Significance: Electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) are both commonly used methodologies for neuronal source reconstruction. While EEG has high temporal resolution (millisecond-scale), its spatial resolution is on the order of centimeters. On the other hand, in comparison to EEG, fNIRS, or diffuse optical tomography (DOT), when used for source reconstruction, can achieve relatively high spatial resolution (millimeter-scale), but its temporal resolution is poor because the hemodynamics that it measures evolve on the order of several seconds. This has important neuroscientific implications: e.g., if two spatially close neuronal sources are activated sequentially with only a small temporal separation, single-modal measurements using either EEG or DOT alone would fail to resolve them correctly. Aim: We attempt to address this issue by performing joint EEG and DOT neuronal source reconstruction. Approach: We propose an algorithm that utilizes DOT reconstruction as the spatial prior of EEG reconstruction, and demonstrate the improvements using simulations based on the ICBM152 brain atlas. Results: We show that neuronal sources can be reconstructed with higher spatiotemporal resolution using our algorithm than using either modality individually. Further, we study how the performance of the proposed algorithm can be affected by the locations of the neuronal sources, and how the performance can be enhanced by improving the placement of EEG electrodes and DOT optodes. Conclusions: We demonstrate using simulations that two sources separated by 2.3-3.3 cm and 50 ms can be recovered accurately using the proposed algorithm by suitably combining EEG and DOT, but not by either in isolation. We also show that the performance can be enhanced by optimizing the electrode and optode placement according to the locations of the neuronal sources.

中文翻译：

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使用联合脑电图和漫射光学断层扫描增强神经元活动的时空分辨率成像


意义：脑电图（EEG）和功能性近红外光谱（fNIRS）都是神经元源重建的常用方法。虽然脑电图具有很高的时间分辨率（毫秒级），但其空间分辨率为厘米量级。另一方面，与EEG、fNIRS或扩散光学断层扫描（DOT）相比，当用于源重建时，可以实现相对较高的空间分辨率（毫米级），但其时间分辨率较差，因为它测量的血流动力学以几秒的量级演化。这具有重要的神经科学意义：例如，如果两个空间上接近的神经元源被顺序激活且仅具有很小的时间间隔，则单独使用 EEG 或 DOT 的单模态测量将无法正确解决它们。目的：我们尝试通过联合 EEG 和 DOT 神经元源重建来解决这个问题。方法：我们提出了一种利用 DOT 重建作为 EEG 重建的空间先验的算法，并使用基于 ICBM152 脑图谱的模拟来证明改进。结果：我们表明，与单独使用任一模态相比，使用我们的算法可以以更高的时空分辨率重建神经元源。此外，我们研究了神经元源位置如何影响所提出算法的性能，以及如何通过改进 EEG 电极和 DOT 光极的放置来增强性能。结论：我们通过模拟证明，通过适当组合 EEG 和 DOT，可以使用所提出的算法准确恢复相距 2.3-3.3 cm 和 50 ms 的两个源，但不能单独使用任何一个。 我们还表明，可以通过根据神经元源的位置优化电极和光极放置来提高性能。