FIG. 2.

Head and eye movement traces during head impulse testing on a single individual using search coils (A) versus video-oculography (B). In all panels, head movements are in red, and eye movements are in blue. The x-axis corresponds to time in milliseconds (ms); the axes for search coil and VOG are somewhat offset, given differences in the systems regarding when the first head impulse occurs relative to time 0, that is, the offset does not represent real-time latency differences. Note the covert saccades (occurring during head movement) and overt saccades (occurring after head movement stops) present in both the search coil and VOG data for both right- and leftward head impulses.