The three reflexes of stress. discussed by Thomas Hanna in his definitive article on clinical somatic eduction, are emotional reactions. They involve the limbic system -- mammalian brain -- however much they may also involve the reptilian brain (brain stem).
Let's take this discussion of FM further and deeper.
In habituation, the neocortex disengages, leaving the limbic system and cerebellum in control. Reactions are automatic.
That's the state of the majority of humanity most of the time.
Exceptions: moments of deliberate action, creativity, learning
Habituation forms with the onslaught of experience -- individual, cultural, species, and planetary memory -- and "befouls" (as well as constitutes) the memories and functional capacities of the individual. "Birth Trauma" is better framed as "Life Trauma" -- meaning compounded forms of Trauma Reflex. The onslaught of experience is like gravity -- an ongoing influence that endlessly "tests" our balance and fluidity.
"The Fair State" of which Thomas Hanna wrote is an ideal, asymptotically approached (but never reached), in which responses are increasingly free, creative, and finely tuned and in which attention is increasingly discerning and accurate -- both toward "the world" (3d and 2nd person) and toward ourselves (1st person) -- and leading to transpersonal awakening ("0"th person).
Thus, a life may be seen as a struggle to overcome the onslaught of experience, which drives us, again and again, to lower levels of function -- lower levels of brain function (below the neocortex). By "rebound" (refusal of limitation), we may awaken at the neocortical level and creatively develop means to exceed those limitations, leading to new habit formation and subsidence of the higher cortical functions.
Thus, humans alternately awaken to our higher potential and then sink to lower levels and then, in conditions of crisis, rise again. Such accounts for the rise and fall of civilizations (including our own). (That's why people have trouble following instructions.)
"Sensory-motor amnesia" describes the most rudimentary form of this habituation -- gross movement and fine motor control.
"Attentional-intentional amnesia" describes the more complex forms of habituation -- emotion, conceptualization/cognition -- observable 3d-person as habits of action and interiorly-feelable pattens of tension identified (mistakenly or only provisionally) as, "self" -- sometimes clinically diagnosed as, "fibromyalgia" and usually, as "ageing".
More primitive than habituation is incompetence -- or immaturity.
"Sensory-motor obliviousness" describes the most rudimentary form of incompetence or immaturity.
"Attentional-intentional obliviousness" describes the more complex forms of incompetence or immaturity identified (mistakenly or only provisionally) as, "self".
Clearing up all of these forms of befoulment or incompetence is the proper scope of somatic education -- escape from the sense of the gravity of life and the accelerated awakening of and to our own unrealized potentials.
The Ultimate Structure of All Senses of Identity