Popular Science Monthly/Volume 24/April 1884/The Faculty of Speech
| THE FACULTY OF SPEECH.[1] |
By E. F. BRUSH, M. D.
UNTIL the beginning of this nineteenth century, the mind was considered as a unit. Early in the century, Gall, a distinguished German physician, noted the fact that those students whose super-orbital plates were depressed sufficiently to produce protruding eyes and baggy under-lids excelled in memory, oratory, philology, and the ability to acquire languages. This observation may be called the foundation of phrenology, for it led Gall to divide the mind into faculties, and to locate the faculty of speech in the anterior lobes of the cerebral hemisphere. This was the basis of his system. But the enthusiasm with which he constructed this system, and the sweeping deductions which he and his follower, Spurzheim, drew from this one prominent fact, failed to interest the scientific mind. Soon after this, without paying any regard to the conclusions of Gall and Spurzheim, the pathologists discovered how frequently the loss of speech co-existed with diseases or injuries of the anterior lobes of the brain, and that sometimes the only symptom of cerebral lesions was a loss of the power of articulate language. These observations led Bouillaud, in 1825, to divide the faculty of speech into two phenomena, internal speech—the faculty to create and to represent ideas—and external speech, or the co-ordinating power necessary to articulate the words created. In medical literature, the loss of the faculty of speech is termed aphasia, and when it affects the internal speech it is designated as amnesic aphasia, and when external speech is affected the term ataxic aphasia expresses it.
But without going into detail respecting the weighty pros and cons in the discussion of this subject during the last fifty years up to the present time, it is safe to state that the power of speech is twofold, namely, mental and motor. Now, as a mental fact, the faculty of articulate language implies perception, intellectual distribution of perception, excitation of emotion, will to enunciate. As an illustration: we see a man across the street; we recognize him as John Jones, from Johnsonville; we experience pleasure, and say, "My dear friend, I am glad to see you." Thus it will be seen that the mind as regards speech can be divided into perception, intellect, emotion, and will. These are the mental attributes, and the impairment of any one of them will interfere with the culminating act of speech. The perception may be impaired, then the friend across the street would not start the mental train. Furthermore, if perception was perfect and the intellect impaired, we would see the man, perceive the color of his hair and eyes, the style of his clothing, and so forth, but not be conscious that we had met him before, and that he was a friend. Still further, if the emotion was impaired and the two other faculties normal, we would see the man, know he was a friend, but not be stimulated to further action. Again, if the three above faculties were normal and will-power wanting, we would see, recognize, and wish to speak to him, but be powerless to do so. All the best evidence of recent times indicates that these faculties reside in the gray matter which is spread over the surface of the cerebral hemispheres, with their manifold sulci and convolutions, and the depth of which is an index of the intellectual power, rather than the mere mass of the brain, as was previously supposed. Now, this gray matter may be intact and, consequently, all the functions above enumerated may be perfect, and still the ability to articulate may be wanting, because the motor power which is supposed to reside in the white matter, and to preside over the co-ordinating power, controlling the nerves and muscles of articulation, may be impaired, and then, although our ideas may be correct, the ability to express them would be wanting. Medical literature abounds with cases which illustrate this condition. I select the following instance as a perfect illustration of this state: An intelligent man, sixty years old, suddenly became incoherent and quite unintelligible to those around him. He had forgotten the names of every object in nature; his recollection of things seemed to be unimpaired, but the words by which men and things were designated were entirely obliterated from his mind, or rather he had lost the faculty by which they were called up at the control of will. He was, however, by no means inattentive to what was going on, and he recognized friends and acquaintances quickly, but their names, or even his own, or his wife's name, or the names of any of his domestics appeared to have no place in his recollection. One morning, much against the wishes of his family, he went to his workshop, and, when visited by his physician, gave him to understand by a variety of signs that he was perfectly well in every respect, with the exception of some slight sensations referable to the eyes and eyebrows. He was so well in bodily health that he could not be confined to the house, and his judgment, so far as an estimate could be formed of it, was unimpaired, but his memory of words was so much a blank that the monosyllables of affirmation and negation were the only two words of the language the use and signification of which he never entirely forgot. He comprehended perfectly every word that was spoken or addressed to him, and, although he had ideas adequate to form a full reply, the words by which these ideas are expressed seemed entirely obliterated from his mind. By way of experiment, the name of a person or thing was mentioned to him, his own name for example, or that of one of his domestics; he would repeat it once or twice distinctly, but generally before he could do so a third time the word was gone from him as completely as though he had never heard it pronounced. When any one read to him from a book he had no difficulty in perceiving the meaning of the passage, but he could not himself then read. He had forgotten the elements of written language. He became very expert in the use of signs, and his convalescence was marked by his imperceptibly acquiring some general terms which were with him at first of very extensive and varied application. All future events and objects before him were, as he expressed it, "next time"; but past events and objects behind him were designated "last time." One day being asked his age, he pointed to his wife and uttered the words "Many times" repeatedly, as if he meant that he had often told her his age. When she said "Sixty," he answered in the affrmative. Some months afterward he suddenly became paralyzed on the right side, and a few months later died from an attack of apoplexy. His brain was found extensively diseased in the white portion of the anterior lobe of the left hemisphere.
This case was purely and simply an impairment of external speech. On looking over the medical literature on the subject I have been unable to find as striking a case of impairment of internal speech, and this fact can be readily understood when we consider that a lesion necessary to produce this condition would be a destruction of the gray or cortical matter of the brain, and when this is injured the whole intellect becomes disjointed, as we see in the maniac, where the simple mechanical power of speech is perfect, but the incoherency and the wrong interpretation of external impressions are evident. I have said that these cases of the derangement of the faculties of internal speech are chiefly found in lunatic asylums. But, when I think, I remember to have met many mild cases outside of asylums, cases which can be best described by our Americanism of "talking too much with their mouth."
I have said the faculty of speech resides in the anterior lobes of the brain. But the evidence gleaned from pathology is convincing that the faculty is confined to a comparatively limited portion of the frontal lobe of the left cerebral hemisphere. This localization of a function to a single side of the brain is a curiously interesting fact. But when it is known that the left side of the brain presides over the motions and sensations of the right side of the body, it may be conceived that because we are right-handed we are left-minded. Why we are right-handed involves a discussion which would be beyond the limits of the present essay. But that the left side of the brain is almost always larger than the right is a well-known fact, and this asymmetry of the encephalon was prominently brought before the public during the Guiteau trial, with its prominent, ghastly rhombo-cephalic.
A curiously complicated and wonderful adaptation is this faculty of speech, sometimes bearing weighty loads of truth, at other times the veriest dregs of gorged society—words, windy words. The highest and best result of education is to form our ideas into words, to crystallize them into speech. We all feel that here we fail. Our thoughts well up and almost burst their limits, but faulty speech will not give the color and glow which the soul infuses into the thoughts. We can all say with the poet:
"Our whitest pearls we never find,
Our ripest fruit we never reach;
The flowering moments of the mind
Drop half their petals in our speech."
- ↑ Read at a meeting of the Mount Vernon Athenaeum, January 24, 1883.