Multistability as a mechanism for modulation of EEG coherences

Abstract

Event Abstract Back to Event Multistability as a mechanism for modulation of EEG coherences Jonathan Drover1*, Jonathan Victor1, Shawniqua T. Williams1, Mary Conte1 and Nicholas Schiff1 1 Weill Medical College of Cornell University, United States Coordinated activity between multiple cortical areas is necessary for organized behavior and cognitive activity. It is speculated that deep brain structures, specifically the reticular thalamus, play an important role in coordinating this activity. In previous work we developed a mean field model of a thalamocortical network consisting of two thalamocortical modules (each module containing cortical, thalamic relay, and thalamic reticular populations) coupled via a shared population of reticular neurons. We showed that this network is capable of spontaneous transitions, distinguishable by changes in the coherence between the two cortical populations modeled. These transitions can occur when the parameters of the model are such that there are multiple stable attractors. There are two types of attractors that we were interested in: symmetric solutions, where each module maintains a similar activity level; and winner-take-all solutions, where one of the modules suppresses the other. We show that the multistable region has, as boundaries, a winner-take-all generating fold bifurcation and a subcritical pitchfork bifurcation that destabilizes the symmetric solution. We show that this configuration is persistent over a wide range of values of the parameters that determine the strength of the connections within the thalamocortical modules, and a realistic range of time constants. Because this was a striking and consistent feature of model behavior, we sought to determine whether it was present in the human EEG. We analyzed EEG/CCTV recordings from three patients with severe brain injury, characterized by metabolic (resting PET) and anatomical (MRI, DTI) studies and behavioral observations. Via the multitaper method, we calculated time-localized EEG spectra and coherences from 30 segments of artifact-free EEG obtained during eyes-open rest. We then applied principal components analysis to the coherograms obtained from pairs of channels within each hemisphere, revealing bimodal behavior. Thus, time-varying patterns of coherence can be identified in the EEG of human subjects, as well as in the model. In these brain-injured patients, this dynamical feature appeared to correlate with relatively more preserved functional or structural integrity. In sum, a population-based model of thalamocortical interactions robustly demonstrates multistability, and this dynamical feature can be identified in the human EEG, supporting a role for the thalamus in establishing changing patterns of cortical coherence. Moreover, its predominance in the relatively more preserved hemisphere of brain-injured patients suggests an EEG-based approach to assaying the integrity of thalamocortical interactions. Conference: Computational and Systems Neuroscience 2010, Salt Lake City, UT, United States, 25 Feb - 2 Mar, 2010. Presentation Type: Poster Presentation Topic: Poster session II Citation: Drover J, Victor J, Williams ST, Conte M and Schiff N (2010). Multistability as a mechanism for modulation of EEG coherences. Front. Neurosci. Conference Abstract: Computational and Systems Neuroscience 2010. doi: 10.3389/conf.fnins.2010.03.00184 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 03 Mar 2010; Published Online: 03 Mar 2010. * Correspondence: Jonathan Drover, Weill Medical College of Cornell University, New York, United States, jod2017@med.cornell.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jonathan Drover Jonathan Victor Shawniqua T Williams Mary Conte Nicholas Schiff Google Jonathan Drover Jonathan Victor Shawniqua T Williams Mary Conte Nicholas Schiff Google Scholar Jonathan Drover Jonathan Victor Shawniqua T Williams Mary Conte Nicholas Schiff PubMed Jonathan Drover Jonathan Victor Shawniqua T Williams Mary Conte Nicholas Schiff Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.