Lizard brain: an anatomy lesson worth understanding
Rage reactions start from the amygdala, an almond-shaped region at the base of the brain near the top of the spinal cord. The amygdala is a warehouse for emotional memories, but also serves as a router for our nerve signals. Data coming from our surroundings passes through the amygdala, where it sends the information on to either the limbic or cortex areas of the brain.
The limbic region is not very highly evolved and is the same part that kicks your leg out when the doctor taps you below the knee. In this way, the amygdala plays an important role in our ability to survive – perceiving threats almost instantly and reacting quickly to stop or avoid them. Alternatively, thinking, logic, and judgment come from the cortex, or the lobes at the top and front of the brain. The cortex contains what we think of as “memory” (information we’ve learned) and is used in making decisions. Because of all the neurons involved in the cortex, rational thoughts take more time and energy.
If incoming sensory data triggers a strong association with a painful past event, the amygdala will immediately send a signal to the limbic system. That incoming data could be in the form of someone yelling at us or even just an angry look on another’s face. Even if the threat is not real and just “looks like” something that was painful to us in the past, the amygdala routes it to the part of our brain that will produce a reflex-like reaction.
Unfortunately, the base of our brain has a limited set of responses: fight or flee. We fight or flee to protect ourselves, or we risk being hurt again. What’s more, our minds sometimes misperceive events and circumstances to be much larger and scarier than they really are. This is why we over-react to certain things that happen to us or are said to us. When our brain misinterprets something to be very dangerous, we don’t consider consequences, rationalize actions, or figure out the best way to respond. The cortex, which would be able to perform those functions, is not involved! This phenomenon is called an amygdala hijacking or “lizard brain” because a lizard’s brain is dominated by the basal parts and is not capable of rationalizing its responses.