Summary

To elucidate cortical correlates of vestibulo-ocular re¯ex (VOR) modulation, we observed cortical activation during ®xation suppression and habituation of caloric vestibular nystagmus in 12 normal subjects, using PET. Signi®cant positive correlation between regional cerebral blood ¯ow (rCBF) and slow phase eye velocity of caloric nystagmus was observed in the middle and posterior insula, inferior parietal lobule, temporal pole, right fusiform gyrus, lingual gyrus, and cerebellar vermis and hemisphere. The rCBF increase in the insular region and the inferior parietal lobule was lateralized depending on the direction of the nystagmus. Caloric nystagmus was suppressed as a result of visual ®xation, during which time the area around the right frontal eye ®eld, temporal pole, inferior temporal gyrus