Too much stress at one time or too many stressors over time can similarly, but more complexly, shift the homeostatic midpoints for the multiple sites affected by neurotransmitters involved in the body’s response to stress. In turn, these homeostatic shifts correlate strongly with changes in the neural architecture themselves, although at this point, researchers are still unclear about which—the homeostatic shift or changes to the neural architecture—results in the other.

The arousal mechanisms operate simultaneously on the macro and micro levels and cannot be demonstrated in separate personal examples. However, very important to note is the speed with which the SNS is activated greatly increases after a traumatic event and in PTSD. For example, when driving shortly after the car accident, I was not aware of continuously scanning the rearview mirror for oncoming vehicles, but the moment I saw one, I was panicked—not a bit upset, but completely panicked. In automotive terms, I went from zero to 60 in a nanosecond and calming that response required months of conscious intervention: “No, the car will not crash into you; it is slowing down.” Although in this one instance, I credit the impact of conscious intervention for eventually calming me, neuroscientists might argue that perhaps calming occurred because my distress simply had run its course—or I had acquired a sufficient number of no traumatic driving experiences to assure my brain’s pattern seekers that I could stop looking for another accident. Understanding how (and which) modes of learning can interrupt or alter ensuing patterns of distress response—on the macro and micro levels, therefore, should reveal much about how the body and mind develops and remembers strategies to survive successfully those stressors. As researchers learn more about PTSD, a disorder affecting subconscious or automatic memory for traumatic stimuli and affecting conscious memory formation for events and facts, they also learn about how human beings learn—under both stressful and no stressful circumstances.