Die verschiedenen Formen der Sinnesdelirien. Ein Beitrag zur Erweiterung der psychiatrischen Symptomatologie und zur psysiologischen Psychologie. by K. Kahlbaum. Centralblatt für die medicinischen Wissenschaften, No. 57, 23 December 1865. p. 908ff.
PAREIDOLIA - DR. KARL LUDWIG KAHLBAUM
When discussing the visual perception of objects that are not actually physically present, the word pareidolia, a term from Psychiatry, is another useful term which basically is a synonym for the concept imaginative illusion.
Although the word pareidolia was not introduced until the 1860's, the visual phenomena of pareidolia is as old as human perception. Seeing "The Man in the Moon" as a face or "The Big Dipper" as a dipper are but two examples. Leonardo da Vinci and Shakespeare, along with many others known for their extraordinary imaginations, wrote about the phenomena now defined by the word pareidolia. The American painter/writer Washington Allston, and many of Allston's associates also wrote about this phenomena and encouraged people to enjoy the experience as a sublime experience with Nature.
The word pareidolie was used, perhaps originally, by Dr. Karl Ludwig Kahlbaum in articles published in two German language Psychiatric journals, one in 18651 and the other in 1866.2 In 1867 pareidolie was translated into English as pareidolia in a British medical journal review of Dr. Kahlbaum’s 1866 article.3 The phenomena of pareidolia was discussed by Karl Jaspers in his now classic General Psychopathology,4. Originally published in German in 1913, Jaspers' General Psychopathology has been republished in many editions and languages. The term pareidolia remains in use in Psychiatry, and is now also in general use.
… there is necessary an external and individual object very nearly corresponding in character to the false perception, whose objective stimulus blends with the deficient subjective stimulus, and forms a single complete impression. This last is called by Dr. Kahlbaum, changing hallucination, partial hallucination, perception of secondary images, or pareidolia.6Dr. Kahlbaum called the perception of a pareidolia a "false perception" because the object seen is not physically present, although the actual external object and the individual object known from experience both are "corresponding in character." For example, with The Big Dipper seen as a dipper, the "external" pattern of those seven stars and the "individual object" in the mind of the viewing individual known as a dipper from previous experience are "very nearly corresponding in character." With the example of the Moon's surface seen as a face, the "external" pattern of the surface of the moon and the "individual object" in the mind of the viewing individual, a face, are also "very nearly corresponding in character."
A type of intense imagery that persists even when the subject looks at a real object in the external environment; image and percept exist side by side, but the image is usually recognized as unreal.Here is my translation into simpler terms: