HomeostasisThe concept of homeostasis was first articulated by the French scientist Claude Bernard (1813-1878) in his studies of the maintenance of stability in the milieu interior. The term itself was coined by American physiologist Walter Cannon, author of The Wisdom of the Body(1932).
"Homeostasis" is derived from the Greek words for "same" and "steady." The term refers to ways the body acts to maintain a stable internal environment in spite of environmental variations and disturbances. Both the mind/brain and the body are endowed with a multitude of automatic mechanisms of feedback-inhibition that counteract influences tending toward disequilibrium.
Homeostatic stability is advantageous in the realm of osmoregulation, temperature-control, and the regulation of blood sugar levels. It is a terrible scourge for the millions of people cursed with chronic low mood or high anxiety. Victims of the hedonic (or dolorous) treadmill cannot escape their predicament by 'natural' means. Their unavailing struggle to alleviate suffering or find lasting happiness no more resets the dial of their emotional thermostat than running on a real-life treadmill permanently resets the bodily thermostat. Even the most heroic exertion simply doesn't work.
A tendency to chronic anxiety or depression was often genetically adaptive for low-ranking individuals among small social groups of African hominids. Episodes of conditionally activated misery and malaise tended to maximise the inclusive fitness of selfish DNA. Neurotic mothers tended to lose less offspring to predators than happy-go-lucky optimists. Likewise, the global prevalence of a horrific spectrum of depressive disorders appears to be the hereditary penalty we pay as individuals for the benefits of group living on the African savannah. Isolates tend to get eaten and outbred.
Yet in the new reproductive era of designer-babies, it is unlikely that prospective parents will wish to recreate such ugly states of consciousness indefinitely. Selection pressure will favour the spread of a very different set of heritable fitness-enhancing traits. Post-humans may not be endowed with positive feedback loops for bliss; but the homeostatic mechanisms underwriting the mental health of our descendants will probably be far better constructed than our own. Genetic engineering can already be used to breed happy rats with an abundance of "50-kHz positive affective vocalizations". There is no technical reason why human primates can't be born constitutionally happy too. Strictly speaking, the hedonic treadmill may never be dismantled: the (re-engineered) molecular machinery of homeostasis may regulate posthuman moods and emotions no less than in the Darwinian era. But transhuman reward circuitry is likely to encode a far higher hedonic set-point of emotional health.
and further reading
The Orgasmic Brain
The Good Drug Guide
The Animal Rights FAQ
The Abolitionist Project
Buddhism and Suffering
Utilitarianism On The Net
Utopian Brain Stimulation
The Hedonistic Imperative
Electrical Brain Stimulation
Critique of Brave New World
God and the Temporal Lobes
The Transcranial Magnetic Stimulator
Wireheads and Wireheading in Science Fiction
Repetitive transcranial magnetic stimulation (rTMS)
Pleasure Evoked by Electrical Stimulation of the Brain
Compulsive thalamic self-stimulation: a case study (1986)(pdf)