Christof Koch's Consciousness: Confessions of a Romantic Reductionist is the best book I've read in years. If you want to understand consciousness, this is the book for you. It is much kinder and gentler than the author's 2004 tome, The Quest for Consciousness, 429 pages, 1.7 footnotes per page, 100 pages for glossary, references and index. You need a knife & fork to read Quest. There are no footnotes in Confessions and a mere 15 pages of chapter notes, references and index. If you want to delve deeper, those 15 pages have plenty of pointers.
In Quest, Koch focusses on the NCC, the neuronal correlates of consciousness. This allows him to sidestep the definition of consciousness. In Confessions, he is still leery of the definition:
P 32 Defining Jazz is notoriously difficult hence the saying, "Man, if you gotta ask, you're never gonna know". The same holds true for consciousness.
However, for the sake of discussion he offers four ad hoc definitions:
1) common sense - our inner mental life while awake.
2) behavioral - a checklist of actions or behaviors we use to certify consciousness, for example, the Glasgow Coma Scale.
3) neuronal - the functioning of the cortico-thalamic complex and the brain stem
4) philosophy - what it is like to feel something. (p.33)
This more informal treatment means that one key assertion might just appear in support of the larger point. For example, the assertion that we are not conscious of the highest levels of cognition (i.e. decision making) is just mentioned while he is making a point about free will. Other key experiments are brought into the narrative and fully explained, such as Libet's experiment showing that the brain's initiation of an action happens before we are conscious of deciding to act.
That this book uses Mr. Koch's personal journey for the context of his life's work does not diminish the academic rigor of the presentation. His story does not intrude into the exposition of the neuroscience, except for occasional fun anecdotes of meetings of competitive scientist and discussion of his tribe. In a very real sense, his story is the story of the scientific study of consciousness. When he first used physics to understand the biology of nerve cells he "was quarantined". He is now at Cal Tech and Chief Science Office at AIBS with this working model:
"Biology is about unheard-of complexity and specificity at the molecular-cellular level. Chemistry made no progress when matter was conceived to be a mixture of the four Greek classical elements of earth, water, air and fire. And so it is with consciousness. Phenomenal experience does not arise from active or silent brain regions but from the ceaseless formation and dissolution of coalitions of neurons whose complexity and representational capacity is the ultimate substrate of our most intimate thoughts."
Where his own story takes a broader brush is where it is the story of all humans, even if particulars of how we ask the big questions differ. And big questions are raised. Why do we have this gift of consciousness? Is it an evolutionary advantage or is it a byproduct - confabulatory cheesecake - a powerless narrator trying to take credit for and rationalizing decisions that are being made by the animal it is riding. This is the question of Free Will. My own easier question is "Do we have control of our conscious thought?" Concede the dorsal pathway, the limbic system and other overrides of consciousness. Consider the mind in a contemplative moment, free of biological or emotional urges. If one the above mentioned coalitions of neurons can linger or influence the next winning coalition, then we ultimately have free will, IMHO.
Another big question/theme this book cogitates is Dualism. The best early definition by Descartes is that the brain and body obey the laws of physics, but the mind transcends the material world. The problem dualism must resolve is how the nonmaterial mind can effect the physical brain. Many mechanisms have been tried, from the pineal gland to quantum mechanics, but, Koch concedes that Physicalism/materialism rules the day and that makes things simple, but "impoverished". Perhaps I am missing something, but, if the brain has 1000 different types of neurons and dozens if not hundreds of little functional engines as well as a many, many massive feedback loops, do we need a supernatural mind?
I'm glad Christof Koch does not like poverty. He argues that consciousness is a fundamental property of complex things - mind expanding! I am sure I will not do this justice, but, I love skating on the thin ice. A possible mechanism for consciousness as a property is Guilio Tononi's Integrated Information theory. There are two axioms: consciousness 1) reduces entropy and 2) is highly integrated - a conscious state cannot be subdivided. The theory is that the amount of integration is a measure of consciousness. Then there is some math, so, it has to be right :-). There is the fun notion that each different conscious state can be represented as a very high dimensional polygon (polytope). Koch elaborates panpsychism - that everything has consciousness to some degree as measured by its integrated information. The fewer possible states, the lower the consciousness.
The terminus for panpsychism is Pierre Teilhard de Chardin's Noosphere, which I will oversimplify to mean a global consciousness in which all conscious beings participate. While Cristof Koch is not pushing these as accepted theories, he proposes that some mechanism for this notion of consciousness is possible. He ends the chapter with a plea for humility, pointing out that dark matter was only "discovered" 2 decades ago. Anyone that can take me from Claude Shannon to Teilhard de Chardin in eight coherent pages has my vote!
Christof Koch also has a column in SciAm Mind and fascination with the subject matter, of which I believe he is the leading authority. Let me end with a quote that you do not see in every book on neuroscience: "The conclusion of this experiment, that the words you hear or use shape your behavior, would not be news to my grandmother, who always preached that tipping, bringing small gifts, and being polite pays off in unknown ways."
While I was writing this, New York Times discusses peer reviewed research (Rumor has it, PloS ONE) that shows that "plants are able to perceive and respond to stress ... of their neighbors" - more than a vegetative state?
Check out Christof Koch, Episode 84 of Brain Science Podcast.
Search - No results found for "confabulatory cheesecake". 2012.04.30
My Amazon review. Perhaps a little over the top?http://www.jch.com/jch/notes/kochConfessions.html 2012.05.03 jch