Long-Term Effects of Dove Prism Vision on Torsional VOR and Head-Eye Coordination

Abstract

Previous experiments with both human (Gonshor and Melvill Jones 1971, 1976a,b; Gauthier and Robinson 1975; Melvill Jones 1977) and animal (Ito et al. 1974; Miles and Fuller 1974; Melvill Jones and Davies 1976; Robinson 1976; Miles and Eighmy 1980) subjects have demonstrated profound effects of optically modified vision upon the horizontal vestibulo-ocular reflex (HVOR) and associated neural pathways (Ito 1979; Keller and Precht 1979; Miles et al. 1980). However, modified vision calls for adaptive changes in sensory motor mechanisms other than the HVOR. For example, since horizontally reversing dove prisms also produce reversal of image movement during head rotation in the frontal, or roll, plane, the question arises whether adaptive changes occur in the torsional vestibulo-ocular reflex (TVOR). As will appear later, this question has important theoretical implications. Again, vision reversal would be expected to disorganize visuo-spinal reflexes associated with posture and head movement control. Indeed marked adaptive effects on postural control have already been reported (Gonshor and Melvill Jones 1980).