CRCNS: Processing speed in the human connectome across the lifespan

人脑中的通路形成了一个支持大脑功能的大网络。这种连接体的结构在整个生命周期中都会发生变化，众所周知，白质通路从童年发展到老年。然而，人们对这些变化如何影响这些以毫秒为时间尺度处理信息的通路之间的功能性交流还不太了解。研究人类大脑功能连接的这些时间特性的一种独特方法是通过单脉冲，颅电极的电刺激，脉冲沿着皮层网络传播，可以研究方向性和传输速度。然而，这些颅内电极被放置在癫痫治疗的临床目的中，导致患者之间的位置有很大的差异。为了能够对特定网络进行全面的研究，我们需要找到一种方法，将多学科颅内神经生理数据整合到一个单一的坐标空间中，并将其结合到一个专用的结构化数据库中。该合作项目将组织一个大型数据库，包括现有的和新获得的单脉冲脑电刺激颅内脑电图（iEEG）数据。通过社区的努力，脑电图数据的标准结构正在开发：脑电图数据结构扩展到脑成像数据结构（eeg - bids）。神经成像数据将与脑电图数据一起存储在BIDS结构中，以绘制每个电极的解剖位置，这样在同一网络上具有电极的受试者可以很容易地识别。所有的BIDS元数据都是人类和机器可读的，允许轻松地提取电极覆盖同一网络的受试者。我们将开发应用程序来确定刺激诱发反应在网络中的速度和方向性，使我们能够评估与年龄相关的人类连接组前馈和反馈处理的时间特性变化，包括许多认知功能和精神疾病所涉及的途径。该项目将为人类连接组在整个生命周期中传输的速度和方向性提供独特的见解，这对于建立人类大脑功能的网络模型和开发调节与金属疾病相关的网络的新型治疗性脑刺激技术是必要的。

The pathways in the human brain form a large network that supports brain function. The structure of this connectome changes across the life span, and it is well known that white matter pathways develop from childhood to old age. It is, however, less well understood how these changes influence the functional communication across these pathways, which processes information on the timescale of milliseconds. A unique way of studying these temporal properties of functional connectivity in the human brain is through single pulse, electrical stimulation of intracranial electrodes, where pulses spread along cortical networks and the directionality and transmission speed can be studied. However, these intracranial electrodes are placed for clinical purposes in epilepsy treatment, resulting in quite some variation in locations across patients. To enable comprehensive research on specific networks, we need to find a way of consolidating multi-subject intracranial neurophysiological data into a single coordinate space, and combine this in a dedicated and structured database. This collaborative project will organize a large database of existing and newly acquired intracranial electroencephalography (iEEG) data with single pulse electrical brain stimulation. Through a community effort, a standard structure for iEEG data is being developed: the iEEG extension to the Brain Imaging Data Structure (iEEG-BIDS). Neuroimaging data will be stored in the BIDS structure alongside iEEG data to map the anatomical location of every electrode, such that subjects with electrodes on the same network can be easily identified. All BIDS metadata are both human and machine readable, allowing the easy extraction of subjects with electrodes covering the same network. BIDS apps will be developed to determine the speed and directionality across networks from the stimulation-evoked responses, allowing us to assess age related changes in the temporal properties of feedforward and feedback processing across the human connectome, including the pathways involved in many cognitive functions and psychiatric illnesses. This project will add unique insight into the speed and directionality of transmission along the human connectome across the life span, which is necessary to build network models of human brain function and develop novel therapeutic brain stimulation technologies that modulate the networks involved in metal illnesses.