Prevailing theory suggests that superior aVOR gains and LogMAR scores during DVA testing with active head rotations relative to passive head rotations may be due in part to the effects of efference copy or pre-programmed eye movements (compensatory saccades). While EC is unlikely to play a significant role during pDVA testing given the lack of an efferent motor command generated by the subject, it is possible that afferent information from retinal sources in the form of a position signal [24], oculomotor proprioceptors [5], or neck proprioceptors [6] could augment vestibular contributions to gaze stability during passive head movements [7].