Brain Action during Study : Part 1

How to Use Your Mind
by Harry D. Kitson, Ph.D.

(Page 4 of 17)

Though most people understand more or less vaguely that the brain acts in some way during study, exact knowledge of the nature of this action is not general. As you will be greatly assisted in understanding mental processes by such knowledge, we shall briefly examine the brain and its connections. It will be manifestly impossible to inquire into its nature very minutely, but by means of a description you will be able to secure some conception of it and thus will be able better to control the mental processes which it underlies.

To the naked eye the brain is a large jelly-like mass enclosed in a bony covering, about one-fourth of an inch thick, called the skull. Inside the skull it is protected by a thick membrane. At its base emerges the spinal cord, a long strand of nerve fibers extending down the spine. For most of its length, the cord is about as large around as your little finger, but it tapers at the lower end. From it at right angles throughout its length branch out thirty-one pairs of fibrous nerves which radiate to all parts of the body. The brain and spinal cord, with all its ramifications, are known as the nervous system. You see now that, though we started with the statement that the mind is intimately connected with the brain, we must now enlarge our statement and say it is connected with the entire nervous system. It is therefore to the nervous system that we must turn our attention.

Although to the naked eye the nervous system is apparently made up of a number of different kinds of material, still we see, when we turn our microscopes upon it, that its parts are structurally the same. Reduced to lowest terms, the nervous system is found to be composed of minute units of structure called nerve-cells or neurones. Each of these looks like a string frayed out at both ends, with a bulge somewhere along its length. The nervous system is made up of millions of these little cells packed together in various combinations and distributed throughout the body. Some of the neurones are as long as three feet; others measure but a fraction of an inch in length.

We do not know exactly how the mind, that part of us which feels, reasons and wills, is connected with this mass of cells called the nervous system. We do know, however, that every time anything occurs in the mind, there is a change in some part of the nervous system. Applying this fact to study, it is obvious that when you are performing any of the operations of study, memorizing foreign vocabularies, making arithmetical calculations, reasoning out problems in geometry, you are making changes in your nervous system. The question before us, then, is, What is the nature of these changes?

According to present knowledge, the action of the nervous system is best conceived as a form of chemical change that spreads among the nerve-cells. We call this commotion the nervous current. It is very rapid, moving faster than one hundred feet a second, and runs along the cells in much the same way as a "spark runs along a train of gunpowder." It is important to note that neurones never act singly; they always act in groups, the nervous current passing from neurone to neurone. It is thought that the most important changes in the nervous system do not occur within the individual neurones, but at the points where they join with each other. This point of connection is called the synapse and although we do not understand its exact nature, it may well be pictured as a valve that governs the passage of the nervous current from neurone to neurone. At time of birth, most of the valves are closed. Only a few are open, mainly those connected with the vegetative processes such as breathing and digestion. But as the individual is played upon by the objects of the environment, the valves open to the passage of the nervous current. With increased use they become more and more permeable, and thus learning is the process of making easier the passage of the nervous current from one neurone to another.

We shall secure further light upon the action of the nervous system if we examine some of the properties belonging to nerve-cells. The first one is _impressibility_. Nerve-cells are very sensitive to impressions from the outside. If you have ever had the dentist touch an exposed nerve, you know how extreme this sensitivity is. Naturally such a property is very important in education, for had we not the power to receive impressions from the outside world we should not be able to acquire knowledge. We should not even be able to perceive danger and remove ourselves from harm. "If we compare a man's body to a building, calling the steel frame-work his skeleton and the furnace and power station his digestive organs and lungs, the nervous system would include, with other things, the thermometers, heat regulators, electric buttons, door-bells, valve-openers, - the parts of the building, in short, which are specifically designed to respond to influences of the environment." The second property of nerve-cells which is important in study is _conductivity_. As soon as a neurone is stimulated at one end, it communicates its excitement, by means of the nervous current, to the next neurone or to neighboring neurones. Just as an electric current might pass along one wire, thence to another, and along it to a third, so the nervous current passes from neurone to neurone. As might be expected, the two functions of impressibility and conductivity are aided by such an arrangement of the nerve-cells that the nervous current may pass over definitely laid pathways. These systems of pathways will be described in a later paragraph.

The third property of nerve-cells which is important in study is _modifiability_. That is, impressions made upon the nerve-cells are retained. Most living tissue is modifiable to some extent. The features of the face are modifiable, and if one habitually assumes a peevish expression, it becomes, after a time, permanently fixed. The nervous system, however, possesses the power of modifiability to a marked degree, even a single impression sufficing to make striking modification. This is very important in study, being the basis for the retentive powers of the mind.

Indiana University, 1921