ABSTRACT
All sensory systems share common tasks, including the transformation of sensory stimuli into electrical signals; the optimization of detection sensitivity, selectivity, speed, and reliability; and the extraction of salient features with the ultimate purpose of helping animals survive and reproduce. In this chapter, the authors examine the major senses: olfaction, taste, audition, and somatosensation. They study olfaction first and in greatest detail, as it differs from the other senses in some important ways, such as the large number of odorant receptors and the direct path by which olfactory signals are transmitted to the cortex. They begin their story with salmon homing. Olfaction begins with the binding of odorants to odorant receptors on olfactory cilia. Vision requires light, while audition and olfaction operate in both light and dark but deal with sensory stimuli that travel at different speeds. Indeed, as they see, a prominent feature of audition is the extraction and representation of information in the temporal domain.
