THE ANATOMY OF CONSTANCY

There is a thread of continuity that links all the days of a lifetime. It is the promise, more implied than explicit, that given each day of life, part of which includes a period of conscious awareness, there is a similar period coming which will also be experienced. Said otherwise it is the awareness of self as a constant element riding time’s arrow, both actor and spectator on the scene which constantly unfolds. Most of us go to sleep without fear of the conscious gulf we know will follow, reasonably certain of our return to the state of perceptive awareness. We endure anaesthesia with greater trepidation, realizing we must cross a gulf of unknown temporal dimension, cognizant that we will miss a set of experiences bound to affect us in rather dramatic manner, and sobered by the realization that when (if) we awaken, it will be within a new experiential frame marked by pain and helplessness. Although feelings about death are more complex, an inevitable feature is the threat of final loss of that continuity-the foreknowledge of closure of our personal life cycle and-except perhaps for the religious-the certainty only of nothing. The idea of a world in progress without us is difficult, or unthinkable, insofar as it denies that process of continuity that has accompanied us emotionally and physiologically through the days of life. Each of us attempts to solve this unsolvable conundrum in his own manner and within his own means. We may build pyramids, or convince ourselves of a better life beyond, or sire many sons who at least will carry on our name, if not our personal identity. And for a tiny and fortunate elite, there is the possibility of immortality gained through artistry, through sharper insights into the physical or biological world or into man’s condition within it. Within the framework of this conference on tonic functions of the nervous system, we take as our theme the idea that substrate for this continuity of living experience or “ego-core,’’ with the inevitability of its cycles and almost open-ended extension in time, must be sought within the core of the brain stem and its rostra1 interplay with diencephalon, basal forebrain region, and septalhippocampal complex. If we overlook neocortex, it is not to indicate lack of involvement, for here must certainly originate most of the contextual richness of our self concepts. But a hypothesis can only stake out so much ground, and we must limit ourselves to the proposed wellspring. We see the reticular core, by analogy, as the keel of a vessel. I t establishes the physical and emotional dimensions of the individual, serves it through time, exerts continuous shaping effects on the entire superstructure that ties into it,