Data_Sheet_1_Antero-Posterior vs. Lateral Vestibular Input Processing in Human Visual Cortex.PDF

Visuo-vestibular integration is crucial for locomotion, yet the cortical mechanisms involved remain poorly understood. We combined binaural monopolar galvanic vestibular stimulation (GVS) and functional magnetic resonance imaging (fMRI) to characterize the cortical networks activated during antero-posterior and lateral stimulations in humans. We focused on functional areas that selectively respond to egomotion-consistent optic flow patterns: the human middle temporal complex (hMT+), V6, the ventral intraparietal (VIP) area, the cingulate sulcus visual (CSv) area and the posterior insular cortex (PIC). Areas hMT+, CSv, and PIC were equivalently responsive during lateral and antero-posterior GVS while areas VIP and V6 were highly activated during antero-posterior GVS, but remained silent during lateral GVS. Using psychophysiological interaction (PPI) analyses, we confirmed that a cortical network including areas V6 and VIP is engaged during antero-posterior GVS. Our results suggest that V6 and VIP play a specific role in processing multisensory signals specific to locomotion during navigation.

视觉-前庭整合（Visuo-vestibular integration）对于躯体运动至关重要，但其相关皮层机制仍尚未被充分阐明。本研究结合双耳单极直流电前庭刺激（binaural monopolar galvanic vestibular stimulation，GVS）与功能磁共振成像（functional magnetic resonance imaging，fMRI）技术，旨在解析人类接受前后向及侧向前庭刺激时激活的皮层网络。我们重点关注了对自我运动匹配光流模式具有选择性响应的功能脑区：人类颞中回复合体（human middle temporal complex，hMT+）、V6脑区、腹侧顶内区（ventral intraparietal，VIP）、扣带沟视觉区（cingulate sulcus visual，CSv）以及后岛叶皮层（posterior insular cortex，PIC）。研究结果显示，hMT+、CSv及PIC脑区在侧向与前后向GVS刺激下的响应程度相当；而VIP与V6脑区仅在前后向GVS刺激下被显著激活，侧向刺激时则无明显响应。通过心理生理交互分析（psychophysiological interaction，PPI），我们证实包含V6与VIP脑区的皮层网络在前后向GVS刺激时处于激活状态。本研究结果表明，V6与VIP脑区在导航过程中处理运动相关多感官信号时发挥着特异性作用。