Written By Maheen Tahir
1.1 Introduction to Amygdale and fear conditioning
Fear, an immensely powerful and primal emotion, has often been underestimated or trivialized in everyday conversations. Yet, its profound impact on human behavior and survival cannot be overstated. The amygdala, nestled within the limbic system, plays a crucial role in processing emotions and forming memories related to fear and anxiety. Its intricate connections to various brain structures enable it to integrate cognitive information with autonomic responses, shaping our physiological reactions to perceived dangers1. However, one of its fundamental functions aside from wired responses is fear conditioning, a process through which an individual learns to associate a neutral stimulus (tone or light) with a fear-inducing event (electrical foot shock). ‘Fear-conditioning paradigms have incorporated the complexity of the physical or social environment’1. Understanding such mechanisms provide valuable insights into how the brain responds to and copes with threatening stimuli, offering potential implication for anxiety-related disorders and seeking help by probably investing in some good therapy (besides your friend).
1.2 Associative Learning: Unraveling Behavioral Responses
Ivan Pavlov's experiment gives us a solid understanding of Pavlovian fear conditioning through his endeavors in classical conditioning in which we have his dog salivating to the sound of a bell. He used a bell (the neutral stimulus) and meat (the unconditioned stimulus) and paired them together, so tone-meat, tone-meat, and so on2.The dog then upon only hearing the tone salivated so the sound of the tone produced by the bell will become a conditioned stimulus (a trigger embedded with repeated pairings). Thus the amygdala is instrumental in helping animals learn and remember the connection between unpleasant experiences and the cues that precede them. Following this study, many experiments were conducted on animals by removing the amygdala and, most importantly developing phobias in them by merely a few sessions of pairing stimuli to elicit a fear conditioning response. But let’s take an interesting example which was a highly
unethical and questionable approach to the theory by John b Watson and Rayner since many factors were overruled nonetheless it’s worth mentioning and that is the little Albert experiment. It’s important to consider that every human has a different cognitive approach to fear or fear-induced learning and so the scientists were informed of the child’s fear of loud clamor noises and they exploited just that. The 8-month-old would be exposed to neutral stimuli like a rat, monkey, mask, etc. In the presence of the rat, a hammer was banged which made the tone an unconditioned stimulus that elicits a fear response from the child. Here’s the thing, our amygdala and hippocampus which is responsible for forming and storing memories are like next-door neighbors that work well together. The child learns to associate the harmless rat with the tone which he is afraid of and this forms a memory and so the conditioned stimulus is now eliciting a conditioned response (fear). Watson and Rayner wrote: "The instant the rat was shown, the baby began to cry. Almost instantly he turned sharply to the left, fell over on [his] left side, raised himself on all fours on all fours began to crawl away so rapidly that he was caught with difficulty before reaching the edge of the table."2 Like Pavlov’s dogs, Little Albert became conditioned.
Fig 1.1 Comparative analysis of Ivan Pavlov’s classical conditioning experiment and Pavlovian fear conditioning by John Watson
2.1 The Amygdala hijack and fear Conditioning
Fear Conditioning involves the amygdala forming these strong associations between neutral and aversive stimuli, as discussed above. Now this leads to instances of amygdala hijack, where intense emotions triggered by conditioned stimuli bypass rational processing. But how did the term “amygdala hijack” come to be, well it was first coined by Daniel Goleman in his 1995 book ‘emotional intelligence’, which sheds light on how our brain's alarm system, the amygdala, can trigger overlearned reactions3. We have to take into account some distinct roles exercised whenever we process a situation. Many studies and brain imaging conducted in 2016 deduce an inverse relation between the Amygdala and prefrontal cortex (PFC) both of which are meant to neutralize each other's extremities. The PFC analyzes the emotional importance and engages other higher cognitive functions to apply logical reasoning to a perceived threat so a logical and structured response makes its way to the amygdala. In high-stress situations, the thalamus assesses the situation as one that doesn't necessitate thorough logical analysis. Instead, it fast-tracks the information directly to the amygdala, which then triggers the 'fight or flight' response. This response can hinder the optimal functioning of the cortex's working memory, potentially affecting our ability to think clearly and make rational decisions. Rationality is overwhelmed by emotions. Individuals dealing with PTSD often have an amygdala that's highly responsive due to their past experiences of fear conditioning. As a result, they encounter what can be called an "amygdala hijack" more frequently compared to those without this condition. This means they're prone to perceiving danger even when it's not present (triggered by conditioned stimuli), leading them to react with fear and anxiety, often without the opportunity for thoughtful consideration.6
2.2 Understanding PTSD
The connection between fear conditioning and PTSD lies in the way traumatic experiences can lead to the development and persistence of fear-related associations. When someone experiences a traumatic event, their brain may encode the traumatic memory along with the sensory cues present at the time of the event. These cues can become associated with the intense fear or distress experienced during the trauma and act as overwhelming triggers and send the body to a ‘flight and fight mode to protect itself from re-experiencing the trauma7. The chronic hyperarousal state caused by amygdala hijack explains the common symptoms of PTSD which are broken into 4 categories; experiencing the event, avoiding reminders (the triggers), depression or social withdrawal, and hyper alertness. This deadly combination alone makes such individuals 15 times more likely to commit suicide8.But a big breakthrough in memory research showed that after bringing up a memory, it becomes vulnerable to change for a short time. This special process is called reconsolidation. During reconsolidation, memories can be modified before becoming stable again. This is a temporary chance to update and rewrite memories and it may be an optimistic back door to those diagnosed with PTSD9.
Fig-2 This figure depicts how fake evidences are often used to define imaginary real things.
2.3 Conclusion
The discussion thus far has delved into a particularly significant mechanism governed by the amygdala: fear conditioning. This process stands distinct from the innate, hardwired fears crucial for our survival. The discovery of this novel phenomenon emerged through experiments conducted on rats, where fear could be instilled merely by associating neutral stimuli with aversive ones. This groundbreaking revelation gave birth to an entirely new concept, one that aimed to induce intense emotional reactions akin to a nightmarish state of amygdala hijack. The connection between fear conditioning and post-traumatic stress disorder (PTSD) is profound, rooted in the way traumatic experiences can forge and perpetuate fear-related associations. These associations etched deeply
within our psyche, serve as a testament to the enduring impact of our amygdala's intricate workings on our emotional well-being. This revelation not only sheds light on the intricacies of human emotional responses but also underscores the significance of further exploration into these mechanisms for the betterment of mental health and well-being. My enlightened input would be to take a prompt step and research more on how therapists can actually work with their patient who has PTSD to find their brain in a vulnerable state when traumatic memories can be rewritten or develop neurofeedback techniques that allow individuals to gain conscious control over their amygdala's fear response. This could have applications in fear extinction therapy and PTSD treatment. A wild idea would be creating a virtual hyperreality and creating highly immersive and controlled traumatic experiences for research subjects to allow updated research on the formation and consolidation of fear memories in the amygdala within an ethical framework.
References
1. https://www.simplypsychology.org/amygdala.html
2. https://www.sciencedirect.com/topics/neuroscience/fear-conditioning
3. https://practicalpie.com/little-albert-experiment/
4. https://www.verywellmind.com/the-little-albert-experiment-2794994
5. https://psychcentral.com/health/amygdala-hijack#symptoms
6. https://cascadiahealth.org/ptsd-101/
7. https://www.simplypsychology.org/hypervigilance.html
8. https://cascadiahealth.org/ptsd-101/
9. https://www.sciencedirect.com/science/article/abs/pii/S0149763416300100
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