The strangest thing about this Chinese boy’s light blue eyes is not their color. It’s the purported fact that he can see in the dark. His eyes are just like cat eyes, glowing blue-green when you shine a light in them, says this clip from China’s state-run English TV channel. The boy can catch crickets in the dark without a flashlight and even completes a writing test in a pitch-black stairwell. True, or too good to be?
Natalie Wolchover at Life’s Little Mysteries has rounded up some experts and their collective reaction seems to be, “Hmm…” (It doesn’t help that this video has been posted on YouTube under the name, “Alien Hybrid or Starchild Discovered in China? 2012.”) One possibility they consider is whether the boy has a mutation that produced something like a tapetum lucidum, an extra layer of tissue that helps cats see in the dark. James Reynolds, a pediatric ophthalmologist at State University of New York in Buffalo, puts a stop to that idea:
What’s the News: Georgia Tech researchers have now created a glove that heightens your sense of touch. Presented in May at the IEEE International Conference on Robotics and Automation, the glove—which applies high-frequency vibrations to the side of an exposed fingertip—can improve a wearer’s motor skills and tactile sensitivity. “This device may one day be used to assist individuals whose jobs require high-precision manual dexterity or those with medical conditions that reduce their sense of touch,” Georgia Tech assistant professor Jun Ueda said in a prepared statement.
What’s the News: In the animal kingdom, prey species must follow one rule above all others: keep away from predators. To do this, some animals take chemical cues from the urine they stumble upon. Now, new research published in the Proceedings of the National Academy of Science has identified a single molecule in the urine of many mammalian carnivores that causes rodents to scurry in fear. This chemical could eventually help scientists understand instinctual behavior in animals.
A new model of crowd behavior uses simple visual rules.
What’s the News: When crowds go wrong, they go really wrong—more than 300 people died in a stampede in Cambodia last year during a festival, and hundreds more have been crushed to death in periodic disasters near the Muslim holy city of Mecca. A major flaw of computational models describing how people behave in crowds is that they are often too simplistic or too specific to a situation to explain both normal and disastrous behavior. A new model manages to recreate both types of behavior, working from two basic visual rules: (1) each person will move in the least crowded direction in their line of sight, and (2) they will adjust their speed to maintain a safe distance from visible obstacles.
“This work is an extremely important step in pulling together our fragmented understanding,” says behavioral biologist Iain Couzin, who was not involved in the study (via ScienceNOW). “We’re now approaching a sort of unified understanding of human behavior in crowds.”
What’s the News: The reproductive life of a cuckoo is both easy—it lays its eggs in others birds’ nests, and lets them feed the young—and difficult: cuckoos are involved in an “evolutionary arms race” with other birds, finds a new study. Even as cuckoos improve their counterfeiting skills—producing eggs that look more like others birds’—the host birds get better and better at identifying the forged eggs.
How the Heck:
Knowing that birds have four types of color-sensitive cone cells in their eyes, allowing them to see ultraviolet wavelengths, researchers used a spectroscope to measure the amount of light reflected from hundreds of cuckoo and host-bird eggs. They then fed this data into models to produce images showing how birds see the different types of eggs.
They discovered that while cuckoo and redstart eggs have a high degree of color overlap, cuckoo eggs targeted for dunnock nests did not.
Here’s the kicker: Redstarts and dunnocks don’t spot forgeries equally. Redstarts are more discerning of foreign eggs and readily kick out cuckoo forgeries, while the dumb dunnocks accept even the most mismatched eggs. So these findings suggest that cuckoos targeting redstarts evolved the ability to create better forgeries because the redstart has such a good eye. With dunnocks, that evolutionary force wasn’t at play because the birds are so accepting of forgeries; why bother?
What’s the Context:
What sets this research apart from previous work is how the researchers used UV-sensing equipment to mimic bird vision. (Past research relied merely on human inspection.)
The Future Holds: Scientists still aren’t sure why some hosts, like the dunnock, are so accepting of cuckoo eggs. Some scientists argue that this is because the risk in mistakenly rejecting a real egg outweighs the cost of raising a cuckoo egg. The jury’s still out.
Reference: “AVIAN VISION AND THE EVOLUTION OF EGG COLOR MIMICRY IN THE COMMON CUCKOO” Mary Caswell Stoddard and Martin Stevens. DOI: 10.1111/j.1558-5646.2011.01262.x
The latest diagnostic tool for oncology comes on four paws and is defined by its very effective nose. In a small study, Japanese researchers found that a dog could detect cases of colorectal cancer by sniffing patients’ breath or stool samples. Previous experiments have shown that dogs can sniff out cases of skin, lung, bladder, and breast cancers; researchers think the tumors give off chemical signals that the dog can detect in bodily substances.
The cancer expert in this case was an eight-year-old black Labrador named Marine who was trained to search for disease traces at the St. Sugar Cancer Sniffing Dog Training Center in Chiba, Japan. She must have been a good student. The research, published in the journal Gut, showed that she had a high success rate:
The Labrador retriever was at least 95 percent as accurate as colonoscopy when smelling breath samples, and 98 percent correct with stool samples, according to the study…. The dog’s sense of smell was especially effective in early-stage cancer, and could discern polyps from malignancies, which colonoscopy can’t. [Bloomberg]
Lead researcher Hideto Sonoda says it would be impractical to use dogs for routine bowel cancer screenings, but adds that further research into dogs’ diagnostic ability could lead to the development of an electronic nose.
Dr Sonoda told the BBC: “The specific cancer scent indeed exists, but the chemical compounds are not clear. Only the dog knows the true answer. It is therefore necessary to identify the cancer specific volatile organic compounds [smells] detected by dogs and to develop an early cancer detection sensor that can be substituted for canine scent judgement. To complete the sensor useful in clinical practice as a new diagnostic method is still expected to take some time.” [BBC]
When you’re nature’s ideal killing machine, perhaps color vision is merely an unnecessary affection. New research argues that sharks could be completely colorblind.
An Australian team led by Nathan Scott Hart investigated 17 shark species, peeking at the structure of their rod and cone photoreceptor cells in the retina. Human eyes come with red, green, and blue cone variations, allowing us to see in color. But not shark eyes. They appear to have just one kind of cone.
“Our study shows that contrast against the background, rather than color per se, may be more important for object detection by sharks,” Hart said. [CNN]
That, Hart says, may explain the common wisdom that sharks love yellow (and therefore you ought to avoid sunny swimsuits). It may be the reflective quality of yellow that catches a shark’s eye, not the hue itself.
“Bright yellow is supposed to be attractive to some sharks, presumably because it appears to the sharks as a very bright target against the water,” said Dr Hart. “So perhaps it is best to avoid those fluoro-yellow shorts next time you are in the surf.” [BBC News]
Those delicious chills you get as your favorite piece of music reaches its climax? They’re the result of a glorious spike of dopamine in your brain–that’s the same neurotransmitter that’s involved in reward, motivation, and addiction.
In a nifty series of experiments published in Nature Neuroscience, researchers determined that music provokes floods of dopamine in music lovers. Study coauthor Valorie Salimpoor notes that dopamine has long been known to play a role in more physical activities like taking drugs and having sex, but this research highlights its role in other aspects of our lives.
“It is amazing that we can release dopamine in anticipation of something abstract, complex and not concrete,” Salimpoor said. “This is the first study to show that dopamine can be released in response to an aesthetic stimulus.” [Discovery News]
Embryonic stem cell treatments are edging closer to mainstream medicine. An experimental treatment just approved for clinical trials may provide hope to the 10 to 15 million elderly patients in the United States who suffer from a common form of macular degeneration, which causes gradual blindness.
The biotech company behind the treatment, Advanced Cell Technology, Inc., previously won FDA approval to try an embryonic stem cell treatment on patients with a rare, juvenile form of macular degeneration. The new FDA-approved trial will use similar techniques, but targets a much broader patient base.
“ACT is now the first company to receive FDA clearance for two hESC (human embryonic stem cell) trials, and is now a true translational leader in the field of regenerative medicine,” said chief executive Gary Rabin. “It marks a major step forward, not just within the stem cell sector, but, potentially for modern healthcare techniques.” [AFP]
Embryonic stem cell treatments are finally breaking out of the lab and arriving in the clinic. In October, the first federally approved trial of a treatment derived from these controversial cells got underway in patients with spinal cord injuries. Now, the FDA has approved a second trial, this one to test a treatment for a rare disease that causes serious vision loss or blindness.
The company behind the trial, Advanced Cell Technology, will test the safety and efficacy of the treatment on 12 patients.
The trial will examine the safety of a therapy for Stargardt’s Macular Degeneration, an inherited juvenile eye disease affecting an estimated 1 in 10,000 young people in the US. As the disease progresses, a layer of the retina called the retinal pigment epithelium (RPE) degenerates, causing vision loss. It’s hoped the new therapy would also work for other types of macular degeneration, a widespread cause of blindness, particularly in the elderly. [Nature blog]
In an exciting pilot study, blind people equipped with microchips in their retinas were able to see again–at least dimly–and were able to make out shapes.
Ed Yong explains how the experiment helped a study participant named Miikka:
In people like Miikka with retinitis pigmentosa, the light-detecting cells of the retina break down with age. Eberhart Zrenner and a team of German scientists have designed a chip that does the same job as these defunct cells. Just a few millimetres across, it contains 1,500 light-detecting diodes that detect light and convert it into a current. The brighter the light that hits the chip, the stronger the current it puts out. The current is delivered directly to the bipolar cells, which would normally transmit the signals from the retina’s actual light detectors.
Find out more about how the technology works and get the full story on Miikka and his fellow experiment subjects at Not Exactly Rocket Science. And check out the videos of Miikka trying out his new eyes below.
Deep in your brain there are probably several thousand neurons that will respond only to the sight of Lady Gaga. Several thousand others probably only crackle to the sight of Justin Bieber. It might be nice to reassign those neurons to loftier thoughts. For now, though, neurology can’t help you. What neurology can do for you (if you’re up for a little invasive brain surgery) is let you use those Gaga and Bieber neurons to control a computer.
A team of researchers has built on the previous discovery that specific neurons respond to the images of specific people–like Lady Gaga, or your grandmother. To harness these neurons, the researchers tried out an ingenious brain-machine interface based on images of celebrities who triggered particularly strong responses in 12 patients.
A patient could bring a digital image of a celebrity (like Marilyn Monroe) into the foreground by consciously focusing on the image, which meant that the celebrity-associated neurons were firing. As they describe in a paper in Nature, the patients quickly got the hang of it, activating patches of neurons at will. This has led researchers to wonder if people could one day control devices simply by visualizing certain people, things, or concepts.
You can get the rest of the story on this fascinating but intrusive technology, and can also see a video that Carl made about the experiments, at The Loom.
The simple act of picking something up requires a plethora of decisions: Is the thing light or heavy? How much force do I need to grip it? If I grip too hard, will I crush it with the might of my mighty hands?
As we grow up we become fairly practiced at the art of picking up (objects, that is), so our brains will do most of this for us without a lot of conscious thought. But all those variables—plus adapting to a surprise on the fly—mean that picking things up with the proper force is one of the most difficult skills to teach a robot. That’s why the design by Eric Brown’s team is so clever.
In this week’s Proceedings of the National Academy of Sciences, Brown and colleagues demonstrate (paper in press) their “universal gripper,” a successful prototype of a robot hand. It’s based on an idea that’s been around for a while, and it looks like a beanbag on a robot arm, because, well, that’s kind of what it is.
Your lungs know a bitter sensation when they taste one.
Yes, taste. In a Nature Medicinestudy, Stephen B. Liggett and company found receptors on the smooth muscle in the lungs that respond to bitterness, similar to the bitter taste buds on the tongue. And, Liggett found, the receptors’ reaction to bitterness is to relax the muscles, and therefore to expand airways. That was totally unexpected, he says, and opens intriguing possibilities for pulmonary treatment—for example, asthmatic symptoms could be treated by exposing these receptors to bitter compounds.
Like tastebuds on the tongue, the receptors react to bitterness, but unlike tastebuds they do not send any signals to the brain. The researchers thought the taste receptors might have evolved as a protection against toxic plants [Boston Globe]
A brain is a terrible thing to waste–and your brain knows that. A new study of congenitally deaf cats has shown that some parts of their brains which would typically work on hearing are repurposed, and instead help out with vision. As a result of that clever efficiency, these deaf cats have superior peripheral vision and motion-detection abilities than cats with normal hearing.
Researchers say the human brain may perform the same trick.
For years, researchers have known that deaf people often have superior peripheral vision and motion detection, but just how the brain creates these advantages was unclear. “Over the years, we’ve speculated about how these changes might be taking place,” says neuroscientist Helen Neville of the University of Oregon in Eugene, but a clear cause has been elusive. [Science News]
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].