Sensory Cortical Organization and Cross-Modal Plasticity in Blind Humans

盲人的感觉皮层组织和跨模式可塑性

• 批准号: 8514241
• 负责人: JOSEF P RAUSCHECKER
• 金额: $ 38.88万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8514241
• 关键词: 2 year old; Address; Animals; Area; Auditory; Auditory area; Biological Preservation; Birth; Blindness; Brain; Brain Injuries; Brain region; Cerebral cortex; Code; Cognitive; Complex; Development; Devices; Diffusion Magnetic Resonance Imaging; Dorsal; Environmental Risk Factor; Face; Fiber; Functional Imaging; Functional Magnetic Resonance Imaging; Funding; Genetic; Grant; Hearing; Housing; Human; Image Analysis; Individual; Lateral; Lead; Magnetic Resonance Imaging; Measures; Methods; Modality; Occipital lobe; Ocular Prosthesis; Parietal; Parietal Lobe; Pathway interactions; Patients; Pattern; Performance; Physiological; Process; Property; Recruitment Activity; Rehabilitation therapy; Relative (related person); Role; Self-Help Devices; Sensory; Sensory Deprivation; Series; Shapes; Signal Transduction; Source; Specificity; Stimulus; Stream; Tactile; Temporal Lobe; Testing; Time; Touch sensation; Vision; Visual; Visual Cortex; Visually Impaired Persons; Visuospatial; Work; base; blind; experience; extrastriate visual cortex; fascinate; frontal lobe; fusiform face area; information processing; multisensory; neuropsychological; public health relevance; rehabilitation strategy; research study; response; sensory cortex; sensory system; sight for the blind; somatosensory; sound; visual deprivation; volunteer; white matter

DESCRIPTION (provided by applicant): Visual deprivation and blindness famously cause certain brain regions to reorganize in response to environmental constraints and in order to compensate for the loss of a sensory modality. Studies in visually deprived animals and blind humans have long demonstrated the cross-modal recruitment of the visual cortex to process nonvisual information. Yet, little is known about the functional specialization of the reorganized visual cortex (VC), its precise role in the processing of nonvisual information, or the source and routing of its nonvisual inputs. The main aims of the present project are, therefore, to (1) determine the functional organization of the occipital cortex in blind volunteers using a sensory substitution device, (2) to examine whether nonvisual information is processed hierarchically in the VC of the blind, and (3) identify the structural basis of adaptive changes and the source of nonvisual input to VC in the blind. Results from three years of funding by this grant have demonstrated that spatial and nonspatial processing streams do indeed exist for auditory and tactile processing (Renier et al., 2009). Furthermore, spatial auditory and tactile processing in the VC of the early blind occur in the same dorsal-stream regions as visual spatial processing in sighted subjects (Renier et al., 2010). These findings have led us to hypothesize that functionally specialized modules are preserved in the cortex of the early blind. We will pursue this hypothesis further by testing paradigms within the ventral stream. Thus, using functional magnetic resonance imaging, we will examine brain activity in blind subjects while they identify (via the auditory modality) houses, faces and 2-D geometrical shapes coded into sound patterns. These experiments will allow us to determine whether the parahippocampal place area (PPA), the fusiform face area (FFA), and the lateral occipital complex (LOC) retain their designated functional roles in early blindness, while switching their input modality. We will also examine the organization of VC by testing whether nonvisual information is processed in a hierarchical manner, in the same way that normal sensory information is processed in its intact sensory system. Using complexity-varied pitch information, we will determine if early-to-late visual regions of the blind respond to sound in the direction of simple-to-complex levels of pitch processing. Finally, using diffusion tensor imaging (DTI) and analysis of functional connectivity, we will investigate the structural basis of adaptive changes in the cerebral cortex and white matter of blind subjects. Using DTI, we will examine the strength of white-matter fiber tracts projecting to and from VC in both subject groups, thus determining relative changes in the connections between VC and other cortical areas. We will also test how visual and other sensory areas interact during auditory and tactile information processing in blind and sighted volunteers, and whether this interaction depends on the strength of anatomical pathways connecting these areas. Combining the two different methodological approaches will provide us an excellent opportunity to identify the source of nonvisual inputs to VC in the early blind.

描述（由申请人提供）：视觉剥夺和失明会导致某些大脑区域对环境限制进行重组，并为了弥补感官方式的丧失。长期以来，对视觉剥夺动物和盲人人类的研究表明，视觉皮层的跨模式募集以处理非视觉信息。然而，关于重组视觉皮层（VC）的功能专业知识，其在非视觉信息的处理中的精确作用，或其非视觉输入的源和路由，知之甚少。因此，本项目的主要目的是（1）使用感官替代设备确定盲志愿者枕皮层的功能组织，（2）检查是否在盲人的VC中进行了层次处理的非视觉信息，（3）确定适应性变化的结构性基础和非视觉范围的源源是VC intult of vc in the Indun of vc in the of vc in n of vc in n of vc in n of vc in n of vc in n of vc in n of vc。这笔赠款的三年资金结果表明，确实存在于听觉和触觉处理的空间和非空间处理流（Renier等，2009）。此外，早期盲人风险投资中的空间听觉和触觉处理与视觉受试者的视觉空间处理相同的背流区域发生（Renier等，2010）。这些发现使我们假设在早期盲人的皮层中保存了功能专业的模块。我们将通过测试腹侧流中的范例进一步追求这一假设。因此，使用功能性磁共振成像，我们将在盲人（通过听觉方式）房屋，面部和2D几何形状识别编码为声音模式的情况下（通过听觉模式），检查盲人的大脑活动。这些实验将使我们能够确定Parahampocal Plote区域（PPA），梭形面部（FFA）和外侧枕骨复合物（LOC）是否在早期失明中保留其指定的功能作用，同时切换其输入方式。我们还将通过测试是否以层次方式处理非视觉信息来检查VC的组织，就像在完整的感觉系统中处理正常的感觉信息一样。使用复杂性变化的音高信息，我们将确定盲人的早期视觉区域是否朝着简单到复杂的音高处理水平的方向响应声音。最后，使用扩散张量成像（DTI）和功能连接性分析，我们将研究大脑皮层和白质的自适应变化的结构基础。使用DTI，我们将检查两个学科组中投射和从VC投射和从VC投射的白物纤维道的强度，从而确定VC与其他皮质区域之间的连接相对变化。我们还将测试视觉和其他感觉区域在盲人和视力志愿者中的听觉和触觉信息处理过程中的相互作用，以及这种相互作用是否取决于连接这些区域的解剖途径的强度。结合两种不同的方法论方法将为我们提供一个绝佳的机会，以确定早期盲人中VC的非视觉投入来源。