hMT⁺/V5 is a region in the middle occipitotemporal cortex that responds preferentially to visual motion in sighted people. In cases of early visual deprivation, hMT⁺/V5 enhances its response to moving sounds. Whether hMT⁺/V5 contains information about motion directions and whether the functional enhancement observed in the blind is motion specific, or also involves sound source location, remains unsolved. Moreover, the impact of this cross-modal reorganization of hMT⁺/V5 on the regions typically supporting auditory motion processing, like the human planum temporale (hPT), remains equivocal. We used a combined functional and diffusion-weighted MRI approach and individual in-ear recordings to study the impact of early blindness on the brain networks supporting spatial hearing in male and female humans. Whole-brain univariate analysis revealed that the anterior portion of hMT⁺/V5 responded to moving sounds in sighted and blind people, while the posterior portion was selective to moving sounds only in blind participants. Multivariate decoding analysis revealed that the presence of motion direction and sound position information was higher in hMT⁺/V5 and lower in hPT in the blind group. While both groups showed axis-of-motion organization in hMT⁺/V5 and hPT, this organization was reduced in the hPT of blind people. Diffusion-weighted MRI revealed that the strength of hMT⁺/V5–hPT connectivity did not differ between groups, whereas the microstructure of the connections was altered by blindness. Our results suggest that the axis-of-motion organization of hMT⁺/V5 does not depend on visual experience, but that congenital blindness alters the response properties of occipitotemporal networks supporting spatial hearing in the sighted.

SIGNIFICANCE STATEMENT Spatial hearing helps living organisms navigate their environment. This is certainly even more true in people born blind. How does blindness affect the brain network supporting auditory motion and sound source location? Our results show that the presence of motion direction and sound position information was higher in hMT⁺/V5 and lower in human planum temporale in blind relative to sighted people; and that this functional reorganization is accompanied by microstructural (but not macrostructural) alterations in their connections. These findings suggest that blindness alters cross-modal responses between connected areas that share the same computational goals.

hMT ⁺ /V5 是枕颞叶皮层中部的一个区域，优先对视力正常的人的视觉运动做出反应。在早期视觉剥夺的情况下，hMT ⁺ /V5 增强其对移动声音的反应。 hMT ⁺ /V5是否包含有关运动方向的信息以及在盲人中观察到的功能增强是否是运动特定的，或者还涉及声源位置，仍然是未解决的问题。此外，hMT ⁺ /V5 的这种跨模式重组对通常支持听觉运动处理的区域（如人类颞平面 (hPT)）的影响仍然是模棱两可的。我们使用功能性和扩散加权 MRI 相结合的方法以及个体耳内录音来研究早期失明对支持男性和女性空间听力的大脑网络的影响。全脑单变量分析显示，hMT ⁺ /V5 的前部对视力正常者和盲人的移动声音有反应，而后部仅对盲人参与者的移动声音有选择性。多变量解码分析显示，在盲人组中，运动方向和声音位置信息的存在在 hMT ⁺ /V5 中较高，而在 hPT 中较低。虽然两组人在 hMT ⁺ /V5 和 hPT 中都显示出运动轴组织，但盲人的 hPT 中这种组织减少了。弥散加权 MRI 显示 hMT ⁺ /V5-hPT 连接的强度在各组之间没有差异，而连接的微观结构因失明而改变。 我们的结果表明，hMT ⁺ /V5 的运动轴组织并不依赖于视觉体验，但先天性失明改变了支持视力正常者空间听觉的枕颞网络的反应特性。

意义陈述空间听觉有助于生物体在其环境中导航。对于天生失明的人来说尤其如此。失明如何影响支持听觉运动和声源定位的大脑网络？我们的结果表明，与视力正常的人相比，盲人的 hMT ⁺ /V5 运动方向和声音位置信息的存在程度较高，而人类颞平面的运动方向和声音位置信息的存在程度较低；并且这种功能重组伴随着它们之间的联系的微观结构（但不是宏观结构）的改变。这些发现表明，失明会改变共享相同计算目标的连接区域之间的跨模式响应。