A second contributing factor may be related to the use of a fixation target that moved with the head. The function of the VOR is to stabilize a target image on the fovea during head rotation. Dynamic VOR is mediated by the semicircular canals and otolith organs during horizontal, vertical, and torsional head rotations. Static OCR, in contrast, is primarily driven by the otolith organs during sustained head tilt in response to a change in direction of gravitational acceleration.22,28,29 In this light, the VOR is driven by visual and vestibular inputs. When a target moves with the head, the VOR must be negated to stabilize the target image. Negation of VOR has been demonstrated in animals30 and humans21,31 when a visual display moves with the head; however, unlike its horizontal and vertical counterparts, the gain reduction for dynamic torsional VOR is only partial (approximately 36%).21,30,31 We postulated that VOR negation could also be elicited by a head-fixed target during sustained and static head tilt. To our knowledge, only 1 previous study4 has compared static OCR gains directly between an earth-fixed and a head-fixed target, but they reported no difference in gains. This might be related to their4 choice of visual stimulus, which consisted of a horizontal grating that oscillated sinusoidally in a frontal plane at 0 to 0.6 Hz with amplitude that varied from 6° to 33°. The transient nature of this stimulus may not be strong enough to evoke VOR negation. In the present study, we used a constant visual stimulus with strong spatial orientation cues to elicit VOR negation. As predicted, we found a reduction in static OCR gain (40%) when participants viewed a head-fixed target compared with an earth-fixed target.