Behavioral calibration of eye movement recording systems using moving targets

Equipment used to measure eye movements must generally be calibrated to the individual subject. Some methods of measuring eye position are quite non-linear, requiring that the system's output be linearized. We describe an approach of behavioral calibration and linearization that utilizes tracking of moving targets. The key aspect of this approach is to use tracking of horizontally moving targets to calibrate vertical eye position and vice versa. This method is especially convenient for use with cats, whose fixation of eccentric stationary targets is often unreliable. It allows one to obtain an accurate calibration without having to judge whether or not tracking saccades reliably hit the target.