Brain imaging studies related to spatial orientation were reviewed. Visual perception of motion and space is processed primarily in the dorsal visual pathway, in which the dorsal cuneus, parieto-occipital sulcus area, MT, MST and parietal cortex play essential roles. However, the lingual gyrus and fusiform gyrus in the ventral pathway also play important roles in visuo-spatial perception. In the parietal cortex, the intraparietal sulcus and inferior and superior parietal lobules are activated by various tasks that are related to visual perception of orientation, location and motion in space. In addition to these areas, visuo-spatial attention activates the anterior cingulate gyrus and premotor cortex, and the insula and hippocampus are activated by tasks related to perception and memory of self-motion, and navigation in space. Most of these regions also become active by vestibular and somatosensory stimuli, and contribute to controlling ocular and body movements. Several imaging studies have demonstrated reciprocal inhibitory interactions among visual, vestibular and somatosensory systems. Inhibitory interaction between different sensory perception systems may contribute to developing consistent and unified self-image and appropriate behavior in space when they disagree.
