We spend a substantial part of our days visually scanning an area for something we want—our keys or ketchup, for example. For scientists the way we do so “provides a window into how our minds sift through the information that arrives at our eyes,” says Jason Fischer, a cognitive neuroscientist at Johns Hopkins University. Past research has focused on readily apparent visual characteristics such as color, shape and size. But an object's intrinsic physical properties—things we know from experience but cannot see, such as hardness—also come into play.