January 31, 2013
Action-centric video games have gotten a bad rap for their often violent content. Previous research says the brutal material can leak into real-world behavior, producing more aggression and triggering physiological changes in children’s brains. But what about virtual reality situations that put players in rescue-mode without the gore and pillaging?
What happens in these types of fantasy worlds also translates into real-life behavior, but in a different way: People who are given superpowers meant to save someone in virtual reality are more helpful outside of it.
This finding, reached Robin Rosenberg and colleagues from Stanford University’s Virtual Human Interaction Lab and published yesterday in a PLOS ONE study, relies on the illusion that what happens in virtual reality is real. Participants viewed the world through a head-mounted display, a helmet that provides three-dimensional stereoscopic views of a high-resolution rendered environment. An orientation sensor on the helmet tracked participants’ physical head movements and updated their rendered first-person perspective. To enhance the seeming reality of the the experience, virtual sound was added to match the movement of objects and the vibration associated with action.
In the study, each participant was placed separately in a virtual environment and either given the power of flight, a la Superman, or was a passenger in a helicopter. They were then assigned to one of two tasks. The first involved searching through a virtual city for a young, lost diabetic child in need of life-saving insulin, which they were told they held in a vial in their pocket. After three minutes of searching either via human flight or by helicopter, the child appeared, and an end sequence commenced showing its life had been saved. The second involved touring the virtual city, which was designed to be foggy and devoid of cars and people. The city in both circumstances had been evacuated due to an earthquake, participants were told.
After the virtual experience, the experimenter assisting participants “accidentally” knocked over a cup of pens, allowing the participants the opportunity to help pick them up. The researchers found that regardless of the task, those who used superpowers to fly through the fantasy world were quicker to help pick up the pens compared to those who rode in the virtual helicopter. These participants also picked up more pens than their helicopter-riding counterparts. Six participants out of 60 (30 males and 30 females) didn’t help at all–all six had cruised through the fantasy world in a helicopter.
How can a simulation trigger such prosocial behavior? The researchers suggest that embodying a superhuman quality in virtual reality primes people to think like superheros, such as Superman. Researchers made no mention of the word “superhero” or the prefix “super” at any point during the experiment. But by simply possessing a superhuman ability, participants seemed to tap into what they know about the characters that have them—that they use their power for the greater good rather than personal gain. Researchers believe cognitive channels linking “super” activity and its related stereotypes to heroism and helping behavior may have opened up, influencing participants’ decision to help.
And it doesn’t seem difficult for people to internalize what they see happening to their avatars (their computer-rendered, 3D selves) in virtual reality. For instance, people walking on top of a virtual log to cross a rendered chasm exhibit increased levels of stress measured by skin conductance. They know they’re not actually balancing atop a pit, about to fall, yet they experience multiple psychological symptoms associated with that fear.
Virtual reality’s penchant for inducing behavioral changes has been studied before, and the resulting good behavior moves beyond just picking up pens. A 2011 study found participants in a weight-loss program involving traditional gym sessions lost similar amounts of weight and body fat as those whose workouts were delivered online in a 3D virtual world.
In another study published in 2011, also conducted by the Virtual Human Interaction Lab at Stanford University, researchers found that virtual behavior affected people’s feelings about helping the environment. Participants were forced to saw down virtual trees using a joystick called a haptic device, which vibrated in their hands to simulate the real feeling of cutting through wood. Following the task, participants believed more strongly that they could personally improve environmental conditions than those who simply read a detailed description of deforestation. They also used less paper when cleaning up an “accidental” water spill in the physical world.
Researchers in the recent study suggest there may be more to the resulting prosocial effects than just priming effects. Pretending to possess a superpower may shift a person’s self-concept so he or she sees himself or herself as “someone who helps,” an identify change that could have lasting effects on behavior.
January 24, 2013
Science has shown us that a number of organisms use the stars for navigation: songbirds, harbor seals and, of course, humans. But a new study by a team of Swedish and South African researchers published today in the journal Current Biology indicates that a rather unexpected creature can be added to this list—the lowly dung beetle.
The beetles are known for creating small balls made of animal feces (i.e. dung) and rolling them in straight lines over long distances. They do this because the dung is their main food source—and other beetles often try to steal the dung once it’s been rolled into a ball. The surest way of retaining the valuable dung once it’s been packed into a ball is to move it away from the original dung pile as quickly as possible:
Researchers, though, have long been mystified by the tiny beetles’ ability to roll the dung balls in straight lines at night. “Even on clear, moonless nights, many dung beetles still manage to orientate along straight paths,” said lead author Marie Dacke of Lund University in Sweden. “This led us to suspect that the beetles exploit the starry sky for orientation—a feat that had, to our knowledge, never before been demonstrated in an insect.”
To test the hypothesis, the scientists set up a circular ring with a radius of about 4 feet outside and placed a dung pile at the center. They tested how long it took the beetles to reach the ring from the center—a measure of how straight their paths were—and found that their navigational abilities were relatively similar with either a full moon in the sky or at least a clear view of the stars. When they placed tiny blinders on the beetles’ eyes or subjected them to overcast conditions, though, their paths became much more windy.
Next, they placed a number of beetles in a planetarium and performed a similar test. Their paths were straightest with all the stars turned on, but were almost as true with just the Milky Way—indicating that they are particularly dependent on the Milky Way’s streak of light for navigation.
When the researchers turned on a large number of dim stars—many of which lie in the band of the Milky Way—the beetles’ navigation speed still remained similar. It was only when they left on just 18 of the brightest stars that their pathways became significantly windier.
The authors say that this proves that the beetles don’t rely on one particular star or celestial object for navigation, but rather take in the totality of the Milky Way—which appears as a startlingly bright band of light in many rural areas—to orient themselves on the ground.
January 22, 2013
Over thousands of years, gold has been used to treat rheumatoid arthritis, inner ear infections, facial nerve paralysis, fevers and syphilis. Now, preliminary findings suggest a new application for tiny grains of gold—destroying cancer cells.
Gold-carrying nanoparticles are capable of killing a common type of cancer that attacks antibody-making B cells in the blood, according to a study published today in the journal Proceedings of the National Academy of Sciences. This cancer, B-cell lymphoma, originates in the lymph glands and is the most common type of non-Hodgkin lymphoma. Last year, it resulted in nearly 19,000 deaths.
Developed by researchers at Northwestern University, the nanoparticle mimics the size, shape and surface chemistry of high-density lipoprotein—natural HDL—the preferred meal of these cancer cells. HDL is the “good” cholesterol that cruises through the bloodstream, removing dangerous buildups of LDL, the harmful, “bad” cholesterol.
The bits of gold tucked inside these particles are tiny—just five nanometers wide. A billionth of a meter, a nanometer is a measurement used to size bacteria, X-rays and DNA. The width of a double helix is about two nanometers.
Despite its microscopic size, the synthetic particle packs a big punch—more accurately, two of them. Recent research has shown that B-cell lymphoma is dependent on the uptake of natural HDL, from which it derives fat content, to spur cell proliferation. The nanoparticle cuts off its supply. Masquerading as natural HDL, the nanoparticle latched on to cholesterol receptors on deadly lymphoma cells. First, the nanoparticle’s spongy surface sucked out the cell’s cholesterol. Then, it plugged up the cancer cell, preventing it from absorbing natural HDL particles in the future. Deprived of this essential nutrient, the cell eventually died.
Natural HDL alone didn’t kill the cells or inhibit tumor growth in the study. The blinged-out particle was key to starving the lymphoma cell—and it did so without the help of cancer drugs.
It also didn’t appear to be toxic to other human cells normally targeted by HDL particles, to normal lymphocytes (a type of white blood cells) or to mice, in which the particle actually inhibited tumor growth. Developing a drug therapy using this nanoparticle depends on further extensive testing, but it could take chemotherapy off the table for the thousands of patients diagnosed with B-cell lymphoma.
January 21, 2013
Over the weekend, the Sun moved into the constellation Aquarius, blocking it from view in the night sky. Although the “Age of Aquarius” of popular culture is far off, tonight some Western Hemisphere observers will get a little bit of astronomical free love as the Jupiter–the second brightest planet in the night sky (the brightest being Venus)–kisses the Moon.
To sky watchers in most of North America, the planet and the Moon will flirt: Jupiter will be less than a finger’s width from the waxing Gibbous Moon. The time of their closest approach varies by location–observers on the East coast will see it at around 11:30 p.m. Central time stargazers should look up at around 10:00 p.m., while those in Mountain time will see Jupiter’s nearest approach to the Moon at about 8:30 p.m. Pacific time observers will catch their best view early in the evening, at roughly 7:00 p.m. The close approach can be best seen with a wide-field telescope at low magnifications (40x or lower) or binoculars, but can even be viewed with the naked eye.
From much of South America, the planet will appear touch the Moon; in some regions, the Moon will completely hide Jupiter from view. This game of hide-and-go-seek, termed occultation, will cause Jupiter to disappear and reappear from the skies over much of central South America. However, when viewed from much of the east coast of Brazil and Uruguay, the Moon will set before Jupiter reemerges.
For the past few days, Jupiter has been close to the Moon at sunset, but today, careful observers may even be able to spot Jupiter in the late afternoon, before the Sun sets. “First locate the Moon medium-high in the east; then look a few Moon-widths left or lower left of the Moon for Jupiter,” explained Tony Flanders, associate editor at Sky & Telescope magazine. “It should be easy to spot with binoculars if the air is clear,” he said in a statement.
Those with telescopes can even see Jupiter’s Great Red Spot between 9:00 p.m. and 10:40 p.m. EST today. In addition, Jupiter’s moon Europa will pass in front of Jupiter between 8:13 and 10:37 p.m. EST, although the moon’s shadow–which crosses Jupiter from 10:22 p.m. to 12:46 a.m. will be easier to spot. Have fun planet-watching!
January 17, 2013
Barnacles are renowned for the size of their penises. The strange-looking creatures, which live inside shells glued to rocks or boat hulls, have outsized members that are among the longest in the animal kingdom relative to their size—their penises can stretch up to eight times their body length. Barnacles can even change the size and shape of their penis depending on the amount of wave action in their ocean real estate.
Perhaps this is why the sex lives of barnacles have long been of interest to scientists—luminaries such as Darwin, among others, closely studied the subject. Until recently, though, scientists recognized just two methods of reproduction in the species, and both left unanswered questions.
Pseudo-copulation, in which the penis enters a neighboring barnacle’s shell and deposits sperm, has been observed, but this method restricts them to reproducing only with others in their vicinity. Scientists have also observed that individual barnacles with no neighbors can reproduce, and they assumed this was accomplished through self-fertilization, because most barnacles are hermaphrodites.
Now, though, researchers at the University of Alberta, Edmonton and Bamfield Marine Sciences Centre in British Columbia seem to have discovered a new reproduction method while studying the gooseneck barnacle (Pollicipes polymerus), upending more than 150 years of theory. Previously, the researchers had noticed that in other studies of the gooseneck barnacle, self-fertilization was never observed. They also saw sperm leaking from the barnacles in the field, which made them consider the possibility that barnacles could pick up sperm from the water.
In the study, the scientists collected gooseneck barnacles—both isolated and in pairs—along with their fertilized eggs from Barkley Sound in British Columbia to take back to the lab so they could genetically analyze the paternal combinations. The DNA of the fertilized eggs revealed that none of the isolated barnacles had produced embryos through self-fertilization—so one hundred percent of these eggs must have been fertilized by capturing sperm from the water.
Surprisingly, though, even some of the barnacles that resided in pairs had embryos that had been fertilized with sperm from a non-neighbor. This left one possibility: that the barnacles release their sperm into the ocean and let the water carry it to distant neighbors. This type of fertilization has been observed in other marine animals that can’t or don’t move, but it was always assumed that barnacles can’t reproduce in this way.
The authors point out that this mode of reproduction may be unusually common in this particular barnacle species because of the small size of their penis—but the fact that this phenomenon occurs at all opens the door to re-thinking the biology of these creatures. Other barnacle species might also have more mating options, with fathers coming from farther afield than previously thought.
Learn more about the ocean from the Smithsonian’s Ocean Portal.