Memory
It is evident that some of the physical mechanisms that are employed
for the lower grade mental processes at least can be explained on the
neuroglia theory. Memory we share to a great extent with the animals,
and for this the physical processes can be rather interestingly
studied. We have all had the experience of being unable to recall a
word when we wanted it. Commonly the word is a proper name with which
there are n
t many direct connecting ideas, so that, somehow, we seem
unable to trace the word to its depository in the brain. Occasionally
we are sure that we know the first letter of the word. Sometimes we
are able to name this letter, and, if we do so, the rest of the word
will usually turn up a moment later. At times, however, the word fails
to come and we grope for it. Then if we stop deliberately seeking it,
the word will often after a longer or shorter time, come up
spontaneously.
This experience is familiar to everyone. It is especially frequent
with public speakers. Certain words have a habit of slipping away just
when we want them. At times by beginning a sentence confidently,
even though there is a feeling that there is a missing word ahead, the
word will turn up in time. Often it will not, and then a weak
circumlocution must be indulged in. If it is a proper name, a
description may have to be substituted, sometimes a confession may
have to be made that the name will not come and the audience, unless
it is very young, will sympathize with the speaker.
If we accept the idea that the memory has a definite location in the
brain, the process is easily understood. Just how we cannot say, but
somehow brain cells serve as the media by which our memory processes
revert to knowledge that has been previously stored up. If now we
assume that the repetition of things known is accomplished by bringing
brain cells into connection with one another, and with the organs of
speech, it is easy to understand that somehow the connection with a
particular cell or set of cells cannot be secured at a given moment.
This delay prevents us from being able to repeat things that we know,
and know that we know, though we cannot somehow get at them. The will
fails to reach the proper insulating plug of a neuroglia cell, which,
if acted upon, would put a cell or group of cells in communication
with others. As a result the message from it cannot flow down. We feel
that we have it on the tip of our tongue, as we say, that a little
effort may bring it to us and sometimes that effort succeeds. If there
is any disturbance of consciousness by secondary motives, however, as
by the excitement of public speaking or the flustering that comes to
some people when they try to introduce even old-time friends and
forget their names, then we cannot control the brain processes and
memory fails. We do not for a moment think of attributing this failure
of memory to the faculty of memory itself. We have the feeling that
there is some mechanical obstacle. Ramon y Cajal's theory enables us
to understand this obstacle better, perhaps, than any other.
An interesting phase of this lapse in memory helping us to a
revelation of something of the physical process which underlies the
faculty, is the fact that it implies a very intricate machine.
Recalling has become such an obvious incident that we do not think of
the complexity of action involved. Many things are brought together,
and relations of all kinds serve to recall various facts and names and
dates. Some of these relations are most bizarre. Particular names
recall a definite series of facts. A color will bring up a scene or
the memory of an individual. An odor will recall scenes long since
apparently forgotten and will set trains of thought at work that are
quite unexpected. Sometimes we wake in the morning with a name or a
fact on our lips that we have been looking for for several days.