1.  35
    Propofol Induction Reduces the Capacity for Neural Information Integration: Implications for the Mechanism of Consciousness and General Anesthesia.UnCheol Lee, George A. Mashour, Seunghwan Kim, Gyu-Jeong Noh & Byung-Moon Choi - 2009 - Consciousness and Cognition 18 (1):56-64.
    The cognitive unbinding paradigm suggests that the synthesis of neural information is attenuated by general anesthesia. Here, we analyzed the functional organization of brain activities in the conscious and anesthetized states, based on functional segregation and integration. Electroencephalography recordings were obtained from 14 subjects undergoing induction of general anesthesia with propofol. We quantified changes in mean information integration capacity in each band of the EEG. After induction with propofol, mean information integration capacity was reduced most prominently in the γ band (...)
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  2.  31
    The Directionality and Functional Organization of Frontoparietal Connectivity During Consciousness and Anesthesia in Humans.UnCheol Lee, Seunghwan Kim, Gyu-Jeong Noh, Byung-Moon Choi, Eunjin Hwang & George A. Mashour - 2009 - Consciousness and Cognition 18 (4):1069-1078.
    Frontoparietal connectivity has been suggested to be important in conscious processing and its interruption is thought to be one mechanism of general anesthesia. Data in animals demonstrate that feedforward processing of information may persist during the anesthetized state, while feedback processing is inhibited. We investigated the directionality and functional organization of frontoparietal connectivity in 10 human subjects anesthetized with propofol on two separate occasions. Multichannel electroencephalography and a computational method of assessing directed functional connectivity were employed. We demonstrate that directed (...)
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  3.  40
    The Temporal Organization of Functional Brain Connectivity is Abnormal in Schizophrenia but Does Not Correlate with Symptomatology.Walter Schoen, Jae Seung Chang, UnCheol Lee, Petr Bob & George A. Mashour - 2011 - Consciousness and Cognition 20 (4):1050-1054.
    Previous work employing graph theory and nonlinear analysis has found increased spatial and temporal disorder, respectively, of functional brain connectivity in schizophrenia. We present a new method combining graph theory and nonlinear techniques that measures the temporal disorder of functional brain connections. Multichannel electroencephalographic data were windowed and functional networks were reconstructed using the minimum spanning trees of correlation matrices. Using a method based on Shannon entropy, we found elevated connection entropy in gamma activity of patients with schizophrenia; however, gamma (...)
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  4.  9
    Estimating the Integrated Information Measure Phi From High-Density Electroencephalography During States of Consciousness in Humans.Hyoungkyu Kim, Anthony G. Hudetz, Joseph Lee, George A. Mashour & UnCheol Lee - 2018 - Frontiers in Human Neuroscience 12.