Neural Plasticity Associated with Braille Learning

与盲文学习相关的神经可塑性

• 批准号: 6942264
• 负责人: Alvaro Pascual-Leone
• 金额: $ 42.5万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6942264
• 关键词: auditory pathways; behavioral /social science research tag; blindness; clinical research; functional magnetic resonance imaging; hearing; human subject; learning; neural information processing; neural plasticity; occipital lobe /cortex; perception; performance; psychophysics; sensorimotor system; sensory discrimination; touch; transcranial magnetic stimulation; vision tests; visual cortex; visual deprivation

DESCRIPTION (provided by applicant): In our initial funding cycle we compared sighted subjects who were visually deprived for five days with non-visually deprived sighted subjects as they learned tactile Braille character recognition. Serial psychophysics and functional magnetic resonance imaging (fMRI) studies revealed that (1) visually deprived subjects learn tactile Braille reading significantly faster than non-visually deprived sighted subjects; and that (2) learning Braille in visually deprived subjects is associated with activation of occipital visual cortex. Furthermore, we found that auditory information processing can also be associated with activation of the occipital cortex in visually deprived subjects. These results are reminiscent of the findings in early blind subjects in whom the occipital cortex is recruited for tactile Braille reading and auditory processing. However, the rapid time course of our findings in the blindfolded sighted subjects is remarkable and raises questions about its functional significance and underlying mechanisms. The present proposal is designed to address these issues. Visually deprived normal subjects with or without intensity tactile stimulation and Braille teaching will be compared with sighed controls. Comparisons will be made with-in subjects across time and across subjects comparing the different study groups. All subjects will undergo three experiments repeated at various times during the study. First, we will use fMRI of a spatial and a non-spatial visual, tactile and auditory task to reveal information about which specific brain areas are activated in association with a given perceptual operation and sensory modality. We hypothesize that (1) the same occipital areas recruited during visual spatial tasks in sighted subjects will also be recruited, in the visually-deprived state, during auditory and tactile spatial tasks; and (2) the same relation will be true for the non-spatial tasks, but less involvement of the occipital cortex will be noted. Second, transcranial magnetic stimulation (TMS) will be used to provide information about whether and when the contribution of a given cortical region is critical for task performance. We hypothesize that (1) in blindfolded subjects performance in spatial tasks (both tactile or auditory versions) will be disrupted by TMS of the occipital cortex easier than performance in non-spatial tasks; and that (2) the timing of TMS of the occipital cortex for disruption of spatial tactile and auditory tasks will be different. Finally, transcranial stimulation during fMRI will be used to study changes in functional connectivity of the visual cortex that may arise during the visual-deprivation and account for the activation of the visual cortex during tactile and auditory processing. The results will further characterize cross modal plasticity during visual deprivation, and illustrate fundamental aspects of the mechanisms involved in determining cortical functional specificity and those engaged in perceptual representation of the world.

描述（由申请人提供）：在我们最初的资助周期中，我们将视力受损的正常受试者与非视力受损的正常受试者进行了五天的比较，因为他们学习了触觉盲文字符识别。一系列心理物理和功能磁共振成像（fMRI）研究表明：(1)视障被试学习触觉盲文阅读显著快于非视障被试；(2)盲文学习与枕部视觉皮层的激活有关。此外，我们发现听觉信息处理也可能与视觉剥夺受试者枕皮质的激活有关。这些结果让人想起早期失明受试者的发现，他们的枕叶皮层被用于触觉盲文阅读和听觉处理。然而，我们的研究结果在蒙眼视力受试者中的快速时间过程是显著的，并提出了关于其功能意义和潜在机制的问题。本提案旨在解决这些问题。将视障正常受试者进行或不进行强烈触觉刺激和盲文教学，并与叹气对照组进行比较。比较将在不同时间的研究对象之间进行，并在不同研究小组之间进行比较。所有受试者将在研究期间的不同时间重复进行三个实验。首先，我们将使用空间和非空间视觉、触觉和听觉任务的功能磁共振成像来揭示与给定的感知操作和感觉模式相关的特定大脑区域被激活的信息。我们假设：(1)视力正常的受试者在视觉空间任务中所招募的枕部区域在视觉剥夺状态下也会在听觉和触觉空间任务中被招募；(2)非空间任务也存在同样的关系，但枕叶皮层的参与较少。其次，经颅磁刺激（TMS）将被用来提供关于特定皮质区域是否以及何时对任务表现起关键作用的信息。我们假设：(1)蒙眼受试者在空间任务（包括触觉或听觉）中的表现比在非空间任务中的表现更容易受到枕叶皮层经颅磁刺激的干扰；(2)枕叶皮层对空间触觉和听觉任务中断的TMS时间会有所不同。最后，fMRI期间的经颅刺激将用于研究视觉剥夺期间可能出现的视觉皮层功能连通性的变化，并解释触觉和听觉加工期间视觉皮层的激活。这些结果将进一步表征视觉剥夺期间的跨模态可塑性，并说明决定皮质功能特异性和参与世界感知表征的机制的基本方面。