Zwangsmässige Lichtempfindungen durch Schall und verwandte Erscheinungen auf dem Gebiete der anderen Sinnesempfindungen

Abstract

As the authors (two medical students of Zürich) were conversing on chemistry in the autumn of 1878, Bleuler beiig asked what was the appearance of cetones (substances of which acetone or naphtha is the type), got out of the difficulty at once by saying, “They are yellow, because their name contains an o.” Lehmann, astonished, inquired what such an apparently absurd answer meant, and then found that from childhood Bleuler, on hearing, or even thinking of any vowel or word, immediately saw a colour, and that many of his relatives were in the same condition. Such was the origin of this investigation, and it is remarkable for having been carried on by one who always saw the colours (Bleuler) and one who never saw them (Lehmann). Such appearances of colour generated by sound are here called photisms, while sensations of sound generated by colour are termed phonisms, and both are called “secondary sensations or perceptions,” the authors not knowing exactly in which category to place them. The authors have examined 596 persons (383 men and 213 women), and found among them 76 “positive” (that is, capable of seeing photisms), and 520 “negative” (that is, incapable of seeing photisms). This proportion is about 1 to 7. Particulars of the examinations of all are given. The photisms for the same sounds differ much from individual to individual, but remain constant for the same individual, as shown by receiving identical answers to thousands of questions after intervals of more than a year. The photisms are not always distinct or of definite forms, but are projected on to the spot whence the sounds arise. Other senses produce sensations of colour as well as hearing; thus there are taste and smell photisms. There are also emotional photisms. The authors are unable to give any explanation, but they are clear that simple association does not suffice, and they examine a number of suggestions made to them, showing that they do not account for cases observed. They themselves think that the solution of the difficulty is to be sought in the nature of nervous processes, but they do not admit that “secondary sensations” are psychopathological. This little book is full of curious and interesting details evidently connected with Francis Galton's “mental images,” and localisation and sometimes colouring of numbers in the mind's eye. The following account of the general conclusions obtained, given on the last page of the book, will show what a curious page of nervous physiology is here opened out.

Zwangsmässige Lichtempfindungen durch Schall und verwandte Erscheinungen auf dem Gebiete der anderen Sinnesempfindungen

(Sensations of Light generated by Sound, and related Phenomena in the Sensations of other Organs of Sense). By E. Bleuler and K. Lehmann. 8vo, pp. 96. (Leipzig: Fues's Verlag, 1881.)