How valuable are earmuffs? The answer to this simple question can depend. What brand are they? Are they good quality? What is the weather like? Given the choice between earmuffs and suntan lotion, most people would choose to have the earmuffs on a cold winter day and the lotion on a sunny day at the beach. This ability to place different values on objects depending on the environmental context is something that we do all the time without much thought or effort. But how does it work? A new study led by Assistant Professor Jun Kunimatsu at the University of Tsukuba in Japan and Distinguished Investigator Okihide Hikosaka at the National Eye Institute (NEI) in the United States has discovered the part of the brain that allows this type of learning to occur.