Fig. 4. Reproduced from Vieussens: ›Neurographia universalis›, Tabula XVI. Illustrates the passage of the coarse fibres of the middle region of the brain’s medullary substance through the capsula interna, pons and the pyramids on the front of the medulla oblongata downwards to the anterior part of the spinal cord.
To the anterior region he attributed the actual operation of the soul, while he supposed that the posterior region was chiefly engaged in the animation of the blood. He adds, however, ›it cannot be denied that sensations reach even the posterior region of the brain, yet our mind does not become conscious of them to the same degree as it does in the anterior region› (›The Brain›, No. 71).
In this anterior region of the cerebrum he distinguished three lobes, or so called ›curiae›, the first one highest up, ›in the crown›, a middle one below it, and a third one lowest down, i. e., nearest to the fissure of Sylvius.[73] In these three lobes the actual psychic life is developed, and that so much the more clearly and perfectly, the higher up in the region these intricate processes occur. It is here that perceptions, thoughts, judgments, conclusions, come into being; it is from here that ultimately will and determination issue. (See ›The Brain›, Nos. 12, 66, 71, 88, 98, 100, 102).
As regards the sensory part of the psychic activity, Swedenborg does not make any attempt at a detailed localization; but as regards the motor functions he arranges their centres within the above-mentioned regions as follows: ›The muscles and actions which are in the ultimates of the body or in the soles of the feet seem to depend more immediately upon the highest parts (of the brain), upon the middle lobe the muscles which belong to the abdomen and thorax, and upon the third lobe those which belong to the face and head;› and he adds, ›for they seem to correspond to one another in an inverse ratio› (›The Brain›, No. 68).
Whence did Swedenborg get all this? Whence the whole of this doctrine of localizations? In his first great anatomical work, ›Œconomia Regni Animalis›, nothing is said about it; first in his last anatomical work, ›De Cerebro›, is it advanced, and then — — — quite finished! One is at first glance tempted to think that he had succeeded in finding some new clinical experiences, upon which he could found this doctrine. For he had not even finished the account of the function of the brain’s anterior region, before interjecting: ›Therefore, if this portion (the anterior region) of the cerebrum is wounded, then the internal senses—imagination, memory, thought—suffer; the very will is weakened, and the power of its determination blunted. This is not the case if the injury is in the back part of the cerebrum› (›The Brain›, No. 88). But afterwards he does not bring forward (in ›De Cerebro›) any observations which could serve as proof with regard to this. And if one examines the cases he has referred to in his preceding works, one cannot possibly arrive at the localization of the psychic functions which he has here (in ›De Cerebro›) sketched; for the evidence concerning the position of the injuries in the cortex are entirely too scanty and incomplete. But if we consult the original descriptions, we find there many other and more particular data than those quoted by Swedenborg when he was only concerned in explaining the function of the cortex as a whole. Wepfer, for instance, reports in his ›Historiæ apoplecticorum› concerning the woman seventy years of age, who suddenly lost the power of speech, that the cavity, filled with blood, which was found in the cortex at the autopsy, was located in the right hemisphere, just behind the forehead (›ad frontem fere antrorsum›), and that it extended rather far both backwards and upwards; even measurements were given (length 8, breadth 4, depth about 2 uncias). It was also stated that the blood-vessels whose bursting caused bleeding belonged to the antero-lateral branches of the carotid artery in the brain. It is also mentioned that no changes were found in the left hemisphere of the brain; and from the clinical account it appears that even after the stroke the woman was able to move the extremities of the right side.[74] — — — All this indicates quite evidently that the lesion of the cortex was situated in the anterior region of the brain!
And Pacchioni reports concerning the youth, who was afflicted with the right-sided facial paralysis, that even the extremities of the right side were somewhat paralysed, and that the cyst, which at the post mortem examination was found on the left hemisphere, extended from the crown to the region of the temple (›a capitis vertice in temporalem regionem›).[75] Thus this case also furnishes an unmistakable indication that the cortical lesion was situated in the anterior region of the brain.
It seems strange that Swedenborg did not here supply an account of these interesting and convincing cases, which he nevertheless, as we have seen, was well acquainted with. For his habit is to furnish the chapters of his works with an introduction in which he reports, often in very detailed form, the statements of the authors upon which he bases his conclusions. Since in the present case such an account is lacking, this may depend: either upon the fact that this last anatomical work of Swedenborg, ›De Cerebro›, was not quite completed and finally edited for the press, or thereon that Dr. Rudolf Tafel, who edited the translation which is now accessible in print, excluded it. For Dr. Tafel says in a note that the introduction to the chapter in question would be introduced into Part II., chapters 1 and 2, but—Part II. was never printed! Since, however, the Royal Swedish Academy of Sciences will publish ›De Cerebro› in its edition of Swedenborg’s Scientific works, this question will no doubt be cleared up. But this much is quite clear from what has already been adduced, that the cases of paralysis which Swedenborg previously quoted in a brief form are in the original descriptions reported so completely and in such detail that one can without the least doubt localize the cortical lesions reported in those cases in the anterior (superior) region of the cerebrum.
We now pass to an examination of the anatomical literature to which Swedenborg had access. And, as we shall find, we can here see whence Swedenborg derived material for his detailed doctrine concerning the function of the brain’s anterior region. This becomes evident on comparing Swedenborg’s mode of thinking of the brain’s psychical activity with the descriptions of preceding authors in anatomy.
The group of nuclei, ›corpus striatum›, in the cerebrum had been an object of special interest for preceding authors.