Visual-vestibular processing in the human Sylvian fissure

Abstract

Frank SM, Wirth AM, Greenlee MW. Visual-vestibular processing in the human Sylvian fissure. J Neurophysiol 116: 263-271, 2016. First published April 13, 2016 doi:10.1152/jn.00009.2016.-Unlike other sensory systems, the cortical organization of the human vestibular system is not well established. A central role is assumed for the region of the posterior Sylvian fissure, close to the posterior insula. At this site, activation during vestibular stimulation has been observed in previous imaging studies and labeled as the parieto-insular vestibular cortex area (PIVC). However, vestibular responses are found in other parts of the Sylvian fissure as well, including a region that is referred to as the posterior insular cortex (PIC). The anatomical and functional relationship between PIC and PIVC is still poorly understood, because both areas have never been compared in the same participants. Therefore, to better understand the apparently more complex organization of vestibular cortex in the Sylvian fissure, we employed caloric and visual object motion stimuli during functional magnetic resonance imaging and compared location and function of PIVC and PIC in the same participants. Both regions responded to caloric vestibular stimulation, but only the activation pattern in right PIVC reliably represented the direction of the caloric stimulus. Conversely, activity in PIVC was suppressed during stimulation with visual object motion, whereas PIC showed activation. Area PIC is located at a more posterior site in the Sylvian fissure than PIVC. Our results suggest that PIVC and PIC should be considered separate areas in the vestibular Sylvian network, both in terms of location and function. area PIC; area PIVC; caloric vestibular stimulation; Sylvian fissure; vestibular cortex NEW & NOTEWORTHY In this paper we examine vestibular and visual processing at the center of human vestibular cortex in the Sylvian fissure. We find that two areas, referred to as parietoinsular vestibular cortex (PIVC) and posterior insular cortex (PIC), are located in the Sylvian fissure and exhibit different functional specializations. Our results suggest a more complex organization at the putative core of human vestibular cortex than previously assumed.A CENTRAL FUNCTION OF THE vestibular sensory system is to signal our position and acceleration in space. This information is of critical relevance for guiding locomotion and for process- There is accumulating evidence that the potential hub of the cortical vestibular network is located in a region including the posterior part of the Sylvian fissure (also called lateral sulcus), perisylvian cortex, and the posterior insula. At this site, functional imaging studies in humans found activation during vestibular stimulation (Bense et al. 2001;Dieterich et al. 2003;Eickhoff et al. 2006;Fasold et al. 2002;Lobel et al. 1998) and labeled it the parieto-insular vestibular cortex (PIVC), following terminology in the primate brain (Akbarian et al. 1988;Chen et al. 2010;Grüsser et al. 1990; Shinder and Newlands 2014...

Neural bases of self‐ and object‐motion in a naturalistic vision

“…Area PIC in the Sylvian fissure is a motion region responding to visual and vestibular motion, presumably supporting the integration of motion information from visual and vestibular senses for the perception of self-motion (Frank, Sun, et al, 2016;Frank, Wirth, & Greenlee, 2016). A recent study by Huang et al (2015) found that the right PIC (there called PIVC) responds to active dodges suggesting that it plays an active role in sensing and guiding translational egomotion.…”

“…, Amunts,Mohlberg, & Zilles, 2006;Fasold et al, 2002;Friberg, Olsen, Roland, Paulson, & Lassen, 1985;Indovina et al, 2005), or visual stimuli(Cardin & Smith, 2010). Thus, previously reported activations in posterior lateral sulcus during self-motion induced by visual motion(Cardin & Smith, 2010;Huang et al, 2015;Uesaki & Ashida, 2015) might fall within PIC, or at least partially overlap with PIC, rather than PIVCFrank, Sun, et al, 2016;Frank, Wirth, & Greenlee, 2016;Greenlee et al, 2016). PIVC is located more anteriorly, in correspondence of the lateral end of the central sulcus.…”

“…Like CSv, CMA, and PIC also show vestibular responses (Fasold et al, 2002;Frank, Sun, et al, 2016;Frank, Wirth, & Greenlee, 2016).…”

“…But recent evidence has showed that along the insula in humans there are two motion regions, named PIVC and PIC . PIVC is located might fall within PIC, or at least partially overlap with PIC, rather than PIVC Frank, Sun, et al, 2016;Frank, Wirth, & Greenlee, 2016;Greenlee et al, 2016). Here, as we used a pure visual stimulation, we refer to this region as PIC area.…”

Neuroticism modulates brain visuo-vestibular and anxiety systems during a virtual rollercoaster task

“…To define the PIVC bilateral ROI, we used 8‐mm radius spheres centered on the coordinates reported in Cardin and Smith, transformed in the Montreal Neurological Institute (MNI) space ( x : 41, y : −30, z : 18 and x : −40, y : −30, z : 20 for right and left PIVC, respectively) [Cardin and Smith, ]. This region has also been known as the Posterior Insular Cortex [Frank et al, ; Orban et al, ]. To define the hMT+/V5 and TPJ bilateral ROIs, we used 8‐mm radius spheres centered on the MNI coordinates reported in Bosco and colleagues (Right TPJ: x : 65, y : −36.6, z : 30.1; Left TPJ: x : −62.5, y : −36.2, z : 3; Right hMT+/V5: x : 55, y : −67.8, z : 1.8; Left hMT+/V5: x : −49.8, y : −71.0, z : 3.3) [Bosco et al, ].…”