Brain Complexity Offers Clues to Levels of Consciousness (1 of 3) (video) American Association for the Advancement of Science Share Print E-Mail Loading video... Caption This video illustrates the basic steps required to calculate PCI and the main results obtained in sleep, anesthesia and brain-injured patients. Measuring PCI involves perturbing the brain with transcranial magnetic stimulation and recording its immediate response by means of electroencephalography. Zipping the brain's response to a magnetic perturbation to calculate its information content allows discriminating between conscious and unconscious subjects. This video relates to a paper that appeared in the August 14, 2013, issue of Science Translational Medicine, published by AAAS. The paper, by A.G. Casali at the University of Milan in Milan, Italy, and colleagues was titled, "A Theoretically Based Index of Consciousness Independent of Sensory Processing and Behavior." Credit Video courtesy of Adenauer G. Casali Usage Restrictions Please cite the owner of the video when publishing. This video may be freely used by reporters as part of news coverage, with proper attribution. Non-reporters must contact Science for permission. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.