Final answer:
The semicircular canals are responsible for the vertical nystagmus produced during stimulation of the VOR reflex.
Step-by-step explanation:
The semicircular canals are responsible for the vertical nystagmus produced during stimulation of the VOR reflex. The semicircular canals are three ring-like extensions of the vestibule that detect rotational movement of the head. By comparing the relative movements of the ampullae within the canals, the vestibular system can detect the direction of head movements in three-dimensional space.