Brain scans show that in action and imagination many of the same parts of the brain are activated. That is why visualizing can improve performance.
Studies have demonstrated that experience can change the level of defensiveness and the strength of neurotransmission between the amygdala and the hypothalamus, pathways important to the learning and regulation of fear.
In all systems, including development of the brain, there is an unusual sensitivity to initial conditions.
Ontogeny recapitulates phylogeny.
Early exposure to dissociative experiences makes one more susceptible to experience later dissociative states, often potentiated with less activation because the neural circuits have been laid down.
Dissociation has its roots in the brain’s opiod system which secretes endorphins to blunt strong painful feelings. Opiods are the body’s narcotics and act to numb feelings, along with which people feel a sense of depersonalization and derealization.