Significance: Designing optode layouts is an essential step for functional near-infrared spectroscopy (fNIRS) experiments as the quality of the measured signal and the sensitivity to cortical regions-of-interest depend on how optodes are arranged on the scalp. This becomes particularly relevant for fNIRS-based brain–computer interfaces (BCIs), where developing robust systems with few optodes is crucial for clinical applications. Aim: Available resources often dictate the approach researchers use for optode-layout design. We investigated whether guiding optode layout design using different amounts of subject-specific magnetic resonance imaging (MRI) data affects the fNIRS signal quality and sensitivity to brain activation when healthy participants perform mental-imagery tasks typically used in fNIRS-BCI experiments. Approach: We compared four approaches that incrementally incorporated subject-specific MRI information while participants performed mental-calculation, mental-rotation, and inner-speech tasks. The literature-based approach (LIT) used a literature review to guide the optode layout design. The probabilistic approach (PROB) employed individual anatomical data and probabilistic maps of functional MRI (fMRI)-activation from an independent dataset. The individual fMRI (iFMRI) approach used individual anatomical and fMRI data, and the fourth approach used individual anatomical, functional, and vascular information of the same subject (fVASC). Results: The four approaches resulted in different optode layouts and the more informed approaches outperformed the minimally informed approach (LIT) in terms of signal quality and sensitivity. Further, PROB, iFMRI, and fVASC approaches resulted in a similar outcome. Conclusions: We conclude that additional individual MRI data lead to a better outcome, but that not all the modalities tested here are required to achieve a robust setup. Finally, we give preliminary advice to efficiently using resources for developing robust optode layouts for BCI and neurofeedback applications.

中文翻译：

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使用单个 (f)MRI 数据指导功能性近红外光谱光极布局设计：对信号强度的影响


意义：设计光极布局是功能性近红外光谱 (fNIRS) 实验的重要步骤，因为测量信号的质量和对皮质感兴趣区域的敏感性取决于光极在头皮上的排列方式。这对于基于 fNIRS 的脑机接口 (BCI) 尤为重要，其中开发具有少量光极的强大系统对于临床应用至关重要。目标：可用资源通常决定研究人员用于光极布局设计的方法。我们研究了当健康参与者执行 fNIRS-BCI 实验中通常使用的心理意象任务时，使用不同数量的特定受试者磁共振成像 (MRI) 数据引导光极布局设计是否会影响 fNIRS 信号质量和对大脑激活的敏感性。方法：我们比较了四种方法，这些方法在参与者执行心理计算、心理旋转和内心言语任务时逐渐融入特定于受试者的 MRI 信息。基于文献的方法 (LIT) 使用文献综述来指导光极布局设计。概率方法 (PROB) 采用来自独立数据集的个体解剖数据和功能 MRI (fMRI) 激活的概率图。个体功能磁共振成像 (iFMRI) 方法使用个体解剖和功能磁共振成像数据，第四种方法使用同一受试者的个体解剖、功能和血管信息 (fVASC)。结果：四种方法产生了不同的光极布局，并且在信号质量和灵敏度方面，信息更丰富的方法优于最小信息方法 (LIT)。此外，PROB、iFMRI 和 fVASC 方法也产生了类似的结果。 结论：我们的结论是，额外的个体 MRI 数据会带来更好的结果，但并非此处测试的所有模式都需要实现稳健的设置。最后，我们提供了初步建议，以有效利用资源为 BCI 和神经反馈应用开发强大的光极布局。