Visual cortex plasticity in blindness: a window into flexibility of human cortex

失明时的视觉皮层可塑性：了解人类皮层灵活性的窗口

基本信息

批准号：
10203995
负责人：
Marina Bedny
金额：
$ 44.9万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-30 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10203995
关键词：
6 year old Adult Affect Age Arithmetic Behavior Birth Blindness Brain Code Cognition Cognitive Data Development Developmental Disabilities Equation Functional Magnetic Resonance Imaging Functional disorder Future Grant Human Impairment Individual Language Light Linguistics Longevity Mathematics Neurologic Parietal Participant Pattern Physiology Population Publishing Rest Rod Series Short-Term Memory Side Sound Localization Stroke Structure Testing Time Tissues Touch sensation Transcranial magnetic stimulation Traumatic Brain Injury Vision Visual Visual Cortex Visual Pathways Visual impairment Visually Impaired Persons Work base blind clinical application cognitive control cognitive disability cognitive function cognitive neuroscience cognitive performance cognitive task design developmental disease experience experimental study flexibility insight mathematical difficulties pluripotency relating to nervous system response retinotopic sound theories

项目摘要

PROJECT SUMMARY How functionally flexible is human cortex? The current proposal approaches this question by studying visual cortex plasticity in blindness. In individuals who are blind from birth, so-called “visual” cortices respond to touch and sound. How similar are these new functions to the original visual computations? A longstanding view is that functional reorganization is limited, even in cases of plasticity. Our recent published work and preliminary data, however, suggest that functional reorganization in the visual cortices of blind individuals may be more radical than previously thought. We find that regions within retinotopic visual cortices are active during language and math tasks, and that this activity is sensitive to the grammatical structure of sentences and the difficulty of math equations. Such functional repurposing is striking, in light of the cognitive and evolutionary differences between vision, language and mathematics. These new findings offer an unprecedented opportunity to test the limits of human cortical flexibility. In this proposal we test the hypothesis that human cortex is functionally pluripotent: capable of assuming a wide range of cognitive functions depending on input, where input is determined by experience and connectivity. We hypothesize that language-related plasticity in visual cortices is part of a broader phenomenon whereby, in blindness, visual cortices are colonized by multiple distinct higher-cognitive functions as a result of strong connectivity between visual cortex and higher-cognitive networks, and fronto-parietal networks in particular. Up until now there has been little evidence for specialization within visual cortices of blind individuals. Aim 1 tests the prediction that in individuals who are blind from birth different regions within visual cortices are specialized for: language, number, and cognitive control and that specialization is related to connectivity with different fronto-parietal networks. In the first part of Aim 2, we use multi-voxel pattern analysis and fMRI adaptation to test the prediction that visual cortices of blind individuals represent higher-cognitive information, such as the meanings of words and numerical quantity. Next we test the prediction that visual cortices are functionally relevant to higher-cognitive behavior using transcranial magnetic stimulation (TMS). Aim 3 examines the time-course of visual cortex plasticity during the lifespan. By working with individuals who lost their sight at different ages we test the hypothesis that cortex assumes higher-cognitive functions only during a sensitive period of development. This work is highly relevant to understanding the pathophysiology of visual impairments and uncovering the timing and mechanisms by which blindness affects the human brain. The insights about plasticity to be gained from the proposed project have far-reaching relevance for optimizing cortical function in the context of neurological and cognitive disabilities.

项目摘要人皮质在功能上的灵活性如何？当前的建议通过研究视觉皮层来解决这个问题失明中的可塑性。在从出生时失明的个人中，所谓的“视觉”皮层对触摸和声音做出了反应。这些新功能与原始视觉计算有多相似？长期以来的看法是功能即使在可塑性的情况下，重组也是有限的。但是，我们最近发表的工作和初步数据表明盲人视觉皮层中的功能重组可能比以前想象的更为激进。我们发现视网膜视觉皮层中的区域在语言和数学任务中处于活动状态，并且此活动是对句子的语法结构和数学方程的难度敏感。这样的功能重新调整是鉴于视觉，语言和数学之间的认知和进化差异，引人注目。这些新调查结果提供了一个前所未有的机会，可以测试人类皮质柔韧性的极限。在此提案中，我们测试了假设人皮质在功能上是多能的：能够假设广泛的认知功能取决于输入，其中输入取决于经验和连接性。我们假设与语言有关的视觉皮质中的可塑性是一种更广泛现象的一部分，在盲目中，视觉皮质被殖民由于视觉皮层和高认知之间的牢固连通性，多种不同的高认知功能网络，尤其是额叶网络。到目前为止，几乎没有证据表明专业盲人的视觉皮层。 AIM 1测试以下预测，即在出生失明的个体中视觉皮层内的区域专门用于：语言，数字和认知控制，并且专业化是相关的与不同的额叶网络连接。在AIM 2的第一部分中，我们使用多素模式分析和 fMRI改编以测试盲人的视觉皮质代表更高认知信息的预测，例如单词和数值的含义。接下来，我们测试视觉皮层是功能上的预测使用经颅磁刺激（TMS）与高认知行为相关。 AIM 3检查寿命期间视觉皮层可塑性。通过与在不同年龄段失去视线的个人一起工作，我们可以测试假设Cortex仅在敏感的发展时期才具有更高的认知功能。这项工作是与理解视觉障碍的病理生理学高度相关，并发现时间和机制失明会影响人脑。关于从拟议项目中获得可塑性的见解已有在神经和认知障碍的背景下优化皮质功能的深远相关性。