Discovered: Revisiting an experiment used to disprove free will; creatine helps women batlle depression; dilated eyes show sexual attraction; mothers underestimate the rise of childhood obesity in China. 

To find out someone's sexual orientation, gaze deeply into their eyes. Pupil dilation can tell you whether a person is attracted to people of the same or opposite gender. Working off this premise, researchers at Cornell University used an infrared lens to gauge the pupil dilations of people watching erotic films. Pupils widen when people experience sexual attraction, and the researchers were able to use their observations to successfully predict participants' sexual orientations. "We wanted to find an alternative measure that would be an automatic indication of sexual orientation, but without being as invasive as previous measures. Pupillary responses are exactly that," says lead author Gerulf Rieger. [Science Daily]

Bulking up to beat depression. Scientists have a new recommendation for women suffering from major depression: pump it up. The muscle-building supplement creatine has been shown to speed recovery from depression, according to research from the University of Utah and partners from three South Korean universities. Inside the body, creatine becomes phosphocreatine and gets stored in muscle. Phosphocreatine is converted into ATP during high-intensity exercise. The mechanism for how creatine helps women overcome depression isn't yet known, but the results from an eight-week study of 52 South Korean women show strong improvement in the half of the participants who took creatine in addition to an antidepressant. [University of Utah]

Freeing up the debate about free will. EEG experiments on the brain activity of people making spontaneous movements conducted by UC San Francisco neuroscientist Benjamin Libet in the early 1980s have been used by many to disprove the notion of free will. Our brains know how we will act 200 milliseconds before we consciously enact them, free will critics say. But those who believe in free will may not be discounted just yet: the results of the classic experiment might have been misinterpreted. Libet's "readiness potential" may not actually be the sign of a brain predicting movement says says Aaron Schurger of the National Institute of Health and Medical Research in Saclay, France. "We argue that what looks like a pre-conscious decision process may not in fact reflect a decision at all," says Schurger. "It only looks that way because of the nature of spontaneous brain activity." [New Scientist]

Obesity on the rise in China. Though childhood obesity is becoming more common in China, mothers and children there are underestimating the extent of it. Researchers looked at data on Chinese children aged 6 to 18 from nine different provinces. When asked whether they were underweight, normal weight or overweight, the children themselves underestimated their weight 69 percent of the time, and mothers underestimated their children's weight 72 percent of the time. "Because many overweight Chinese children underestimate their weight, they are less likely to do anything to improve their diet or exercise patterns," says Penn State grad student Nengliang Yao. "If they don't make changes, they are likely to be obese and have a lot of health problems in the future—as we often see in the United States already." [Penn State]