We often only realize how important our sense of smell is when it is no longer there: food is not as tasty as it once was, or we no longer react to dangers such as the smell of smoke. Researchers have investigated the neuronal mechanisms of human odor perception for the first time. Individual nerve cells in the brain recognize odors and react specifically to the smell, the image and the written word of an object, for example a banana. The results of this study close a long-standing knowledge gap between animal and human odor research.