The connections and pathways going out from the amygdala to the rest of the brain are pretty much their at birth, so the amygdala is able to communicate to the rest of the brain and the body. The primary role of the amygdala is to communicate danger or life threatening situations and manage the response to that danger or threat. But the return connections have not yet developed at birth. The reason these connections haven’t yet developed is that our brains are flexible and adaptive to experience and environment (especially early experiences and environment). That way we have the ability to adapt and develop to many different environments, with different levels of danger or threat, based upon our early experiences.

It is now widely understood and accepted that, in infants and children (and even the foetus!) subjected to prolonged or intense distressing emotional experiences (or even moderate, prolonged distress), the development of the return paths from the cortex to the limbic system (inc. Amygdala), especially an area of the frontal cortex called the anterior cingulate; which regulates and controls the emotional/fear response of the amygdala, are affected and are noticeably poorly or incompletely developed when tested in subsequent adult life . This, on closer analysis, appears to be a survival adaptation; in other words, in an environment of high threat or danger, we don’t want the frontal cortex to interfere with the response to danger or threat. In an environment of high danger, this is a positive adaptation. But in our modern world, where most of our dangers and threats are removed. This becomes extremely dysfunctional and leads to a state called “cognitive dissonance” as a result of the amygdala sending one message that conflicts with the appraisal of the frontal cortex. But, because the return paths from the frontal cortex have been disrupted in development, the frontal cortex struggles to overrule the amygdala. In response to this, the amygdala, to some extent, develops its own autonomy and executive function. The cortex, in trying to make sense of this and the fact it can perceive no cognitive explanation for the amygdala response, seeks out a way to try and make “the story” better fit the situation, to better explain the “feelings” it is receiving from the amygdala and the body. Hyperarousal, Hypersensitivity and Hypervigilance work to accumulate evidence that supports the “Danger” signals being received from the amygdala, maintaining a consistency of “story”, so as to maintain the false image we have of ourselves as beings of a singular executive function.

Thus many people who have experienced early developmental distress, will later respond to situations (or people) as if they are life threatening, when they aren’t life threatening at all. What they are responding to is a misperception and misinterpretation of false signals, stemming from emotional memories, from the amygdala. If the early developmental distress involved early emotional attachments, these people will be prewired to experience emotional attachment as life threatening and become destructive towards any relationships that trigger latent emotional memories. In other words, these people are responding to the original life threatening situation from the past, but displaying an autonomous preservation behaviour in the present, protecting them from a reoccurrence of the original experience.

Essentially, you have a situation of one way traffic, with threat signals coming out from the amygdala, but limited traffic in the other direction, telling the amygdala to calm down and that there is no present threat.