Field of Science


Preemptive Boredom Had Better Not Be My Psychic Power

Did you read A Wrinkle in Time as a kid? Charles Wallace, the telepathic baby brother in the book, would have been way less endearing if his psychic skill was to guess when an erotic picture was about to appear on a computer screen. And Matilda would have been a pretty dull book if the heroine's talent was getting bored before something boring happened. These are not the kinds of paranormal abilities anyone aspires to. But a research paper claiming to have found evidence for these abilities has been causing a lot of hubbub.

Daryl Bem, an emeritus professor at Cornell, is going to have his paper published in an upcoming issue of the Journal of Personality and Social Psychology. He's a respected researcher and it's a respected publication. These are not the circumstances under which you usually read about ESP--or "psi," as psychologists call it. Nevertheless, Bem's paper passed through peer review, which may have you feeling angry, confused, excited, or (if you possess precognitive abilities) totally unsurprised.

Bem's paper, "Feeling the Future" (you can see the unpublished version here), consists of 9 experiments that take standard psychological effects and reverse them. For example, say you're given a list of 48 nouns to read. Then you do an exercise--rearranging lists of words--in which you see half of those nouns again. Finally, you're asked to recall as many of the original 48 words as you can. You're expected to do better at remembering the words you "rehearsed" in the list exercise. Bem reversed this experiment by showing subjects 48 words, then asking them to recall as many as possible, and then giving them an exercise that used half the words (randomly selected by a computer). Bem reports that his subjects had better recall of the words they would rehearse later, because they had psychically anticipated practicing those words.

Another set of experiments studied "habituation," which non-psychologists call "getting used to stuff." Scary or gross pictures might prompt a strong reaction the first time we see them, but less of a reaction the second or third time. In a normal habituation experiment, a photo of a dangerous-looking snake might flash on a computer screen too quickly for you to register it consciously. Then you'd be shown the same snake photo next to a photo of, say, a spider, and asked which you like better. You're expected to prefer the snake, because seeing it subliminally has made you habituated--it doesn't bother you as much anymore. Bem's experiment reversed this: First subjects chose which of two pictures they liked better, and then one of them was flashed subliminally on the screen. The strongest results came when, instead of negative-reaction photos, the computer flashed erotic photos. (In that case, subjects supposedly preferred the erotic photo they were not about to see subliminally, because they weren't preemptively habituated to it.)

These effects weren't big; just a shade away from the results you'd get by guessing. But for 8 of his 9 experiments, Bem reports that the results were "statistically significant." If you've taken college science classes, you know what this means: A statistical test found the odds that the result would have occurred by chance alone to be lower than 5%. Of course 5% is an arbitrary cutoff; unlikely things happen by chance all the time. But scientists generally accept a result (called a p-value) under 5% as noteworthy.

For his erotic-picture experiment, Bem reports an even better p-value of .01. This is a less-than-1% possibility that chance alone could have caused his results. But think of the p-value as a medical test. Let's say your doctor tells you you've tested positive for a rare genetic disorder. The test is quite reliable: it has a false positive rate of just 1%. Things are sounding pretty bad for you, no? Now let's say this disorder only affects one in a million people. Out of a million people, 1%, or 10,000 people, would get a false positive on the medical test. That means there's still a 99.99% chance that you're fine.

This kind of analysis is called Bayesian statistics. Instead of assuming that your experiment takes place in a vacuum, it takes into account how likely your result would have seemed beforehand. A low p-value on one experiment might mean ESP is 100 times more likely to exist than it previously was. But if the sum of scientific knowledge before this paper was published said that telepathy was astronomically unlikely--well, we're probably still fine.

So this paper tells us a lot--but not about ESP. Whatever its author's intentions were, "Feeling the Future" will probably go down in history as an important paper about statistics. JPSP, recognizing this, is publishing a critique in the same issue as Bem's paper. In the critique, a group of scientists will share their own, Bayesian analysis of Bem's data. According to Science, this analysis "concludes that, if anything, [the data] support the hypothesis that ESP does not exist."

Or maybe Bem's results are real, and someone out there already knows exactly how this whole drama will play out.

Ten thousand and one thanks to Doug for teaching me about statistics.

Lost and Found

Back in December, I reported that NASA had lost a solar sail in space. Good news: they found it again!

The solar sail started out tightly bundled inside a tiny satellite called NanoSail-D. Actually, NanoSail-D is a "nanosatellite," and it was launched inside a "microsatellite" called FASTSAT. At the beginning of December, like a parade of nesting dolls (or iPod iterations), the microsatellite was supposed to eject the nanosatellite, which was then supposed to eject and unfurl its cargo: a 100-square-meter reflective sail.

But when NanoSail-D failed to report back to scientists, they reluctantly admitted that something had gone wrong. Maybe the sail had tangled or the satellite had lost power. Whatever it was, they wouldn't be able to gather any data about the solar sail. This enticing technology, which might someday carry spacecraft through the sky, gathers its power from the sea of photons sent out by the sun.

On January 21, NASA announced that the missing satellite, and its sail, had turned up. After dawdling inside its parent satellite for weeks, NanoSail-D popped free on January 17, then opened its sail as planned. Now it's in orbit around Earth, where it will remain for 70 to 120 days before burning up in the atmosphere. You can track its orbit here and wave hello when it passes overhead. (Naturally, the satellite also has a Twitter feed.)

Science Guy and solar sail researcher Bill Nye congratulated the NanoSail-D team on the good news. But congratulations are also due to the ham radio club members who first heard the satellite beeping away up there.

Image: NASA.

Robot Cars Are Coming

Few things will say "It's the future!" like robotic cars. While phones have become all-in-one personal assistants and video games no longer need controllers, the car has stayed stubbornly analog. Sure, you can unlock it with a remote control and listen to a thousand channels of satellite radio, but you still have to drive the darn thing.

Finally, it seems like self-driving cars are really around the corner. Google, for one, has been test-driving autonomous cars all around California. They seem to work pretty well. But if the technology does become widely available, it will be many years down the road (so to speak). The cars will have to be made safer than safe; new laws have to be written; trust will have to be gained.

The benefits to having everyone behind the wheel of a smart, self-driving car are undeniable. With perfectly efficient driving, we'd use less fuel. Without antsy drivers changing lanes or rubberneckers slowing at accidents, congestion might become a thing of the past. Without human error, how many of the 40,000 motor vehicle deaths per year would be eliminated? How many of the 10 million accidents? 

Though fully self-driving cars are far in the distance, little pieces of the technology--automatic parallel parking, automatic braking, that horrible beeping thing when you're close to another object--are appearing in the cars people buy today. By the time the robot cars get here, it might not seem so strange to hand one the keys.

In the meantime, there's a compromise that might give us the benefits of smart driving without surrendering all control to the machines. Volvo just demonstrated its progress in a project called SARTRE, or Safe Road Trains for the Environment. (Only in Europe would a highway transportation project be named after an existentialist.) The "road train" is really a convoy of cars electronically linked to one another. A professional driver controls a lead car, and the cars behind latch on to that car via computer. Then the drivers in the platoon can sit back and relax while their cars automatically follow the lead driver. The cars stay close together, preventing other drivers from interrupting their train while reaping the benefits of smart driving. (Obviously, this system relies heavily on the competence of the lead driver.)

The pseudo-car at the top of this post represents another step toward fully autonomous vehicles. It's an Electric Networked Vehicle, made by GM. Not quite a car and not quite a transformer, the vehicle snaps its driver inside, then balances itself on two wheels to travel down the road. The EN-Vs can communicate with each other and drive autonomously. Tiny and lightweight, the vehicles would be fuel efficient if they used fuel--but they're entirely electronic. This is the future, after all.


Stopping Enza

Back when kids passed the time by reciting rhymes about viral illnesses, the children of the 1918 flu epidemic jumped rope to this little ditty: "I had a little bird / Its name was Enza. / I opened the window / And in-flew-Enza!" It's appropriate that Enza was a bird, because bird flu (or avian influenza) has been a problem since well before you ever read a headline about swine flu. Now, British scientists think they've come up with a way to stop avian influenza in its tracks. Instead of using a vaccine, they put the roadblock right into birds' genes.

Influenza is widespread in wild birds, which usually carry the virus without becoming sick. But a highly  deadly type of avian influenza has been touring Asia for the past several years, often leading nations to slaughter millions of domestic birds at a time. Aside from killing poultry, the virus occasionally leaps to humans, where it can also be deadly. So far, bird flu doesn't spread easily between humans. But since influenza is always mutating, scientists worry that avian influenza is one tweak away from becoming the next human pandemic.

The researchers inserted DNA into chickens that let them produce, in effect, a decoy for influenza's machinery to latch on to. The piece of machinery in question is an enzyme called polymerase. It's supposed to attach to the virus's genetic material and chug along, like a train on train tracks, replicating that genetic material to make new viruses. But the chicken decoy mimics influenza's latching-on spot, so the polymerase attaches to the decoy and sits there uselessly.

When the genetically altered chickens were infected with bird flu, they...died as usual. But! The infected chickens did not efficiently spread the flu to the birds around them. Usually, avian influenza sweeps through groups of birds mercilessly. But the genetically altered chickens were less contagious than usual, sparing the lives of some of their coop-mates.

It's not clear exactly how the decoy DNA made the chickens less contagious. The study shows, though, that genetic engineering might be able to prevent deadly infections. Vaccines are impractical for preventing the flu in chickens--since new strains of influenza appear so often, they'd presumably need a new shot every year, just like we do. But the genetic decoy in this study is general enough to snag any type of avian influenza. If research in this area goes forward, genetic engineering could be the key to controlling flu outbreaks on farms--and preventing future pandemics in humans.

I'll Take Penguins in Peril for 500, Alex. (a quiz)

Which of this week's science news stories did you catch? I know Watson would ace this quiz.

1. Distressingly, a long-term study has shown that king penguins with tracking bands attached their flippers are more likely to:
a. die
b. develop infections
c. become obese
d. abandon their young

2. Testing anxiety can cause students to underperform on exams. But researchers at the University of Chicago showed that in a high-stakes test environment, both high-school and college students did better on exams when they:
a. studied less
b. wrote about their feelings for 10 minutes before the test
c. ate chocolate before the test
d. watched a film about Stephen Hawking before test

3. Daily Double!! What is this?
a. a colony of bioluminescent bacteria
b. the surface of an exoplanet
c. a picture of the universe
d. part of Fermilab's particle accelerator, which will be shut down this year

4. At a 6,000-year-old site in an Armenian cave, researchers discovered the world's oldest:
a. zoo
b. flower garden
c. bakery
d. winery

5. In February, you'll be able to watch a Jeopardy match on TV between Watson, IBM's Jeopardy-playing robot, and two humans. Who won this week's demonstration match?
a. Human champion Ken Jennings, who won 74 games in a row in 2004
b. Human champion Brad Rutter, biggest all-time money winner on Jeopardy
c. The computer
d. No one, because the match was suspended when Watson froze just before Double Jeopardy

Answers are in the comments.

Image: M. Blanton and the SDSS-III

Rewriting History (in Fungus Ink)

When researchers first unearthed the bones of the extinct ibis Xenicibis xympithecus, they thought the fossils came from a seriously diseased individual. The wing bones were deformed in a way no one had ever seen before. But as more of the ancient bird's bones turned up, scientists were forced to conclude that the weird deformity was actually serving a purpose.

Last week, Nicholas Longrich and Storrs Olson reported that this ancient, flightless bird, as far as they can tell, used its clublike wing for whacking other animals. The bone at the far end of the wing is large, heavy and curved. The long upper-arm bone would have allowed for a good swing, like a baseball bat. 

Although the bird looks pretty menacing, it was only about the size of a chicken. The scientists speculate that Xenicibis may have used its wing-fists to fight other members of its species, or to defend its eggs or young from predators. 

Though no other bird, living or extinct, has a wing like this, steamer ducks do have modified wings that they whomp each other with. They often fracture their bones in these fights, so the researchers looked for signs of fractures in Xenicibis. Sure enough, there were healed fractures in some of the fossilized wing bones.

What's unusual about this bird is that it became flightless even though there were predators living around it. The ibis might have had a trick up its sleeve (so to speak) to protect its young, and the whacking wing would have been a good start.

In other news of prehistoric relics that aren't what they seem, researchers have discovered that some Australian rock paintings actually contain no paint. Studying the Bradshaw rock art, a group of paintings 46,000 to 70,000 years old, the researchers noticed that the artwork was covered in a film of fungi and bacteria. On further inspection, it turned out that all the original paint was gone. 

Lead researcher Jack Pettigrew says these colonies of microorganisms explain how the Bradshaw paintings have managed to resist fading, in spite of millennia of exposure to rain and sun. The bacteria and fungi appear to have been feeding on each other for countless generations, staying within the outlines of the paintings. The first organisms to colonize the paintings must have eaten the paint itself. 

This "living pigment," as the authors call it, comes in various shades of red, brown, and black, depending which species are dominant in that patch of art. Though the bacteria and fungi have destroyed the artwork's original colors, they created new, vivid paintings with an indefinite lifespan. 

Images: Proceedings of the Royal Society B; Antiquity/J. Pettigrew

#The Animals Are Dying

Have you heard about all these fish and birds dying? That's probably a silly question, because everyone has heard about it. I went to a trivia night this week where one of the questions was, "In what state did thousands of dead blackbirds fall from the sky on New Year's Eve?" and everyone in the room laughed because the question was so easy.

Given that you've heard about it, are you panicking? Conspiracy theorists seem to be on every online comment thread, speculating that the U.S. government, terrorists, or a shift in the earth's magnetic field are to blame for wildlife deaths. Meanwhile, the AP published a helpful article yesterday that includes actual facts and scientists. Die-offs like these, it turns out, are quite common. But most of these events are not as visible (or Twitter-able) as Arkansas's "aflockalypse." Ornithologist and conservation scientist John Wiens is even relaxed enough to pun about it, saying that large die-offs "generally fly under the radar."

The federal government's National Wildlife Health Center publishes a list of reported mammal, bird, amphibian and reptile die-offs going back to 1995. Wildlife disease specialist LeAnn White says in the AP article, "Depending on the species, these things don't even get reported." Still, an average of 163 events are reported to the U.S. government each year. In 2009, these events included the deaths of 20,000 assorted birds in Idaho (botulism), hundreds of thousands of bats everywhere (more on that in a moment), and one million toads in Washington (fungal infection). If 163 events are reported in this country alone each year, not counting fish kills, then this week's events--a handful of die-offs worldwide, including fish--seems statistically unsurprising.

The poor Arkansas blackbirds apparently died from a trauma they experienced in the air, such as violent weather or a firework explosion. The Arkansas fish likely had a disease, while fish in the Chesapeake Bay may have died after a rapid temperature drop. So far, no need to stock up on canned goods.

But you would still be justified in feeling a little apocalyptic. Forget about the birds for now--how about the bees? Bumblebees have been dramatically declining over the past two or three decades, with the range of some species shrinking by up to 87%. Honeybees are famously disappearing due to the mysterious "colony collapse disorder." Bats are being rapidly wiped out by a fungus called white-nose syndrome. 

Scientists don't know exactly what's killing the bees and bats. But climate change is already affecting the ranges of parasites, fungi, and disease-carrying insects, exposing wildlife (and people) to illnesses they're not prepared for. Extreme weather events are expected to become more likely in the future. And animals and plants, on land and in the sea, will find themselves in warmer (or colder) temperatures than they're used to. 

Entire species are dropping from the sky. Maybe someone can think of a clever hashtag for that.

Take Two Sugar Pills and Call Me in the Morning

Placebos without the lying: that's what a group of researchers, led by Ted Kaptchuk* at Harvard, were after in a study published at the end of December. The placebo effect is well known for making people feel better when no "real" medicine has been used. It's not a measure of gullibility, but a testament to the body's power of anticipation. Just as you start to salivate before your tasty food reaches your lips, you might start to feel better simply by visiting a doctor.

If placebo weren't a medically powerful effect, trials of new drugs and treatments could just include a no-treatment group, instead of a fake-treatment group. It's assumed that people receiving the placebo treatment will show some improvement, which researchers can then subtract from the observed effect of the real treatment. (Placebo also has a black-sheep cousin called nocebo, which makes people feel worse.)

In a medical study, researchers warn patients that they may receive either a placebo treatment or the real drug. This is because doctors, reasonably, consider lying outright to a patient to be unethical. Yet half the doctors in a 2008 survey admitted to sometimes prescribing an "impure placebo" to a patient: a vitamin, sedative, or antibiotic, for example, that isn't really intended to treat the patient's condition.

Interested in harnessing the power of placebo without so much lying, Kaptchuk and his colleagues recruited a group of 80 people with irritable bowel syndrome for "a novel mind-body management study of IBS." The subjects heard a lengthy explanation from a doctor or nurse about the power of the placebo effect. They were told that the mere suggestion of treatment could cause their bodies to react "like Pavlov's dogs." Then half the patients were given a bottle of inactive pills--clearly labeled "Placebo"--and told to take them twice a day. The other half received no treatment at all.

IBS may have been a convenient disorder for studying the placebo effect, because it can only be measured subjectively. There are no medical tests for IBS, just patients' reports of certain symptoms such as constipation or diarrhea. 

When the subjects returned 21 days later to rate their symptoms, the results were impressive. The subjects who'd taken the placebo pills reported a substantial--and statistically significant--improvement when measured on three different numerical scales. In fact, the authors point out that the percentage of patients reporting "adequate relief" of their symptoms after taking the placebo pill (59%) was better than in a recent trial of an actual drug called alosetron.

It will be exciting to see what future placebo studies turn up. This study was only three weeks; would the same effect hold up in the long term? Can "open-label" placebo treatments cause significant improvements in symptoms with objective measurements, too? Even if it only works for subjectively measured symptoms, an honest placebo could be promising for people suffering from fibromyalgia or chronic fatigue syndrome. Like IBS, these disorders are collections of symptoms with no established cause or treatment. Maybe the effect of the mind over the body, instead of being a secret kept by doctors, could be an empowering discovery for the chronically unwell.

*No relation to CAPTCHA, the test that makes you decipher wiggly letters in order to prove you're not a spambot.