BRAIN ACTION DURING STUDY
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.
Having examined the action of the
nervous system in its simplicity, we have now to examine
the ways in which the parts of the nervous system
are combined. We shall be helped if we keep to
the conception of it as an aggregation of systems
or groups of pathways. Some of these we shall
attempt to trace out. Beginning with those at
the outermost parts of the body, we find them located
in the sense-organs, not only within the traditional
five, but also within the muscles, tendons, joints,
and internal organs of the body such as the heart,
and digestive organs. In all these places we
find ends of neurones which converge at the spinal
cord and travel to the brain. They are called
sensory neurones and their function is to carry
messages inward to the brain. Thus, the brain
represents, in great part, a central receiving station
for impressions from the outside world. The nerve-cells
carrying messages from the various parts of the body
terminate in particular areas. Thus an area in
the back part of the brain receives messages from
the eyes; another area near the top of the brain receives
messages from the skin. These areas are quite
clearly marked out and may be studied in detail by
means of the accompanying diagram.
There is another large group of nerve-cells
which, when traced out, are found to have one terminal
in the brain and the other in the muscles throughout
the body. The area in the brain, where these neurones
emerge, is near the top of the brain in the area marked
Motor on the diagram. From here the fibers
travel down through the spinal cord and out to the
muscles. The nerve-cells in this group are called
motor neurones and their function is to carry
messages from the brain out to the muscles, for a
muscle ordinarily does not act without a nervous current
to set it off.
So far we have seen that the brain
has the two functions of receiving impressions from
the sense-organs and of sending out orders to the
muscles. There is a further mechanism that must
now be described. When messages are received
in the sensory areas, it is necessary that there be
some means within the brain of transmitting them over
to the motor area so that they may be acted upon.
Such an arrangement is provided by another group of
nerve-cells in the brain, having as their function
the transmission of the nervous current from one area
to another. They are called association
neurones and transmit the nervous current from
sensory areas to motor areas or from one sensory area
to another. For example, suppose you see a brick
falling from above and you dodge quickly back.
The neural action accompanying this occurrence consists
of an impression upon the nerve-cells in the eye, the
conduction of the nervous current back to the visual
area of the brain, the transmission of the current
over association neurones to the motor area,
then its transmission over the motor neurones,
down the spinal cord, to the muscles that enable you
to dodge the missile. The association neurones
have the further function of connecting one sensory
area in the brain with another. For example,
when you see, smell, taste and touch an orange, the
corresponding areas in the brain act in conjunction
and are associated by means of the association
neurones connecting them. The association
neurones play a large part in the securing and
organizing of knowledge. They are very important
in study, for all learning consists in building up
associations.
From the foregoing description we
see that the nervous system consists merely of a mechanism
for the reception and transmission of incoming messages
and their transformation into outgoing messages which
produce movement. The brain is the center where
such transformations are made, being a sort of central
switchboard which permits the sense-organs to come
into communication with muscles. It is also the
instrument by means of which the impressions from
the various senses can be united and experience can
be unified. The brain serves further as the medium
whereby impressions once made can be retained.
That is, it is the great organ of memory. Hence
we see that it is to this organ we must look for the
performance of the activities necessary to study.
Everything that enters it produces some modification
within it. Education consists in a process of
undergoing a selected group of experiences of such
a nature as to leave beneficial results in the brain.
By means of the changes made there, the individual
is able better to adjust himself to new situations.
For when the individual enters the world, he is not
prepared to meet many situations; only a few of the
neural connections are made and he is able to perform
only a meagre number of simple acts, such as breathing,
crying, digestion. The pathways for complex acts,
such as speaking English or French, or writing, are
not formed at birth but must be built up within the
life-time of the individual. It is the process
of building them up that we call education. This
process is a physical feat involving the production
of changes in physical material in the brain.
Study involves the overcoming of resistance in the
nervous system. That is why it is so hard.
In your early school-days, when you set about laboriously
learning the multiplication table, your unwilling
protests were wrung because you were being compelled
to force the nervous current through new pathways,
and to overcome the inertia of physical matter.
Today, when you begin a train of reasoning, the task
is difficult because you are opening hitherto untravelled
pathways. There is a comforting thought, however,
which is derived from the factor of modifiability,
in that with each succeeding repetition, the task
becomes easier, because the path becomes worn smoothly
and the nervous current seeks it of its own accord;
in other words, each act and each thought tends to
become habitualized. Education is then a process
of forming habits, and the rest of the book will be
devoted to the description and discussion of habits
which a student should form.