Studying States of Conciousness

A new study suggests that the line between awake and unconscious are not necessarily black or white. Research has shown that some patients under anesthesia have been shown to respond to questions and showed brain activity during the prompts. It has also been shown that primitive parts of the brain such as the thalamus awake first after states of unconsciousness before the parts that are responsible for higher level thinking. A certain anesthetic known as dexmedetomidine leaves patients suspended between consciousness and unconsciousness with no memory of the events.

http://www.nytimes.com/2012/04/17/science/studying-states-of-consciousness.html?_r=1