Human Consciousness: requires whole brain (Humans)

by David Turell , Wednesday, January 27, 2016, 15:18 (3224 days ago) @ dhw

Twelve subjects were given propofol to compare conscious and unconscious brain activity:-http://medicalxpress.com/news/2016-01-brain-consciousness-optimal-degree-connectedness.html-"Human beings, when awake, exist in a state of consciousness that is uniquely difficult to define. Scientists try by agreeing that it is the ability to have subjective experiences and to enjoy a first-person perspective on the "reality" of the world. But that does not explain the voice that is our own self, nor the varying degrees of consciousness, such as the differences between being asleep, versus partially awake, versus being completely unconscious. In this new effort, the researchers sought to learn more about the state that exists in the mind when consciousness occurs by enlisting the assistance of 12 volunteers who agreed to be made unconscious by the drug propofol, normally used to put people under during surgical procedures (and notably, also the drug that led to the death of singer Michael Jackson) while undergoing fMRI scans.-"Scientists (and surgeons) believe that propofol causes people to become completely unconscious, which by definition would mean to become incapable of processing thoughts. The brain should not be able to process pain signals, for example, thus making surgery a pain free experience. To gain a better perspective on the various states of consciousness, the team watched blood flow changes in the brains of the volunteers as they moved from a conscious state, to unconsciousness and then back to consciousness.-"In studying the scans, the researchers found that when the volunteers were conscious, there was what they describe as "a flurry of ever-changing activity," with a lot of activity between the various neural networks. In contrast, they found that while unconscious, the brains of the volunteers were engaged in far less interconnectivity and were less variable over time.-"These findings, the team suggests, show that consciousness in the brain is merely, in a physical sense, a state where there is an optimal level of neural network connectedness."-Comment: Consciousness requires the whole brain in action, not surprising.