Lizard, Mouse, Monkey
Hello, and welcome back to Brain Bytes! Before we dive into today's issue, let's do a quick recap.
Last time, we talked about the mind/brain distinction, defined neuroplasticity, and wrapped up with a quick exercise on taking in the good. We'll need to keep these basics in mind as we continue with this series. If you'd like to brush up, you can view a web-archived version of the last newsletter here.
Today, we're going to be talking about different layers of the human brain. First, there's the "lizard brain" or "reptile brain." In brain-talk, this is called the amygdala, and it's the smallest layer. In evolutionary terms it's the oldest part of our brain. It's the foundation, both physically and functionally. Just think brain stem.
After that, there's the limbic system, which is often called the "mouse brain" or "mammalian brain." It sits on top of the amygdala.
Finally, there's the "monkey brain," or the cortex. This is a distinctly primate piece of hardware, and it's the lumpy gray stuff we usually think of when we think of the brain. It's far bigger than the older layers.
It can be tempting to treat the amygdala, the least developed part of the brain, as inferior. But in fact, each part of the brain plays a vital part in keeping us going.
Amygdala: Reactive and reflexive action; avoid hazards
Limbic: Memory, emotions, and behavior; approach rewards
Cortex: Abstract thought, language, empathy, cooperation, social cognition; attach to others
While one may be dominant for some tasks, each part is working with all the others at any given moment. So while it's true that the small, ancient lizard brain isn't well suited to most of our modern day-to-day activities, we can't forget about how important each layer is.
You can see parallels to Thera Rising's strategies here. Remember the "walnut brain" that we use when we're angry? That's the amygdala. Just think about how dense we can be when we get mad. That goes to show how differently we think and act depending on which part of the brain we're activating.
Understanding the functions of each part of the brain is critical in neuroplasticity. For example, as you move "back in time" from the cortex to the amygdala, neuroplasticity decreases. In Rick Hanson's words, "the lizard takes a lot of petting."
If you'd like to read more about the different parts of the brain, Rick Hanson's blog has an article on each.
Thanks for reading! Next time, we'll get to the heart of the positive neuropsychology: the negativity bias. See you then!