Fig. 2-2. A classic case of a man who lost the ability to read even though he had normal visual acuity and could copy written words (alexia without agraphia) was described by Joseph Jules Dejerine in 1892. Postmortem analysis of the man's brain showed that the left visual cortex and the splenium of the corpus callosum (dark areas) had been destroyed, in this case by an occlusion of the left posterior cerebral artery. The spenium is the region that transfers visual information between the two hemispheres. The man's left visual cortex was damaged giving him a right homonomous hemianopia. He could see normally off to the left side of his visual world, but could not relay that information to the left hemisphere for interpretation. Thus, words remained as meaningless patterns.