In the December, 2010 edition of Discover Magazine, neuroscientist Antonio Damasio sets forth his understanding of human consciousness. Damasio has recently published a new book on this topic, Self Comes to Mind. Here's a short excerpt from page 66 of his deeply thought-provoking article at Discover (not available yet online):

Conscious minds result from the smoothly articulated operation of several, often many, brain sites. The ultimate consciousness product occurs from those numerous brain sites at the same time and not in one site in particular, much as the performance of a symphonic piece does not come from the work of a single musician or even a whole section of an orchestra. The oddest thing about the upper reaches of a consciousness performance is the conspicuous absence of a conductor before the performance begins, although as the performance unfolds, a conductor comes into being. For all intents and purposes, a conductor is now leading the orchestra, although the performance has created the conductor--the self--not the other way around. Building a mind capable of encompassing one's lived past and anticipated future, along with the lives of others added to the fabric and the capacity for reflection to boot, resembles the execution of a symphony of Mahlerian proportions. But the true marvel is that the score and the conductor become reality only as life unfolds. The grand symphonic piece that is consciousness encompasses the foundational contributions of the brainstem, forever hitched to the body, and the wider-than-the-sky imagery created in the cooperation of cerebral cortex and sub cortical structures, all harmoniously stitched together, is ceaseless forward motion, interruptible only by sleep, anesthesia, brain dysfunction, or death.

Damasio, well known for his groundbreaking work in his early book, Descartes's Error, takes special care to describe the complexity of the mind, the marvel of this emergence of consciousness, and he specifically points out the importance of the emotions for a thorough understanding of consciousness: Emotions are complex, largely automated programs of actions concocted by evolution. The actions are carried out in our bodies, from facial expressions and postures to changes in viscera and internal millieu. Feelings of emotion, on the other hand, are composite perceptions of what happens in our body and mind when we are emoting. As far as the body is concerned, feelings are images of actions rather than actions themselves. While emotions are actions accompanied by ideas and certain modes of thinking, emotional feelings are mostly perceptions of what our bodies do during the emoting, along with perceptions of our state of mind during that same period of time. [More . . . ]