Emanuel Swedenborg's Investigations in Natural Science and the Basis for His Statements Concerning the Functions of the Brain

by Martin Ramström

that the fibres of the uppermost region led down to the posterior region of the spinal cord; (›ad posticam spinalis medullæ regionem›);[77]

that the fibres of the middle region, which were especially coarse and traversed the capsula interna and pons, forming thick tracts, could be clearly followed down into the anterior portion of the spinal cord, (›in anticam spinalis medullæ partem›), where they came into connection with the anterior origins of the spinal nerves, (›ad antica nervorum spinalium principia›), also paying, on their passing through the medulla oblongata, ›necessary tribute›, (›necessarium vectigal›), as it is expressed, to certain of its nerves;[78]——See the figure 4!——

that the fibres of the lowest region were distributed to certain nerves, which proceed from the medulla oblongata, and to some of the anterior origins of the spinal nerves (›quædam illius pars ad quosdam e Medulla oblongata prodeuntes, altera vero ad antica nervorum spinalium principia›).[79]

In Swedenborg’s time it was, however, known that the muscles which produce the movements of the head and face receive their nerves just from the medulla oblongata and the uppermost part of the spinal cord; and it therefore lay near at hand for Swedenborg, when he saw that paralyses arose when certain cortical regions were destroyed, to draw the conclusion, that the muscles and movements which belong to the face and head, depend more immediately upon the lowest region of the third lobe of the cerebral cortex.

And as it was also known that the muscles of the thorax and abdomen receive their nerves from the superior portion of the spinal cord, whither just the tracts of coarse fibres from the middle region of the brain could be followed, (see figure 4), so Swedenborg could likewise draw the conclusion from this that the muscles and movements which belong to the thorax and abdomen depend more immediately upon the middle region or lobe.

It might now appear tempting to continue the conclusion by connecting the remaining highest lobe and the lower extremity. But probably Swedenborg did not consider that he had sufficient ground for this. The description by Vieussens did not here furnish any suitable guidance, for it was possible that the coarse fibres of the middle region continued so far down into the spinal cord that they could innervate not only the muscles of the abdomen but also those of the lower extremity. For this reason Swedenborg refrains from localizing exactly the centre of motion of the lower extremity and contents himself with stating in general terms only that this centre might lie above that of the abdomen. He therefore says: ›the order seems to be so disposed that——the muscles and actions, which are in the ultimates of the body, or in the soles of the feet, depend more immediately upon the highest parts (of the brain)›, whereas concerning the thorax and abdomen he says that they depend upon the middle lobe, and of the head that it depends upon the third lobe. (›The Brain›, No. 68). I believe that this is the reason why Swedenborg’s doctrine of localizations as concerns the motor centre of the lower extremity is expressed in such vague terms.

From a comparison of these descriptions by Swedenborg and Vieussens we have found that there are such considerable similarities between them that they in many respects agree point for point. And it therefore seems to me rather probable that Swedenborg derived his conception of the more detailed localization of the soul’s activity from the descriptions of Vieussens.

THE ›CEREBELLULAR THEORY›.

But Swedenborg was not satisfied with knowing only that the psychical functions arise within certain regions of the cortex of the large anterior region of the cerebrum: but he continued his search for their inmost origin, and thus he came to the conviction that the psychical processes in reality result from the joint work which is performed by the minute cortical elements, which Swedenborg called ›Sphaerulae› or ›Cerebellula›, that is, the same bodies which we now call the cortical nerve-cells. These were the units of which the brain was in reality composed and out of which its actual esse was derived. (See ›The Brain›, No. 34). It was to these ›Cerebellula› that the sensory impressions went, and in these they were perceived and brought to consciousness; it was in these that conceptions, thoughts, judgments, conclusions, came into being. (Œc. R. A. II., No. 191, and ›The Brain›, No. 98). And this was possible because there were as many kinds of ›Cerebellula› as there were kinds of sensory impressions, and that these ›Cerebellula› were connected together into groups with different subdivisions. (Œc. R. A. II., No. 193; VII., chap. XX.). It was also from the ›Cerebellula› of the cortex that the determinations and impulses to the various movements of the body emanated. (›The Brain›, No. 99). And this was possible because the ›Cerebellula› cohered each with its own nerve-fibril, which in their turn innervated the muscle fibre, and that the ›Cerebellula› were arranged into groups, these into greater groups, these into convolutions (gyri), etc., corresponding to muscle fibres, muscles, groups of muscles, etc. (Œc. R. A. II., Nos. 146, 156, and ›The Brain›, No. 99). And it is in this connection that Swedenborg refers to experiments on animals by which it might be shown which gyre or part of convolution it is, which answers to this or that muscle in the body.[80]