Neural Basis of Endogenous Potentials in Humans

描述（由申请人提供）：可以通过使用脑电图（EEG）和脑磁图（MEG）测量由活跃神经元产生的微小电流来探测人脑功能。神经元活动也会导致血氧和血流的局部变化，这可以使用功能性磁共振成像（fMRI）来测量。功能磁共振成像（fMRI）提供了认知过程中大脑激活的直接定位，但时间分辨率较差。相反，EEG/MEG提供毫秒级的准确性，但它们在大脑中出现的位置很难确定。该资助的第一个目标是将fMRI的空间分辨率与EEG/MEG的时间分辨率结合起来，以产生大脑激活的时空地图。联合收割机。将使用直接在大脑内进行的EEG记录（进行该记录是为了定位耐药性癫痫患者的癫痫发作病灶）来验证这些标测图的准确性。这些地图将有助于揭示思维过程中大脑区域活跃的位置和时间。该基金的第二个目的是更好地了解这些地图代表了什么样的神经元活动。线性微电极阵列将用于相同的主题和任务，以估计群体突触电流（神经元输入）和神经元放电（输出）在不同的皮层层。因此，在全脑研究中发现的“激活”将被描述为兴奋与抑制，输入与输出，以及自上而下与自下而上的相互作用。拟议的研究应该提供不同的大脑成像模式如何查看功能性大脑活动的见解，以及如何将它们整合以跟踪通过思考的人类大脑的激活通道。这项技术也应该是有用的定位病理活动。此外，所提出的研究可能有助于构建认知功能神经模型。这些模型对于理解神经精神疾病中认知是如何被破坏的是必要的。最后，关于认知电位发生器的更完整的知识将大大增加其作为神经或精神疾病患者特定大脑系统功能测试的价值。具体而言，对语言和记忆的研究将为术前无创性绘制功能皮层提供科学依据。

DESCRIPTION (provided by applicant): Human brain function can be probed by measuring the minute currents produced by active neurons using electroencephalography (EEG) and magnetoencephalography (MEG). Neuronal activity also results in localized changes in blood oxygenation and flow, which can be measured using functional magnetic resonance imaging (fMRI). fMRI provides direct localization of brain activation during cognition, but with poor temporal resolution. Conversely, EEG/MEG provides millisecond accuracy, but the location in the brain where they arise is hard to determine. The first aim of this grant is to combine the spatial resolution of fMRI with the temporal resolution of EEG/MEG to produce spatiotemporal maps of brain activation. The accuracy of these maps will be validated using EEG recordings from directly within the brain (conducted in order to localize the seizure focus in patients with pharmaco-resistant epilepsy). These maps will help reveal where and when brain areas are active during thought. The second aim of the grant is to better understand what kind of neuronal activity these maps represent. Linear microelectrode arrays will be used in the same subjects and tasks to estimate population synaptic currents (neuronal inputs) and neuronal firing (outputs) in different cortical layers. The 'activation' found in the whole-brain studies will thus be characterized as excitation vs inhibition, input vs output, and top-down vs bottom-up interactions. The proposed studies should provide insights into how the different brain imaging modalities view functional brain activity, and how they may be integrated in order to trace the passage of activation through the thinking human brain. This technique should also be useful for localizing pathological activity. In addition, the proposed studies may help in the construction of functional neural models for cognition. Such models are necessary to understand how cognition is disrupted in neuropsychiatric disorders. Finally, more complete knowledge regarding the generators of cognitive potentials should greatly increase their value as functional tests for specific brain systems in patients with neurological or psychiatric disease. Specifically, studies on language and memory will provide a scientific basis for the non-invasive mapping of eloquent cortex prior to surgery.