Let’s try this again, I’m working from my iPad, and this will just not post!

First, as a neuroscientist, I am not accustomed to using these beautiful, poetic terms to describe consciousness—I relate to a line in his introduction in Ch 1, referring to the issues of “terminology and perspective”. From my experience and training, consciousness is the ability to perceive, consciously, your environment, whether this is your internal environment (some of which you CAN perceive) or the world around you.

In chapter 1, Demasio refers to the work of William James: “the presence of the self is so subtle that the contents of the mind dominate consciousness as they stream along,” and also of Hume: “I never can catch myself at any time without a perception and never can observe anything but the perception.”

On “the self”: ” brain architecture that features convergence and divergence of neuron circuitries plays a role in the high-order coordination of images and is essential for the construction of the self and of other aspects of mental function, namely memory, imagination, language, and creativity.” This is what I have always viewed as the “self”. As to the primordial self originating from the brain stem, this is counter to my understanding as “self” being generated in the connections of limbic (“emotional” brain) and cortical areas. Perception of our world is dependent on integration of all of our sensory inputs, plus our memory for previous events—this memory retrieval happens unconsciously—and our conscious perception of our world is a combination of current and prior experiences. The brain is plastic, so each experience we have slightly alters our future perception. I suppose this may most closely correlate to the description of the “self as knower”. “Feelings of knowing” from my understanding, emerge after inputs are processed through this filter of prior experience.

On looking for a neural correlate of consciousness—-Perception is global: although we may bring light information through our eyes and up the optic nerve, we process in visual cortex, and association cortices, taking in information from other sensory modalities as well as memories, to form our perception. We may be “conscious” of these processes, or not (I would argue for often not), in forming our true experiences. Considering subconscious priming and it’s power in influencing behaviors—the consciousness and the “self”, if self-governed, aren’t necessarily the masters of the domain.

Some researchers feel we may be living in the past: http://blogs.scientificamerican.com/observations/2011/09/15/time-on-the-brain-how-you-are-always-living-in-the-past-and-other-quirks-of-perception/

Demarion briefly alludes to quantum mechanics…George Musser has many ideas on how the brain works similar to quantum particles and musings on free will:
http://www.scientificamerican.com/article/humans-think-like-quantum-particles/
http://www.scientificamerican.com/article/quantum-physics-free-will/

The brain is tricky. If the brain sees a piece of information as irrelevant, it will dampen your perception, and therefore, your consciousness of it (motivationally relevant stimuli). When you put on perfume in the morning, you can smell it, but after a while, you habituated to it, and no longer smell it. You aren’t as aware of the feel of your clothes on your body, unless you feel a draft, or are wearing itchy fabrics. When you stub your toe, you withdraw the foot, before you perceive the pain (this has to do with the slow nociceptors, but let’s not get too technical about it). It makes you wonder…if the brain has all of these connections, and molds your perception based on past experiences, how much of what you do, actually YOUR mind and your consciousness. Are you just an actor in the movie that your brain has created for you?

One aspect of the text that has changed since publication is the ability of the brain to generate new neurons (neurogenesis). This DOES happen, but only in a select area governing memory.

http://www.ncbi.nlm.nih.gov/pubmed/17593874

An interesting article—a bit neuroscience-y and not a philosophical type of mind paper, but still interesting, about control of consciousness in the claustrum http://www.newscientist.com/article/mg22329762.700-consciousness-onoff-switch-discovered-deep-in-brain.html#.VOOi53-9KK0