Amygdala Function

Amygdala may not be a very popularly known part of the brain, but it sure is an important part. Located just above the hypothalamus gland of the brain, the amygdala is an almond shaped, one-inch long mass of nuclei, situated deep within the temporal lobes of the brain. We have two amygdalae, each one situated a few inches away from either ear. This tiny mass has been associated with a person's mental and emotional state. This name amygdala comes from the Greek word for almond and has been named so because its size and shape bears semblance to that of an almond. This amygdala features presence of several nerves that connect it to various centers of the brain such as the neocortex and visual cortex and forms a part of the limbic system which is an important part of the nervous system. Let's understand the different amygdala functions in our body.

Function of the Amygdala

Until the 19th century, the existence of this structure was not even known to man. In the 1930s researchers found that damage to the temporal lobe conduced to changes in fear reactivity, sexual behavior and feeding behavior. Later, around the mid century, it was found that emotional processing changes were seen due to damage done to amygdala. Thanks to the pioneering works of several scientists like Ursin & Kaada, Blanchard & Blanchard, Weiskrantz, Heimer, Kapp, McGaugh, LeDoux, & Davis, today we have the privilege of understanding this structure better.

Amygdala is seen to be linked to the orbital frontal cortex, the striatum and thalamus, which are all structures involved in emotional processing. In humans and animals, this amygdala is linked to both fear and pleasure responses. The main function of amygdala is emotional and social processing. It processes and stores memories of emotional events and is also involved in current emotional responses. Researchers also find that the amygdala in men and women respond differently to emotional situations.

We need these amygdalae to feel certain emotions and to perceive them in other people. Emotions such as fear are associated to amygdala functions. For example, seeing a person being murdered causes the heart to beat faster and pound. Extreme fear and worried thoughts plague our minds and we think of ways to escape to safety, lest we get killed too. Such responses are attributed to an active amygdalae in one's brain.

Moreover, the memory of such a horrendous time gets stored by the amygdala, such that the next time we think about the same murder incident, flashes of that day and incident, appear vividly in our mind and the memory is also accompanied by shivering and other reactions of fear to the body. This shows that the amygdala stored emotional memories and feelings as well, which is why it was as if the person was reliving the experience.

However, researchers have observed that people with damaged amygdala, show no signs of fear responses. They do not react fearfully to gun points, spiders, horror movies or other factors that would normally cause fear in the heart of a person. This clearly proves the connection between amygdala and responses of fear.

People who have had strokes that resulted in damage to amygdala are seen to depict every other expression than that of fear. Research conducted by Weiskrantz revealed that lesions caused to amygdala resulted in behavioral and emotional abnormalities. Conditions such as autism, phobias, post-traumatic stress disorder, anxiety and depression are seen to be linked to the abnormal functioning of the amygdala.

People with bipolar disorders are seen to have larger amygdalae, which is why they are gripped by a lot of fear all the time. However, why this is so is still a mystery! Moreover, malfunction of the amygdala also result in violent psychopathic behavior. Damage, neurotransmitter imbalance or developmental problems can be reasons for abnormal functioning of the amygdala.

The amygdala is no longer a region of little scientific interest as it was in the past. Today, it is one of the brain structures on which extensive, in-depth research is being carried out. Understanding amygdala function thoroughly will take quite a bit of effort, after all it has eluded scientists! The whole aspect of how emotions and triggered, processed and stored in the form of memories is quite intriguing!