Sensory-specific and fractional disorders of recent memory in man. I. Isolated loss of visual recent memory.

Two patients who lost, in isolation, visual recent memory following bilateral posterior cerebral artery infarctions are described. Tactile, verbal, and nonverbal auditory recent memory functions were preserved in both patients. Based on computerized tomography scans and behavioral and anatomical data in monkey, isolated loss of visual recent memory in man is best understood as a bilateral disconnection syndrome between the striate cortex and the structures in the medial temporal lobe that are involved with recent memory. The possible existence of two other sensory-specific disorders of recent memory, tactile and auditory, is postulated, and the clinical relationship of prosopagnosia, achromatopsia, and spatial disorientation to visual recent memory loss is discussed.