Causal connectivity according to conscious experience in non-rapid eye movement sleep

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review


  • Minji Lee
  • Benjamin Baird
  • Olivia Gosseries
  • Jaakko Nieminen

  • Melanie Boly
  • Giulio Tononi
  • Seong Whan Lee

Research units

  • Korea University
  • University of Wisconsin-Madison
  • University of Liege


The understanding of human consciousness based on brain connectivity is considered important for brain-machine interfacing. In this study, we investigated changes in causal connectivity in electroencephalography data related to conscious and unconscious experiences during non-rapid eye movement sleep after parietal transcranial magnetic stimulation (TMS). A serial awakening paradigm was used to determine whether subjects had had a conscious experience or not. We calculated direct transfer function (DTF) as a measure of effective connectivity in five frequency bands focusing on frontal and parietal-occipital regions. The DTF showed significant differences in frontal-to-parietal flow between reported unconsciousness and consciousness. During the first 100 ms after TMS, the outward links of the parietal region at low frequencies were higher in no conscious experience than in conscious experience. During the next 100 ms, however, the outward links of the frontal region were higher in the conscious experience than the no conscious experience at low frequencies. Changes with causal connectivity over time after TMS indicate that the spatial roles in brain regions associated with consciousness are different. These findings may help clarify the cortical mechanisms related to conscious experience.


Original languageEnglish
Title of host publication2019 IEEE International Conference on Systems, Man and Cybernetics, SMC 2019
Publication statusPublished - 1 Oct 2019
MoE publication typeA4 Article in a conference publication
EventIEEE International Conference on Systems, Man, and Cybernetics - Bari, Italy
Duration: 6 Oct 20199 Oct 2019

Publication series

NameConference Proceedings - IEEE International Conference on Systems, Man and Cybernetics
ISSN (Print)1062-922X


ConferenceIEEE International Conference on Systems, Man, and Cybernetics
Abbreviated titleSMC

ID: 40263764