning to make the change, but its editors shouldn't feel too bad: Hughes said he couldn't ...

A murder suspect sits in a quiet room with electrodes placed on her head. The prosecution reads out its narrative of the crime and the suspect’s alleged role in it. As she listens, the machines record her brain activity and reveal that she experienced aspects of the crime that only the murderer could have. Teased out by technology, her own memories have betrayed her. The verdict is guilty.

This scenario might seem far-fetched, but it’s actually what happened in an Indian trial that took place in 2008. The judge “explicitly cited a scan as proof that the suspect’s brain held “experiential knowledge” about the crime that only the killer could possess, sentencing her to life in prison.” There has been a smattering of attempts to use of brain-scanning technology in this way, accompanied by an uproar about the technology’s readiness.

But a new study by Jesse Rissman from Stanford University suggests that these promises are overplayed. Together with Henry Greely and Anthony Wagner, he has shown that brain scans can accurately decode whether people think they remember something, but not whether they actually remember something. And that gap between subjective and objective memory is a vast chasm as far as the legal system is concerned.

Our memories are stored within networks of neurons so it’s reasonable to think that by studying the patterns of activity within these networks, we should be able to decipher individual memories. Studies have already started to show that this is possible with our existing brain-scanning techniques, and with every positive result, the temptation to use such advances in a practical setting grows.

The courtroom is an obvious candidate, especially because our brains respond differently when it experiences something new compared to something old. You could use brain scans to tell if someone has actually seen a place, person or thing, reliably corroborating the accounts of witnesses and suspects without having to rely on the vagaries of accurate recall and moral fortitude. For this reason, techniques like functional magnetic resonance imaging (fMRI) have been enticingly billed as the ultimate in lie detection technology and claims of “mind-reading machines” and “psychic computers” have abounded in the press.

To assess these claims, Rissman asked 16 volunteers who studied 210 faces for four seconds each. An hour later, they saw 400 faces, half of which were old and half were new. They had to separate the two and for each face, they had one of five responses – a certain recollection, or a sense that it was old or new, with either high or low confidence. Throughout these trials, Rissman scanned their brains using fMRI. He used pattern recognition software to analyse the scans and identify patterns of activity that corresponded to each response – a “neural signature” of viewing an old face, or a new one.

At first, his software seemed to be very accurate. When Rissman analysed trials where the recruits correctly classified the faces, his software could separate the old and new faces, based on brain activity alone, with an average accuracy of 83%. In trials where the volunteers were most confident in their judgments, that score rose as high as 95%.

The software passed other challenges too. For trials when the faces were all old (or all new), it separated ‘hits’ (where the volunteers rightly said that they’d seen the faces before) from ‘misses’ (where they incorrectly said that the faces were new) with an accuracy of 75%. It could separate trials where the recruits felt certain or confident in their judgments from those where they weren’t so confident with accuracies between 79 and 90%. And best of all, the software could even reliably decode the brain scans of one individual after it was “trained” on the data from another.

So far, everything seemed promising. But all of these tests focused on the recruits’ subjective memories – what they thought they remembered. If fMRI scans are to be truly admissible in court, they have to do better than that. Scientists must be able to use them to decode a person’s objective memories – whether they actually remember something they saw.

To assess that, Rissman focused on trials where the recruits classified a face as old with low confidence. He wanted to see if the software could tell the difference between faces that were actually old and correctly remembered, from those that were actually new and falsely remembered. It succeeded, but only just, with an average accuracy of 59%. For trials where they classified faces as new with low confidence, the program did even worse at telling the right assessments from the wrong ones – guesswork would have been just as good.

These results were bolstered by a variation on the same experiment. Again, Rissman showed seven recruits a set of 210 faces but this time, he told them to rate their attractiveness rather than memorise them. When they saw the larger set of 400 faces, they initially only had to say if they were male or female. The brain scans should still be able to reveal whether they recognised the faces even when they aren’t explicitly trying to do so. But they couldn’t – it only achieved an accuracy of 56%, not significantly different from a guesswork.

These results are impressive and disappointing at the same time. They demonstrate that fMRI can decode the neural signatures of subjective recognition, at least under controlled laboratory conditions. It also shows that software trained on one person can be used to reliably decode the brain activity of another – that’s fascinating in itself because it suggests that these neural signatures are highly consistent from person to person. Vaughan Bell from King’s College London (and the excellent Mind Hacks blog) says, “In other words, it is identifying brain activation patterns for conscious experiences of remembering, which seem to generalise across people.”

But given all that, the technique’s inability to separate what people think they saw from what they actually limits its use as a source of legal evidence. It means that the scans are only as good as the memories of the people who are being scanned, and we know that our memories are fickle and sometimes untrustworthy things.

Bell says, “Any potential fMRI ‘lie detector’ technology may be equally as liable to the memory distortions that affect eye witness testimony or other forms of courtroom recall. Perhaps a little speculatively, this may mean that although such technology could pick up someone who deliberately lies about what they remember, it may not be able to distinguish between someone whose memory had become distorted over time or who has come to believe false information.”

Of course, fMRI scans have already found their way into courtrooms and more attempts are on the horizon. Just last week, a Brooklyn judge dismissed fMRI evidence from an employer-retaliation case, and Wired reports that on May 13, a Tennessee court will hear arguments over the admissibility of fMRI evidence in another hearing. Both cases involved a company called Cephos (whose CEO has, incidentally, turned up on this blog before).

But Rissman’s work casts serious doubts over the role of suggests that there are massive barriers to the use of fMRI scans in court. Of course, evidence with dodgy reliability is often used in trials, but the big danger for brain scans is their appearance of reliability. What could be more compelling than a view inside someone’s mind? And what could be more dangerous than an unreliable source of evidence that is over-interpreted as being reliable, as the recent Indian case attests to?

Rissman concludes his paper with a stark warning. He says, “The neuroscientific and legal communities must maintain an ongoing dialogue so that any future real-world applications will be based on, and limited by, controlled scientific evaluations that are well understood by the legal system before their use. Although false positives and false negatives can have important implications for memory theory, their consequences can be much more serious within a legal context.”

Reference: PNAS http://dx.doi.org/10.1073/pnas.100102810 If this link isn’t working, read why here

Image by http://www.flickr.com/photos/killermonkeys/304439098/

More on fMRI scans:

• Your brain on Oprah and Saddam (and what that says about Halle Berry and your grandmother)
• Creating God in one’s own image
• Will vs. Grace – are people honest because they resist temptation or because they don’t feel it?
• Pre-emptive blood flow raises big questions about fMRI
• Computer predicts brain activity associated with different objects

So you already spend all your time on Facebook—that’s not enough for the social networking giant. Soon, it will want to know where you spend all your time (in the real world).

Over the weekend, TechCrunch identified a glitch in Facebook’s mobile site that allowed them to see a space for a new feature called “places” being built in the code.

Based on the code, this is what it seems that Facebook is about to launch: A mobile version of the site using the HTML5 location component to grab your location information from your phone. Once it does that, you’re taken to this new Places area of Facebook that presumably will have a list of venues around you. From here you can click a button to check-in. Yes, there will be check-ins [TechCrunch].

It appears that Facebook plans to jump into the world of being a location-based service in the vein of Foursquare or Gowalla. But rather than launching its own service to crush the two smaller companies, Facebook may consider buying up Foursquare. Rumors to that effect circulated this weekend because in addition to the code leak, Facebook CEO Mark Zuckerberg paid a visit to Foursquare CEO Dennis Crowley.

The possibilities are tantalizing, especially because we think if Foursquare really wants to sell, Facebook would be its best buyer. We’re also pretty sure Facebook has interest in Foursquare at the right price. Remember, a few months ago there were some rumors that Facebook kicked the tires on Foursquare rival Gowalla [San Francisco Chronicle].

Evaluating the pros and cons of all this, PC World notes that Facebook’s embrace of location-based service will open up the idea to a lot of people who wouldn’t seek out one of the smaller companies, and could expand some of the advantages—like getting discounts for visiting a store and checking in a certain number of times—to many more businesses than currently participate. The drawbacks? Privacy, of course.

Facebook has taken some public beating about privacy for its public statements (Zuckerberg is alleged to have said, “People don’t really want privacy, anyway“), its new features that force more connectivity on users, and its gaffes like a bug last week that rendered some private chats viewable to other users. And then there’s the fact that navigating Facebook’s maze of security section to get the privacy setting you want requires a tour guide and a reservoir of patience. For your convenience, the Electronic Frontier Foundation has posted the evolution (or erosion) of Facebook’s privacy standards over the last five years.

Even Congress has taken note of the expanding Facebook:

It is also facing trouble on Capitol Hill. Last month, lawmakers called on the company to stop automatically sharing user information with third-party websites and to streamline its privacy policy. Led by Chuck Schumer, a New York Democratic senator, they said that Facebook users should have to opt-in to data-sharing arrangements, rather than being forced to opt-out if they do not wish to participate [Financial Times].

Related Content:
80beats: Facebook CEO: People Don’t Really Want Privacy Nowadays, Anyway
80beats: Facebook and Myspace Kick Out Thousands of NY Sex Offenders
Discoblog: Are Happy Facebook Pics Proof That You Aren’t Depressed?
Discoblog: Desperate For Facebook Friends? Buy Some!
Discoblog: Computer Program Can “Out” Gay Facebook Users

Image: flickr / benstein

I just got a note that tonight’s (Monday May 10) episode of Discovery Channel’s "How the Universe Works" is about extreme stars, and once again the episode is infected with interviews of me. Although the interview I did for it was about a year ago, I do remember waving my hands a lot and talking about massive stars chewing through their fuel and exploding. Expect the usual bombast, and check your local listings.

According to one of the stranger pieces of research in Nature Methods this month, humans aren't the only ones to show discomfort via their facial expressions: Mice also grimace when they've been physically hurt. This is the first study (at least, the first formal study) to examine non-human facial expressions in response to pain. Unfortunately, experiments essentially consisted of "expert expression-spotters" watching mice's faces while they were in pain, such as when injected with acid. The furry creatures narrow their eyes, puff out their cheeks and move their whiskers in response to pain, and more severe pain caused stronger grimaces in the animals. In fact, the authors were able to come up with the aptly named Mouse Grimace Scale, or MGS, but not without putting a few poor rodents through plenty of trials, according to Nature News:
Grimaces were most pronounced for pain that lasted for a matter of minutes or hours, and for discomfort in joints and internal organs. Superficial harm such as immersing the tail in hot water evoked fewer grimaces. Mice and humans show similar variability in pain response, Mogil says. Pained expressions differed from those associated with stress and illness, the team found. In addition, more harmful stimuli drew more ...