Department of Psychology, Jagiellonian University, 6 Ingardena Street, 30-060, Krakow, Poland.
Laboratory of Brain Imaging, Neurobiology Center, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteura Street, 02-093, Warsaw, Poland.
Sci Rep. 2017 Dec 12;7(1):17448. doi: 10.1038/s41598-017-17738-8.
Training can induce cross-modal plasticity in the human cortex. A well-known example of this phenomenon is the recruitment of visual areas for tactile and auditory processing. It remains unclear to what extent such plasticity is associated with changes in anatomy. Here we enrolled 29 sighted adults into a nine-month tactile Braille-reading training, and used voxel-based morphometry and diffusion tensor imaging to describe the resulting anatomical changes. In addition, we collected resting-state fMRI data to relate these changes to functional connectivity between visual and somatosensory-motor cortices. Following Braille-training, we observed substantial grey and white matter reorganization in the anterior part of early visual cortex (peripheral visual field). Moreover, relative to its posterior, foveal part, the peripheral representation of early visual cortex had stronger functional connections to somatosensory and motor cortices even before the onset of training. Previous studies show that the early visual cortex can be functionally recruited for tactile discrimination, including recognition of Braille characters. Our results demonstrate that reorganization in this region induced by tactile training can also be anatomical. This change most likely reflects a strengthening of existing connectivity between the peripheral visual cortex and somatosensory cortices, which suggests a putative mechanism for cross-modal recruitment of visual areas.
培训可以诱导人类大脑皮层的跨模态可塑性。这种现象的一个著名例子是视觉区域对触觉和听觉处理的招募。目前尚不清楚这种可塑性与解剖结构的变化有多大关联。在这里，我们招募了 29 名视力正常的成年人参加为期九个月的触觉盲文阅读培训，并使用基于体素的形态测量学和弥散张量成像来描述由此产生的解剖结构变化。此外，我们还收集了静息状态 fMRI 数据，将这些变化与视觉和躯体感觉-运动皮层之间的功能连接相关联。在盲文阅读训练之后，我们观察到早期视觉皮层（外围视野）前部的灰质和白质有大量的重组。此外，与后部的中央凹部分相比，早期视觉皮层的外周代表在训练开始之前就与躯体感觉和运动皮层有更强的功能连接。先前的研究表明，早期视觉皮层可以被功能性地招募用于触觉辨别，包括识别盲文字符。我们的结果表明，由触觉训练引起的该区域的重组也可能是解剖学上的。这种变化很可能反映了外周视觉皮层和躯体感觉皮层之间现有连接的增强，这表明了跨模态招募视觉区域的一个潜在机制。
