Sociochemosensory and emotional functions: behavioral evidence for shared mechanisms.

Olfaction and emotion are distinctively different systems. Nevertheless, there are reasons to suspect that they influence each other on the social level. Functionally, olfactory chemosensory communication is used by a wide range of animals to convey individual and group identity, as well as attraction or repulsion. Anatomically, the olfactory brain overlaps with the socioemotional brain, and is believed to have contributed to the evolution of the latter. Little is known about how the functional and anatomical links are manifested in behavior, however. Using human olfaction as a model, we demonstrate that chemosensory recognition of individuals-one of the most ubiquitous forms of social communication-is interconnected with both the cognitive and the visual processing of emotion. Our results provide the first behavioral evidence for mechanisms being shared by a sensory system and emotion.