Friday, January 15, 2010

Brain Basics

Let's talk about that three pounds of jelly under your hair that separates you from a starfish.  You use it every minute of every day and it is a crucial part of your functioning in this world, but most of us never even give it a second thought and take its miraculous and still somewhat mysterious workings completely for granted. I know I did.  I also know that you would give it a second and third thought if something about it did not work as it should. It was not until after my brain injury that I took notice.  When I couldn't even do something as simple as run because my arms and legs would not cooperate, I thought "Why, can't I do this?  I know how."

If you take your hand and make a fist with your thumb folded cozily inside, this is a "handy" model of your brain.  Your thumb is your brain stem.  It connects to your spinal cord and is the most primitive part of the brain sometimes referred to as the reptilian brain.  It controls the basic, automatic bodily functions like respiration and heart beat.  The fight or flight response is housed here also because it was necessary to keep us from being eaten by a wooly mammoth way back when.

The back of your hand is your cerebellum.  It mostly controls coordination and balance while also being involved in some known language and attention functions.

Your fingers are the cerebrum or your mammalian brain.  The back area primarily processes the external world, and, generally, as you move from the back to the front here, we become more and more human and the functioning becomes more complex.  Our ape friends must think we are really ugly because our brains have grown so enormous as to push our foreheads out kinda funny like. It really is a good thing.  It is the brain behind these large foreheads that allow us to be humans with complex thoughts, emotions, imaginations and problem solving skills.

The cerebellum is divided into two halves.  The left side usually houses the more analytical functions like math and writing skills while the right side is the more abstract and generally is where creative functioning is located.  Except on the head, the opposite side of the brain is in charge of the opposite side of the body.

Your brain is extremely complex.  It is much more sophisticated than the most expensive computer with all the latest whiz bang gadgets.  It contains more information than google.  The adult brain has about 100 billion nerve cells that branch out and connect at more than 100 TRILLION!! points called synapses.  I don't even know how many zeros that is.  This makes a dense, tangled up neuron forest - think Christmas lights.

Signals travel across the nerves and synapses as electric impulses carried by neurotransmitters.  The electrical activity of these signals is manifested in a brain wave.  In order for a brain to function optimally, brain waves need to be within a certain voltage range called amplitude.  Amplitude varies for different points in the brain and each point has a spectrum of wave ranges that serve different purposes.  Signals also have to be able to get through the neuronal maze quickly and with no road blocks.  This is connectivity. While specific parts of the brain do correspond to very specific functions, the brain is also global and operates as a whole.  It takes several regions of the brain cooperating and communicating to create a thought, feeling or sensation.

Because I used to not know how many nickels were in a dollar and many other similar things, I have deduced that my left brain was more damaged than my right, but my injury was global.  A quantitative EEG showed my amplitudes to be very low overall and my connectivity was like a bad cell phone connection.

For me, having to live out of my right brain was kinda good actually because it forced me to think more abstractly and creatively and imaginatively.  It shut down the pragmatic, pessimistic more realistic voices that had told me my whole life that "you can't!"  My brain injury allowed me to think, I believe, more openly and more positively.  The voices now said "Why not? Anything is possible." I have since come to believe that the mind and the brain are two seperate things entirely. Changing one allows you to change the other and vice versa, but that is a whole different blog.

Because the brain is very delicate, it is protected by the thick bones of the skull, but is still very susceptible to damage and must maintain a very sophisticated, intricate balance.  The most common forms of physical damage are closed head injuries such as a blow to the head or a stroke or exposure to neurotoxic chemicals.  Genetically based conditions, such as Parkinson's, multiple sclerosis or autism are a malfunction of the brain processes.  A number of psychiatric conditions are thought to be physically based in the brain.

Neurologists estimate that a person is aware of about 2,000 bits of information per minute.  As impressive as this is, your brain is actually processing 400 billion bits of information per minute.  Miraculously, the brain remains in control of each one and filters out what is not required to function at the present moment.  So even when you think you are not doing much of anything, you are doing a lot.

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