To get inside the head of a homing pigeon as it navigates towards its roost, researchers turned a flock of pigeons into cutting-edge techno-birds. The scientists outfitted the birds with “neurologgers” consisting of an electroencephalograph (EEG) to read the bird’s brain waves and a GPS tracker to record its location; by matching a bird’s position to its brain activity, the researchers could determine the bird’s reaction to the landscape below it. They found that, just like humans, the pigeons use visual landmarks in their navigation.
How homing pigeons find their way back to a starting point is not completely known. Studies have shown that the birds variously use the position of the Sun and the Earth’s magnetic field as a compass, and sense of smell and visual cues as navigation aids. But the use of visual cues has been difficult to study, because if a bird flies over a landmark and doesn’t change its course, it’s impossible to know whether the bird has not perceived the cue or is ignoring it [The New York Times].
A noisy Italian disco may not seem like a conducive location for scientific experiments, but for a couple of researchers investigating hearing and language processing it was perfect. The undercover scientists studied clubbers who were trying to talk while the music was pumping, and found that they showed a decided preference for speaking into each other’s right ears. What’s more, when the researchers approached clubbers with a request for a cigarette, they found the unwitting test subjects were much more likely to comply if the petition was made in the right ear.
Previous lab studies have also suggested that humans tend to have a preference for listening to verbal input with their right ears and that given stimulus in both ears, they’ll privilege the syllables that went into the right ear. Brain scientists hypothesize that the right ear auditory stream receives precedence in the left hemisphere of the brain, where the bulk of linguistic processing is carried out [Wired.com]. Researchers say this bias holds true for both lefties and righties.
When a person pick up a rake or a croquet mallet or any other tool, their mental image of their body expands subtly, according to a new study. To move our bodies around in space, the brain builds what’s called a “body schema,” a representation of all our various parts. And this so-called schema is frequently updated to keep up with our ever-changing bodies [Scientific American]. This new study, published in Current Biology, found that using a tool for even a brief amount of time caused volunteers to update their body schema, and to consider the tool a part of their bodies.
Lead researcher Alessandro Farnè first asked volunteers to point at and grab wooden blocks with their hands, then had them perform the same motions with a grabber tool, and finally returned to the hands-only gestures. The researchers recorded all of these tasks using a high-resolution three-dimensional motion-tracking system, so that they could compare in detail the movements performed in each task. They found that after using the grabber, the volunteers approached the blocks with slightly lower acceleration and velocity, although their accuracy was not affected. “They behave like their arm is longer,” says Farnè. “They aren’t clumsy, but they are slower and more determined” [Nature News].
Rats in laboratory tests learned to gamble based on a system of punishments and rewards, strategizing like human gamblers. And when researchers tweaked the animals’ brain chemistry to mimic that of humans with a gambling addiction, the mice began taking risks like pathological gamblers, according to a study published in the journal Neuropsychopharmacology.
To create this animal model of gambling addiction, researchers created a system in which options that could bring greater rewards also could yield stronger punishment. In this case, however, instead of gambling for money, the rats aimed to get as many sugar pellets as possible. The rodents were placed in specially built boxes whose walls incorporated four “response holes.” Each opening was associated with a possibility of earning treats - from one up to four, depending on the aperture chosen. When an animal poked its snout into a hole, the movement would break an infra-red light across the opening, signaling a computer with a “probabilistic” reward-punishment schedule to assign a pellet win or a “timeout” loss. Playing against the clock, the rats had only 30 minutes to accumulate as many sugar pellets as they could [The Canadian Press].
The rats quickly caught on that by choosing the openings that offered the greatest number of pellets, they also risked the longest time-outs during which they could not play the game. The test was based on an evaluation for decision-making in humans called the Iowa Gambling Test. In that game, there are some “bad” decks of cards that offer high rewards and punishments, and other “good” decks that offer lesser rewards and punishments.
For six years, psychiatrists thought they had found a genetic clue as to what makes some people more prone to depression when they’re hit with an emotional blow: a single gene. A 2003 study created a sensation among scientists and the public because it offered the first specific, plausible explanation of why some people bounce back after a stressful life event while others plunge into lasting despair [The New York Times]. But now a broader analysis of 14 studies has found no link between the gene and the risk of depression, and researchers argue that the 2003 findings were prematurely heralded as a breakthrough. “I think what happened is that people who’d been working in this field for so long were desperate to have any solid finding” [The New York Times], says Kathleen R. Merikangas, one of the authors of the new study.
The so-called “depression gene” that researchers focused on in the 2003 study helps regulate levels of serotonin, a brain chemical that plays a major role in depression and is a key target of antidepressant drugs. Researchers … found from a long-term study of 847 people in New Zealand that those with a short version, or allele, of the serotonin transporter gene were more likely to become depressed by adverse life events than were those with only long alleles [ScienceNOW Daily News].
It may sound like a paradox, but a new theory suggests that one of humanity’s most noble instincts, altruism, evolved on bloody battlefields in prehistoric times. Evolutionary biologist Samuel Bowles argues that prehistoric culture may have selected for individuals who behaved altruistically towards other individuals in their social groups. The story begins with the climactic swings that occurred between approximately 10,000 to 150,000 years ago in the late Pleistocene period may have pushed once-isolated bands of hunter-gatherers into more frequent contact with one another…. “I think that’s just a recipe for high-level conflict” [New Scientist], says Bowles.
These conflicts weren’t large-scale pitched battles, Bowles explains. “We’re talking about groups of men who got out in twos or threes or fives,” he says. “They didn’t have a chain of command and it’s hard to see how they could force people to fight.” For this reason, altruistic intent on the part of each warrior is key. Each person would do better to stay home than to put their life on the line for their neighbours – yet they still went out and risked their lives, Bowles says [New Scientist].
Parents might know that sitting children in front of the television for hours at a time isn’t the best way to encourage intellectual growth. But a new study published in the Archives of Pediatrics and Adolescent Medicine shows that simply having the TV on in the background can stifle interaction between parent and child, decreasing the number of words spoken and possibly slowing the development of a baby’s language skills.
Scientists have long suspected that TV viewing can damage early development. In fact, the American Academy of Pediatrics recommends avoiding exposure to television before an infant is two years old, a period when important cognitive changes take place. “We’ve known that television exposure during infancy is associated with language delays and attentional problems, but so far it has remained unclear why,” said lead researcher Dimitri Christakis [LiveScience].
Researchers have more evidence that takes aim at the old stereotype that boys are better at math than girls. Psychologist Janet Hyde had previously studied scores on standardized math tests in the United States, and found no difference in performance between girls and boys. Her new study expands the scope of the work by analyzing international data. She and her colleague analyzed studies from around the world on math performance along with gender inequality as measured by the World Economic Forum’s Gender Gap Index. This index measures the gap between men and women in economic opportunity, educational attainment and other socioeconomic factors [LiveScience].
They found that countries with poor gender equality, like India, had a larger gender gap in math, while in countries with excellent gender equality, like the Netherlands, girls performed as well as boys. If males really did have an innate advantage in math, the researchers note, that advantage should be obvious throughout all these cultures. Instead, the study suggests that cultural issues are the basis of the math gender gap.
Inserting a “pacemaker” into the brain to emit regular pulses of electricity and quell disordered neural activity may sound like a therapy of last resort, but if current experiments show beneficial results the brain surgery may one day be commonplace. But some scientists are cautioning that research on so-called deep brain stimulation may be pressing ahead too quickly, and warn that long-term effects of the surgery are not yet clear.
A growing number of psychiatric researchers are testing the method’s effectiveness on a host of psychiatric disorders. Until recently, deep brain stimulation was approved in the U.S. only to treat certain movement disorders, primarily those of Parkinson’s disease, for which it diminishes tremors and rigidity and improves mobility. To date, more than 60,000 patients worldwide have had the devices implanted [Los Angeles Times]. But now large clinical trials are in the works that will test the use of deep brain stimulation for obsessive compulsive disorder, epilepsy, and depression. Smaller experiments are beginning to assess the therapy’s effectiveness on a wide range of disorders including anorexia, drug addiction, obesity, traumatic brain injury, and Alzheimer’s.
Researchers have endowed lab mice with the human version of a gene involved in language, and while the mice didn’t exactly sit up and start reciting poetry about cheese, they did show some intriguing differences in both their vocal patterns and brain structure.
Mice have their own form of the gene, called FOXP2, but they and all other animals lack key changes found only in humans and our evolutionary cousins, Neanderthals. Some researchers speculate that these differences may help explain why humans are the only animal able to communicate with complex languages, and not simple grunts, barks or songs [New Scientist]. By tweaking the gene in mice and changing it to the human form, researchers hoped to get a clue as to how our early hominid ancestors were changed by the new form of the gene.
Tumors may physically trigger depression by producing chemicals that induce negative mood swings, according to a new study. The research, conducted in rats, allowed for the isolation of “just the physiological effects of the tumors from the psychological effects…. The tumors themselves are sufficient to induce depression” [The Scientist], says lead researcher Leah Pyter.
The new study, published in the Proceedings of the National Academy of Sciences, showed first that rats who had cancer exhibited several behavioral symptoms associated with depression. The researchers gave a forced swimming test to 100 rats, some healthy and some with cancer, and found that the sick rats did not try as hard to escape—a behavior similar to that seen in humans with depression. The sick rats were also less interested in sugar water, which is the the clear preference for healthy rats.
Deciding to reach out your arm and grab something and physically doing it are very different things, a fascinating new study has shown, and are controlled by two distinct regions of the brain. Researchers found that by directly stimulating a brain region called the parietal cortex, they could give test subjects the strong urge to move various body parts, like arms and lips. An even stronger jolt produced a false belief that they actually had moved. On the flipside of the experiment, when researchers stimulated a different part of the brain, the premotor cortex, the subject jerked or twitched, but wasn’t aware of it. The findings suggest that “we need intention to be aware of what we are doing,” says [study coauthor Angela] Sirigu. The brain’s intention and its prediction of what will result from carrying out that intention create our experience of having moved, she says [ScienceNOW Daily News].
The unusual study took advantage of a common operating room practice. As part of their preparation for surgery, neurosurgeons sometimes electrically stimulate the brains of their patients, who are awake under local anesthetic, to map the brain and minimize surgical complications [ScienceNOW Daily News]. In the case of this new study, published in Science, the patients were undergoing operations for brain tumors, but had agreed to take part in an experiment before the main surgery commenced. In all but one of the seven cases, the cancer was located far from the brain regions being stimulated.
It may be the first example of a serious scientific study being launched by a viral video. Neuroscientist Aniruddh Patel was astonished when someone e-mailed him a link to a YouTube video of a sulfur-crested cockatoo named Snowball dancing to the Backstreet Boys.”I said, you know, this is much more than just a cute pet trick. This is potentially scientifically very important,” recalls Patel [NPR].
Researchers had previously assumed that only humans move in time to a beat, but Snowball appeared to bob and rock to the rhythm just like any dancer. But Patel still wondered if the tail-shaking cockatoo had simply learned one dance routine that happened to synchronize to the Backstreet Boys song. For his study, published in Current Biology, Patel made slowed down and sped up versions of the song, and played them back to the bird while Snowball’s owner videotaped the reaction. They found that Snowball did adjust his moves to match the tempo. At slower speeds the bird swayed rhythmically from side to side, and when the beats came fast and furious, the bird erupted into rapid head-bobbing.
Researchers may have determined the method by which some animals can literally sniff out a sick individual–and hence avoid it to protect their own health. A team of scientists has identified a type of smell receptor in mice that seems to respond to disease-related molecules produced by bacteria, viruses, or as the result of inflammation [New Scientist].
Scientists have previously identified a number of mouse smell receptors, cell-surface proteins in the animals’ noses that pick up everything from the fragrance of food to the scent of fear…. Neurogeneticist Ivan Rodriguez of the University of Geneva in Switzerland and colleagues wondered whether there might be additional such receptors that respond to a disease “scent,” perhaps by detecting chemicals associated with bacteria and inflammation [ScienceNOW Daily News]. After scanning the mouse genome for genes in the olfactory system, they detected genes for five new smell receptors that seemed to be likely candidates. The receptors are part of a known family of proteins that are involved in immune response; other proteins in the same family detect chemicals given off by pathogens in an animal’s own blood.
Researchers have found fundamental differences between the brains of people who prefer to rise and greet the dawn each day, and those who don’t mind seeing a sunrise, but only if it’s at the end of a long night. A new study used brain scans and alertness tests to probe the brains of early birds and night owls, and found that people tend to favor mornings or nights based at least in part on how they react to a kind of competition in the brain [National Geographic News].
Two factors control our bedtime. The first is hardwired: A master clock in the brain regulates a so-called circadian rhythm, which synchronizes activity patterns to the 24-hour day. Some people’s clocks tell them to go to bed at 9 p.m., others’ at 3 a.m…. The second factor–called sleep pressure–depends not on time of day but simply on how long someone has been awake already [ScienceNOW Daily News]. Sleep pressure builds up as hours of wakefulness increase. The new study, published in Science, suggests that early birds are more susceptible to sleep pressure, giving night owls the advantage in stamina.
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
The posts are journalistic mashups, with quoted text in blue and the source of the quoted material identified in brackets—with a link, of course.
80beats is written primarily by Eliza Strickland, who darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Contact her at [estrickland at discovermagazine dot com]. Allison Bond contributes posts as well.
As 80beats makes fair use of the work of many excellent publications, we think it's only proper to offer up our content for use by others. DISCOVER holds the exclusive copyright to each 80beats post for 30 days after publication, but on the 31st day the text is licensed under Creative Commons (please note that the images aren't ours to give away). Check out the link below for the details of our terms of use.
To get inside the head of a homing pigeon as it navigates towards its roost, researchers turned a flock of pigeons into cutting-edge techno-birds. The scientists outfitted the birds with “neurologgers” consisting of an electroencephalograph (EEG) to read the bird’s brain waves and a GPS tracker to record its location; by matching a bird’s position to its brain activity, the researchers could determine the bird’s reaction to the landscape below it. They found that, just like humans, the pigeons use visual landmarks in their navigation.
A noisy Italian disco may not seem like a conducive location for scientific experiments, but for a couple of researchers investigating 
When a person pick up a rake or a croquet mallet or any other tool, their mental image of their body expands subtly, according to a new study. To move our bodies around in space, the brain builds what’s called a “body schema,” a representation of all our various parts. And this so-called schema is frequently updated to keep up with our ever-changing bodies [
Rats in laboratory tests learned to gamble based on a system of punishments and rewards, strategizing like human gamblers. And when researchers tweaked the animals’ brain chemistry to mimic that of humans with a gambling 
For six years, psychiatrists thought they had found a genetic clue as to what makes some people more prone to 
It may sound like a paradox, but a new theory suggests that one of humanity’s most noble instincts, 
Parents might know that sitting children in front of the television for hours at a time isn’t the best way to encourage 
Researchers have more evidence that takes aim at the old stereotype that boys are better at math than girls. Psychologist Janet Hyde had previously 
Inserting a “pacemaker” into the brain to emit regular pulses of electricity and quell disordered neural activity may sound like a therapy of last resort, but if current experiments show beneficial results the brain surgery may one day be commonplace. But some scientists are cautioning that research on so-called 
Researchers have endowed lab mice with the human version of a gene involved in 
Tumors may physically trigger 
Deciding to reach out your arm and grab something and physically doing it are very different things, a fascinating new study has shown, and are controlled by two distinct regions of the brain. Researchers found that by directly stimulating a brain region called the parietal cortex, they could give test subjects the strong urge to move various body parts, like arms and lips. An even stronger jolt produced a false belief that they actually had moved. On the flipside of the experiment, when researchers stimulated a different part of the brain, the premotor cortex, the subject jerked or twitched, but wasn’t aware of it. The findings suggest that “we need intention to be aware of what we are doing,” says [study coauthor Angela] Sirigu. The brain’s intention and its prediction of what will result from carrying out that intention create our experience of having moved, she says [
Researchers may have determined the method by which some animals can literally sniff out a sick individual–and hence avoid it to protect their own health. A team of scientists has identified a type of smell receptor in mice that seems to respond to disease-related molecules produced by bacteria, viruses, or as the result of inflammation [
Researchers have found fundamental differences between the brains of people who prefer to rise and greet the dawn each day, and those who don’t mind seeing a sunrise, but only if it’s at the end of a long night. A new study used brain scans and alertness tests to probe the brains of early birds and night owls, and found that people tend to favor mornings or nights based at least in part on how they react to a kind of competition in the brain [
