An approach to the problem of the skin blood flow artifact in near-infrared spectroscopy signals

一些研究声称，在语言流畅性任务（VFT）中，通过近红外光谱（NIRS）测量的前额脑血流信号在各种精神疾病中显示出不同的模式。在这项研究中，另一方面，我们报告说，近红外光谱信号可以反映任务相关的皮肤血流量的变化。这可能表明用于临床诊断的NIRS信号可能受到与任务相关的皮肤血流动力学的影响。此外，为了揭示其生理机制，我们阐明了前额和指尖对VFT的皮肤血流动力学反应的差异。我们发现，皮肤血流动力学信号中的脉动分量的幅度在前额上增加，但在任务期间在指尖上减少，而在这两个区域中的速率增加。前额皮肤血管系统对心理任务的反应机制可能不同于其他区域。

Several studies have claimed that cerebral blood flow signals measured by near-infrared spectroscopy (NIRS) on the forehead showed different patterns in various psychiatric disorders during a verbal fluency task (VFT). In this study, on the other hand, we reported that NIRS signals could reflect task-related changes in skin blood flow. This may indicate a possibility that the NIRS signals used in clinical diagnosis might be influenced by task-related skin hemodynamics. Furthermore, to reveal the physiological mechanism, we clarified the differences in skin hemodynamic responses to VFT between the forehead and the fingertip. We found that the magnitude of the pulsatile component in skin hemodynamic signals increased on the forehead but decreased on the fingertip during the task, whereas the rate increased in both areas. The skin vasomotor system in the forehead could have a different complex sympathetic vascular response mechanism to psychological tasks compared to other areas.