Electrophysiological representations of odor in the human brain

Olfactory perception relies on the brain’s ability to extract and represent different features of an odor stimulus. For example, stimulus intensity and identity are fundamental stimulus features that must be segmented for accurate perception; the same odor can be encountered in the environment at different strengths. Rodent work has identified a number of neural correlates of odor concentration and chemical structure, but it remains unclear how these representations relate to perceptual intensity and identity. A major gap in our understanding of odor perception is the missing link between direct perceptual ratings (easily obtainable in humans) and neural responses (much easier to obtain in rodents). Research proposed here aims to determine how odor intensity and identity are presented in human brain, both in human piriform cortex and across distinct networks defined by low and high frequency oscillations. We will accomplish these aims using direct invasive recordings of neural activity from human olfactory cortex, while single-trial perceptual ratings are collected. Our findings will reveal how odor features are represented in the human brain, contributing fundamental basic understanding of the olfactory system. Olfactory brain areas are implicated in neurodegenerative diseases such as Alzheimer’s Disease, Parkinson’s Disease and epilepsy. Increased understanding of coding mechanisms in these areas, and interactions between these areas and the rest of the brain may lead to better understanding of the mechanisms of diseases that involve olfactory cortical areas.