Examples of a representative saccade from one subject. (A and B) Eye positions (ordinate) are plotted versus time (abscissa). (A) Black trace represents visually-guided saccade and gray trace the remembered saccade. (B) Saccade made under closed eyelids. (C) Eye velocities of visually-guided saccades (black) and of saccades to the remembered location (gray) are plotted versus time. (D) Eye velocity of saccade under closed eyelids is plotted versus time. (E and F) Eye acceleration (and deceleration) during a visually-guided saccade, saccade to a remembered location, and saccade under closed eyelids are plotted versus time. Notice the fivefold greater time scale in panels B, D, and F as compared to A, C, and E. (G) Phase-plane plot comparing eye velocity with eye acceleration during visually-guided (black) and memory-guided (gray) saccades. (H) Phase-plane plot of the saccade made under closed eyelids.