Center for Mind/Brain Studies, University of Trento, Trento, Italy.
Cognitive Architecture for Collaborative Technologies (CONTACT) Unit, Italian Institute of Technology, Genoa, Italy.
Neuroimage. 2021 Apr 15;230:117816. doi: 10.1016/j.neuroimage.2021.117816. Epub 2021 Jan 29.
In early deaf individuals, the auditory deprived temporal brain regions become engaged in visual processing. In our study we tested further the hypothesis that intrinsic functional specialization guides the expression of cross-modal responses in the deprived auditory cortex. We used functional MRI to characterize the brain response to horizontal, radial and stochastic visual motion in early deaf and hearing individuals matched for the use of oral or sign language. Visual motion showed enhanced response in the 'deaf' mid-lateral planum temporale, a region selective to auditory motion as demonstrated by a separate auditory motion localizer in hearing people. Moreover, multivariate pattern analysis revealed that this reorganized temporal region showed enhanced decoding of motion categories in the deaf group, while visual motion-selective region hMT+/V5 showed reduced decoding when compared to hearing people. Dynamic Causal Modelling revealed that the 'deaf' motion-selective temporal region shows a specific increase of its functional interactions with hMT+/V5 and is now part of a large-scale visual motion selective network. In addition, we observed preferential responses to radial, compared to horizontal, visual motion in the 'deaf' right superior temporal cortex region that also show preferential response to approaching/receding sounds in the hearing brain. Overall, our results suggest that the early experience of auditory deprivation interacts with intrinsic constraints and triggers a large-scale reallocation of computational load between auditory and visual brain regions that typically support the multisensory processing of motion information.
在早期失聪的个体中，听觉剥夺的颞叶脑区会参与视觉处理。在我们的研究中，我们进一步检验了这样一个假设，即内在功能特化指导了剥夺听觉皮层中跨模态反应的表达。我们使用功能磁共振成像来描述早期失聪和听力正常个体对水平、放射状和随机视觉运动的大脑反应，这些个体在使用口语或手语方面相匹配。视觉运动在“失聪”的中外侧颞平面中表现出增强的反应，这是一个对听觉运动具有选择性的区域，正如在听力正常的人群中通过单独的听觉运动定位器所证明的那样。此外，多元模式分析显示，这个重新组织的颞区在失聪组中显示出对运动类别的增强解码能力，而视觉运动选择性区域 hMT+/V5 与听力正常人群相比，解码能力则降低。动态因果建模显示，“失聪”的运动选择性颞区显示出与 hMT+/V5 的功能相互作用的特定增加，并且现在成为一个大规模视觉运动选择性网络的一部分。此外，我们观察到“失聪”的右颞上皮质区对放射状视觉运动的反应优先于水平视觉运动，而在听力正常的大脑中，该区域也对接近/远离声音表现出优先反应。总的来说，我们的结果表明，早期听觉剥夺的经历与内在限制相互作用，引发了听觉和视觉脑区之间计算负荷的大规模重新分配，这些脑区通常支持运动信息的多感觉处理。
