“Express” smooth pursuit

For the majority of human smooth pursuit eye movements made to a horizontal ramp target of unpredictable direction, the reciprocal of the latency appears to have a Gaussian distribution of the same general form as for saccades to step targets, but with smaller median. There are more latencies shorter than some 100 msec than would be expected from such a distribution: they form a distinct population ("express smooth pursuit responses") whose distribution is similar to that of express saccades. They still occur in the absence of a cue, when the target is unpredictable.