Matar Haller

Parameterizing neural power spectra into periodic and aperiodic components

Abstract:

Electrophysiological signals exhibit both periodic and aperiodic properties. Periodic oscillations have been linked to numerous physiological, cognitive, behavioral and disease states. Emerging evidence demonstrates that the aperiodic component has putative physiological interpretations and that it dynamically changes with age, task demands and cognitive states. Electrophysiological neural activity is typically analyzed using canonically defined frequency bands, without consideration of the aperiodic (1/f-like) component. We show that standard analytic approaches can conflate periodic parameters (center frequency, power, bandwidth) with aperiodic ones (offset, exponent), compromising physiological interpretations. To overcome these limitations, we introduce an algorithm to parameterize neural power spectra as a combination of an aperiodic component and putative periodic oscillatory peaks. This algorithm requires no a priori specification of frequency bands. We validate this algorithm on simulated data, and demonstrate how it can be used in applications ranging from analyzing age-related changes in working memory to large-scale data exploration and analysis.

Authors:

  • Thomas Donoghue

  • Matar Haller

  • Erik J Peterson

  • Paroma Varma

  • Priyadarshini Sebastian

  • Richard Gao

  • Torben Noto

  • Antonio H Lara

  • Joni D Wallis

  • Robert T Knight

  • Avgusta Shestyuk

  • Bradley Voytek

Date: 2020

DOI: https://doi.org/10.1038/s41593-020-00744-x

View PDF


Persistent neuronal activity in human prefrontal cortex links perception and action

ABSTRACT

How do humans flexibly respond to changing environmental demands on a subsecond temporal scale? Extensive research has highlighted the key role of the prefrontal cortex in flexible decision-making and adaptive behaviour, yet the core mechanisms that translate sensory information into behaviour remain undefined. Using direct human cortical recordings, we investigated the temporal and spatial evolution of neuronal activity (indexed by the broadband gamma signal) in 16 participants while they performed a broad range of self-paced cognitive tasks. Here we describe a robust domain- and modality-independent pattern of persistent stimulus-to-response neural activation that encodes stimulus features and predicts motor output on a trial-by-trial basis with near-perfect accuracy. Observed across a distributed network of brain areas, this persistent neural activation is centred in the prefrontal cortex and is required for successful response implementation, providing a functional substrate for domain-general transformation of perception into action, critical for flexible behaviour.





AUTHORS

  • Matar Haller

  • John Case

  • Nathan E. Crone

  • Edward F. Chang

  • David King-Stephens

  • Kenneth D. Laxer

  • Peter B. Weber

  • Josef Parvizi

  • Robert T. Knight

  • Avgusta Y. Shestyuk

Date: 2017

DOI: 10.1038/s41562-017-0267-2

View PDF