RING SCOTOMA AND TUBULAR FIELDS

with the question whether the symptoms are "organic" or "psychogenic." If there is a history which is typical of a well defined syndrome or if a lesion can be demonstrated, the symptoms are accepted as organic. However, if the patient manifests signs of increased emotional tension or if the symptoms and signs are "atypical" or inconsistent or do not follow well known organic patterns, they are often considered psychogenic. Sometimes there is a combination of the two types. In either instance the symptoms are due to a disorder in function. The patient's reactions in the case of an organic disorder are just as functional as in the case of a neurosis. The difference between the two lies in the origin of the functional disorder and in the manner in which the symptoms manifest themselves. Nevertheless, close analysis will reveal that in many instances apparent hysterical reactions follow consistent and specific physiologic patterns, and in such cases it may be difficult to differentiate the organic from the psychogenic syndrome. In the course of an investigation of perceptual changes in a large group of patients with battle injuries of the brain, visual disturbances were noted in a considerable number of cases.1 In 1 case a so-called ring scotoma, combined with an occasional tendency toward concentric contraction of the monocular and binocular fields, was discovered.