An enhanced role for right hV5/MT+ in the analysis of motion in the contra- and ipsi-lateral visual hemi-fields.
An enhanced role for right hV5/MT+ in the analysis of motion in the contra- and ipsi-lateral visual hemi-fields.
复制标题
右 hV5/MT 在对侧和同侧视觉半视野运动分析中的作用增强。
DOI：
10.1016/j.bbr.2019.112060
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发表时间：
2019
影响因子：
2.7
通讯作者：
Strong SL
中科院分区：
文献类型：
--
作者：
Strong SL
先前的实验已经证明，经颅磁刺激（TMS）的人V5/MT+，在左或右大脑半球，可以诱导缺陷的视觉运动知觉在其各自的对侧和同侧的视觉半场。然而，当TMS应用于右半球相对于左半球的V5/MT +时，同侧半野中的运动缺陷更大。这种不对称性的一个可能的解释可能在于两个半球V5/MT +内的细分的差异刺激。V5/MT +有两个主要的亚区：MT/TO-1和MST/TO-2，后者包含具有大感受野（RF）的神经元，其比前者向同侧半野延伸15°。我们想研究是否应用TMS MT/TO-1和MST/TO-2分别可以解释以前报道的功能不对称的同侧运动处理在V5/MT +左右大脑半球。MT/TO-1和MST/TO-2在7名受试者中使用fMRI定位器进行了鉴定。在心理物理学实验中，受试者确定了平移方向（上/下）的连贯移动的点在左或右视野，而重复TMS（25 Hz; 70%）同步应用与刺激呈现。在右半球的MT/TO-1和MST/TO-2上应用TMS影响了对侧和同侧视野中的平移方向辨别。与此相反，TMS应用于左半球的MT/TO-1和MST/TO-2后的运动知觉缺陷仅限于对侧视野。这一结果表明，右半球在处理整个视野的平移运动中的作用增强。
Previous experiments have demonstrated that transcranial magnetic stimulation (TMS) of human V5/MT+, in either the left or right cerebral hemisphere, can induce deficits in visual motion perception in their respective contra- and ipsi-lateral visual hemi-fields. However, motion deficits in the ipsi-lateral hemi-field are greater when TMS is applied to V5/MT + in the right hemisphere relative to the left hemisphere. One possible explanation for this asymmetry might lie in differential stimulation of sub-divisions within V5/MT + across the two hemispheres. V5/MT + has two major sub-divisions; MT/TO-1 and MST/TO-2, the latter area contains neurons with large receptive fields (RFs) that extend up to 15° further into the ipsi-lateral hemi-field than the former. We wanted to examine whether applying TMS to MT/TO-1 and MST/TO-2 separately could explain the previously reported functional asymmetries for ipsi-lateral motion processing in V5/MT + across right and left cerebral hemispheres. MT/TO-1 and MST/TO-2 were identified in seven subjects using fMRI localisers. In psychophysical experiments subjects identified the translational direction (up/down) of coherently moving dots presented in either the left or right visual field whilst repetitive TMS (25 Hz; 70%) was applied synchronously with stimulus presentation. Application of TMS to MT/TO-1 and MST/TO-2 in the right hemisphere affected translational direction discrimination in both contra-lateral and ipsi-lateral visual fields. In contrast, deficits of motion perception following application of TMS to MT/TO-1 and MST/TO-2 in the left hemisphere were restricted to the contra-lateral visual field. This result suggests an enhanced role for the right hemisphere in processing translational motion across the full visual field.