(This post was first published in January 2014.)
Lying to your doctor is encouraged in one situation: when your doctor is a student and you’re an actor asked to portray a certain condition. My friend Amy Savage does this for work. In between fake symptom bouts, I asked her to write a guest post sharing what she’s learned from being poked for practice.
Have you ever been asked to “please dislocate your left breast,” or if you “have noticed any hairs growing in places you normally wouldn’t have hairs”? Or maybe someone told you to “have a nice day” after your spouse just passed away or you’d received a cancer diagnosis. Not only do I hear things like this from time to time at my job, but I have grown to expect them.
I have been working for several months as a so-called standardized patient. The local medical school runs an excellent program that lets students conduct histories and physical exams in a simulated, standardized setting. This means I (and many others) pad around in rubberized socks and breezy hospital gowns and feign myriad diseases, syndromes, conditions, and (sometimes nasty) habits. It also means I overuse hand sanitizer and have many strangers listen to my heart, palpate my abdomen, and poke me with a broken wooden Q-tip to test my sensation. One time I even let someone stick their gloved hand in my mouth and squeeze my tongue a little. Read More
Siri doesn’t need your love (sorry). But she does need your trust. At least, she does if you’re going to use her in the way Apple intends. For us to make artificially intelligent technologies like smartphones and self-driving cars a part our routines, we have to be willing to turn over important parts of our lives to them—like our calendars, or our actual lives. Now a study suggests that having a voice and a name is all it takes for a computer to gain that trust.
Adam Waytz, a psychologist at Northwestern University’s Kellogg School of Management, tested people’s trust of technology using a driving simulator named Iris. (Yes, as in “Siri” backward. It was, Waytz says, “the idea of my much cleverer co-author Nick Epley” at the University of Chicago.) Iris’s voice was provided by their colleague Heather Caruso, who happens to do a good computer impression. But, Waytz adds, “I would be interested in testing whether male versus female voices might produce different effects.”
Waytz recruited 100 adults to take the driving simulator for a spin. One group of them used the simulator on a normal setting, driving it just like a real car. For another group, the simulator had autonomous (self-driving) features that they could turn on by pressing buttons on the steering wheel. The final group of subjects was introduced to the simulator as “Iris.” Its self-driving features were the same as for the second group of subjects, but now Iris spoke to subjects directly, giving explanations that had come from an experimenter in the other group. (“Hello, I’m Iris. I can control the gas, brakes, and steering.”) Read More
Before they become butterflies, some caterpillars transform themselves into ants. Rather than living out in the open and braving predators while they grow up, these caterpillars sneak into ant nests for free food and lodging—or they just eat the ants. Either way, scientists have found, part of the caterpillars’ disguise involves mimicking the sounds of an ant queen. When worker ants hear this tune, they drop everything to tend to the mooching invaders.
At the beginning of its life, a caterpillar of the genus Maculinea hangs out on its favorite plant and munches away, like any other future butterfly. Its food plants are within the foraging grounds of Myrmica ants, the caterpillar’s targets. Once it finishes growing, the caterpillar waits until an evening between 6 and 8 PM—prime foraging time for the ants—then lets go of its perch and falls to the ground. There, it waits.
When a Myrmica ant that’s out searching for food stumbles across the caterpillar, it stops and feels it with its antennae. This assessment may take only a few sends, or may be an hours-long “adoption ritual,” explains University of Turin biologist Luca P. Casacci. Then the ant picks up the giant baby (“Whoops, how did one of our larvae get out here?”) and carries it back to the ant nest.
How the caterpillar takes advantage of its new home depends on its species. Read More
In the fight for attention from researchers, there are winners and there are civets.
That’s what researchers found when they analyzed almost 16,500 published papers about animals from walruses to weasels. They saw clear trends in which animals are the most popular to study. And it matters because the most popular animals aren’t necessarily the ones most in need of attention.
Zoe Brooke, a researcher at the Zoological Society of London, and her coauthors looked at every peer-reviewed paper they could find that was published between 1900 and 2010 about an animal in the order Carnivora. This is a set of 286 mammal species that all—as their name suggests—eat meat, at least sometimes. Medical papers that used animals to model a disease were excluded (sorry, lab mice). Papers on pets were also left out, though feral cats and dogs were fair game.
Winners: Big Guys
There are 15 families within Carnivora. Some of those families contain many more species than others, so the authors ranked the families by the average number of published papers per species. Bears (family Ursidae) crushed the competition, averaging more than 250 papers per species. Read More
If your parents ever groaned that you and your siblings were aging them rapidly with your bickering or loud music, they may have been right—especially if they were jackdaws. Scientists who artificially increased or decreased the size of these birds’ broods found that extra-large families make parents die sooner.
One theory of aging says that it comes from accumulated damage to a body’s cells, and that animals have a limited amount of resources to spend fixing that damage. Using more resources on something like having and raising offspring may leave an animal with a smaller reserve for keeping its cells in good shape. This means reproducing might make it age sooner.
Some long-term studies of wild animals have found evidence that this is true. But, writes Jelle Boonekamp, a biologist at the University of Groningen in the Netherlands, these studies compared animals that naturally had larger or smaller numbers of young. So there might have been an unseen third variable at work—some trait that gives parents more young while also shortening their lives.
To address this problem, Boonekamp and his coauthors stole babies from some birds and tricked others into adopting them. Read More
As bats squeak and swoop through pitch-black Mexican caves, the pale fish that inhabit the pools below them perform a soundless imitation. These fish are blind but sense the world through subtle pressure changes on their skin. To navigate the cave floors, they also use a tool that’s never been observed in another animal: the waves of suction they make each time they open and close their mouths. These pulses warn them of nearby obstacles like the calls of an echolocating bat do.
Mexican blind cavefish, or Astyanax fasciatus, are a kind of small tetra sometimes found in home aquariums. At some point in their evolutionary past, these fish moved into caves and lost their eyeballs entirely. They have a close relative that lives outside of caves and still has its eyes—in fact, the blind and sighted fish are so closely related that they’re still considered one species.
While it gave up its sight, the blind tetra also gained skill at navigating in the dark. To find its way, it takes advantage of something called the “lateral line.” This is a sensory system that all fish have. Through receptors on their heads and bodies, the lateral line lets fish feel movements and pressure changes in the surrounding water.
“The lateral line of the blind fish is much more sensitive” than that of its sighted relatives, even though they’re the same species, says Tel Aviv University zoologist Roi Holzman. The blind cavefish has more sensors on its body, and each of them is twice as sensitive as a sighted fish’s receptors. It can feel its way around by judging disturbances in the ripples sent out by its own swimming body.
Yet Holzman, watching the cavefish swim and make O’s with its mouth like any other fish, wondered whether there was even more to its navigational prowess. Could it also be using suction from its mouth to steer around obstacles? Read More
No matter how much of a critical thinker you consider yourself, your brain is pretty gullible. With a few minutes and a couple of props, your brain can be convinced that one of your limbs is made of rubber or invisible, or that your whole body is the size of a Barbie doll’s. All these illusions depend on your senses of vision and touch interacting. But a new illusion trades sight for sound. By hearing the sound of a hammer striking marble each time it tapped their hands, subjects came to feel that their limbs were made of stone.
In the original rubber hand illusion, first published in 1998 by psychologists Matthew Botvinick and Jonathan Cohen, subjects sit with one forearm resting on a table. A little wall blocks the subject’s own arm from his or her sight, while a rubber arm just inside the wall is clearly visible. A researcher sitting on the opposite side of the table simultaneously strokes the backs of the rubber hand and the real hand with paintbrushes. As subjects watch the paintbrush stroking the rubber hand and feel the action on their own skin at the same time, they come to feel a powerful illusion that the rubber hand is their hand.
Scientists have since performed many variations of this experiment, bending people’s perceptions of their own bodies in all kinds of freaky ways. (See below for links to stories about a few of those studies.)
“The focus of those experiments is embodiment,” says Irene Senna, a psychologist at Milano-Bicocca University in Milan, Italy. “Can our body incorporate an external body part?” The findings are relevant to amputees and people learning to use artificial limbs. But Senna and her coauthors were interested in a slightly different question: instead of convincing ourselves that an inanimate hand is our own, can we come to believe that one of our existing body parts is made of a non-human material?
This being Italy, the material the researchers chose wasn’t novelty-shop rubber, but stately marble. Read More
Kids who love books know the world is a perilous place. Any day a tornado may carry away your house; your little brother may be kidnapped by a disembodied alien brain; a rhinoceros may eat your parents. But when it comes to more ordinary dangers, kids who read the classics might be left confused: Is an ordinary fever likely to kill you? How many days home from school does it take before someone sends you to the seaside to recover?
The illnesses of fictional characters may be the first medical education a kid gets. And that education can be a little out of date. In Peter and Wendy, the Darling children are looked after by a nurse named Nana: “She believed to her last day in old-fashioned remedies like rhubarb leaf, and made sounds of contempt over all this new-fangled talk about germs, and so on,” J. M. Barrie writes. Of course Nana is a large dog, not a human, but we’re told she’s quite competent.
If the characters in our favorite books did have access to modern medicine, though, some of their stories would barely be worth reading.
The Velveteen Rabbit
If you’re somehow not familiar with this 1922 book by Margery Williams, think Pinocchio with less misbehavior and more heartbreak. It’s told from the perspective of a stuffed rabbit that’s given to a boy for Christmas. The boy comes to love the rabbit and carries it around until its fur falls off. Then the boy gets scarlet fever. Read More
The classic, swirling shell of a conch helps protect it from hungry birds and sea creatures, but when a human decides to pluck one from shallow water and boil it for supper, there’s not much the animal can do. Its only defense is to evolve, as a species, to be smaller and less appealing to people. That’s what conchs in the Caribbean have done—today’s humans get 40 percent less food out of a conch than our ancestors did. But that’s not so surprising to a 12-year-old girl who described almost the same thing in a piece of fiction.
To explain the fictional version, I have to insert myself into this story—hello! In my day job I edit a kids’ science magazine called Muse. We recently ran a contest that asked readers to write a brief, made-up story in the style of the magazine’s science news page. (The results were sometimes hilarious. “Too Much Coffee Makes Adults Feel Young” was an office favorite.)
One winner of this contest was a 12-year-old named Madeline. Her submission was about a new species, the “broken-shelled hermit snail” (Mendacious latibulum), discovered on the beaches of North America. It had gone undetected until now, the story went, by evolving a mangled-looking shell that kept human collectors away.
“She is almost certainly right in theory,” says Aaron O’Dea, a marine historical ecologist and paleobiologist at the Smithsonian Tropical Research Institute in Panama. As long as the mollusk were still alive while on the beach and vulnerable to collection, evolving an ugly shell could help it survive. O’Dea knows all about mollusks evolving to avoid humans; he recently discovered that the West Indian fighting conch (Strombus pugilis) has done exactly that. Read More
An ant is not exactly the picture you see in the dictionary next to “rule-breaker.” Colonial ants work together to collect food and generally act in the best interest of the group. Yet certain enormous ants in South America break a basic rule in biology: as you move up the food chain, you should find a smaller group of organisms at each step. These ants are top predators that take up far more than their fair share of space. To find out what their secret is, scientists staked out the forest floor.
“We’re all ant nerds,” says Chad Tillberg, a biologist at Linfield College in Oregon, of himself and his coauthors. So when they started visiting a park in northeastern Argentina and noticed what seemed like a whole lot of Dinoponera australis ants, they thought it might be an illusion created by their excitement. Plus, Tillberg points out, “Dinoponera are huge.” The seven species in this genus, which can be more than an inch long, are some of the largest ants in the world.
There are many plentiful bugs in the rainforest, of course. But an abundance of this particular ant—which locals call hormiga tigre, the “tiger ant”—demands an explanation. That’s because the species is known as a top predator of the soil. Other champion carnivores—like, say, an actual tiger—are rare, compared to the things they eat. Read More