The Englishman, Thomas Willis, had for example in his ›Cerebri anatome› (published in 1667) portrayed them as a kind of junction, ›internodes›, by which the cerebrum coheres with the medulla oblongata; and he pays special attention to it on account of its peculiar structure (›The Brain›, No. 476); and he is said even to have attributed to them the ›Sens commun›.[76]
And the professor in Montpellier, Raimond Vieussens, had given in his ›Neurographia universalis› (published in 1685) a very exact description of the ›corpus striatum›, (not only of its ›superior nuclei›: ›Corp. striat. sup. ant.› = Nucleus caudatus and ›Corp. striat. sup. post.› = ›Thalamus opticus›, but also of its lower lateral nucleus = ›Nucleus lentiformis›) as also of the mighty medullary tract of nerve fibres, i. e., ›capsula interna›, which passes through the same, and which on the one hand is distributed to the brain, especially to its anterior (superior) region, and on the other hand by means of the nerves radiates into the various parts of the body.
(In order to facilitate orientation we may refer to C. Toldt: ›Anatomischer Atlas›, 1899, 8 Lieferung, Fig. 92: ›Querschnitt des verlängerten Markes und der Gehirnstiele. Verlauf der Pyramidenbahn von der Pyramidenkreuzung an durch die Pyramide, die Brücke und die Basis des Grosshirnstiels in die innere Kapsel, woselbst sie in den Stiel des Stabkranzes, Pedunculus coronæ radiatæ, eingeht.›)
Swedenborg, who had studied and often quoted both Willis and Vieussens, likewise attributed a very great significance to the corpus striatum. All the sensory impressions pass through it to the brain, and all the voluntary impulses to motion pass out by the same path. (›The Brain›, No. 67). ›It is›, says he in his figurative way, ›in a certain sense, the Mercury of the Olympus; it announces to the soul what is happening to the body, and it bears the mandates of the soul to the body› (›The Brain›, No. 67).
And as the corpus striatum lay most immediately under the anterior (superior) region of the brain, and was in close connection with it, so the sensory impressions would for the most part pass to this region, and the voluntary impulses to motion would likewise proceed from it (›The Brain›, Nos. 66, 67).
The same Vieussens had furnished a very detailed description of the passage of the nerve tracts in question, which pass through the corpus striatum and capsula interna, and had followed them both upwards towards the hemispheres of the brain and downwards towards the spinal cord. When he followed them upwards, he found that they formed three regions in the ›centrum ovale›: the regio superna, highest up nearest the crown, the regio media, in the middle, and the regio infima, lowest down, and consequently nearest the fissure of Sylvius. (R. Vieussens: ›Neurographia univ.›, pp. 115 and 117).
In these regions of the cerebral medulla, especially in the highest, Vieussens considered that the soul’s activity had its seat: with the help of ›spiritus animalis› the soul here had an opportunity of receiving the sensory impressions, and in the fine and finest nerve fibres there were here formed sensory images, conceptions, (Op. cit. p. 129), here the memory images were preserved, (Op. cit. p. 135), and here the faculty of judgment had its seat, (Op. cit. p. 137), etc.
In these regions, especially in the highest, the will also had its seat and origin, and at its command the ›spiritus animalis› streamed out through the nerves, thus conveying the impulses to motion to the various muscles of the body. (Op. cit. pp. 122, 123, 188, et seqq.).
For Swedenborg, who had arrived at certainty with regard to the seat of the soul’s activity in the cerebral cortex, and not in the cerebral medulla!, and who through Malpighi and others had been led to see that the fibres of the cerebral medulla were continuations of the processes of the cortical elements,—for Swedenborg it naturally lay very near at hand to follow the fibres of the three regions of Vieussens out to the cortical substance on the surface of the brain; and so Swedenborg has his three cortical lobes! And to them, especially to the highest, he could now attribute the source of the soul’s life.
When Vieussens followed the nerve tracts of the corpora striata and capsula interna downwards, he found: