The Tenacity of Fear
The amygdala plays multiple key roles in the brain and nervous system. As an organ of appraisal, it stores memories of positive and negative experiences in order to inform our approach and avoidance decisions in the service of survival. Fully developed before birth, the amygdala makes us capable of experiencing and remembering both positive and negative experiences from the first moments of life. Its dense connections with the autonomic nervous system allow it to trigger the fight/flight/freeze response and, as such, is the center of our first and most primitive central executive system. As a core component of the social brain, it plays a central role in attachment, affect-regulation, and adaptive social behavior.
One of the amygdala’s roles is that of a sentry, monitoring the inner and outer environments for threat. Gathering information from the rest of the cortex, it becomes alert when something novel occurs or if anything happens which matches and memories of past threats. It records who is safe and who is dangerous, what things and situations have been paired with anxiety, fear, or pain, as well as those experiences matched with positive states of body and mind. Although the amygdala gradually becomes one of three executive networks during development, it remains capable of inhibiting these other systems in situations of real or imagined danger, or when highly valued and motivating opportunities arise.
“It is the perpetual dread of fear, the fear of fear, that shapes the face of a brave man.”
The tenacity of human fear is related to at least three different characteristics of amygdala functioning. The first is that it appears to have evolved to remember any and all threats to our survival. These can be threats to our physical survival that resulted in physical pain and/or a fear for our lives. Threats can also be to our sense of self and our social identity where we feel humiliated, bullied, or ostracized. At a neurofunctional level, the amygdala has been described as demonstrating “persistent dendritic modeling,” which means that it is designed to maintain memories as opposed to updating them based on new learning (this is in contrast to a model of fluid updating seen in the hippocampus). As Aaron Beck once said, “Nature favors an anxious gene” which has shaped the amygdala to never forget.
When we are able to get over a fear or phobia, or decrease symptoms of arousal in PTSD, it isn’t because we have erased the memory from the amygdala, it is instead because we have built descending inhibitory structures down from the cortex to inhibit the output of the amygdala to the autonomic nervous system. Although anxious and intrusive symptoms can be reduced and even stopped, this change relies on the ongoing inhibitory mechanisms of the cortex so that “what happens in the amygdala, stays in the amygdala.”
The tenacity of fear is also related to another bias in amygdala functioning; the tendency to generalize threat memories to other situations. For example, if you get bitten by one dog, your fear may well generalize to all dogs, other animals, or even other places that remind you of where you were bitten. In contrast, the hippocampus is constantly remodeled in response to new information and can easily differentiate one furry animal from another. This tendency to generalize is why a panic attack outside the home can eventually lead to agoraphobia as the sufferer’s amygdala strives to avoid all possible causes of the anticipatory terror of another attack.
The third mechanism supporting the tenacity of fear is that the amygdala can inhibit the very processes of thinking that could help us break the fear cycle. Because high levels of amygdala activation can inhibit our other executive systems, fear can downgrade our thinking, as well as our ability to relate to others. One recognized symptom of trauma is “neophobia,” the fear of anything new. We become afraid of taking risks and learning new things, which can result in closed logical and experiential loops. The result may be for those who are sick, to remain sick. Once our brains have been shaped by fear to perceive, think, and act in stereotyped ways, we tend to remain in rigid patterns that are repeatedly reinforced because the amygdala interprets our survival as “proof of concept.”
Our internal logic is self-perpetuating, making it difficult for us to find answers that are different from the ones we already know. Although our best chance of learning rests in getting input from other people, fear may lead us to keep them at arm’s length. When people are hurt or afraid, caring relationships are difficult to come by and not easily entered into. Openness and trust are fragile creatures, even with the people we love most. The ability of the amygdala to inhibit the social and self-awareness functions of the default mode network make it all the more difficult to break out of our closed logical loops.
The therapeutic relationship has been designed to counteract these processes that keep anxiety in place. Within the consulting room, therapists attempt to be amygdala whisperers and work to reactivate networks of new cortical learning, self-awareness, and social connectivity. Warmth, empathy, and positive regard can create a state of mind that enhances neuroplastic processes, increases the likelihood of positive change, and help clients break free of a prison of fear.