Feeling Fear After Damage to the Amygdala
The journal Scientific American published in 2013 and article titled "Humans Can Feel Terror Even If They Lack the Brain's 'Fear Center.'" The article describes an experiment and its findings regarding subjects who had suffered damage to the amygdala through disease, making them seemingly incapable of normal fear-responses.
The experiment describes the subjects' calmness when exposed to stimuli expected to frighten them, and the hypothesis of the experimenters that exposure to Carbon Dioxide, which the normal body will meet with a fear-response, would not elicit the same result in their amygdala-damaged subjects. Contradictory to expectations, the subjects did indeed have a fear-response which escalated activity and arousal. The authors highlight how this suggests multiple structures in the brain being involved in the fear-response than just the amygdala.
In class we had spoken about the amygdala and its role in our perception of emotion and the sympathetic nervous system, preparing us for danger and action. When discussing fear the amygdala is, in my experience, the only structure strongly touted, and the results of the experiment of this article clearly delineate the subjects' responses from being PFC grounded logic-responses that compensate for emotional, activating fears.
We've spoken at length about how damage to the brain structures can be compensated for in other areas or in the other hemisphere if damage is laterally isolated, and this falls neatly into that operational assumption. We know that many more specialized structures in the brain have their roles critically massed in their regions (such as the hippocampus), but having the fear-response-- something critical to survival and protection, be spread out among multiple structures in the brain is an exciting look at the adaptability and flexibility of the human blueprint. As the article is nearly four years old, I'm pumped to see what other relevant research has been conducted.
The article:
https://www.scientificamerican.com/article/humans-can-feel-terror-even-if-they-lack-brains-fear-center/
The experiment describes the subjects' calmness when exposed to stimuli expected to frighten them, and the hypothesis of the experimenters that exposure to Carbon Dioxide, which the normal body will meet with a fear-response, would not elicit the same result in their amygdala-damaged subjects. Contradictory to expectations, the subjects did indeed have a fear-response which escalated activity and arousal. The authors highlight how this suggests multiple structures in the brain being involved in the fear-response than just the amygdala.
In class we had spoken about the amygdala and its role in our perception of emotion and the sympathetic nervous system, preparing us for danger and action. When discussing fear the amygdala is, in my experience, the only structure strongly touted, and the results of the experiment of this article clearly delineate the subjects' responses from being PFC grounded logic-responses that compensate for emotional, activating fears.
We've spoken at length about how damage to the brain structures can be compensated for in other areas or in the other hemisphere if damage is laterally isolated, and this falls neatly into that operational assumption. We know that many more specialized structures in the brain have their roles critically massed in their regions (such as the hippocampus), but having the fear-response-- something critical to survival and protection, be spread out among multiple structures in the brain is an exciting look at the adaptability and flexibility of the human blueprint. As the article is nearly four years old, I'm pumped to see what other relevant research has been conducted.
The article:
https://www.scientificamerican.com/article/humans-can-feel-terror-even-if-they-lack-brains-fear-center/
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