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

一些研究声称，在言语流利任务(VFT)中，通过前额近红外光谱(NIRS)测量的脑血流信号在不同的精神障碍中显示出不同的模式。另一方面，在这项研究中，我们报告了近红外信号可以反映与任务相关的皮肤血流变化。这可能表明临床诊断中使用的近红外光谱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VFT的生理机制，我们阐明了额部和指尖对VFT的皮肤血流动力学反应的差异。我们发现，在任务过程中，皮肤血流动力学信号中脉动成分的幅度在前额增加，而在指尖减少，而在这两个区域的比率都增加了。与其他区域相比，额部的皮肤血管运动系统可能对心理任务具有不同的复杂交感血管反应机制。

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.