Hecker Lukas, Giri Amita, Pantazis Dimitrios, Adler Amir
IEEE Trans Biomed Eng. 2025 Apr;72(4):1486-1497. doi: 10.1109/TBME.2024.3509741. Epub 2025 Mar 21.
Understanding neural sources behind MEG and EEG signals is significant for basic and clinical neuroscience. Existing techniques, such as Recursively Applied and Projected Multiple Signal Classification (RAP-MUSIC) and Alternating Projection (AP), rely on limited current dipoles, representing focal sources with zero spatial extent. However, this oversimplifies realistic neural activity, which exhibits varying spatial extents.
To address this, we enhanced the AP approach, creating FLEX-AP, capable of localizing discrete and extended sources. FLEX-AP simultaneously optimizes location and spatial extent of candidate sources.
FLEX-AP demonstrated superior performance, reducing localization errors compared to AP, RAP-MUSIC, and FLEX-RAP-MUSIC, particularly with extended sources. Moreover, FLEX-AP exhibited enhanced robustness against modeling errors in realistic scenarios. Applying FLEX-AP to MEG recordings of auditory responses validated its effectiveness, underscoring potential in advancing neuroscientific investigations.
FLEX-AP offers a robust, flexible framework for M/EEG source localization, overcoming limitations of simplistic zero-extent dipole models. By accurately estimating position and spatial extent of neural sources, FLEX-AP bridges the gap between theoretical models and realistic activity, demonstrating utility in simulated and real-world scenarios.
FLEX-AP advances source imaging techniques with implications for basic neuroscience and clinical applications. Modeling extended sources precisely enables more accurate investigations of brain dynamics, potentially improving diagnostic and therapeutic approaches for neurological and psychiatric disorders.
了解脑磁图（MEG）和脑电图（EEG）信号背后的神经源对于基础神经科学和临床神经科学具有重要意义。现有技术，如递归应用和投影多信号分类（RAP-MUSIC）以及交替投影（AP），依赖于有限的电流偶极子，这些偶极子表示空间范围为零的局灶性源。然而，这过度简化了现实中的神经活动，而现实中的神经活动具有不同的空间范围。
为了解决这个问题，我们改进了AP方法，创建了FLEX-AP，它能够定位离散源和扩展源。FLEX-AP同时优化候选源的位置和空间范围。
FLEX-AP表现出卓越的性能，与AP、RAP-MUSIC和FLEX-RAP-MUSIC相比，定位误差更小，特别是对于扩展源。此外，在现实场景中，FLEX-AP对建模误差表现出更强的鲁棒性。将FLEX-AP应用于听觉反应的MEG记录验证了其有效性，突出了其在推进神经科学研究方面的潜力。
FLEX-AP为脑磁图/脑电图源定位提供了一个强大、灵活的框架，克服了简单的零范围偶极子模型的局限性。通过准确估计神经源的位置和空间范围，FLEX-AP弥合了理论模型与现实活动之间的差距，在模拟和现实场景中都显示出实用性。
FLEX-AP推动了源成像技术的发展，对基础神经科学和临床应用具有重要意义。精确建模扩展源能够更准确地研究脑动力学，可能改善神经和精神疾病的诊断和治疗方法。
