© Dr. Chris Schriner 2005
Mission Peak Unitarian Universalist Congregation
November 20, 2005

The poet, Walt Whitman, wrote, "I am large. There is a multitude within." If you attended the first sermon in this series, I hope you are already convinced that there is indeed a multitude of abilities and possibilities and perhaps even personalities within your own brain. But it's easy to underestimate the awesome capacities that are sandwiched between our ears. Once when I gave a talk on brain science, someone asked me afterward, "Chris, don't you think there's more to people than just our little brains?" Well, there may be more to people than their brains, but those who consider the brain "little" just don't get it. The brain is a very big place in a very small space.

The basic building block of brain power is the connections between nerve cells. Your brain contains one hundred trillion of those connections, and the number of ways these cells could be connected is far, far greater than the number of sub-atomic particles in the entire universe. That's why the human mind can do things that seem like magic and miracles.

In the first sermon my goal was to convince you that your brain is amazing. Today I will talk about how understanding the brain helps us cope with everyday life. And in the third sermon, I speculate about how brain science might revolutionize religion.

So how can learning about neuroscience help us cope with everyday life? Well, first of all, it is very useful to realize that the mind is something physical, at least in many respects. That means that if I want to change my mind, I need to do physical work, as if I were digging a ditch or renovating a kitchen. We have got to get over the idea that we can alter the way our minds work just by wishing they would change. Modifying the mind is more like sculpting a statue out of a block of stone than like turning a light switch off and on. It takes effort and persistence.

It is also important to recognize that my brain creates what is reality for me. It assembles my universe. And it does this using patterns of neural activity. One neuron fires and sends a signal to thousands of other nerve cells, and these send signals to thousands more, forming a specific pattern. It's like a kaleidoscope. Each turn of the kaleidoscope gives us a unique experience. One brain-pattern might be a visual experience of a bright red slice of watermelon. Another pattern might be the ice-cold sweetness of the melon when you savor that first delightful bite. Still another configuration of the mental kaleidoscope might be a memory of a picnic last summer when you were also eating melon.

We are starting to learn about the specific neural patterns that constitute experiences such as sights and sounds. And scientists have even been able to hook up electrodes to individual neurons in laboratory animals, to see how they contribute to our experiences.

So the brain creates our version of reality, through complex patterns of nerve-connections. And we need to realize that the inner world which the brain creates is not the same as the outside world. We reshape reality for our own purposes.

Suppose we are looking at an object that is equally bright all over its surface. To us it will seem brighter at the edges and at the corners than in the middle. The nervous system brightens up edges and corners, to make it easier to tell one thing from another. How convenient to see a universe of specific objects that stand out from each other, instead of one big homogenous blob of atoms in motion.

Below is an example of the way the brain creates our version of reality - a diagram that seems to have a white triangle in the center, with the apex pointing upward. But there is no white triangle! We make up the triangular shape in our minds, out of bits and pieces of other shapes in this diagram.

The brain also manufactures its own version of reality in more complicated matters, such as our political opinions. Some scientists believe "that people's gut-level reaction to issues like the death penalty, taxes and abortion is strongly influenced by genetic [patterns]" which are physically etched into their brains. Several studies have shown "that people's general approach to social issues - more conservative or more progressive - is influenced by genes." (Benedict Carey, New York Times, 6/21/05, p. F1)

Whether we're talking about the way an object looks or the way we feel about war and peace, we can only know the reality which is presented to us by our cerebral servant. But most people think that the story we make up about the world is just the way things are. I have pointed out that this is a lot like Biblical fundamentalism, the idea that God's word is revealed in the Bible in a clear and obvious way. All of us, including Unitarian Universalists, are susceptible to what we could call experiential fundamentalism - whatever I experience is The Truth.

Here's the bottom line: I am learning not to take my brain's version of reality so seriously. So much of what I think is important is just a great big game that I'm playing with life. I need to let go of so much of this fantastical story that I have written for myself, to strip back down to what I can know with confidence: I know I am here, and so are you, and we need to work together to make our world a better place.

The brain also creates reality for us by forming our memories. And the basic process is fairly simple. Neurons that fire together wire together. What does this mean? Well, when a nerve cell is activated so that an electrical impulse flows through it, we say that it has "fired." When groups of neurons that are connected with each other fire at the same time, this wires them up more tightly so they are more likely to do that again. Suppose you're looking at our flaming chalice.

You experience the way the chalice looks because some particular constellation of nerve cells is firing in a certain way. The longer you look at it, the more you strengthen the connections between those cells that represent the experience of seeing the chalice. As a result, if you think about the sermon later today, the same cluster of cells may all decide to hold hands with each other again. If so, an image of the chalice will pop into mind.

Even though we speak of memories as being "stored" in the brain, they are not stored like papers in a filing cabinet. They are only "stored" in the sense that a bunch of nerves which once were connected by firing at the same time are more likely to fire together again later on.

All of us know that repetition is a key to making memories, so that if we want to learn some fact it helps to say it over and over. This works because we are causing our neurons to be linked over and over in the same pattern. As an English teacher once told his college freshmen, "Say a word three times, and it will be yours forever." A young fellow in the back was heard to murmur, "Jennifer, Jennifer, Jennifer."

We need to practice forming memories, and but we also need to practice retrieving memories. Nowadays I actively practice recollection. If something pops into my mind and then falls right out, I don't just give up and say, "Oh, well." I stop and see if I can dredge up what I'm searching for. This exercises the recollection-system that runs through the hippocampus and other memory-related structures. It's almost as simple as building strong biceps through repeated exercise.

A recent episode of Brian Crane's comic strip, "Pickles," talks about a phenomenon called muscle memory. A little boy named Nelson comes to his grandfather with a long pencil:

"Nelson: Grampa, can you sharpen my pencil with your pocketknife?
Grampa: Sure. [whittle whittle ...]
Nelson: Wow, how can you do it so fast?
Grampa: It's called 'muscle memory,' Nelson. You see, if you so something over and over, your muscles learn how to do it all by themselves. After a while you don't even have to use your brain anymore. Pretty amazing, huh? [He gives Nelson his pencil back, and now it's sharp ... but short!]
Nelson: Yeah ... [looking down at small stub of a pencil] But I think I like it better when you use your brain too. (The Argus, Sunday Comics, 11/13/05)

Of course, in muscle memory it is not really the muscles that remember how to move. Patterns are laid down within the brain that then tell the muscles what to do, and when we form a muscle memory, parts of the brain actually change shape.

You can see this in the diagram below which shows a part of the brain before and after a monkey was given a task that used its second and third fingers.

After three months of using these two fingers a lot, the brain space devoted to these fingers had increased, and you can see obvious changes in the diagram, before and after. So if you learn a new sport or a new language, the size and shape of parts of your brain literally change as a result. That's why practice makes perfect.

Below is another diagram that shows a shape within the brain - a drawing of a little person. (Scientific American, September, 1992, p. 85)

This is an artist's rendering of a collection of neurons called the somatosensory homunculus, which is a brain map of sensory input. This diagram shows the relative size of the areas of the brain that receive sensory input from each point on the body. Look at those big lips. We use our lips for important purposes - eating, talking, and kissing - so a lot of brain space is devoted to mapping sensory input from the lips. (You may also notice that this individual is lacking a certain organ, one which actually would be rather large had it been included. Isn't it odd that with so much blatant sexual display in our society, a magazine like Scientific American would show vestiges of prudishness?)

So we are learning about how the nervous system creates sensory experiences, how it stores memories, and how it is organized. We are also learning how it creates emotions and moods. For example, researchers have located pleasure centers inside our heads. When rats are hooked up so that they can stimulate the ecstacy center by pressing a lever, they will continue to press the pleasure button - until they die of starvation! They are so hooked on feeling good that they won't stop to eat. Right now scientists are working on a medication to help stop compulsive gambling by modifying the way the pleasure-center operates. (San Francisco Chronicle, 10/23/05, p. A16.)

Scientists are also charting the anatomy and chemistry of displeasure. You probably know that certain biochemical problems cause depression, and that antidepressants sometimes provide a relief that seems almost magical.

Just last week Rutgers researchers reported finding a gene in mice that causes fear reactions. (The Argus, November 18, 2005, News 8) And the lack of a chemical known as 5-HIAA may be involved in extremely severe depression. In one study, researchers noticed that a high percentage of deeply depressed people had abnormally low levels of 5-HIAA. The scientists followed up on these patients two years later. To their horror, one fourth of the low 5-HIAA people were dead, as a result of successful suicide. So many decisions are partly based on our own biochemistry, ranging from what we order for lunch to whether we do ourselves in. How tragic to be killed by a chemical hiccup.

We are learning a lot about the neurology of people with mental illnesses such as schizophrenia. For example, in most people a surprising event such as a sudden and unexpected sound produces a brain wave known as the P-300. (The Harvard Medical School Mental Health Letter, date unknown) If I suddenly clap my hands (like this!) you will experience the cerebral tingle of the P-300. In many schizophrenic patients, the P-300 is delayed, weaker, and particularly feeble in the left temporal lobe. Apparently people with this illness do not process surprising events quickly and easily. (But please don't use the hand-clap test for self-diagnosis. If your P-300 seemed weak, maybe you're just a little sleepy this morning.)

One more thing we are discovering about the three-pound universe within our heads - it doesn't always work to boss our brains around like a general giving orders to an army. Despite the title of my sermon, the brain is not really our servant, nor should it be our master, pulling our strings as if we were puppets. It's hard to make our brain obey orders, because the brain is more decentralized than we once thought. It is more like a federation than a monarchy. If we could easily rule our own neurons, we could effortlessly eliminate a destructive style of thinking or keep our thoughts focused in a certain way. But eliminating a habitual thought pattern can take years. And as we discover when learning to meditate, most of us cannot precisely control our thoughts for more than a few seconds.

I suggest that we replace the idea that one part of the brain dominates another with a more cooperative model, so that all facets of the mind serve and support each other. For example, neuroscience suggests a way to stop procrastinating and get started on a project you have been avoiding. All you need to do is activate a brain system that is interested in the project. If I don't want to start writing a sermon, I can just get out a book that deals with my sermon topic and start thumbing through, reading chapter headings and little bits of text. Soon it's as if I've sounded the trumpet for Reveille and hundreds of little teams of neurons have awakened. Then I let them begin outlining the sermon.

Thanks to thousands of mostly-unknown scientists, we are finally getting to know what is inside our heads. We now see that changing our minds means changing a physical structure, as if we were sculpting a statue. We are learning how our brains create our version of reality, and this can help us give up experiential fundamentalism - the way the world seems to me is just how it is. We know more about how memories are created and retrieved. What you wire together today will fire together tomorrow. We are discovering physical reasons why we feel happy and sad, and what goes wrong in mental illness. We need to admit that the conscious mind cannot be an all-powerful dictator that pushes the rest of the brain around. We need to facilitate collaboration among all of our many selves.

In this season of Thanksgiving, let us be thankful for this marvelous mind-machine that is like absolutely nothing else we know of in the universe.

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