Walk into the little girls' aisle at a toy store, and you'll be inundated with pink. We take for granted gender differences in color preference, but for more than 100 years, studies have failed to find a biological basis for the disparity. New research confirms that girls go for red whereas guys do not and links the mechanism to the biology of vision. Our color likes and dislikes may be a remnant of the different roles that men and women played in our distant hunter-gatherer past.  
Studies from as long ago as 1897 have hinted at differences in color preference between genders, suggesting that more females preferred reds than did males. But the data were murky and inconsistent, according to experts.  
Hoping to clear the air, neuroscientists Anya Hurlbert and Yazhu Ling of Newcastle University in the U.K. performed an experiment on 171 British Caucasians and 38 recent immigrants from China aged 20 to 26. Each subject chose his or her favorite from a series of color pairs on a computer screen. Humans judge color on two scales--one red-green and one blue-yellow. Hurlbert and Ling assigned each color values on these same two scales and compared each gender's preferences.
The body's clock may lose track of time during winter hibernation, scientists have found in a species of hamster.  
The genes responsible for regulating circadian rhythms in the brain normally follow a 24-hour cycle, with their activity waxing and waning in step with day and night. But what happens during hibernation?  
Brain activity resembles that of deep slumber, and the body slows its metabolism to a crawl. The internal temperature of arctic ground squirrels, for instance, can plummet below freezing. It's thought that hibernation evolved from sleep as a way to save energy during lean winter months.  
Some studies have hinted that factors such as body temperature continue to oscillate up and down in a daily cycle during this winter period, although not nearly so much as during normal conditions. But no one had tapped directly into the brain or looked at the genes that control the body clock to see what was happening there.
When Shyness turns deadly
As a personality trait, shyness probably ranks as one of the more benign characteristics that someone can possess, but new research suggests that at least some forms of shyness may have violent, and often deadly, consequences.
Sugar and spice and everything nice hold no interest for a cat. Our feline friends are only interested in one thing: meat (except for saving up the energy to catch it by napping, or a round of restorative petting) This is not just because inside every domestic tabby lurks a killer just waiting to catch a bird or torture a mouse, it is also because cats lack the ability to taste sweetness, unlike every other mammal examined to date.  
The tongues of most mammals hold taste receptors—proteins on the cellular surface that bind to an incoming substance, activating the cell's internal workings that lead to a signal being sent to the brain. Humans enjoy five kinds of taste buds (possibly six): sour, bitter, salty, umami (or meatiness) and sweet (as well as possibly fat). The sweet receptor is actually made up of two coupled proteins generated by two separate genes: known as Tas1r2 and Tas1r3.
When I hear other parents talk about kid's entertainment, they typically use terms worthy of a sudden drop through Dante's nine circles of hell. Comedians, commentators and chronicles of parenting, such as Neal Pollack's recent book Alternadad, describe the likes of Baby Einstein videos and the Wiggles as lesser demons, with Barney the Dinosaur occupying Satan's place at the center.  
The likes of Boohbah and Caillou grate on me as much as the next parent, but my perspective's a little different. As a pop-culture critic, I've always been interested in cartoons, puppetry and comic books, both the "mature" and kid-friendly versions. I'm sort of a volunteer on the front lines of children's media, rather than a draftee.
A Swiss woman who fell off her bicycle has yielded a unique insight into how auditory hallucinations are generated.  
The woman suffered damage to the part of the brain where speech is generated and could speak only in short, stunted words and sentences. Five months later, when she suddenly developed epilepsy, she began "hearing" voices with the same speech impediments as herself.
Patch Helps Heart Grow New Cells
A special patch placed on a damaged area of the heart regenerates cardiac cells after heart attack and improves heart function, a new study finds.  
Success with the patch in rats may lead the way to new methods of repairing damaged human hearts and possibly spare some patients the need for a heart transplant, according to researchers reporting in the July 15 online edition of Nature Medicine.
The humpback whale is known as the gregarious, singing "gentle giant" of the sea. But the herring it inventively preys upon—one whale in a gang blows "air bubble nets" around a school of fish while another screams until the poor things are scared to the surface—would probably disagree with this assessment.  
In any case, the auditory and communicative behaviors within groups of humpbacks reveal remarkable intelligence. However, since whale specimens are rare—either harvested from beached whales or sick aquarium residents—scientists know only the basics of their brain surface anatomy and are virtually ignorant about what goes on underneath.  
But last summer, neuroscientists from Mount Sinai School of Medicine got their hands on one of these rare brain samples and studied it. Now they've published a thorough morphological analysis of the humpback brain, and have compared it to a host of other species. Their study, published in the Nov. 27 early online edition of the journal The Anatomical Record, reveals that the humpback brain contains many anatomical curiosities, including one type of neuron involved in high-level cognitive functions previously thought to be unique to primates.
How racism hurts - Literally
FOUR YEARS AGO, researchers identified a surprising price for being a black woman in America. The study of 334 midlife women, published in the journal Health Psychology, examined links between different kinds of stress and risk factors for heart disease and stroke. Black women who pointed to racism as a source of stress in their lives, the researchers found, developed more plaque in their carotid arteries -- an early sign of heart disease -- than black women who didn't. The difference was small but important -- making the report the first to link hardening of the arteries to racial discrimination.  
The study was just one in a fast-growing field of research documenting how racism literally hurts the body. More than 100 studies -- most published since 2000 -- now document the effects of racial discrimination on physical health. Some link blood pressure to recollected encounters with bigotry. Others record the cardiovascular reactions of volunteers subjected to racist imagery in a lab. Forthcoming research will even peek into the workings of the brain during exposure to racist provocations.
Scientists in Southern California have discovered a mysterious booming population of endangered desert pupfish in man-made research ponds designed for an entirely different purpose.  
Although no one knows exactly how they got there, the fish probably took a 1.5-mile joyride through the piping used to deliver water to the ponds.  
Includes pictures and video of the rare fish
How rage can make you ill
The baby-faced kid is crushed against the chain-link octagon, swallowing punches from a fighter twice his size. His skin glows under the lights, until something gives way, and soon he's covered in blood. He's done — pinned, but too proud to tap out — yet the crowd jeers when the ref stops the fight. Even his father protests. Somehow, this Cleveland cage fight has become Caesar's coliseum.  
Why so angry? That's the question I'm mulling ringside. And I'm not talking about the grapplers. As combatants in the unofficial minor leagues of the Ultimate Fighting Championship, one of the fastest-growing sports in America, their anger is subsidized. I'm talking about the fans. According to a 2006 Harvard study, 10 million adult men in the United States are so angry, they're sick. In fact, their disease has a name: intermittent explosive disorder, or IED.
Giving a squirrel a big, sweet cookie can be a kind gesture, and now scientists have found it also encourages the critter to watch for predators. The conclusion, in a newly published study, has implications for other species, including the survival of those facing human-caused changes to their habitats.
Call it a flimsy silver lining to a noxious blue cloud: Long-term smokers have half the risk of Parkinson's disease that nonsmokers do, according to a new report. In 12,000 people studied, those who smoked the most—the equivalent of at least a pack a day for 60 years—had the lowest risk. And after smokers stubbed out their last butts, the protective effect faded.  
Cigarette, cigar, and pipe smoking appear to offer similar anti-Parkinson's benefits, according to the report in the July Archives of Neurology.  
Monkeys imitate what they see, but so do humans, only more discreetly. Whether any muscles actually flex, our brains fire up the same pathways needed to perform any action we observe another person perform. But new work on disabled volunteers indicates that the brain instead activates alternate circuits when faced with an action its body cannot physically copy. The research suggests that the brain's motor system may be wired to work toward a goal rather than just duplicating a movement.  
Every time you watch someone press a computer key or pick up a cup, regions of your brain unconsciously respond, mapping what you see onto the motor pathways you would use to carry out that same motion. Researchers believe that this so-called mirror neuron system, which consists of a subclass of motor neurons, is critical to learning new behaviors, and perhaps for developing skills like recognizing facial expressions. But neuroscientists have long wondered how the brain reacts if the body lacks the ability to replicate the action.  
In a study reported 12 July in Current Biology, a team from the Netherlands, Italy, and France showed videos of hands performing simple actions, like grasping a cup, to 16 "normal" people and two aplasic people born without hands or arms. While the volunteers watched the video, the researchers spied on their brain activity using MRI.
Reversing Fragile X Syndrome
An ongoing controversy in the murder-suicide case of pro wrestler Chris Benoit is whether his seven year-old son had a form of mental retardation called "Fragile X Syndrome." The disorder is poorly understood, but new research suggests there may be a way to reverse it.