Dora Hermes

Advances in human intracranial electroencephalography research, guidelines and good practices

Abstract:

Since the second half of the twentieth century, intracranial electroencephalography (iEEG), including both electrocorticography (ECoG) and stereo-electroencephalography (sEEG), has provided an intimate view into the human brain. At the interface between fundamental research and the clinic, iEEG provides both high temporal resolution and high spatial specificity but comes with constraints, such as the individual's tailored sparsity of electrode sampling. Over the years, researchers in neuroscience developed their practices to make the most of the iEEG approach. Here we offer a critical review of iEEG research practices in a didactic framework for newcomers, as well addressing issues encountered by proficient researchers. The scope is threefold: (i) review common practices in iEEG research, (ii) suggest potential guidelines for working with iEEG data and answer frequently asked questions based on the most widespread practices, and (iii) based on current neurophysiological knowledge and methodologies, pave the way to good practice standards in iEEG research. The organization of this paper follows the steps of iEEG data processing. The first section contextualizes iEEG data collection. The second section focuses on localization of intracranial electrodes. The third section highlights the main pre-processing steps. The fourth section presents iEEG signal analysis methods. The fifth section discusses statistical approaches. The sixth section draws some unique perspectives on iEEG research. Finally, to ensure a consistent nomenclature throughout the manuscript and to align with other guidelines, e.g., Brain Imaging Data Structure (BIDS) and the OHBM Committee on Best Practices in Data Analysis and Sharing (COBIDAS), we provide a glossary to disambiguate terms related to iEEG research.

Authors:

  • Manuel R. Mercier

  • Anne-Sophie Dubarry

  • François Tadel

  • Pietro Avanzini

  • Nikolai Axmacher

  • Dillan Cellier

  • Maria Del Vecchio

  • Liberty S. Hamilton

  • Dora Hermes

  • Michael J. Kahana

  • Robert T. Knight

  • Anais Llorens

  • Pierre Megevand

  • Lucia Melloni

  • Kai J. Miller

  • Vitória Piai

  • Aina Puce

  • Nick F. Ramsey

  • Caspar M. Schwiedrzik

  • Sydney E. Smith

  • Arjen Stolk

  • Nicole C. Swann

  • Mariska J Vansteensel

  • Bradley Voytek

  • Liang Wang

  • Jean-Philippe Lachaux

  • Robert Oostenveld

Date: 2022

DOI: https://doi.org/10.1016/j.neuroimage.2022.119438

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iEEG-BIDS, extending the Brain Imaging Data Structure specification to human intracranial electrophysiology

Description:

The Brain Imaging Data Structure (BIDS) is a community-driven specification for organizing neuroscience data and metadata with the aim to make datasets more transparent, reusable, and reproducible. Intracranial electroencephalography (iEEG) data offer a unique combination of high spatial and temporal resolution measurements of the living human brain. To improve internal (re) use and external sharing of these unique data, we present a specification for storing and sharing iEEG data: iEEG-BIDS.

Authors:

  • Christopher Holdgraf

  • Stefan Appelhoff

  • Stephan Bickel

  • Kristofer Bouchard

  • Sasha D’Ambrosio

  • Olivier David

  • Orrin Devinsky

  • Benjamin Dichter

  • Adeen Flinker

  • Brett L. Foster

  • Krzysztof J. Gorgolewski

  • Iris Groen

  • David Groppe

  • Aysegul Gunduz

  • Liberty Hamilton

  • Christopher J. Honey

  • Mainak Jas

  • Robert T. Knight

  • Jean-Philippe Lachaux

  • Jonathan C. Lau

  • Christopher Lee-Messer

  • Brian N. Lundstrom

  • Kai J. Miller

  • Jeffrey G. Ojemann

  • Robert Oostenveld

  • Natalia Petridou

  • Gio Piantoni

  • Andrea Pigorini

  • Nader Pouratian

  • Nick F. Ramsey

  • Arjen Stolk

  • Nicole C. Swann

  • François Tadel

  • Bradley Voytek

  • Brian A . Wandell

  • Jonathan Winawer

  • Kirstie Whitaker

  • Lyuba Zehl

  • Dora Hermes

Date: 2019

DOI: https://doi.org/10.1038/s41597-019-0105-7

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Human motor cortical activity is selectively phase-entrained on underlying rhythms

Authors:

  • Kai J. Miller

  • Dora Hermes

  • Christopher J. Honey

  • Adam O. Hebb

  • Nick F. Ramsey

  • Robert T. Knight

  • Jeffrey G. Ojemann

  • Eberhard E. Fetz

Date: 2012

DOI: 10.1371/journal.pcbi.1002655

PubMed: 22969416

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Abstract:

The functional significance of electrical rhythms in the mammalian brain remains uncertain. In the motor cortex, the 12-20 Hz beta rhythm is known to transiently decrease in amplitude during movement, and to be altered in many motor diseases. Here we show that the activity of neuronal populations is phase-coupled with the beta rhythm on rapid timescales, and describe how the strength of this relation changes with movement. To investigate the relationship of the beta rhythm to neuronal dynamics, we measured local cortical activity using arrays of subdural electrocorticographic (ECoG) electrodes in human patients performing simple movement tasks. In addition to rhythmic brain processes, ECoG potentials also reveal a spectrally broadband motif that reflects the aggregate neural population activity beneath each electrode. During movement, the amplitude of this broadband motif follows the dynamics of individual fingers, with somatotopically specific responses for different fingers at different sites on the pre-central gyrus. The 12-20 Hz beta rhythm, in contrast, is widespread as well as spatially coherent within sulcal boundaries and decreases in amplitude across the pre- and post-central gyri in a diffuse manner that is not finger-specific. We find that the amplitude of this broadband motif is entrained on the phase of the beta rhythm, as well as rhythms at other frequencies, in peri-central cortex during fixation. During finger movement, the beta phase-entrainment is diminished or eliminated. We suggest that the beta rhythm may be more than a resting rhythm, and that this entrainment may reflect a suppressive mechanism for actively gating motor function.