How Neural Circuit Plasticity Constructs Odor Perception
Thomas A. Cleland, Psychology, wants to determine how odor learning modifies neural circuitry, altering how the brain responds to identical odors based on what those odors came to mean to an animal in the past. His lab uses both behavioral and perceptual studies and recordings of neural activity from the brain. The project's goal is to ascertain how neural circuit properties within the olfactory bulb underlie and constrain animals' abilities to distinguish among similar odorants.
The researchers are interested in more than understanding olfaction: Odors are highly idiosyncratic and arbitrary sensory objects, requiring high-dimensional representations that support generalization. This suggests that odors, as represented in the brain, can model some of the properties of arbitrary concepts, such as cheese, science, or nation-state. Specifically, odors cannot be easily reduced to simple physical properties such as color or frequency, but still have meaningful similarities with one another that are partly based on physical reality and partly on learned implications.
The classic analogy is the psychological question, "What defines a table?" Tables often have properties in common, and people largely agree on whether something is or is not a table, but no specific set of properties reliably defines a table. Some combination of physical properties and highly contextual learning generates this consensual reality. The olfactory system is a useful physical analogue for this psychological concept, in that the combination of sensory physics and learning that construct odor representations can be concretely studied in an experimentally accessible neural circuit. NIH Grant Number: 1R01 DC014701