Human olfaction: A view from the top

Although our understanding of human olfactory perception has increased dramatically, it remains less well understood how olfaction interacts with cognitive processes. In this overview, we review the claim that olfaction evolved to predominantly embody “novelty detection”, a framework that leaves little room for cognitive representations and processes. We challenge this framework by pointing to several perceived limitations. Instead, we argue that human olfaction is best understood in terms of its reliance on top-down processes; visual or verbal contexts may generate predictions of odor qualities, and a fundamental role of olfaction is to evaluate such predictions. We hypothesize that olfaction is to a large extent dependent on “top-down” cognitive processes. We discuss how this framework differs from other contemporary approaches to human olfactory perception. We conclude that in contrast to other frameworks that characterize olfaction primarily in terms of stimulus-driven perception, human olfactory processing is best understood by invoking a “view from the top”.