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Paper: PS-2A.29
Session: Poster Session 2A
Location: H Lichthof
Session Time: Sunday, September 15, 17:15 - 20:15
Presentation Time:Sunday, September 15, 17:15 - 20:15
Presentation: Poster
Publication: 2019 Conference on Cognitive Computational Neuroscience, 13-16 September 2019, Berlin, Germany
Paper Title: Aperiodic EEG activity tracks 1/f stimulus characteristics and the allocation of cognitive resources
Manuscript:  Click here to view manuscript
License: Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License.
Authors: Leonhard Waschke, University of Lübeck, Germany; Thomas Donoghue, Sydney Smith, Bradley Voytek, University of California, San Diego, United States; Jonas Obleser, University of Lübeck, Germany
Abstract: The statistics of many natural phenomena including the human electrophysiological response follow a power law, that is, they share a 1/f distribution. The reduction in signal magnitude with increasing frequency is aptly captured by the slope, or exponent chi of the power spectral density. The spectral exponent of electrophysiological recordings recently has been hypothesized to reflect the balance of excitatory and inhibitory activity (E:I ratio) in populations of cortical neurons. It is unclear, however, to which degree exogenous stimulus characteristics or endogenous processes such as the selective allocation of cognitive resources alter the electrophysiological spectral exponent. We here present evidence from an experiment, during which we recorded electroencephalography (EEG) while participants (N = 25) detected faint target stimuli in streams of auditory or visual noise. Importantly, all noise stimuli were generated to exhibit different chi values in their modulation spectra. Spectral exponents over auditory and visual sensory cortices tracked chi values of the respective stimulus domain on the single trial level. Furthermore, attention reduced spectral exponents, which suggests increased E:I ratio (E>I) in sensory regions of the attended domain.