FIG. 1.

Eye and head velocity traces in yaw, pitch, and roll head rotations during passive DVA testing in yaw (top), pitch (middle), and roll (bottom) for a healthy control subject. Eye velocity closely approximates head velocity for yaw and pitch, less so for roll. Eye traces have been inverted only for the respected head plane of rotation (yaw eye velocity is inverted only for the yaw head rotations). Note that for roll right rotations, a consistent downward deflection occurs between 120 and 200 ms, not as apparent during roll to the left. Similarly, the pitch trace is also deflected (upwards). This represents a resetting torsional quick phase.