通过TMS评估MT/V5、V6、V6A区和前庭前运动皮层对可见及遮挡弹道轨迹拦截的差异性贡献

文献信息

中文摘要

引言： 多个皮层区域被认为参与拦截动作的控制，例如MT/V5区、后顶叶区域、颞顶交界处（TPJ）参与重力内部表征的前庭区域以及前运动区。在此，我们评估了视觉区V6和V6A以及另一个与下额回前庭网络相关的额下回（IFG）前运动区域的潜在贡献，这些区域基于其连接性和已知功能特性可能参与其中，并将其与MT/V5区的贡献进行比较。
方法： 我们在拦截弹道轨迹期间应用了三脉冲经颅磁刺激（tpTMS），这些轨迹要么与自然重力一致（1g），要么被恒速曲线扰动（0g）。轨迹要么完全可见，要么在落地前被遮挡。在轨迹扰动或遮挡后立即对每个皮层位点应用tpTMS。
结果： MT/V5区的tpTMS在可见和遮挡轨迹下均对拦截表现产生显著变化，通过调节具有连续可用视觉信息的中央处理延迟，同时在遮挡运动下对视觉外推做出贡献。V6刺激仅在可见轨迹下产生显著效应，通过调节MT/V5下游的中央处理延迟。IFG在拦截动作的空间和时间方面表现出独特贡献，涉及基于视觉信息和内化重力信息的预测信号的整合。V6A刺激似乎无效。
结论： 总之，这些皮层区域之间出现的功能分离支持参与抛射运动拦截的皮层网络的复杂、平行分布式组织。

英文摘要

INTRODUCTION: Several cortical regions have been implicated in the control of interceptive actions, such as area MT/V5, posterior parietal areas, a vestibular area in the temporo-parietal junction (TPJ) involved in an internal representation of gravity, and premotor areas. Here, we assessed the potential contributions of visual areas V6 and V6A and of another premotor region in the inferior frontal gyrus associated to the vestibular network (IFG), which could potentially contribute based on their connectivity and known functional properties, and compared them with those of MT/V5.
METHODS: We applied triple-pulse transcranial magnetic stimulation (tpTMS) during interception of ballistic trajectories, either congruent with natural gravity (1g) or perturbed with constant-velocity profiles (0g). Trajectories were either fully visible or occluded prior to landing. tpTMS was applied on each cortical site right after the trajectory perturbations or occlusions.
RESULTS: tpTMS of MT/V5 produced robust changes in the interceptive performance with both visible and occluded trajectories, by modulating central processing delays with continuously available visual information, while contributing to visual extrapolation with occluded motion. V6 stimulation produced significant effects only with visible trajectories by modulating the central processing delays downstream of MT/V5. IFG showed distinct contributions to the spatial and temporal aspects of the interceptive action with respect to the integration of predictive signals based on visual information and on internalized gravity information. V6A stimulation was seemingly ineffective.
CONCLUSION: Altogether, the functional dissociations emerging among these cortical areas support a complex, parallel distributed organization of the cortical network involved in the interception of projectile motion.