The Neuroscience of Screwing Up

Sunday, August 8th, 2010

Jonah Lehrer demonstrates the neuroscience of screwing up with an anecdote:

It all started with the sound of static. In May 1964, two astronomers at Bell Labs, Arno Penzias and Robert Wilson, were using a radio telescope in suburban New Jersey to search the far reaches of space. Their aim was to make a detailed survey of radiation in the Milky Way, which would allow them to map those vast tracts of the universe devoid of bright stars. This meant that Penzias and Wilson needed a receiver that was exquisitely sensitive, able to eavesdrop on all the emptiness. And so they had retrofitted an old radio telescope, installing amplifiers and a calibration system to make the signals coming from space just a little bit louder.

But they made the scope too sensitive. Whenever Penzias and Wilson aimed their dish at the sky, they picked up a persistent background noise, a static that interfered with all of their observations. It was an incredibly annoying technical problem, like listening to a radio station that keeps cutting out.

At first, they assumed the noise was man-made, an emanation from nearby New York City. But when they pointed their telescope straight at Manhattan, the static didn’t increase. Another possibility was that the sound was due to fallout from recent nuclear bomb tests in the upper atmosphere. But that didn’t make sense either, since the level of interference remained constant, even as the fallout dissipated. And then there were the pigeons: A pair of birds were roosting in the narrow part of the receiver, leaving a trail of what they later described as “white dielectric material.” The scientists evicted the pigeons and scrubbed away their mess, but the static remained, as loud as ever.

For the next year, Penzias and Wilson tried to ignore the noise, concentrating on observations that didn’t require cosmic silence or perfect precision. They put aluminum tape over the metal joints, kept the receiver as clean as possible, and hoped that a shift in the weather might clear up the interference. They waited for the seasons to change, and then change again, but the noise always remained, making it impossible to find the faint radio echoes they were looking for. Their telescope was a failure.
[...]
For the radio astronomers, the breakthrough was the result of a casual conversation with an outsider. Penzias had been referred by a colleague to Robert Dicke, a Princeton scientist whose training had been not in astrophysics but nuclear physics. He was best known for his work on radar systems during World War II. Dicke had since become interested in applying his radar technology to astronomy; he was especially drawn to a then-strange theory called the big bang, which postulated that the cosmos had started with a primordial explosion. Such a blast would have been so massive, Dicke argued, that it would have littered the entire universe with cosmic shrapnel, the radioactive residue of genesis. (This proposal was first made in 1948 by physicists George Gamow, Ralph Alpher, and Robert Herman, although it had been largely forgotten by the astronomical community.) The problem for Dicke was that he couldn’t find this residue using standard telescopes, so he was planning to build his own dish less than an hour’s drive south of the Bell Labs one.

Then, in early 1965, Penzias picked up the phone and called Dicke. He wanted to know if the renowned radar and radio telescope expert could help explain the persistent noise bedeviling them. Perhaps he knew where it was coming from? Dicke’s reaction was instantaneous: “Boys, we’ve been scooped!” he said. Someone else had found what he’d been searching for: the radiation left over from the beginning of the universe. It had been an incredibly frustrating process for Penzias and Wilson. They’d been consumed by the technical problem and had spent way too much time cleaning up pigeon shit — but they had finally found an explanation for the static. Their failure was the answer to a different question.

And all that frustration paid off: In 1978, they received the Nobel Prize for physics.

Kevin Dunbar’s research on researchers found that science is a deeply frustrating pursuit:

Although the researchers were mostly using established techniques, more than 50 percent of their data was unexpected. (In some labs, the figure exceeded 75 percent.) “The scientists had these elaborate theories about what was supposed to happen,” Dunbar says. “But the results kept contradicting their theories. It wasn’t uncommon for someone to spend a month on a project and then just discard all their data because the data didn’t make sense.” Perhaps they hoped to see a specific protein but it wasn’t there. Or maybe their DNA sample showed the presence of an aberrant gene. The details always changed, but the story remained the same: The scientists were looking for X, but they found Y.
[...]
According to Dunbar, even after scientists had generated their “error” multiple times — it was a consistent inconsistency — they might fail to follow it up. “Given the amount of unexpected data in science, it’s just not feasible to pursue everything,” Dunbar says. “People have to pick and choose what’s interesting and what’s not, but they often choose badly.” And so the result was tossed aside, filed in a quickly forgotten notebook. The scientists had discovered a new fact, but they called it a failure.

Lehrer’s advice on how to learn from failure:

  1. Check your assumptions.
  2. Seek out the ignorant.
  3. Encourage diversity.
  4. Beware of failure-blindness.

Posted in Science | No Comments »

For Humans, Slow And Steady Running Won The Race

Thursday, August 5th, 2010

For its “human edge” series, NPR looks at how slow and steady running won the race:

“Most animals are designed for speed, for power, not for endurance,” Lieberman explains, as we make a turn onto the bridge. “And we are a special species in having been selected for endurance, not speed.”

So we grew longer legs and lighter feet; the joints in the legs and pelvis got bigger to absorb a lot of impact; and we grew a bigger butt muscle.

Lieberman says these and other changes allowed us to run down and exhaust prey, like antelopes. He notes that “persistence hunters” in Africa have been known to do that. And the payoff would’ve been big for early humans: lots of high-calorie meat to feed a bigger brain.

Lieberman is creating a computer model of how we run — in contrast to how other primates might run:

“There are no humans out there with faces as large as Neanderthals,” he explains as he rummages through a cupboard, “so people wear weights in their mouths, which then changes the center of gravity of their head.”

Understanding head control is important. If you don’t keep your head still, you can’t focus your eyes. Lieberman says modern humans, unlike apes, have a special muscle that connects each arm to the neck and head. As you swing your arms, they become counterweights to stabilize your head.

Posted in Animals, Fitness, Science | No Comments »

Breast Milk Sugars Give Infants a Protective Coat

Thursday, August 5th, 2010

A large part of human milk cannot be digested by babies — but it can be digested by a subspecies of Bifidobacterium longum:

The indigestible substance that favors the bifido bacterium is a slew of complex sugars derived from lactose, the principal component of milk. The complex sugars consist of a lactose molecule on to which chains of other sugar units have been added. The human genome does not contain the necessary genes to break down the complex sugars, but the bifido subspecies does, the researchers say in a review of their progress in today’s Proceedings of the National Academy of Sciences.

The complex sugars were long thought to have no biological significance, even though they constitute up to 21 percent of milk. Besides promoting growth of the bifido strain, they also serve as decoys for noxious bacteria that might attack the infant’s intestines. The sugars are very similar to those found on the surface of human cells, and are constructed in the breast by the same enzymes. Many toxic bacteria and viruses bind to human cells by docking with the surface sugars. But they will bind to the complex sugars in milk instead. “We think mothers have evolved to let this stuff flush through the infant,” Dr. Mills said.

Posted in Science | No Comments »

A Handy Bunch

Wednesday, August 4th, 2010

Modern humans are a handy bunch — much handier than the first handy man, Homo habilis:

Handy man made tools, but they were crude. That could be because his wrists and hands were still pretty ape-like. Now, apes make tools. Scientists have trained a bonobo, called Kanzi, to do that. But Kanzi’s not much good at it.

“He just can’t get the motions down,” Williams says. That’s because he can’t grip the stones, his thumbs aren’t long enough and his fingers are too long and he’s clumsy. He can’t move his wrists — he can’t extend his wrist and get this important “snap.” He makes a mess.

An ape’s brain is up to the task, but his anatomy isn’t. He doesn’t have the hands. It took millions of years of evolution to produce the hands of a skilled flint-knapper like [Dennis Sandgathe, an archaeologist from Simon Fraser University in Canada].
[...]
On an office table, Orr has laid out the skeletal hands of three apes and a human. The apes’ hands are enormous — the orangutan’s is like a catcher’s mitt.

But their thumbs are tiny and splayed out to the side; the fingers are long and curved. They look powerful, but Orr says the strength runs vertically, from the wrist up through the fingers. That’s good for hanging on tree limbs, but not for much else.

The human hand is smaller, and it works differently. Orr hands me a two-foot-long club to illustrate.

“Here, try to hold this without using your little finger, and just using those other digits,” he says. That’s the way an ape might hold it. I make to swing it but realize it will fly out of my hand if I do.

The strength in my hand extends across my palm. My thumb is stronger, and so is my pinky. I can wrap that thumb over my other fingers and then secure the grip at the bottom with my pinkie. An ape can’t manage that very well.

And my opposed thumb and wider fingertips also mean I can grip a round stone — like a hammerstone — with more control than an ape can.
[...]
“When I flip the arm over so that the palm is up you can see, underneath these tendons, that we have just a ton of muscles that are just in our palms that help us finely move our fingers.”

It’s a spider’s web of muscles and tendons under the skin, many of them unique to the human hand. The hand’s exquisite architecture allows us to play Bach, shuffle a deck of cards, or write poetry — the things we often think of that define us as human. And all it took to get it was a few million years of whacking two rocks against each other.

Posted in Animals, Science, Technology | No Comments »

The Human Edge

Tuesday, August 3rd, 2010

NPR has a “special series” on how evolution gave us the human edge.

Naturally the piece on shoulder anatomy and thrown weapons caught my attention:

Shea explains that the secret of the modern shoulder is its ability to move the arm in almost any direction, even behind the back. That, combined with other early human traits, enabled us to throw with power and accuracy.

“We have a wrist that can move like a whip, that can accelerate through throwing,” he explains. “And your gluteus muscles — you know, your rear end, your thighs, your calves — these are things that make for good running, but they also make for good throwing.”

Early humans first used rocks as weapons to kill prey. As our bodies evolved, we became more able to use advanced weapons like spears and bows and arrows.

It also caught my attention that NPR was presenting the case that a meat-based diet made us smarter:

Our earliest ancestors ate their food raw — fruit, leaves, maybe some nuts. When they ventured down onto land, they added things like underground tubers, roots and berries.

It wasn’t a very high-calorie diet, so to get the energy you needed, you had to eat a lot and have a big gut to digest it all. But having a big gut has its drawbacks.

“You can’t have a large brain and big guts at the same time,” explains Leslie Aiello, an anthropologist and director of the Wenner-Gren Foundation in New York City, which funds research on evolution. Digestion, she says, was the energy-hog of our primate ancestor’s body. The brain was the poor stepsister who got the leftovers.

Until, that is, we discovered meat.

“What we think is that this dietary change around 2.3 million years ago was one of the major significant factors in the evolution of our own species,” Aiello says.

That period is when cut marks on animal bones appeared — not a predator’s tooth marks, but incisions that could have been made only by a sharp tool. That’s one sign of our carnivorous conversion. But Aiello’s favorite clue is somewhat ickier — it’s a tapeworm. “The closest relative of human tapeworms are tapeworms that affect African hyenas and wild dogs,” she says.

So sometime in our evolutionary history, she explains, “we actually shared saliva with wild dogs and hyenas.” That would have happened if, say, we were scavenging on the same carcass that hyenas were.

But dining with dogs was worth it. Meat is packed with lots of calories and fat. Our brain — which uses about 20 times as much energy as the equivalent amount of muscle — piped up and said, “Please, sir, I want some more.”

Posted in Animals, Fitness, Science, War, Weapons | No Comments »

Morphosaurs

Sunday, August 1st, 2010

My childhood knowledge of dinosaurs is drifting away — not from senescence but from obsolescence. First they went from slow and cold-blooded to quick and warm-blooded. Then the brontosaur reverted to the apatosaur. Now the triceratops may be a torosaur:

Triceratops had three facial horns and a short, thick neck-frill with a saw-toothed edge. Torosaurus also had three horns, though at different angles, and a much longer, thinner, smooth-edged frill with two large holes in it. So it’s not surprising that Othniel Marsh, who discovered both in the late 1800s, considered them to be separate species.

Now [ John Scannella and Jack Horner at the Museum of the Rockies in Bozeman, Montana] say that triceratops is merely the juvenile form of torosaurus. As the animal aged, its horns changed shape and orientation and its frill became longer, thinner and less jagged. Finally it became fenestrated, producing the classic torosaurus form (see diagram, [left]).

This extreme shape-shifting was possible because the bone tissue in the frill and horns stayed immature, spongy and riddled with blood vessels, never fully hardening into solid bone as happens in most animals during early adulthood. The only modern animal known to do anything similar is the cassowary, descended from the dinosaurs, which develops a large spongy crest when its skull is about 80 per cent fully grown.

Posted in Animals, Science | No Comments »

Does Language Influence Culture?

Wednesday, July 28th, 2010

Lera Boroditsky explores the Sapir-Whorf hypothesis — Does Language Influence Culture? — without mentioning it by name:

For example, in Pormpuraaw, a remote Aboriginal community in Australia, the indigenous languages don’t use terms like “left” and “right.” Instead, everything is talked about in terms of absolute cardinal directions (north, south, east, west), which means you say things like, “There’s an ant on your southwest leg.” To say hello in Pormpuraaw, one asks, “Where are you going?”, and an appropriate response might be, “A long way to the south-southwest. How about you?” If you don’t know which way is which, you literally can’t get past hello.

About a third of the world’s languages (spoken in all kinds of physical environments) rely on absolute directions for space. As a result of this constant linguistic training, speakers of such languages are remarkably good at staying oriented and keeping track of where they are, even in unfamiliar landscapes. They perform navigational feats scientists once thought were beyond human capabilities. This is a big difference, a fundamentally different way of conceptualizing space, trained by language.

Differences in how people think about space don’t end there. People rely on their spatial knowledge to build many other more complex or abstract representations including time, number, musical pitch, kinship relations, morality and emotions. So if Pormpuraawans think differently about space, do they also think differently about other things, like time?

To find out, my colleague Alice Gaby and I traveled to Australia and gave Pormpuraawans sets of pictures that showed temporal progressions (for example, pictures of a man at different ages, or a crocodile growing, or a banana being eaten). Their job was to arrange the shuffled photos on the ground to show the correct temporal order. We tested each person in two separate sittings, each time facing in a different cardinal direction. When asked to do this, English speakers arrange time from left to right. Hebrew speakers do it from right to left (because Hebrew is written from right to left).

Pormpuraawans, we found, arranged time from east to west. That is, seated facing south, time went left to right. When facing north, right to left. When facing east, toward the body, and so on. Of course, we never told any of our participants which direction they faced. The Pormpuraawans not only knew that already, but they also spontaneously used this spatial orientation to construct their representations of time. And many other ways to organize time exist in the world’s languages. In Mandarin, the future can be below and the past above. In Aymara, spoken in South America, the future is behind and the past in front.

In addition to space and time, languages also shape how we understand causality. For example, English likes to describe events in terms of agents doing things. English speakers tend to say things like “John broke the vase” even for accidents. Speakers of Spanish or Japanese would be more likely to say “the vase broke itself.” Such differences between languages have profound consequences for how their speakers understand events, construct notions of causality and agency, what they remember as eyewitnesses and how much they blame and punish others.

In studies conducted by Caitlin Fausey at Stanford, speakers of English, Spanish and Japanese watched videos of two people popping balloons, breaking eggs and spilling drinks either intentionally or accidentally. Later everyone got a surprise memory test: For each event, can you remember who did it? She discovered a striking cross-linguistic difference in eyewitness memory. Spanish and Japanese speakers did not remember the agents of accidental events as well as did English speakers. Mind you, they remembered the agents of intentional events (for which their language would mention the agent) just fine. But for accidental events, when one wouldn’t normally mention the agent in Spanish or Japanese, they didn’t encode or remember the agent as well.

In another study, English speakers watched the video of Janet Jackson’s infamous “wardrobe malfunction” (a wonderful nonagentive coinage introduced into the English language by Justin Timberlake), accompanied by one of two written reports. The reports were identical except in the last sentence where one used the agentive phrase “ripped the costume” while the other said “the costume ripped.” Even though everyone watched the same video and witnessed the ripping with their own eyes, language mattered. Not only did people who read “ripped the costume” blame Justin Timberlake more, they also levied a whopping 53% more in fines.

Beyond space, time and causality, patterns in language have been shown to shape many other domains of thought. Russian speakers, who make an extra distinction between light and dark blues in their language, are better able to visually discriminate shades of blue. The Piraha, a tribe in the Amazon in Brazil, whose language eschews number words in favor of terms like few and many, are not able to keep track of exact quantities. And Shakespeare, it turns out, was wrong about roses: Roses by many other names (as told to blindfolded subjects) do not smell as sweet.

Posted in Linguistics, Science | 1 Comment »

A Batesian Mimicry Explanation of Business Cycles

Tuesday, July 27th, 2010

Erik Falkenstein went to grad school to become a macroeconomist and understand business cycles, but he quickly realized that no one understood business cycles.  Now he presents his own Batesian mimicry explanation of business cycles:

My argument is that business cycles are best understood though the framework of Batesian mimicry, an endogenous mechanism for booms and busts thru a misallocation in the horizontal structure of production. In ecosystems, Batesian mimicry is typified by a situation where a harmless species (the mimic) evolves to imitate the warning signals of a harmful species (the model) directed at a common predator (the dupe). For example, venomous coral snakes have red, yellow, and black bands, while the non-venomous scarlet king snake has the same colors in a different order. Animals afraid of venomous snakes would do well to avoid 4 foot long snakes with red, yellow and black stripes, in the process avoiding the scarlet king snake (alternatively, one could remember the rule “Red on yellow, kill a fellow; red on black, friend of Jack”).

The process has been observed in insects, reptiles, mammals, and plants, and sometimes occurs between species. By parasitizing the true warning signal of the protected species, the Batesian mimic gains the same advantage without having to go to the biological expense of maintaining a poison. The species being mimicked, on the other hand, is disadvantaged, along with the dupe who misses out on tasty mimic meals. If imposters appear in high numbers, positive experiences by the predator with the mimic may result in the model species losing the benefits of signaling its poison.

Atsushi Yamauchi has shown that when there are density effects on the model species, there is no stable equilibrium. Nonlinear dynamics make the system’s aggregate features unpredictable in specifics, but most importantly, it is not a stable equilibrium to have no mimics over long periods of time: the gains are large to the mimic because predators obey the model’s high-quality signal.

While it’s conceivable one could generate a formal economic model with these qualitative results, note that the ecological literature mainly looks at comparative statics for one species, noting what assumptions generate stable equilibria, and which do not. There is no attempt to generate a dynamic model of the mimic or models success over time, presumably because the highly nonlinear, recursive system is so sensitive to results would merely be qualitative, like the comparative statics.

In an expansion investors are constantly looking for better places to invest their capital, while entrepreneurs are always overconfident, hoping to get capital to fund their restless ambition. Sometimes, the investors (dupes) think a certain set of key characteristics are sufficient statistics of a quality investment because historically they were. Mimic investors seize upon these key characteristics that will allow them to garner funds from the duped investors. The mimic entrepreneurs then have a classic option value, which however low in expected value to the investor, has positive value to the entrepreneur. The mimicry itself may involve conscious fraud, or it may be more benign, such as naïve hope that they will learn what works once they get their funding, or sincere delusion that the characteristics are the essence of the seemingly promising activity. The mimicking entrepreneurs are a consequence of investing based on insufficient information that is thought sufficient, but they make things worse because they misallocate resources that eventually, painfully, must be reallocated.

Once the number of mimics is sufficiently high, their valueless enterprises become too conspicuous and they no longer pass off as legitimate investments. Failures caused by insufficient cash create a tipping point, notify investors that certain assumptions were incorrect. Areas that for decades were very productive, are found to often contain exceptional levels of fraud, or operate with no conceivable expectation of a profit. Everyone outside the industry with excessive mimics marvels at how such people—investors, entrepreneurs, and their middlemen–could be so short-sighted, but the key is that the mimics and duped investors chose those business models that seemed most solid based on objective, identifiable characteristics that were, historically, correlated with success. An econometric analysis would have found these ventures a good bet, which is why investors did not thoroughly vet their business models (banks, up through 2007, were one of the best performing industries since industry data has been available in the US, and performed well in the 2001 recession).

In the 1990’s tech firms in general and internet firms in specific were doing very well. The internet bubble was filled with a naïve lack of skepticism that allowed otherwise absurd business ventures to get funding. Using hindsight there were so many businesses with doomed business models, you wondered how they could have been taken seriously, but investors were looking primarily at a few key criteria—net presence, branding—and these did work well for several years until the March 2000 crash, especially using the criteria of their stock price. Consider that Enron was able to engage in negative cash flow activities for at least 5 years while their stock price kept climbing, highlighting that if you hit the key signals investors are naively prioritizing, they can be fooled, just not forever.

Posted in Economics, Eric Falkenstein, Science | No Comments »

Adventures in Very Recent Evolution

Wednesday, July 21st, 2010

Steve Sailer reviews Nicholas Wade’s recent New York Times science column, Adventures in Very Recent Evolution — but first he introduces it with this preamble:

Sometimes I get discouraged when I realize that I’ve been debunking dumb ideas for many years now, yet dumb ideas remains wildly popular.

But think how Nicholas Wade, the genetics correspondent of the New York Times, must feel. He has the top soapbox in the world for educating the public, the New York Times, and he covers for the NYT the trendiest topic in science, genetics. He has spent the last decade (here are VDARE articles I wrote praising Wade’s NYT work in 2003 and 2006) diligently debunking the reigning dumb ideas of our age, such as “Race doesn’t exist,” “Race is just skin deep,” and “Racial differences couldn’t have evolved because there hasn’t been enough time.” For nine or ten years, he has used dozens of New York Times articles to aim a firehose of the latest scientific findings at these dogmas… and, as far as I can tell, nobody ever notices.

They don’t Watson him. I’ve never noticed anybody objecting to Wade. They just don’t ever get what he’s saying. It doesn’t register. The conventional wisdom is so comforting and so status-raising that relentless reporting in the New York Times can’t dent it, or even make most NYT readers notice that their favorite beliefs are being subverted. Wade has been engaging in Popperian falsification of the age’s dominant theories, and nobody notices.

Posted in Policy, Science | No Comments »

New Nicaraguan sign language shows how language affects thought

Tuesday, July 20th, 2010

In the 1970s, a critical mass of deaf schoolchildren came together in Nicaragua’s new special-education schools, and they spontaneously developed Nicaraguan Sign Language, which quickly evolved — and this evolution allowed scientists to explore how language affects thought:

By studying children who learned NSL at various stages of its development, [Jennie Pyers from Wellesley College] has shown that the vocabulary they pick up affects the way they think. Specifically, those who learned NSL before it developed specific gestures for left and right perform more poorly on a spatial awareness test than children who grew up knowing how to sign those terms.

The idea that language affects thought isn’t new. It’s encapsulated by the ‘Sapir-Whorf hypothesis’, which suggests that differences in the languages we speak affect the way we think and behave. Typically, scientists test this link between language and thought by either comparing people who speak different languages, or by watching children as they, and their linguistic skills, develop. But both approaches have problems. Speakers of different languages also vary in many other ways that can affect the way they think, while growing children are also developing in many other aspects of their mental skills, which could confuse any effect of language alone.

But NSL cuts through both of these problems. Here is a language that was learned by successive waves of children whose mental skills were relatively mature, who all came from the same culture, and who all learned the language at the same age.

In most sign languages, signers map the positions of real-world objects using their hands, rather than using words like ‘left’, ‘inside’ or ‘over’. Someone signing a cat on a table would place one hand, representing a cat, over the other, representing the table, with no separate sign for ‘on’. The same works for left and right, with the added rule that usually, the signer represents the scene from their own perspective.

But NSL hasn’t quite got to that stage yet. In the first version developed in the 1970s, the children hadn’t settled on a consistent way of indicating left and right, and the locations of objects in their conversations are fairly ambiguous. The second group of children to expand NSL in the 1980s had more specific conventions for position.

Pyers compared the abilities of people from both groups, now fully grown adults, in two spatial tests. First, she led them into a small room with a single red wall. She hid a token in one corner of the room, blindfolded the children and spun them around until they lost their bearings. When she removed the blindfold, the children had to say where the token was. The second test, like the first, involved hiding a token in the corner of a room, but this time the room was a tabletop model that was rotated while the children were blindfolded.

In both tests, the second group of adults (who learned the more advanced form of NSL) outperformed the first group. Even though their memories and ability to understand the tasks were just as good, the expanded vocabulary of geographical gestures that they learned as children also gave them better spatial abilities well into adulthood.

By comparing the first group of NSL signers to typical children, Pyers also learned something about what’s going on in their heads. Children find the task easy and answer quickly but they often make mistakes. They’ll orient themselves to the geometry of the room, using the long and short walls to tell them where the token is. But they tend to ignore the red wall landmark so when they make mistakes, they usually go for the corner diagonally opposite to the correct one.

The first group of NSL signers were very different. They were more accurate, suggesting that their experience and maturity does at least count for something. Their mistakes are evenly distributed around the three other corners, suggesting that they use neither the landmark nor the room’s geometry to help them. And they took a long time over the test and said that they found it very difficult. They were aware of their own uncertainty, as adults often are, but they simply didn’t have a reliable mental map of the room and its hidden token.

Pyers explains, “The first-cohort signers find these tasks challenging because they do not have the language to encode the relevant aspects of the environment that would help them solve the spatial problem.” She added, “[They] did not have a consistent linguistic means to encode ‘left of’.”

This is a fascinating result, especially since the first group of adults were older and had been signing for a longer time. It’s clear evidence that our spatial reasoning skills depend, to an extent, on consistent spatial language. If we lack the right words, our mental abilities are limited in a way that extra life experience can’t fully compensate for. Even 30 years of navigating through the world won’t do the trick. And they may never catch up, even though the language they invented has advanced – after all, some studies with American Sign Language suggest that people who learn spatial terms later on in life never master them.

Posted in Linguistics, Science | No Comments »

What’s your favorite Heinlein novel?

Monday, July 19th, 2010

Tor Books is about to release the first-ever authorized biography of Robert Heinlein, and they’ve asked a number of SF authors the obvious question, What’s your favorite Heinlein novel?.

David Brin picks a not-so-obvious answer, Beyond This Horizon:

I consider Robert Heinlein’s most fascinating novel to be his prescriptive utopia Beyond This Horizon. (A prescriptive utopia is where an author “prescribes” what he or she believes a better civilization would look like.) While Heinlein did opine, extensively, about society in many books, from Starship Troopers to Glory Road, it is in Beyond This Horizon (BTH) that you’ll find him clearly stating This Is The Way Things Ought To Be. And it turns out to be a fascinating, surprisingly nuanced view of our potential future.

I haven’t read Beyond This Horizon, but it seems like an odd mix of ideas: eugenics leading to superhumans with telepathy; an armed, and thus polite, society; a post-scarcity economy, where work has become optional; and reincarnation.

Apparently Heinlein’s approach to eugenics is now known as the Heinlein solution:

I was amazed by many other aspects of this wonderful book-within-a-book, especially by Heinlein’s startlingly simple suggestion for how to deal with the moral quandaries of genetic engineering — what’s now called the “Heinlein Solution” — to allow couples to select which sperm and ova they want to combine into a child, but to forbid actually altering the natural human genome. Thus, the resulting child, while “best” in many ways (free of any disease genes, etc), will still be one that the couple might have had naturally. Gradual human improvement, without any of the outrageously hubristic meddling that wise people rightfully fear. It is a proposal so insightful that biologists 40 years later are only now starting to discuss what may turn out to be Heinlein’s principal source of fame, centuries from now.

Posted in Media, Policy, Robert Heinlein, Science | 7 Comments »

Robins can literally see magnetic fields

Monday, July 19th, 2010

Robins can literally see magnetic fields — but only if their right eye can see clearly:

Years of careful research have told us that the ability depends on light and particularly on the right eye and the left half of the brain. The details still aren’t quite clear but, for now, the most likely explanation involves a molecule called cryptochrome. Cryptochrome is found in the light-sensitive cells of a bird’s retina and scientists think that it affects just how sensitive those cells are.

When cryptochrome is struck by blue light, it shifts into an active state where it has an unpaired electron — these particles normally waltz in pairs but here, they dance solo. The same thing happens in a companion molecule called FAD. Together, cryptochrome and FAD, both with unpaired electrons, are known as a “radical pair”. Magnetic fields act upon the unpaired electrons and govern how long it takes for the radical pair to revert back to their normal, inactive state. And because cryptochrome affects the sensitivity of a bird’s retina, so do magnetic fields.

The upshot is that magnetic fields put up a filter of light or dark patches over what a bird normally sees. These patches change as the bird turns and tilts its head, providing it with a visual compass made out of contrasting shades.

To test the bounds of this ability, Stapput wanted to see what would happen if she blurred a robin’s vision. She outfitted her robins with somewhat unflattering goggles, with clear foil on one side and frosted foil on the other. Both allowed 70% of light to get through, but the frosted foil disrupted the clarity of the image.

The robins were kept in cages until they were ready to migrate and let loose in funnel-shaped cages lined with correction fluid. As they orientated themselves and changed course, they created scratches on the cage walls which told Stapput which direction they were heading in. These scratches revealed that with both eyes open, the robins flew straight north as they would normally do in the wild. If their left field of vision was frosted, they went the same way. But if their right eye was covered, they became disorientated, heading in completely random directions.

Posted in Animals, Science | No Comments »

Drug mitigates toxic effects of radiation in mice

Friday, July 16th, 2010

Investigators at the University of North Carolina (UNC) Lineberger Comprehensive Cancer Center have found an oral drug that mitigates the toxic effects of radiation in mice by inhibiting enzymes involved in cell division:

Several decades of work have shown that cells which are not dividing are resistant to agents that damage DNA, like radiation. Workers in the Sharpless lab were then able to show that the induction of PQ [Pharmacological Quiescence, the drug-induced cessation of cell-division] immediately before or up to 20 hours after radiation exposure were able to protect mice from a lethal dose of radiation. PQ protected all the normal cells of blood, including platelets, red cells and white cells.

(Hat tip to Nyrath.)

Posted in Science | No Comments »

How Microbes Defend and Define Us

Wednesday, July 14th, 2010

If you’re squeamish, you may not want to dig into the details of bacteriotherapy:

In 2008, Dr. Khoruts, a gastroenterologist at the University of Minnesota, took on a patient suffering from a vicious gut infection of Clostridium difficile. She was crippled by constant diarrhea, which had left her in a wheelchair wearing diapers. Dr. Khoruts treated her with an assortment of antibiotics, but nothing could stop the bacteria. His patient was wasting away, losing 60 pounds over the course of eight months. “She was just dwindling down the drain, and she probably would have died,” Dr. Khoruts said.

Dr. Khoruts decided his patient needed a transplant. But he didn’t give her a piece of someone else’s intestines, or a stomach, or any other organ. Instead, he gave her some of her husband’s bacteria.

Dr. Khoruts mixed a small sample of her husband’s stool with saline solution and delivered it into her colon. Writing in the Journal of Clinical Gastroenterology last month, Dr. Khoruts and his colleagues reported that her diarrhea vanished in a day. Her Clostridium difficile infection disappeared as well and has not returned since.

The procedure — known as bacteriotherapy or fecal transplantation — had been carried out a few times over the past few decades. But Dr. Khoruts and his colleagues were able to do something previous doctors could not: they took a genetic survey of the bacteria in her intestines before and after the transplant.

Before the transplant, they found, her gut flora was in a desperate state. “The normal bacteria just didn’t exist in her,” said Dr. Khoruts. “She was colonized by all sorts of misfits.”

Two weeks after the transplant, the scientists analyzed the microbes again. Her husband’s microbes had taken over. “That community was able to function and cure her disease in a matter of days,” said Janet Jansson, a microbial ecologist at Lawrence Berkeley National Laboratory and a co-author of the paper. “I didn’t expect it to work. The project blew me away.”

(Hat tip to Aretae.)

Posted in Science | No Comments »

Cats with Big Guns

Thursday, July 8th, 2010

Everyone knows that the sabertooth “tiger” (Smilodon fatalis) had massive fangs — I can’t bring myself to call the big cat’s teeth canines — but its secret weapon was exceptional forelimb strength:

The sabertooth cat, Smilodon fatalis, was an enigmatic predator without a true living analog. Their elongate canine teeth were more vulnerable to fracture than those of modern felids, making it imperative for them to immobilize prey with their forelimbs when making a kill. As a result, their need for heavily muscled forelimbs likely exceeded that of modern felids and thus should be reflected in their skeletons.
[...]
Using radiographs of the sabertooth cat, Smilodon fatalis, 28 extant felid [cat] species, and the larger, extinct American lion Panthera atrox, we measured cross-sectional properties of the humerus [upper arm bone] and femur [thigh bone] to provide the first estimates of limb bone strength in bending and torsion.

We found that the humeri of Smilodon were reinforced by cortical thickening to a greater degree than those observed in any living felid, or the much larger P. atrox. The femur of Smilodon also was thickened but not beyond the normal variation found in any other felid measured.

(Hat tip to io9.)

Posted in Animals, Science | No Comments »

« Older Entries
Newer Entries »