What's the best way to think about the brain? It's insanely complicated. Everything connects to everything, uh, a gazillion little subres. Um, amid all that complexity, there's a broadly. Sort of simplifying way to sort of think about aspects of brain function when it comes to behavior. And this was an idea put forth by this guy, Paul McClean, a grand puma on the field.

Um, conceptually of thinking in the brain of the brain is coming in three functional layers. The triune brain, and again, this is. Highly schematic. The brain really doesn't come in three layers, but one can think of the first most, the bottom, most, the most ancient as being what's often termed the reptilian brain, where basically the parts in there, we've got the same wiring as in a lizard, isn't a any ancient creature.

It's been there forever. Ancient, ancient wiring at the base of the brain, most inside. And what does that region. All the regulatory stuff, your body temperature changes, it senses it, and causes you to sweat or shiver. It's monitoring your blood glucose levels. It's like releasing hormones that are essential to sort of everyday shop keeping.

It's just. You know, keeping regulatory stuff in balance. Sitting on top of that is conceptually what could be termed the limbic system, the emotional part of the brain, and this is very much a mammalian specialty. Lizards are not well known for their emotional lives. Part of the brain having to do with fear, arousal, anxiety, sexual longings, all those sorts of things, very mammalian.

You're off there in the grasslands, butting heads with somebody else with antlers, and it's your limbic system that's heavily involved in that. Then sitting on the top is the. Layer three, the cortex, the cortex, spanking new, most recently evolved part of the brain. Everybody's got a little bit of cortex, but it's not until you get to primates that you got tons and then apes and then us.

So functionally, it's very easy to think of this simplistic flow of commands. Layer two, the limbic system could make layer one, the reptilian brain activate. When is that your heart speeds faster, not because of a regulatory reptilian thing. Ooh, you've been caught something painful, but oh, an emotional state.

Download Transcript