Understanding how attention relates to consciousness is central to consciousness research. Unlike consciousness, attention can be systematically manipulated in experiments. Most studies focus on spatial visual attention, but this review introduces attention to the olfactory modality. It clarifies where attention to smells fits in a general taxonomy of attention, reviews the mechanisms and neuroanatomy of attention and consciousness in the olfactory system, and uses this framework to argue that attention is necessary for consciousness.
Olfaction offers advantages for consciousness research due to its computational and phenomenological simplicity, which aids in identifying basic principles, and its unique features that distinguish it from vision. These qualities make olfaction an ideal system for testing theories of consciousness. This collection presents recent research findings on olfactory consciousness.