In2-MeC

Skopje, Macedonia
28 July 2004

Scientific Certainty
A Seminar by Dr. Don Key
Part Three

At the end of yesterday's seminar, I stated that we are coming to a major philosophical question: does the world outside our brain exist at all? In today's seminar we will take that up. But I feel a need to start off by clearing something else up. I want to tell you more about neurotransmission first.

Dr. Don Key, Professor of Religious Science, University of Vineland

I've already alluded to neurotransmission a number of times. I told you about signals being sent to the brain from the eye, and about these signals converging in the visual center at the rear of the brain. I told you that our visual experience is the brain's interpretation of these signals. My presentation was simplistic because I wanted to get the ball rolling. Now it's time to get into a little more detail.

Scientists are certain that without neurotransmission there would be no awareness, perception nor movement in the body. There are two means by which nerve impulses are transmitted: electrical means, and chemical means. (Since the chemical means involves a transference of electric charge, it can be called electro-chemical). Electrical transmission is considered the more primitive system, but it is still essential to the human organism. In this seminar I will discuss only chemical neurotransmission because it is the system employed by the organism for sense perception and thinking.

Essential to neurotransmission are the synapses. A synapse is a junction in the nervous system. There are junctions between neurons (nerve cells), and there are junctions between a neuron and a gland or muscle cell, called effectors because they initiate work signaled by the neuron. I will discuss only the first kind of junction since we are concerned with perceptive and cognitive brain functions, not motor nor gland functions. I'll add for information that the chemical means of neurotranmission involves a different type of synapse from the electrical means. Here I'll only talk about the chemical synapse. I mentioned already that in a chemical synapse, what is transmitted is also an electrical charge. The difference is that in a chemical synapse, electrically charged ions flow across a chemical bond that specially forms between two cells to complete the junction. In an electric synapse, ions flow from cell to cell through channels called gap junctions. Since electric synapses are used in organic functions outside the topic of this seminar, that's all I will say about them.

The five sense organs have receptor nerves that respond to data inputs from outside the body. These receptors organize the data before transmitting it onward to a data collector and regulator in the brain called the thalamus. This is a large mass of gray matter in the forebrain. The way data travels from each sense organ to the thalamus is called the sensory pathway. From nerve cell to nerve cell along the whole length of the pathway are the synapses. At every synapse data is reorganized in important ways. By the time it arrives at the thalamus, the data is far from being the original input that stimulated the receptors.

The thalamus transmits sensory data to appropriate areas of the cortex, the brain's wrinkled outer layer of gray matter. In these areas, data is processed and interpreted as experience. The thalamus is also where emotional and other responses to the data are regulated. Regarding the cortex, it is a "plastic" region of the brain. This means that, although specific areas of the cortex have been mapped by science as being the sites of specific processing and interpretation, this map can change. Other areas of the cortex are called association areas. Here data from the different senses is integrated. The result is what we call mental activity. It must be noted that researchers have not identified with precision how the brain collects messages from the sensory receptors, sifts them and arranges them to form a complete representation of the world and the individual's place in the world.

In any case, it is certain is that every step of the way, synaptic neurotransmission is involved. We know that what happens at the synapses shapes consciousness. For example, some hallucinogenic drugs that dramatically alter consciousness are known to change transmission at the synapses. But never mind the effect of drugs. As I pointed out, the synapses themselves greatly alter what is being transmitted from the senses before it reach the brain. This again raises the question of whether what we experience as "the world" inside our brain is a true representation of what is actually outside of us.

Here is a computer animation of a synapse performing neurotransmission. The gap between the two nerve endings is called the synaptic cleft. Of course, what you see here is greatly magnified. In reality, synapses are too small for the eye to see. The synaptic cleft is only about 0. 02 microns wide.

The previous animation made neurotransmission look quite simple. In fact it is a bafflingly complicated process. At higher levels of magnification we can get between the synaptic cleft and see the process of neurotransmission much closer. What you see in the next animation displays just a fraction of the stupendous complexity of a single nerve cell. It looks like the surface of a distant planet! Beneath the "sea" of the surface membrane you can see tiny organs called synaptic vesicles. These release a chemical substance called a neurotransmitter. This diffuses in quantum units across the cleft, which here looks like a gap between two worlds. The chemical neurotransmitter binds to molecules on the membrane of the opposite nerve ending. Electrically charged ions can then cross the gap. This changes the electric charge of the opposite membrane. If the change is great enough, that excites the opposite nerve cell to generate a new nerve impulse. The crossing of the synaptic cleft shown here takes one-half a millisecond.

It is too easy to compare electronic digital data transmission to neurotransmission. The resemblance between them is superficial. Computer technology is well-understood, being a product of human design. Brain technology is understood only sketchily. Speaking of the hardware (or "wetware" as it is often termed), it is a case of "the more we learn, the more we need to know. " About the software we can say next to nothing. We cannot even say whether the brain transmits data in binary numbers (in "on-off" pulses like Morse code, which is what modern computers do in a very sophisticated way). The data system of the brain, its values, its code, are unknown to us.

To put it in musical terms, each nerve cell performs an enormous "improvisation" upon the "theme" composed by the receptors in the sense organs. Neuron by neuron, improvisation by improvisation, data passes from the senses to the brain where it continues to be moved by neurons here and there. Finally it is blended with many other improvisations in a symphony of brain-experience. This final symphony is what know of as the world!

Now we can return to the question posed at the end of yesterday's seminar: does the world outside our brain exist at all?

The certain answer that science gives us is: there is no way we can know that.

In fact, scientific evidence can be used to make a strong argument that the answer is: no.

Does neurotransmission within the data processing and interpretation areas of the cortex only work with inputs coming from senses actively engaged with their objects? No. Each one of us is quite familiar with imagery created within the brain absent of any external stimulation. We experience such imagery every night in dreams.

When we sleep, the functions of the sense organs are in suspension. But that does not mean we have no perceptions. Though cut off from the external world, we perceive the brain-world and even perform activities there.

Is the brain imagery of dreams less real than the brain imagery we experience while awake? Subjectively, no. What we experience in a dream is just as real for us as what we experience in wakefulness.

From the wakeful point of view, which we suppose is more objective than the dream-state, we look back upon our dreams and generally dismiss them as fantastic fabrications of the mind. A standard argument is that the dream-world is fleeting, illogical and without a reliable basis. Rarely if ever does anyone dream night after night of one stable setting in which the dreamer has a regular position in relation to other clearly-defined entities. Each night, most of us seem to dream of a very different world from the one we dreamt of the night before. But we awake into the same world that was there when we got into bed. Therefore we can safely consider wakeful experiences to be real as compared to dreams.

This argument loses force when we take perspective into consideration. After all, we become dismissive of a dream only from the perspective of wakefulness. During the dream, it is real for us. Modern science has given us different perspectives from our "normal" one. Take your wakeful life on this planet and consider it from the macrocosmic perspective--from the standpoint of millions of light-years of universal space-time. Suddenly that life appears as fleeting as a dream. If you look at it from the microcosmic perspective--from the standpoint of the quantum wave-particles that make up what we perceive to be solid matter--suddenly that life loses its stable, logical foundation. Whatever perspective we adopt we cannot escape consciousness. As I have shown, our conscious experience happens inside the brain. All these perspectives are there and, practically speaking, nowhere else. This means they are as plastic as our cortical functions. Dreams bleed into wakefulness, wakefulness bleeds into dreams, logic bleeds into illogic and vice versa. The cosmic perspectives cannot be separated from the more mundane ones. And all of them cannot be separated from the brain.

Part Four of Dr. Don Key's seminar will follow soon!

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