Brain activation studies on visual-vestibular and ocular motor interaction

Despite their different sensorimotor functions. saccades, pursuit eye movem ents, small-field optokinetic nystagmus and visual motion stimulation with the eyes stationary evoke a common complex pattern of activation in various cortical, basal ganglia, brain-stem and cerebellar areas, On closer inspec tion, however, typical subregions can be delineated that allow differentiat ion of adjacent but separate loci for specific functions (e.g. the separati on of the two parallel corticocortical systems to control saccades and purs uit in the cortical eye fields). It is becoming increasingly clear that sti mulation of one sensory system affects other sensory systems, and generally this is via an inhibitory reciprocal mode of interaction. For example, ves tibular stimulation deactivates the visual cortex and visual stimulation de activates the vestibular cortex. Curl Opin Neurol 13:13-18. (C) 2000 Lippin cott Williams & Wilkins.