Cortical organization of object knowledge before and after brain surgery

项目摘要 切除脑内肿瘤的手术可能会导致意外的认知障碍。这是 特别是当为了接近肿瘤而必须切除健康组织（皮质切除术）时的情况。的 皮质切除术对神经功能和认知结果的影响仍然知之甚少。最近 功能磁共振成像在脑区动态相互作用研究中的进展 （功能磁共振成像）数据收集，而受试者在休息，没有明显的刺激或任务，开辟了新的视野， 研究根治性切除脑内肿瘤的神经后果。这种成像方式是很好的 适合在临床环境中应用和开发，因为数据可以从以下患者收集： 异质认知能力作为他们标准临床评估的一部分。 根据对象的功能识别和使用对象的能力（例如，叉子，锤子，铅笔）需要 颞叶和顶叶皮层的多个大脑区域之间的协调处理。这些认知能力 可能在切除颞叶或顶叶脑肿瘤的神经外科手术后受损。拟议 一项研究计划使用静息功能磁共振成像来研究大脑皮层网络的组织， 共同的对象。在颞叶和顶叶有脑瘤的病人将接受刺激扫描- 在手术前和手术后将进行详细的神经心理学测试。 使用基于刺激的fMRI定义的感兴趣区域（ROI），将量化功能连接 在支持客体知识的颞顶叶皮层网络中。根据以前的PI 研究，具体的假设是先进的预期变化的连接作为一个功能， 脑肿瘤的位置和切除肿瘤的手术方法的性质。这些假设 然后通过将手术后数据与手术前数据进行比较，并将功能变化 连接到认知能力的变化。为此，开发了一种新的方法，该方法应用分析 一种将病变-症状映射到功能磁共振成像连接图的工具，以便能够导出全脑图 显示功能连接的变化如何与认知表现的变化相关。 这项研究计划有两个目标。首先，它将产生一种新型的反馈， 神经外科医生的结局，将为接受脑内切除术的患者的手术计划提供信息 肿瘤的第二，关于支持视觉物体识别的脑功能网络的假设， 物体的使用进行测试，因果推理得出的大脑过程，有利于这些复杂的 行为。

Project Summary Surgery for removal of intrinsic brain tumors can lead to unintended cognitive impairments. This is particularly the case when healthy tissue must be resected (corticectomy) in order to access the tumor. The consequences of corticectomy for neural function and cognitive outcome remain poorly understood. Recent advances in studying dynamic interactions among brain regions using functional magnetic resonance imaging (fMRI) data collected while subjects are at rest, with no overt stimulus or task, open up new horizons for studying the neural consequences of radical resection of intrinsic brain tumors. This imaging modality is well suited for application and development within a clinical setting, as data may be collected from patients of heterogeneous cognitive abilities as part of their standard clinical assessment. The ability to recognize and use objects according to their function (e.g., fork, hammer, pencil) requires coordinated processing across multiple brain regions in temporal and parietal cortex. Those cognitive abilities can be compromised after neurosurgery for removal of temporal or parietal lobe brain tumors. The proposed research program uses resting fMRI to study the organization of the cortical networks supporting knowledge of common objects. Patients with brain tumors in the temporal and parietal lobes will be scanned with stimulus- based and resting fMRI and will undergo detailed neuropsychological testing before surgery and after surgery. Using regions of interest (ROIs) defined with stimulus-based fMRI, functional connectivity will be quantified within the temporal-parietal cortical network supporting object knowledge. On the basis of the PIs previous research, specific hypotheses are advanced about anticipated changes in connectivity as a function of the location of the brain tumor and the nature of the surgical approach for removal of the tumor. Those hypotheses are then tested by comparing the post-surgery data to the pre-surgery data, and relating changes in functional connectivity to changes in cognitive abilities. To this end, a new method is developed that applies the analytical tool of lesion-symptom mapping to fMRI connectivity maps in order to be able to derive whole brain maps showing how changes in functional connectivity are related to changes in cognitive performance. This research program serves two goals. First, it will generate a new type of feedback about patient outcome to neurosurgeons that will inform surgical planning in patients undergoing resection of intrinsic brain tumors. Second, hypotheses about the functional brain networks that support visual object identification and object use are tested, and causal inferences are drawn about the brain processes that subserve those complex behaviors.