Odor discrimination is immune to the effects of verbal labels

For many odors that we encounter in daily life, we perceive their qualities without being able to specifically identify their sources—an experience termed the “tip-of-the-nose” phenomenon. Does learning an odor’s identity alter our experience of it? Past work has shown that labeling odors can alter how we describe and react to them, but it remains an open question whether such changes extend to the level of perception, making an odor actually smell different. Here, in a set of odor classification experiments we tested whether attaching labels to odors can alter their perceptual discriminability. We found that even for odors whose reported similarity changed markedly when their identities were revealed, their discriminability remained unchanged by labels. Our findings indicate that two critical functions of olfaction—parsing the odor environment and supporting the subjective experience of odor qualities—access distinct odor representations within the olfactory processing stream.