Neural basis of Braille literacy in blind adults and children

项目摘要 目前的项目研究了熟练的先天性失明成年人、晚期失明者和盲人的盲文阅读的神经基础。 不同熟练程度的读者和盲童学习阅读，使用功能磁共振成像和高密度 弥散成像（dMRI）。这些盲文识字的研究提供了对人类大脑可塑性和 文化的神经基础。 阅读改变了人类大脑的结构和功能。在视力正常的人中，阅读经验 增强视觉和语言网络内部和之间的解剖学通路。视力良好的读者 枕颞侧腹侧皮层（IVOT）的“视觉词形区”（VWFA），对字母和单词进行调谐。 布莱叶通过区分阅读的哪些方面， 大脑是模态不变的，并且是模态特异性的。目前的建议区分了两个 替代假设根据基于任务的假设，盲人阅读者发展了相同的神经系统。 在lVOT中观察到的阅读机制并显示出类似的连接变化，因为lVOT是 固有地倾向于模态不变形状识别。相比之下， 假设认为连接性和经验对阅读定位有重要影响。因此 预测盲人发展触觉词形区（TWFA）在顶叶区域， 连接到体感和语言网络。它还预测， 这些顶叶网络的解剖连接。 目的1探讨先天性失明成人的神经变化支持这种专家阅读。熟练 盲文阅读器的速度可以达到每分钟200个单词甚至更多。是什么样的神经变化 能力？在一系列的功能磁共振成像实验中，我们使用了MVPA和功能磁共振成像， 适应测试我们的假设，熟练的盲人读者开发'触觉词形区' TWFA在 后顶叶皮层和连接的枕背区。目标2检验了个人 顶叶区的连接性（dMRI）和功能特化的差异预测个体 先天性失明和晚期失明成年人的阅读能力差异，而 早期视觉区域只能预测先天性失明人群的个体差异。目标3测试关键 预测TWFA专业化和盲文阅读相关的连接变化是由于 通过对先天性失明儿童（dMRI和fMRI）的纵向研究，在他们学习阅读的过程中进行扫盲。 揭示成功的盲文识字的神经标记将测试人类大脑可塑性的理论，并促进 并为提高盲人的盲文识字率提供信息。

PROJECT SUMMARY The current project examines the neural basis of Braille reading in proficient congenitally blind adults, late blind readers with varying degrees of proficiency and blind children learning to read, using fMRI and high-density diffusion imaging (dMRI). These studies of Braille literacy provide insights into human brain plasticity and the neural basis of culture. Reading changes the anatomy and function of the human brain. In sighted people, reading experience enhances anatomical pathways within and across visual and language networks. Sighted readers develop a ‘visual word form area’ (VWFA) in lateral ventral occipito-temporal cortex (lVOT), tuned to letters and words. Braille offers insights into the mechanisms of cultural recycling by disentangling which aspects of the reading brain are modality invariant and which are modality specific. The current proposal distinguishes between two alternative hypotheses. According to the task-based hypothesis, blind readers develop the same neural mechanisms for reading as the sighted in the lVOT and show similar connectivity changes, because lVOT is intrinsically predisposed for modality-invariant shape recognition. By contrast, the connectivity-based hypothesis proposes that connectivity and experience heavily influence reading localization. It therefore predicts that blind individuals develop tactile word form areas (TWFAs) in parietal regions with strong connectivity to somatosensory and language networks. It also predicts that Braille literacy enhances anatomical connectivity of these parietal network. Aim 1 investigates the neural changes support this expert reading in congenitally blind adults. Proficient Braille readers can achieve speeds of 200 words per minute and more. What neural changes enable this ability? In a series of fMRI experiments with congenitally blind proficient readers we use MVPA and fMRI adaptation to test our hypothesis that proficient blind readers develop ‘tactile word form areas’ TWFAs in posterior parietal cortex and connected dorsal occipital areas. Aim 2 tests the prediction that individual differences in the connectivity (dMRI) and functional specialization of parietal areas predicts individual differences in reading proficiency among congenitally and late blind adults, whereas individual differences in early visual areas only predict individual differences in the congenitally blind population. Aim 3 tests the key prediction that TWFA specialization and Braille-reading associated connectivity changes emerge as a result of literacy by working with congenitally blind children (dMRI and fMRI) longitudinally, as they learn to read. Uncovering neural markers of successful Braille literacy will test theories of human brain plasticity and facilitate and inform strategies for enhancing Braille literacy among people who are blind.