[JAK]

Originally Posted by <<>> JAK, thanks for the biological information. Can you explain me what that "homeostasis" is all about? Is it to do with consciousness?

Yes, it is the key to consciousness. Consciousness is clearly a brain state, and all brain states appear to be controlled by the hypothalamus (deep within the brain, and high on the brain stem). The hypothalamus is a "feedback system" which works to keep its system indicators within specific ranges. As these are disturbed, the hypothalamus activates other brain systems which enact behaviors designed to bring the indicators back into ideal range. These are the hallmarks of a "control system" (see William T. Powers' "Perceptual Control Theory"). Walter Cannon's description of homeostasis falls right in line with it:

"The coordinated physiological processes which maintain most of the steady states in the organism are so complex and so peculiar to living beings ... that I have suggested a special designation for these states, homeostasis. The word does not imply something set and immobile, stagnation. It means a condition - a condition which may vary, but which is relatively constant." - Cannon, Walter B. The Wisdom of the Body. NEW YORK: W. W. Norton & Company, 1967. ISBN 0-673-38023-8 ... "The main function of the hypothalamus is homeostasis, or maintaining the body's status quo. ... Ultimately, the hypothalamus can control every endocrine gland in the body, and alter blood pressure (through vasopressin and vasoconstriction), body temperature, metabolism (through TSH), and adrenaline levels (through ACTH)." -Molavi, Diana Weedman et al. Neuroscience Tutorial: Hypothalamus and Autonomic Nervous System. ST. LOUIS: Washington Univ. School of Medicine, 1997. http://thalamus.wustl.edu/course/hypoANS.html

To follow the theoretical line of thinking, consciousness evolved to provide behaviors to support the primary function of the hypothalamus. For example, if you get chilled (hypothalamus), you seek warmth. If you are hungry or thirsty (hypothalamus), you seek food or water. If you feel romantic (hypothalamus), you seek an attractive mate. If you have trouble sleeping (hypothalamus), you ask me (or Gregg Henriques) about this theoretical work, and as we get enraptured in the details, any audience will quickly doze off. (My wife is convinced that this theory is a cure for insomnia. "I'm having trouble sleeping, dear, Talk to me again about your theory.")

All brain/body states result in two fundamental behaviors: seek and avoid (Robert Plutchik and others). "Consciousness" is a subset of brain behaviors which also breaks into the two subsets (seek/avoid). The "seek" and "avoid" are designed to get the hypothalamus indicators back with in the ideal range - homeostasis. The hypothalamus is the central point of control - control to measure homeostasis and control to counteract disturbances to it.