Horizontal burst-tonic cell recorded in the left prepositus hypoglossi. A–G, Responses during saccadic eye movements and fixations in darkness (A), smooth target tracking (B), rotation while stabilizing a head-fixed target (RVOR cancellation) (C), rotation (RVOR) or translation (TVOR) at a frequency of 0.5 Hz while stabilizing a space-fixed target (D, E), and rotation or translation at 4 Hz while stabilizing either a space-fixed target [Lgt (light) On] or a remembered target in darkness (Lgt Off) (F, G). EPOS, Eye position (right eye, gray; left eye, black); EVEL, eye velocity; T, target position; HANG, angular head velocity; ALIN, linear head acceleration; IFR, instantaneous firing rate; Lgt, lighting conditions (visual target on/off).