Spatiotemporal dynamics of spontaneous tau-rhythms in human temporal cortex

Poster Session E - Monday, April 15, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Natalie Schaworonkow¹, Peter Donhauser¹, David Poeppel^1,2; ¹Ernst Strüngmann Institute for Neuroscience, Frankfurt am Main, Germany, ²Department of Psychology, New York University, New York, US

Human electrophysiological activity displays intricate oscillations, with the most prominent rhythmic activity manifesting in the alpha-band (8–13 Hz). While the organization of alpha-band rhythms in occipital and sensorimotor cortex has been extensively studied, this is not the case for tau-rhythms, the rhythms in the alpha-band in the temporal cortex. On the hypothesis that these rhythms are basic building blocks for processing functions that are reused across separate sensory domains, tau-rhythms are important to understand for auditory and speech processing. However, this requires a careful differentiation of tau-rhythms from rhythmic or evoked activity in the theta- and delta-bands and an in-depth description of its spatiotemporal dynamics. Here we investigate dynamics and generators of tau-rhythms using high-resolution invasive electrophysiological data. A large dataset, encompassing both subdural grid as well as stereotactically placed depth electrodes, was analyzed to delineate alpha-rhythm generators. We identified rhythms with independent amplitude in the alpha-band, and mapped them to cortical and subcortical regions. Focusing on tau-rhythms in the temporal cortex, we found several independent oscillatory sources for selected individual participants, with differential spatial spread across the temporal cortex and event-related desynchronization to sound. Next, we explored generative models of these rhythms using leadfield simulations, considering the possibility of traveling waves or separate oscillatory sources. We characterized the human tau-rhythm, identifying several oscillatory sources within temporal cortex. The findings contribute to the understanding of the family of different alpha-band rhythms and provide a necessary foundation for future investigation into the functional significance of tau-rhythms in perceptual processing.

Topic Area: PERCEPTION & ACTION: Audition