This is a landmark book, almost irrespective of how accurate all of Antonio Damasio's extensive theoretical formulations turn out to be. He is the first to admit (in the book itself) that things are changing so fast in this area of neuroscience that virtually nothing on the table at this point can be considered doctrinal, or not subject to potentially major modifications. That being said, I suspect that much of Damasio's more original terminology, terms such as "proto-self," "core-self," "autobiographical self," "core consciousness," and "extended consciousness" will quickly become part of the basic lexicon in consciousness neuroscience in many quarters, due to the shear force of his ideas and the volume of original thought in this work. At the heart of this enterprise is Antonio Damasio's supposition (generally not informing much theorizing about consciousness) that the brain can't be conscious unless it represents not just objects, but a primitive self, and also represents the basic manner in which the self is being altered by interaction with the object(s). In other words, consciousness requires that the brain must represent not just the object, not just a basic self structure, but the interaction of the two. This is still an atypical foundation for a theory of consciousness, given that until recently, it was implicitly assumed that the self could be safely left out of the equation. There has been a recent sea change on this crucial point, parallel with the cogent formulations in Damasio's book.
The book will challenge and delight the most sophisticated readers, while rarely leaving the less sophisticated lost or overwhelmed. Damasio makes great use of the rich empirical database provided by the neurology of diseases of consciousness that some theorists of consciousness seem to know almost nothing about, and pay little attention to. The book also addresses in a most thoughtful and sophisticated fashion the problem(s) of self, and carefully unbundles the mostly conflated hierarchical nature of self and consciousness into separate but intimately related systems. It is tightly and carefully reasoned and empirically grounded. It integrates emotion and the body in the story of consciousness. Damasio deals skillfully with conceptual pitfalls in our commonplace terminology of "maps," "neural (neurodynamic) patterns," and "representations" (don't miss it stashed in the appendix!!) The book integrates classical RAS theory and neo-classical ERTAS (extended reticular thalamic activating system) theory into a broader theory about the ventral brain, that of "proto-self mappings and structures." Damasio admits readily this formulation is without the differential functional specificity for the proto-self structures (as perhaps the earliest functionally concerted, distributed system?) that he deeply hopes to see further developed. Further understanding of the functionally concerted and re-entrant operations of the various proto-self structures may be a great frontier in the neurology of consciousness. The core chapter of the book - The Neurology of Consciousness - in which he bridges concepts of proto-self, homeostatic and visceral regulation with traditional RAS and later ERTAS notions into a comprehensive theory of brainstem functions is brilliantly integrative and original, among the two or three finest pieces of neurological writing I have ever read. Added to this impressive menu are the delights of a literary, even at times poetic and moving, writing style.
For an in depth treatment of this book, see my review article coming out in the Journal of Consciousness Studies, or email me for reprints.