Students donning sumo suits, racing shopping carts, rappelling down buildings and wielding slingshots, sledgehammers, and bows took over campus for this year's Ditch Day.

Catherine Bingchan Xie, a senior bioengineering major and English minor at Caltech, has been selected to receive a Gates Cambridge Scholarship, which will fund her graduate studies next year.

When offered spinach or a cookie, how do you decide which to eat? Do you go for the healthy choice or the tasty one? To study the science of decision making, researchers in the lab of Caltech neuroeconomist Antonio Rangel analyze what happens inside people's brains as they choose between various kinds of food. The researchers typically use functional magnetic resonance imaging (fMRI) to measure the changes in oxygen flow through the brain; these changes serve as proxies for spikes or dips in brain activity. Recently, however, investigators have started using a new technique that may better tease out how you choose between the spinach or the cookie—a decision that's often made in a fraction of a second.