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September 24, 1892

RETINAL EXCITATION OF CORTICAL ORIGIN IN VISUAL HALLUCINATION.Read in the Section of Neurology and Medical Jurisprudence, at the Forty-third Annual Meeting of the American Medical Association, held at Detroit, Mich., June, 1892.

Author Affiliations


JAMA. 1892;XIX(13):375-377. doi:10.1001/jama.1892.02420130019001f

The question to be considered under this title is: Does ideational activity of the cerebral cortex ever induce centrifugal excitation of sensory end-organs through their afferent sensory nerves, and thus lead to the sense of objectivity, or projection, that is the characteristic feature of hallucination?

For the sake of clearness, consideration of the question is confined to the sense of sight.

Quite commonly hallucination is made to include all phantasms that have no other than a subjective foundation; but to answer the present question, a stricter differentiation of subjective phantasms than the common definition implies, is necessary. Phantasms having a peripheral origin, though without objective, or external, cause, must be distinguished from those having a central origin. Following Emminghaus, the former may be allowed to fall within the term illusion; and hallucination may be made to include only those phantasms that have a purely central origin. In answer to the