Lecturer's Précis - Kussmaul (1878)

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First published online 13:43 GMT 22nd March 2002, Copyright Derek J. Smith (Chartered Engineer). This version [2.1 - link to graphic] dated 09:00 BST 30th June 2018


Kussmaul's (1878) Early Transcoding Diagram

Adolf Kussmaul (1822-1902) was a German physician who became interested in acquired language disorders in the period following the Broca (1861) publication. In his entry in Volume 14 of Von Ziemssen's "Cyclopaedia of the Practice of Medicine", he offered the following improvement on the Wernicke (1874) diagram. Students may detect visual similarities with the Wundt (1902) diagram, and concept similarities with the Freud (1891) diagram and modern transcoding models.

Kussmaul (1878): Here is Kussmaul's early transcoding model. The italicised letter codes (black) are Kussmaul's original scheme for navigating the diagram; the full word captions (green) are our own. We have omitted the flowlines serving the optical image centre (top right). Kussmaul's own explanation is included verbatim in the Appendix below.

If this diagram fails to load automatically, it may be accessed separately at




Redrawn from a coloured original in Kussmaul (1878:779). This version Copyright © 2002, Derek J. Smith.



Kussmaul, A. (1878). Disturbances of speech: An attempt in the pathology of speech. In Von Ziemssen, H. (Ed.), Cyclopaedia of the Practice of Medicine (Volume 14), London: Sampson, Low.


Appendix - Kussmaul's Original Caption

[To be read in conjunction with the black italicised single letter codes in the diagram.]

"The circle J designates the ideational centre or centre of conceptions, in other words all that portion of the cellular network of the cortex in which ideas are produced as a result of impressions of the most varied description made on the senses (object- and word-images).

B and B' are the sensory centres for word-images, B for the acoustic (sound-images), B' for the optical (text-images).

C and C' are the motor centres for the coordination of the sound-movements into spoken-words (C), and of the strokes produced in writing into written-words (C').

a is the acoustic nerve, o the optic. Each of these nerves is seen to divide into two branches, one of which, however, is indicated only by points for the sake of clearness - a b c b d is the collective acoustic motor track for spoken speech, o p q p r the optic motor track for written speech. The adjoining punctated [sic] lines and circles are intended to indicate that still other tracks lead from the nerves of sense through other image-centres to the centre for conceptions; the acoustic nerve, e.g., also conveys melodies, and delivers musical ideas and the sound attributes of object-images (song: the nightingale), the optic nerve brings gesture-images and physiognomic attributes (grimaces: the monkey). For the sake of clearness we leave out the tracks of the other nerves of sense, e.g., the nerve of taste, and the motor centres of co-ordination for all other voluntary expressions, except spoken and written words; the centre for pantomime is also left out.

a b d is the track for the imitative speech of children or parrots who repeat uncomprehended words; o p r is the track for the copying of uncomprehended words; c b d is the track for the utterance of the conceptions in spoken words; q p r for the writing down of the thoughts. The track c x q forms the connection between sound-images and text-images in the centre of conceptions, and renders feasible the change of spoken-signs into written-signs through the intervention of the thoughts.

b r and p d are the tracks between the centre for spoken-images and the motor centre for writing on the one side, and between the centre for written-images and the motor centre for speech on the other side. A person who writes down an uncomprehended word that he has heard, uses the track a b r; one who reads aloud an uncomprehended written word, uses the track o p d. In writing down dictated words that are understood, the longer track a b c b r is employed; in reading aloud written words that are understood, the track o p q p d.

Let us now examine with the aid of the diagram the phenomena of deaf-mutism and of the different dysphasic derangements.

The deaf-mute can never use the tracks a b c b d and a b c b r; they remain closed for him, because the acoustic entrance gate remains unopened. On the other hand, he can arrive at C' and C through o; he can thus learn to write and speak. He learns to transcribe without conceptive comprehension of the text by the path o p r, with conceptive comprehension by the path o p q p r. This, however, does not suffice to unlock and drill the centre C. For this purpose he must erect for himself an optical image -centre B'' for the sounds and words seen coming from the mouth of the speaker, and construct paths from u to z, and back through u to d. This centre B'' acts vicariously for B [].

In complete ataxic aphasia, C is no longer available, and hence the tracks b d and p d are also unserviceable. Spontaneous speech, repetition of words uttered by others, and the reading aloud of text, are impossible. The track a b c, for the comprehension of words heard, is preserved, as is also the track c b, by means of which the conception brings the sound-image into recollection." (Kussmaul, 1878:780-782; italics original.)