The accuracy of two-dimensional saccades in the absence of continuing retinal stimulation.

The ability of observers to execute saccades in the dark to previously visible targets has been demonstrated by Becker and Fuchs (1969) and Becker and Klein (1973). Becker and Fuchs report the occurrence of horizontal saccades when a target, 40’ away from fixation. was extinguished 350 msec prior to the initiation of the saccade. Becker and Klein report that observers, after practicing horizontal saccades to targets were able to continue making goal-directed sac&es in total darkness. The accuracy of these saccades, however, decreased with time. These results imp1y that continuing retinal stimulation is not necessary for the execution of goal-directed saccades. Rather, the saccadic control system appears able to utilize some sort of stored information. The present experiment assessed the accuracy with which the saccadic control system could execute, from memory alone, a consecutive series of two-dimensional saccades to targets randomly located in the fronto-parallel plane.