Key Laboratory of Biomedical Information Engineering of Ministry of Education, Institute of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Biomed Res Int. 2013;2013:459346. doi: 10.1155/2013/459346. Epub 2013 Apr 17.
The goal of this study was to investigate the influence of the brain-to-skull conductivity ratio (BSCR) on EEG source localization accuracy. In this study, we evaluated four BSCRs: 15, 20, 25, and 80, which were mainly discussed according to the literature. The scalp EEG signals were generated by BSCR-related forward computation for each cortical dipole source. Then, for each scalp EEG measurement, the source reconstruction was performed to identify the estimated dipole sources by the actual BSCR and the misspecified BSCRs. The estimated dipole sources were compared with the simulated dipole sources to evaluate EEG source localization accuracy. In the case of considering noise-free EEG measurements, the mean localization errors were approximately equal to zero when using actual BSCR. The misspecified BSCRs resulted in substantial localization errors which ranged from 2 to 16 mm. When considering noise-contaminated EEG measurements, the mean localization errors ranged from 8 to 18 mm despite the BSCRs used in the inverse calculation. The present results suggest that the localization accuracy is sensitive to the BSCR in EEG source reconstruction, and the source activity can be accurately localized when the actual BSCR and the EEG scalp signals with high signal-to-noise ratio (SNR) are used.
本研究旨在探讨脑颅骨电导率比（BSCR）对 EEG 源定位准确性的影响。在本研究中，我们评估了四个 BSCR 值：15、20、25 和 80，主要根据文献进行了讨论。头皮 EEG 信号是通过 BSCR 相关的正向计算生成的，用于每个皮质偶极子源。然后，对于每个头皮 EEG 测量，通过实际 BSCR 和误指定的 BSCR 进行源重建，以识别估计的偶极子源。将估计的偶极子源与模拟的偶极子源进行比较，以评估 EEG 源定位准确性。在考虑无噪声 EEG 测量的情况下，使用实际 BSCR 时，平均定位误差约为零。误指定的 BSCR 会导致显著的定位误差，范围为 2 至 16 毫米。在考虑受噪声污染的 EEG 测量的情况下，尽管在逆计算中使用了 BSCR，但平均定位误差范围仍为 8 至 18 毫米。这些结果表明，在 EEG 源重建中，定位准确性对 BSCR 敏感，并且当使用实际 BSCR 和具有高信噪比（SNR）的 EEG 头皮信号时，可以准确地定位源活动。
