>
> It might go deeper than that. The experience we recognize as
> experience, or feeling like we exist, may be happening in the brain-
> stem, and hence most animal have this self, but don't have a bunch of
> stuff wired up to it like limbic systems and outer cortices.
>
> Your "3-Brains-in-One" Brain
>
> You may have thought all you had was one, but inside there are two
> more brains.
>
> Actually, you already know this from your experience: for example,
> remember a time when you really wanted to do something, but you knew
> you shouldn't? The most illogical or irrational "wants" we have
> probably derive from older parts of our brain, while the understanding
> of smart versus dumb choices comes from the newest part. If that idea
> offends you, or seems just too "Western" or "scientific", you might
> take a "de-tour" for a moment and read this essay on science.
>
> Â Take another example: you can be hungry, but not feel it until you
> pay attention to it; then when you do notice, you realize you've been
> getting hungrier for a long time. Hunger comes from the most basic
> parts of our brain, but our awareness of it is controlled by the
> newest part.
>
> Here are the "3 brains":
>
> Brain One
> -Center of the Brain
> -"R complex"
> -snakes, lizards
>
> Brain Two
> -Wrapped around Brain One
> -"limbic system" or "old mammalian brain"
> -dogs, cats
>
> Brain Three
> -Outside Surface
> -(Wrapped around Brain Two!)
> -"neocortex"
> -primates, especially human primates
>
> Brain One
>
> This is the brain we share with birds, and reptiles. Think of it as
> the "housekeeping brain". Just the basics: hunger, temperature
> control, fight-or-flight fear responses, defending territory, keeping
> safe -- that kind of thing. The structures that perform these
> functions within our brain are extremely similar to those in the
> brains of reptiles. Thus, this brain is called the "R complex" (R for
> reptilian). You can take a Tour of the R complex when you wish; and
> you will see parts of it in the section on obsessions.
>
> Brain Two
>
> As animals became more complex, other structures were added around the
> R complex in a shell, or "girdle". The Latin word for arc or girdle is
> "limbus", and this brain is called the "limbic system". We humans
> share this brain with older mammals like dogs, cats, and horses, and
> even mice (as opposed to newer mammals like chimps; we'll get to them
> in a moment). Their brains, and this part of our brains, are extremely
> similar.
>
> Think about the difference between a mouse and a lizard, or between a
> cat and a snake, and you'll recognize what this mammalian brain adds
> to a creature's capacities. Mammals have "feelings" like ours. We'll
> be looking at the structures of the limbic system in the sections on
> mood, memory, and hormone control. The main parts of the limbic system
> (except the thalamus, which is generally regarded as part of Brain
> One) are shown below. By taking all the Brain Tours you'll see each of
> these parts and get a better sense of how this set of structures is
> positioned underneath the cortex.
>
> Brain Three
>
> Here is the familiar "cortex" you can see from the outside. With this
> brain, primates can do things that horses and cows cannot, like
> complex social interactions and advance planning (such as planning an
> attack on a neighboring troop). In humans the cortex has grown to a
> huge size, somehow in association with our development of language.
> Other primates like chimpanzees, or monkeys, have much less cortex,
> which is surprising since chimpanzee DNA differs from ours by only
> 1.6%%! (stunning, really; I hope you're stunned. Recently some
> technical issues have arisen with this number, but for now, it's still
> generally regarded as, well, amazing!). If you wonder why we humans
> have populated the entire globe, while our chimp relatives are stuck
> in a shrinking rain forest with their nearly identical DNA -- read The
> Third Chimpanzee, by Jared Diamond. You've got a great question, and
> his is a great answer. (Similarly, if you wonder why white-skinned
> humans seem to have an unfair share of the resources and money, his
> other masterpiece offers a solid explanation beside skin color: Guns,
> Germs, and Steel).
>
> Three Brains in One
>
> To keep all this straight, think of the following image (ok, it's a
> little odd, but it seems to work; write if you have another one). The
> R brain is like a golf club. Let's make it a driver, one of those with
> a big fat wooden head. Hold the club so that the head is at the top.
> There's your R complex, with your spine sticking down toward the
> ground. The R brain is just a big swelling at the top of a spinal
> cord, and that's how it developed. Worms have little swellings, snakes
> have bigger ones. OK so far?
>
> Next we'll add the layer that makes mammals behave so differently from
> reptiles. This next "layer", the old mammalian brain, evolved on top
> of the R complex. It was not a remodel so much as an addition, like
> adding on bedrooms all the way around a kitchen/bathroom. This
> addition covers the entire R complex, leaving the R complex deep
> within the brain. In our model, take the golf club, and cover the head
> with a sock; a big thick red one would be nice. Now you have the R
> brain (golf club), with the old mammalian brain wrapped around it
> (sock). Notice that the red sock forms a shell, or continuous border
> around the golf club head.
>
> To complete the brain picture, add a bicycle or hockey helmet on top
> of your red-socked golf club head: that's the newest mammalian
> addition, the "cortex", and it is the grey squiggly stuff you can see
> on the outside. If you'd like a tour of the cortex itself, as you've
> seen it so far (like, what are those colored parts?), click here.
>
>
http://www.psycheducation.org/emotion/triune%%20brain.htm
