David Badre

A rapid theta network mechanism for flexible information encoding

Abstract:

Flexible behavior requires gating mechanisms that encode only task-relevant information in working memory. Extant literature supports a theoretical division of labor whereby lateral frontoparietal interactions underlie information maintenance and the striatum enacts the gate. Here, we reveal neocortical gating mechanisms in intracranial EEG patients by identifying rapid, within-trial changes in regional and inter-regional activities that predict subsequent behavioral outputs. Results first demonstrate information accumulation mechanisms that extend prior fMRI (i.e., regional high-frequency activity) and EEG evidence (inter-regional theta synchrony) of distributed neocortical networks in working memory. Second, results demonstrate that rapid changes in theta synchrony, reflected in changing patterns of default mode network connectivity, support filtering. Graph theoretical analyses further linked filtering in task-relevant information and filtering out irrelevant information to dorsal and ventral attention networks, respectively. Results establish a rapid neocortical theta network mechanism for flexible information encoding, a role previously attributed to the striatum.

Authors:

  • Elizabeth L. Johnson

  • Jack J. Lin

  • David King-Stephens

  • Peter B. Weber

  • Kenneth D. Laxer

  • Ignacio Saez

  • Fady Girgis

  • Mark D’Esposito

  • Robert T. Knight

  • David Badre

Date: 2023

DOI: https://doi.org/10.1038/s41467-023-38574-7

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Oscillatory dynamics coordinating human frontal networks in support of goal maintenance

Abstract:

Humans have a capacity for hierarchical cognitive control—the ability to simultaneously control immediate actions while holding more abstract goals in mind. Neuropsychological and neuroimaging evidence suggests that hierarchical cognitive control emerges from a frontal architecture whereby prefrontal cortex coordinates neural activity in the motor cortices when abstract rules are needed to govern motor outcomes. We utilized the improved temporal resolution of human intracranial electrocorticography to investigate the mechanisms by which frontal cortical oscillatory networks communicate in support of hierarchical cognitive control. Responding according to progressively more abstract rules resulted in greater frontal network theta phase encoding (4–8 Hz) and increased prefrontal local neuronal population activity (high gamma amplitude, 80–150 Hz), which predicts trial-by-trial response times. Theta phase encoding coupled with high gamma amplitude during inter-regional information encoding, suggesting that inter-regional phase encoding is a mechanism for the dynamic instantiation of complex cognitive functions by frontal cortical subnetworks.

Authors:

  • Bradley Voytek

  • Andrew S. Kayser

  • David Badre

  • David Fegen

  • Edward F. Chang

  • Nathan E. Crone

  • Josef Parvizi

  • Robert T. Knight

  • Mark D'Esposito

Date: 2015

DOI: 10.1038/nn.4071

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