The examination of saccadic eye movements--rapid shifts in gaze from one visual area of interest to another--is useful in studying pilot's visual learning in flight simulator training. Saccadic eye movements are the basic oculomotor response associated with the acquisition of visual information and provide an objective measure of higher perceptual processes. In this investigation, three adult subjects fixated a single point of light, which was then extinguished and replaced either by one target which appeared at plus or minus 5, 10, or 15 degrees, or by two targets which appeared symmetrically at those same eccentricities. All subjects showed a directional preference (averaging about 80%) in the two-target condition, and it was found that this preference could be eliminated by delaying by about 40 milliseconds the onset of the target presented in the preferred direction. This indicated that a 40-millisecond "window" of time was allocated for deciding response direction. It was also found that the saccadic latency of responses in the nonpreferred direction was affected more by a second target presented in the preferred direction than vice versa. This asymmetry in the system which controls saccadic eye movements has not previously been described. (JGL)