Odor Object Codes and Categories

It is currently unknown how the brain compiles meaningful olfactory representations of odor objects, qualities, and categories. How does the brain discriminate between the overlapping aromas of peppermint and spearmint, yet at the same time group them into the same perceptual category of "minty" smells? A major scientific goal of our laboratory is to characterize the functional architecture of odor quality coding in the human brain, and to understand the roles of learning, context, and experience in the formation and modulation of these perceptual codes.

Where, and in what form, odor qualities and categories are encoded in the brain remains poorly understood. One plausible candidate is the primary olfactory (piriform) cortex, a three-layer paleocortex closely affiliated with limbic brain networks and located (in humans) at the medial junction of the temporal and basal frontal lobes. Anatomical, physiological, and computational data from animal models of olfaction coalesce around the idea that odor quality is encoded in piriform cortex (PC). To clarify the neuro-scientific underpinnings of odor quality perception in the human brain, our lab is integrating high-resolution olfactory fMRI, psychophysical techniques, physiological recordings, and multivariate statistics. Together these approaches will enable us to characterize voxel-wise ensemble patterns of fMRI activity in human olfactory cortex and to show that these fMRI patterns have direct relevance for the categorical perception of odor objects. We anticipate that results from our studies will be pivotal in relating human brain states to olfactory percepts, providing a critical link between brain and behavior.

Please click on the following links for some specific examples of this line of research.

Human piriform cortex as a potential substrate for encoding higher-order odor representations

Odor quality and odorant structure are functionally dissociable in piriform cortex