Have you ever wondered what the effects of stress on the brain are and how the stress response is actually designed to keep you safe? Specific elements in your brain activate this stress response, and people’s reactions to the same situation can vary drastically. Although it’s a bit technical, understanding this topic can be quite beneficial for the rest of the course.
Let’s look at a diagram that highlights some essential components of your brain structure. You’ll notice the mammalian brain and the neocortex, both of which play a role in your stress response. The mammalian brain, which developed earlier in human evolution, is responsible for processing emotions and feelings. In contrast, the neocortex is more involved in reasoning, planning, language processing, learning, and conscious thinking.
If we delve deeper into the mammalian brain, we find the hypothalamus and amygdala as integral parts of this system. The amygdala’s primary purpose is to protect you from physical or emotional harm. Think of it as a device with a vast hard drive, storing threats or situations it perceives as harmful to you. When you encounter a situation the amygdala deems threatening, it records all the sensory information from that experience. This data storage helps the amygdala recognize and react to similar situations in the future to keep you safe from harm.
Stressful or traumatic experiences are etched into our memories, and the amygdala responds with lightning speed—milliseconds before the neocortex can react. In chronically stressed individuals, the amygdala frequently perceives threats, and the neocortex struggles to compensate.
For instance, if you hear a loud bang while walking down the street, your amygdala might assume it’s gunfire and trigger a stress response. Moments later, your neocortex kicks in and reassesses the situation, realizing it was just a car backfiring. If numerous perceived threats occur throughout the day, the neocortex becomes overwhelmed, leading to fatigue.
Many stressors exist in our daily lives, such as family or health issues. But why do people react differently to the same stressors? The answer lies in our individual histories. A specific situation might not be considered a threat to one person but could trigger another’s amygdala based on past experiences.
For example, two people receive an email from the same individual. While one person remains calm, the other becomes extremely stressed. The person who stays relaxed likely has no history with the sender, so their amygdala doesn’t perceive the email as a threat. However, the stressed person might have argued with the sender the day before, causing their amygdala to go on high alert.
Now that you’re familiar with the brain structures involved in the stress response and why certain situations trigger it for some but not others, it’s time to explore the relationship with your nervous system. As another key player in stress response, the nervous system will be the focus of our next video.
