They were positioned on top of movable stalks called peduncles to help it more easily search for food and look out for predators. (sciencedaily.com)
Some unilateral lesions of the central vestibular pathways, especially unilateral involvement of the flocculonodular lobe of the cerebellum or the supramedullary part of the caudal cerebellar peduncle, produce a head tilt and ataxia directed toward the side opposite to the lesion, and a nystagmus with the fast component towards the side of the lesion. (lowchensaustralia.com)