Properties of Cortical Electrical Phosphenes

The second patient with an inductively-linked visual prosthetic implant (F.B.) has now been tested at intervals for 5 1/2 years. Reports on this patient have considered the extent of visual cortex that gives fixed phosphenes (1); mapping methods and phosphene Braille reading (2); the degree of stability of phosphenes in the map (3); aspects of the representation of the visual field (4); and a method for generating an optimum phosphene map from a large number of observations of the relations between phosphene pairs (5).