Non-invasive Fast Optical Imaging of Visual and Motor Processing

描述(由申请人提供)： 近红外光谱(NIRS)是一种很有前途的工具，是唯一可能同时对神经元活动(快信号)和脑血流动力学敏感的成像技术。我们的建议是对RFA-EB-05-001的回应，旨在展示NIRS使用可能适合于发育障碍人群的脑功能成像的方法非侵入性监测神经活动的能力。我们最近的数据表明，可以从人类头皮非侵入性地记录与任务相关的快速近红外信号，并且可以通过包括1)自适应滤波、2)高通时间滤波、3)时频分解和4)独立分量分析的多步骤信号处理序列来提高微弱快速光信号的信噪比。结果，可以以毫秒范围内的时间分辨率可靠地记录多个频带(例如，θ和伽马频带)内的光学信号中的功能相关的瞬时变化。然后，这些神经元活动的变化可以通过重建技术进行映射，其空间分辨率与功能磁共振成像技术的空间分辨率相当。因此，对神经元活动的快速光学成像可以潜在地获得良好的时间和空间分辨率。拟议项目的目标是：1)开发一个可容纳多达256个电极和光学探测器的传感器网络，从而能够全面覆盖头部并同时记录光学和脑电信号；2)开发改进的仪器和分析方法，以可靠地检测快速近红外信号；3)开发基于快速光学信号的改进的脑成像方法；以及4)通过同时记录光学和高密度脑电信号，证明快速光学信号与神经元活动密切相关，这些自闭症和对照受试者正在执行涉及视觉和感觉运动处理的任务，例如物体识别或反应竞赛。拟议的研究将推进、测试和表征非侵入性快速近红外光谱技术的功能能力，并将确立其在分析健康和疾病中视觉和感觉运动处理的神经机制方面的潜在效用。

DESCRIPTION (provided by applicant): Near-infrared spectroscopy (NIRS) is a promising tool, being the only imaging technique potentially sensitive to both neuronal activity (fast signal) and brain hemodynamics. Our proposal is a response to RFA-EB-05- 001 and aims to demonstrate the ability of NIRS to non-invasively monitor neural activity using methods that may be suitable for functional brain imaging in populations with developmental disorders. Our recent data show that a task-related fast NIRS signal can be recorded non-invasively from the human scalp and that the signal-to-noise ratio of the faint fast optical signal can be improved through a multi-step signal processing sequence that includes 1) adaptive filtering, 2) high-pass temporal filtering, 3) time-frequency decomposition, and 4) Independent Component Analysis. As a result, functionally relevant transient changes in the optical signal within multiple frequency bands (e.g., theta and gamma frequency bands) can be reliably recorded with a temporal resolution in the millisecond range. These changes in neuronal activity can then be mapped through reconstruction techniques with a spatial resolution comparable to that seen with fMRI techniques. Thus, the fast optical imaging of neuronal activity can potentially achieve both good temporal and spatial resolution. The aims of the proposed project are: 1) to develop a sensor net accommodating up to 256 electrodes and optical detectors, allowing full head coverage and simultaneous recording of optical and EEG signals; 2) to develop improved instrumentation and analysis methods in order to reliably detect the fast NIRS signal; 3) to develop improved methods for brain imaging based on the fast optical signal; and 4) to demonstrate that the fast optical signal closely correlates with neuronal activity through simultaneous recording of optical and high-density EEG signals in autistic and control subjects performing tasks involving visual and sensorimotor processing, such as object recognition or response competition. The proposed studies will advance, test and characterize the functional capabilities of the non-invasive fast NIRS technology as well as will establish its potential utility in the analysis of the neural mechanisms underlying visual and sensorimotor processing in health and disease.