The mechanism of consciousness and loss of conciousness by general anesthetics are crucial issue for the anesthesiologists. Recent non-invasive brain-imaging technology brings about light to various our emotions and sensations in human brain; however, neural correlate of consciousness is not yet still elucidated. The concept "the seat of the consciousness (is in the subcortical nuclei)" is now completely denied, but instead the consciousness is based on the idea that connectivity and communications across cortical and thalamocortical networks. Anesthetics and sleep disrupt the networks that encompass complexity and integration. The compatibility between complexity and integration is the key feature of the consciousness, which is represented by complex, extensive, communicative and integrative electroencephalograph currents evoked by transcranial magnetic stimulation, provoking a single unified conscious experience in us, humans.