PHENOMENON OF VISUAL EXTINCTION IN HOMONYMOUS FIELDS AND PSYCHOLOGIC PRINCIPLES INVOLVED

Abstract

During World War I a variety of syndromes due to cerebral injuries were described. Among the numerous interesting signs noted was one of "visual inattention in homonymous fields," or "hemianopsic weakness of attention." Poppelreuter¹ observed 7 cases in which the patient was able to perceive only one of two figures or points simultaneously exposed on the sides of a central point of fixation. However, if only one figure was exposed in the "affected field," the image was seen. Head² noted this phenomenon in a case of a gunshot wound of the left occipito-parietal cortex, with residual aphasia and a right homonymous field defect, but his description lacks details. Riddoch³ reported 2 cases of defective attention in the right homonymous fields, and in both instances there was a neoplasm in the angular and supramarginal gyri on the left side. Akelaitis⁴ described 2 cases of left and 1