Main Article Content
We normally assess consciousness in other individuals based on their ability to interact with the surrounding environment. A the same time, we all know very well that consciousness can be generated entirely within the brain, even in the absence of any interaction with the external world; this happens almost every night when we dream. Because of this fundamental discrepancy, the presence of consciousness may go undetected in brain-injured patients who emerge from coma but remain unresponsive. Developing a reliable, objective measure of the capacity for consciousness is one of the grand challenges for medical science. A challenge that we need to take on and face successfully for the sake of all the patients who survive coma through intensive care medicine. Besides, we may one day have to face the question of whether future artificial intelligence is just a useful zombie or a somehow conscious entity. According to a recently formulated theory, consciousness depends on a special kind of complexity in physical systems, on a unique balance between unity and diversity. Today, empirical measures inspired by this theory can help us in detecting a covert capacity for consciousness in patients who are otherwise completely isolated from the external world. Will they help us, one day, to understand how can a few pounds of jelly matter host the universe of a dream?