Locating an odor in time and space: the evolution of navigation and chemosensory cognition
Dr. Lucia Jacobs, UC Berkeley
Monday, September 23rd at 5:30 p.m., 118 Psychology
Odor shapes learning and memory in profound ways, and not just in humans such as Marcel Proust, recalling the scent of linden tea and madeleine cookies. All living organisms - humans, bacteria, birds, bees and educated fleas - have at least one sensory system in common: the perception, encoding and categorization of chemical stimuli. Perhaps because olfactory perception is less accessible to conscious awareness in humans, chemosensory cognition is sadly neglected, despite the fascinating similarities of perceptual rules and neural structure across diverse taxa and the importance of olfaction for human cognition. Another reason for this neglect may be the framing of the problem, specifically the assumption that the primary function of olfaction is to discriminate odors. I will present the contrary hypothesis that the primary function of olfaction is to map space, for which odor discrimination is needed. This olfactory spatial hypothesis offers a new explanation for longstanding puzzles in olfaction, including rules of perception, neural plasticity and allometric patterns in the structure of vertebrate olfactory systems. Finally, it offers a new framework for thinking about 550 million years of neural evolution, beginning with the appearance of the first nervous systems mapping the location and utility of odor sources, and continuing today as a major influence on memory and thought in humans and other species.
Suggested Readings
Jacobs, L. (2003). The evolution of the cognitive map. Brain, Behavior, and Evolution.[.pdf]
Chai, J, and Jacobs, L. (2009). Sex differences in directional cue use in a virtual landscape. Behavioral Neuroscience.[.pdf]
Jacobs, L. (2012). From chemotaxis to the cognitive map: the function of olfaction. PNAS.[.pdf]