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Joseph Lee

2 papers in the library · publishing 2018-2019

Papers

Relationship of critical dynamics, functional connectivity, and states of consciousness in large‐scale human brain networks

NeuroImage March 1, 2019 Heonsoo Lee, D. Golkowski, D. Jordan et al.

Large-scale brain networks function near a critical state, and partial phase locking—a network science concept—shapes the characteristic functional connectivity and asymmetric anterior-posterior phase lag entropy (PLE) topography at this critical state, with low PLE for high-degree nodes and high PLE for low-degree nodes. Comparing PLE topography at criticality with electroencephalogram data from baseline consciousness, isoflurane anesthesia, ketamine anesthesia, vegetative state/unresponsive wakefulness syndrome, and minimally conscious state shows that topographical similarity and strength of PLE differentiate these pharmacologic and pathologic states of consciousness. This provides a theory-based metric to quantify how far a perturbed brain network deviates from criticality, rather than merely determining critical or non-critical state.

Estimating the Integrated Information Measure Phi from High-Density Electroencephalography during States of Consciousness in Humans

Frontiers in Human Neuroscience February 16, 2018 Hyoungkyu Kim, A. Hudetz, Joseph Lee et al.

A practical method estimates integrated information (Φ), a measure proposed by integrated information theory to be related to consciousness, from 128-channel EEG. The method alone cannot distinguish certain anesthetic states, but combining Φ with four EEG connectivity parameters—power, frequency, functional connectivity, and modularity—differentiates all states of consciousness. The association of Φ with EEG connectivity during anesthesia offers a new approach to applying the theory, potentially useful for characterizing consciousness in sleep, anesthesia, and coma.