Smell is a highly individualized sense: The same odor or olfactory stimulus can trigger common, though not identical, reactions from person to person. A recent study published in the science journal Nature suggests that our diverse experiences with scent have to do with how they are encoded in the brain. “All of us share a common frame of reference with smells,” Sandeep Robert Datta, an associate professor of neurobiology at Harvard Medical School and a senior author of the paper, told The Harvard Gazette. “You and I both think lemon and lime smell similar and agree that they smell different from pizza, but until now, we didn’t know how the brain organizes that kind of information.”