What's the best way to
think about the brain? It's insanely complicated, everything connects to everything. Amid all that complexity, functionally, it's very
easy to think of the brain as coming in three functional layers. This is a broadly simplifying way to think about aspects of brain function when it comes to behavior. 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. We've got the same wiring as in a lizard, as in any ancient creature. Ancient, ancient wiring
at the base of the brain. And what does that region do? 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 that's releasing hormones that are essential to sort
of every day shop keeping. It's just keeping
regulatory stuff in balance. Sitting on top of that
is the limbic system, the emotional part of the brain. This is very much mammalian specialty. They're off there in the grasslands butting heads with
somebody else with antlers and it's your limbic system
that's heavily involved in having to do with fear, arousal, anxiety, sexual longings,
all those sorts of things. Then sitting on the top is
the layer three, the cortex. Most recently evolved part of the brain. It's the part of the brain
that does impulse control, long-term planning, emotional regulation. It's the frontal cortex that
whispers in your ear saying, 'Do you really, really
wanna do that right now?" 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 beats faster, not because of a
regulatory reptilian thing. Ooh, you've been cut, something painful, but an emotional state. You're a wildebeest and
there are some scary, menacing wildebeest threatening you and that emotional state
causes your limbic system to activate the reptilian brain
and your heart beats faster. And you have a stress response, not because a regulatory
change happened in your body, but for an emotional reason. Then it's very easy to
think of layer on top, this cortical area,
commanding your second layer, your limbic system to have
an emotional response. Rather than something emotional, here's a threatening beast
right in front of you. You see a movie that's
emotionally upsetting. These are not real
characters, they're pixels and it's your cortex that's turning that abstract cognitive state
into an emotional response. Likewise, your cortex, layer three could influence
events down in layer one. A purely cognitive state. Ooh, on the other side of the planet, there are people undergoing
some traumatic event and I feel upset about it and
your reptilian brain responds. So it's very easy given that, to think of a three
talks to two talks to one sort of scenario. Just as readily though, one
talks to two talks to three. What's your reptilian brain
talking to your cortex? Remarkable finding, when we're hungry, we make harsher moral judgments about people's transgressions, we're less charitable, we
cheat more in economic games. Our cortex assessing the
effects of pro-sociality, anti-sociality and part of
what it's doing in deciding how it feels about
somebody else's plight is if your stomach's
gurgling, if you're hungry, if you're in pain, that affects very cortical
judgment type areas. Layer one, this ancient reptilian brain that should have nothing to
do with how your cortex works, having tons to do with it. Or layer two influencing layer
three, your limbic system. Your emotional state influence your abstract
cognitive processes. What's the most obvious example of it? When we're under stress, we make stupid impulsive decisions that seem brilliant at the time. It's embedded in the biology
of all of these layers. This interaction between these layers seems it's a very mechanical process, potentially even an unconscious one. How do we consciously have, say, our cortex regulate an
emotion, a limbic two layer? Simple, think about the most
arousing wonderful thing that ever happened to
you umpteen decades ago, and your cortex is evoking a memory that's got your limbic
system humming along in some excited state. Or pull out the memories
of some traumatic event and your limbic system is responding. A lot harder is the inverse, you're sitting there and you
suffer from high blood pressure and either they can marinate
you in antihypertensive drugs for the rest of your life
or an alternative approach, a biofeedback approach. The core of biofeedback is figuring out what sort of conscious
states you can evoke that will affect your reptilian brain in a direction that's
good for your health. Biofeedback approach is: sit there and think about the
happiest day of your life. Think about being in an
open field that's beautiful. Think about your favorite vacation. Think about think about, and if it's the right thinking about suddenly your heart slows down, suddenly your blood pressure goes down. And all you do then is learn
how to get better and better in some stressed
hypertensive circumstance. What conscious active thinking can I mobilize here at this
point that will cause changes in how my big toes blood flow is working? In a case like that, that is very conscious
regulation of more autonomic, more ancient parts of your brain. -Get smarter faster with new videos every week from the world's biggest thinkers.
