Human olfaction: A typical yet special mammalian olfactory system

Abstract

In this chapter we concentrate on human olfaction, asking what the study of human olfaction has taught us about mammalian olfaction in general, and what it has shown as uniquely human olfactory structure and function. We first briefly highlight the superb olfactory capabilities of humans, starting with keen detection and discrimination, through unlikely tasks such as scent tracking, and culminating in complex social chemosignaling. We then describe the neural organization of human olfaction subserving these tasks, noting unique human olfactory sampling strategies, apparently unique organizational features of the human olfactory epithelium and bulb, and functional specializations in olfactory cortex. Although these attributes may constitute nuances of sensory system organization, the most unique aspect of human olfaction, and indeed of humans in general, remains coding into language. It is this language-based key that has allowed uncovering a small but significant portion of the rules by which molecular structures transform into olfactory percepts.