Brain Not So Basics: The Amygdala
Welcome to the last week of Brain Bascs! This week we are actually looking at a not so basic part of the brain that plays a major role in a lot of the things we treat with neurofeedback. The amygdala is a structure deep within the temporal lobes. Its name was derived from the Latin word for almond due to the structure's resemblance to the nut. Despite being small, it is incredibly important in the work we do with neurotherapy to help those with emotional disorders such as depression, anxiety, PTSD, and addiction. Although it is located deep within the temporal lobe, when training this area the sensor is put near your eye. This is because that placement allows the sensor to use the sinus cavity as a sort of direct line or path of least resistance to the amygdala. You can imagine that the sensor is a raft and the messages it is reading are riding a river through the sinus cavity pointed straight to it. As it is part of the limbic system, the amygdala plays a major role in emotional processing. However, as the main emotional center, its role is larger than conscious processing of emotions.
Historically, the amygdala is most well known for its role in fear and stress, especially the fight or flight response. Over stimulation of the amygdala leads to high anxiety and fear. Anxiety is having a fear response to the thought of a possible danger, but one that is not necessarily real. Lesions to the amygdala on the other hand have the opposite effect. In this case, the fear response can be dangerously diminished. This might manifest in a disregard for dangerous situations and a lack of the normal fear responses such as increased heart rate and the desire to leave the situation and reach safety. Sensory signals from the environment can be sent to the amygdala before they are consciously processed so that the body can react without wasting time consciously processing what is happening. This can be very useful in some situations. Imagine you are hiking and see a snake in the grass. Your gut reaction is to jump away, maybe before you even know what you are jumping away from.
The amygdala also plays a major role in recognizing emotions in others. It is thought that originally this was a form of self protection. By being able to see fear and stress in others, the observer could be aware that there is a potential danger in the environment and react appropriately. Now this has evolved into the ability to read others emotions and empathize with others. While the role in fear and anxiety was the first discovered and best understood, growing evidence now shows that it is also responsible for creating positive associations and memories. It links association areas of the brain with memory areas and assigns meaning to events, objects, and situations. For example, you can see a lemon and recognize it is a lemon, or think of a lemon and remember that it is yellow. The amygdala is the structure that would be responsible for giving the memory emotional meaning, like having the thought ‘I like lemons because they remind me of summers as a kid when I was happy and carefree’.
When the amygdala is damaged or dysregulated, emotional issues like anxiety disorders and PTSD are common. Because it controls the fight or flight response, stored trauma in the amygdala can also cause excessive physical and mental stress responses to both real and imagined threats. We now understand that the role of the amygdala goes beyond just the basic emotion of stress, and because of this there are many more possible disorders associated with a dysregulated amygdala. These include depression, a lack of impulse control, anger issues, impulsive behaviors, and even substance abuse disorders. Depending on whether your amygdala is over responsive, under responsive, you have stored trauma, or whatever your specific struggles are neurofeedback training may have several different effects. In an overactive amygdala, doing neurofeedback protocols to calm this structure can reduce anxiety, stress, help with rumination, and help let go of past negative experiences. In others, it could help reduce the feelings of stress and correlating impulsive or dangerous behaviors. In those with depression, neurofeedback can help lift you up and help realize that there are positive environments and interactions to be had out there. In those who have trouble empathizing with others, training could improve the lives of the client and those around them by improving how they sympathize with each other. In some cases improved emotional states can help free those with substance abuse disorder from their addictions.