Neural Plasticity Associated with Braille Learning

与盲文学习相关的神经可塑性

• 批准号: 6611540
• 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/6611540
• 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(申请人提供)：在我们最初的资助周期中，我们比较了视力剥夺5天的视力受试者和非视觉剥夺视力受试者，因为他们学习了触觉盲文字符识别。一系列心理物理学和功能磁共振成像(FMRI)研究表明：(1)视觉剥夺者学习触觉盲文阅读的速度显著快于非视觉剥夺者；(2)视觉剥夺者学习盲文与枕叶视皮层的激活有关。此外，我们还发现，在视觉剥夺的受试者中，听觉信息处理也与枕叶皮质的激活有关。这些结果让人想起在早期失明受试者中的发现，在这些受试者中，枕叶皮质被招募来进行触觉盲文阅读和听觉处理。然而，我们在蒙眼受试者身上发现的快速时间进程是值得注意的，并引发了对其功能意义和潜在机制的质疑。本提案旨在解决这些问题。有或没有强度触觉刺激和盲文教学的视觉剥夺正常受试者将与有叹息的对照组进行比较。将在不同的时间和不同的研究对象之间进行比较，比较不同的研究小组。所有受试者将在研究过程中的不同时间重复进行三次实验。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知觉操作和感觉通道相关的特定大脑区域被激活的信息。我们假设(1)在视觉剥夺状态下，有视力的受试者在听觉和触觉空间任务中也会招募到在视觉空间任务中招募到的相同枕区；(2)对于非空间任务，同样的关系也适用于非空间任务，但枕叶皮质的参与会较少。其次，经颅磁刺激(TMS)将被用来提供关于给定皮质区域的贡献是否以及何时对任务绩效至关重要的信息。我们假设(1)蒙眼受试者在空间任务(无论是触觉任务还是听觉任务)中的表现比非空间任务更容易受到枕叶皮质TMS的干扰；以及(2)枕叶皮质TMS干扰空间触觉和听觉任务的时间不同。最后，功能磁共振期间的经颅刺激将被用来研究视觉剥夺过程中可能出现的视觉皮质功能连接的变化，并解释视觉皮质在触觉和听觉处理过程中的激活。这些结果将进一步表征视觉剥夺过程中的跨模式可塑性，并阐明决定皮层功能特异性的机制和参与世界知觉表征的机制的基本方面。