Cortical organization of object knowledge before and after brain surgery

项目摘要 切除固有脑瘤的手术可能会导致意想不到的认知障碍。这是 尤其是当健康组织必须切除(皮质切除)才能接触到肿瘤的情况下。这个 皮质切除对神经功能和认知结果的影响仍然知之甚少。近期 功能磁共振成像研究脑区间动态相互作用的研究进展 (功能磁共振成像)在没有明显刺激或任务的情况下，在受试者休息时收集的数据，为 研究脑内固有肿瘤根治性切除的神经后果。这种成像方式很好 适合于在临床环境中应用和开发，因为数据可能收集自 不同的认知能力作为他们标准临床评估的一部分。 根据物体的功能(如叉子、锤子、铅笔)识别和使用物体的能力需要 在颞叶和顶叶皮质的多个大脑区域之间进行协调处理。这些认知能力 在切除颞叶或顶叶脑肿瘤的神经外科手术后可能会受到损害。建议数 研究程序使用静息fMRI来研究支持知识的皮质网络的组织 常见对象。患有颞叶和顶叶脑瘤的患者将接受刺激扫描- 并将在手术前和手术后接受详细的神经心理测试。 使用基于刺激的功能磁共振成像定义的感兴趣区(ROI)，功能连接将被量化 在支持对象知识的时间-顶叶皮质网络内。根据先前的个人资料调查 研究中，提出了关于连接作为函数的预期变化的具体假设 脑肿瘤的位置和切除肿瘤的手术入路的性质。那些假设 然后通过比较手术后数据和手术前数据以及相关的功能变化来进行测试 认知能力变化的连通性。为此，发展了一种新的方法，该方法应用于分析 将病变-症状映射到fMRI连接图的工具，以便能够得出整个脑图 展示了功能连接性的变化与认知表现的变化之间的关系。 这项研究计划有两个目标。首先，它将生成一种关于患者的新型反馈 神经外科医生的结果将为固有脑切除患者的手术计划提供信息 肿瘤。第二，关于大脑功能网络的假设，这些网络支持视觉对象识别和 测试对象的使用，并得出关于帮助这些复杂的大脑过程的因果推断 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.