Inferring Cortical Feed-Forward and Feedback Processes with Human Neuroimaging

利用人类神经影像推断皮质前馈和反馈过程

• 批准号: 7454312
• 负责人: SEPPO PENTTI AHLFORS
• 金额: $ 42.43万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7454312
• 关键词: Address; Area; Brain; Cerebral cortex; Characteristics; Cognitive; Communication; Computer Simulation; Computer information processing; Contralateral; Data; Disease; Electroencephalography; Evaluation; Feedback; Fusiform gyrus; Human; Image; Invasive; Ipsilateral; Lead; Magnetoencephalography; Measures; Modeling; Monkeys; Nature; Pattern; Primates; Process; Property; Research; Research Personnel; Resolution; Solutions; Somatosensory Cortex; Source; Stimulus; Structure; Synapses; Testing; Time; Visual; base; cognitive function; cognitive neuroscience; feeding; insight; median nerve; neuroimaging; neuromechanism; novel; object perception; object recognition; relating to nervous system; response; somatosensory; spatiotemporal; theories; white matter

DESCRIPTION (provided by applicant): A central question related to information flow in the human brain is: how do bottom-up and top-down influences interact in the cerebral cortex? A hypothesis is proposed that could form the basis for a novel way to use non-invasive neuroimaging to address this question. Specifically, the direction of the current dipoles detected by magneto- and electroencephalography (MEG, EEG) is expected to be a function of whether the measured activation is a result of top-down (feedback) or bottom-up (feed-forward) flow in the cortex. This hypothesis is founded on the principle that feed-forward and feedback connections into a cortical area have characteristic laminar pattern of synaptic inputs. Consequently, knowing which of the cortical layers received a certain input could be highly informative about the source of this input, and more generally about inter- cortical communication. Such insights about the laminar structure are beyond the resolution of human neuroimaging. However, the proposal that the different types of laminar inputs might result in macroscopic dipoles with different polarities has the potential to provide a powerful non-invasive solution. The overall hypothesis is evaluated using three different approaches: biophysically realistic computational modeling (Aim 1), comparison of somatosensory MEG/EEG responses with intracranial primate recordings (Aim 2), and evaluation of experimental predictions about the polarity of MEG/EEG sources derived from a cognitive neuroscience theory of visual object perception (Aim 3). This research is anticipated to enable non-invasive inference of information flow in networks of cortical areas. It will provide a novel way to apply MEG/EEG recordings to studies of cognitive processing and interpret MEG/EEG in the context of large-scale integrative theories of the brain. It could lead to a better understanding of the neural mechanisms underlying cognitive functions, as well as to potential applications for revealing mechanisms of neural disorders.

描述（由申请人提供）：与人脑信息流有关的一个核心问题是：自下而上和自上而下的影响在大脑皮层中如何相互作用？提出了一个假设，它可以构成一种新型方式使用非侵入性神经影像来解决这个问题的基础。具体而言，预计通过磁脑和脑电图（MEG，EEG）检测到的当前偶极子的方向是测量激活是由于皮质中自上而下的（反馈）还是自下而上（反馈）的结果。该假设建立在以下原则上：进料和反馈连接到皮质区域具有突触输入的特征层流模式。因此，知道哪个皮质层收到的一定输入可能会对此输入的来源有很高的信息，更普遍地讲述了互通信的信息。关于层状结构的这种见解超出了人类神经影像的解决。但是，关于不同类型的层流输入可能会导致具有不同极性的宏观偶极子的提议有可能提供强大的非侵入性解决方案。使用三种不同的方法评估了总体假设：生物物理上现实的计算建模（AIM 1），将体感MEG/EEG反应与颅内灵长类记录（AIM 2）进行比较，以及对MEG/EEG极性的实验预测评估。预计这项研究将使皮质区域网络中信息流的无创推理。它将提供一种新颖的方式，将MEG/EEG记录应用于认知处理的研究，并在大脑的大规模综合理论的背景下解释MEG/EEG。它可能会更好地理解认知功能的神经机制，以及揭示神经疾病机制的潜在应用。