When it comes to early detection of cognitive impairment, a new study suggests that the nose knows. Researchers from Mass General Brigham have developed olfactory tests—in which participants sniff odor labels that have been placed on a card—to assess people’s ability to discriminate, identify and remember odors. They found that participants could successfully take the test at home and that older adults with cognitive impairment scored lower on the test than cognitively normal adults.