The mysteries surrounding our olfactory systems have been the focus of Philadelphia’s Monell Chemical Senses Center since it opened, in 1968, more than 20 years before the discovery of the odorant receptors that we use to perceive scents. Today, it’s the world’s only independent nonprofit organization dedicated to interdisciplinary research around smell and taste. One of the center’s members, Dr. Pamela Dalton, a cognitive psychologist with a background in public health and chemosensory science, began creating and administering smell tests as soon as olfactory impairment emerged as a primary symptom for the novel coronavirus. We recently asked Dr. Dalton how thoughts and emotions impact the way we perceive scents, and what Covid-19 reveals about our noses.