title: Theta Oscillations Rapidly Convey Odor-Specific Content in Human Piriform Cortex.
abstract: Olfactory oscillations are pervasive throughout vertebrate and invertebrate nervous systems. Such observations have long implied that rhythmic activity patterns play a fundamental role in odor coding. Using intracranial EEG recordings from rare patients with medically resistant epilepsy, we find that theta oscillations are a distinct electrophysiological signature of olfactory processing in the human brain. Across seven patients, odor stimulation enhanced theta power in human piriform cortex, with robust effects at the level of single trials. Importantly, classification analysis revealed that piriform oscillatory activity conveys olfactory-specific information that can be decoded within 110-518 ms of a sniff, and maximally within the theta frequency band. This temporal window was also associated with increased theta-specific phase coupling between piriform cortex and hippocampus. Together these findings suggest that human piriform cortex has access to olfactory content in the time-frequency domain and can utilize these signals to rapidly differentiate odor stimuli.
authors.affiliation: Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. Electronic address: hhjiang@u.northwestern.edu.
authors.forename: Heidi
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Stephan
authors.initials: S
authors.lastname: Schuele
authors.affiliation: Department of Neurosurgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Rosenow
authors.affiliation: Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Zelano
authors.affiliation: Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA.
authors.forename: Josef
authors.initials: J
authors.lastname: Parvizi
authors.affiliation: Department of Neurology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: James X
authors.initials: JX
authors.lastname: Tao
authors.affiliation: Department of Neurology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Shasha
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Psychology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL 60208, USA. Electronic address: j-gottfried@northwestern.edu.
authors.forename: Jay A
authors.initials: JA
authors.lastname: Gottfried
mesh_terms: D000328:Adult; D000679:Amygdala / Q000502:physiology; D000069280:Electrocorticography; D058407:Electroencephalography Phase Synchronization; D005260:Female; D065818:Gamma Rhythm / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009812:Odorants; D066195:Piriform Cortex / Q000502:physiology*; D012903:Smell / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*; D055815:Young Adult
keywords: ECoG; epilepsy; hippocampus; intracranial EEG; neural oscillations; odor perception; olfactory system; phase locking; piriform cortex; theta