Abstract-The vestibular system contributes to the control of posture and eye movements and is also involved in various cognitive functions including spatial navigation and memory. These functions are subtended by projections to a vestibular cortex, whose exact location in the human brain is still a matter of debate . The vestibular cortex can be defined as the network of all cortical areas receiving inputs from the vestibular system, including areas where vestibular signals influence the processing of other sensory (e.g. somatosensory and visual) and motor signals. Previous neuroimaging studies used caloric vestibular stimulation (CVS), galvanic vestibular stimulation (GVS), and auditory stimulation (clicks and short-tone bursts) to activate the vestibular receptors and localize the vestibular cortex. However, these three methods differ regarding the receptors stimulated (otoliths, semicircular canals) and the concurrent activation of the tactile, thermal, nociceptive and auditory systems. To evaluate the convergence between these methods and provide a statistical analysis of the localization of the human vestibular cortex, we performed an activation likelihood estimation (ALE) metaanalysis of neuroimaging studies using CVS, GVS, and auditory stimuli. We analyzed a total of 352 activation foci reported in 16 studies carried out in a total of 192 healthy participants. The results reveal that the main regions activated by CVS, GVS, or auditory stimuli were located in the Sylvian fissure, insula, retroinsular cortex, fronto-parietal operculum, superior temporal gyrus, and cingulate cortex. Conjunction analysis indicated that regions showing convergence between two stimulation methods were located in the median (short gyrus III) and posterior (long gyrus IV) insula, parietal operculum and retroinsular cortex (Ri). The only area of convergence between all three methods of stimulation was located in Ri. The data indicate that Ri, parietal operculum and posterior insula are vestibular regions where afferents converge from otoliths and semicircular canals, and may thus be involved in the processing of signals informing about body rotations, translations and tilts. Results from the meta-analysis are in agreement with electrophysiological recordings in monkeys showing main vestibular projections in the transitional zone between Ri, the insular granular field (Ig), and SII. Ó

The vestibular system provides the brain with sensory signals about three-dimensional head rotations and translations. These signals are important for postural and oculomotor control, as well as for spatial and bodily perception and cognition, and they are subtended by pathways running from the vestibular nuclei to the thalamus, cerebellum and the "vestibular cortex."The present review summarizes current knowledge on the anatomy of the thalamocortical vestibular system and discusses data from electrophysiology and neuroanatomy in animals by comparing them with data from neuroimagery and neurology in humans. Multiple thalamic nuclei are involved in vestibular processing, including the ventroposterior complex, the ventroanterior-ventrolateral complex, the intralaminar nuclei and the posterior nuclear group 2 0 1 1 ) 1 1 9 -1 4 6 Abbreviations: 3aHv, 3a-hand-vestibular area; 3aNv, 3a-neck-vestibular area; ASS, anterior suprasylvian cortex; DVN, descending vestibular nucleus; FEF, frontal eye fields; Ig, insula granularis; IL, intralaminar nuclei; LD, lateral dorsal nucleus; LGN, lateral geniculate nucleus; LP, lateral posterior nucleus; LVN, lateral vestibular nucleus; MGmc, medial geniculate nucleus, pars magnocellularis; MGN, medial geniculate nucleus; MIP, medial intraparietal area; MST, medial superior temporal area; MT, middle temporal area; MVN, medial vestibular nucleus; PIVC, parieto-insular vestibular cortex; PO, posterior group of the thalamus; Reipt, area retroinsularis pars parietalis; Ri, area retroinsularis; SGN, suprageniculate nucleus; SVN, superior vestibular nucleus; TPJ, temporo-parietal junction; VA, ventroanterior thalamic nucleus; Vim, nucleus ventralis intermedius; VIP R A I N R E S E A R C H R E V I E W S 6 7 (