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

几项研究声称，在言语流畅性任务（VFT）中，通过近红外光谱（NIRS）在前额上测量的脑血流信号显示出不同精神障碍的不同模式。另一方面，在这项研究中，我们报道了近红外光谱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任务相关皮肤血流动力学的影响。此外，为了揭示生理机制，我们澄清了前额和指尖对VFT的皮肤血流动力学反应的差异。我们发现，在任务过程中，皮肤血流动力学信号的脉动分量在额头上增加，而在指尖上减少，而两个区域的速率都增加了。前额的皮肤血管舒缩系统对心理任务的复杂交感血管反应机制可能与其他区域不同。

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.