Nagaoka University of Technology, Graduate School of Engineering, Nagaoka, Japan.
Nagaoka University of Technology, Graduate School of Engineering, Nagaoka, JapanbATR Brain Information Communication Research Lab Group, Keihanna-Science City, Kyoto, Japan.
J Biomed Opt. 2017 Mar 1;22(3):35008. doi: 10.1117/1.JBO.22.3.035008.
Functional near-infrared spectroscopy (fNIRS) is a widely utilized neuroimaging tool in fundamental neuroscience research and clinical investigation. Previous research has revealed that task-evoked systemic artifacts mainly originating from the superficial-tissue may preclude the identification of cerebral activation during a given task. We examined the influence of such artifacts on event-related brain activity during a brisk squeezing movement. We estimated task-evoked superficial-tissue hemodynamics from short source–detector distance channels (15 mm) by applying principal component analysis. The estimated superficial-tissue hemodynamics exhibited temporal profiles similar to the canonical cerebral hemodynamic model. Importantly, this task-evoked profile was also observed in data from a block design motor experiment, suggesting a transient increase in superficial-tissue hemodynamics occurs following motor behavior, irrespective of task design. We also confirmed that estimation of event-related cerebral hemodynamics was improved by a simple superficial-tissue hemodynamic artifact removal process using 15-mm short distance channels, compared to the results when no artifact removal was applied. Thus, our results elucidate task design-independent characteristics of superficial-tissue hemodynamics and highlight the need for the application of superficial-tissue hemodynamic artifact removal methods when analyzing fNIRS data obtained during event-related motor tasks.
功能性近红外光谱（fNIRS）是基础神经科学研究和临床研究中广泛应用的神经影像学工具。先前的研究表明，源自浅层组织的任务诱发系统性伪影主要可能会妨碍在给定任务期间识别大脑激活。我们研究了这种伪影对快速挤压运动期间事件相关脑活动的影响。我们通过应用主成分分析来估计来自短源-探测器距离通道（15 毫米）的任务诱发的浅层组织血液动力学。估计的浅层组织血液动力学呈现出与典型大脑血液动力学模型相似的时间分布。重要的是，在块设计运动实验的数据中也观察到了这种任务诱发的分布，这表明无论任务设计如何，在运动行为之后都会发生浅层组织血液动力学的短暂增加。我们还证实，与未应用任何伪影去除时相比，使用 15 毫米短距离通道进行简单的浅层组织血液动力学伪影去除过程可以改善事件相关大脑血液动力学的估计。因此，我们的结果阐明了浅层组织血液动力学的任务设计独立性特征，并强调在分析事件相关运动任务期间获得的 fNIRS 数据时需要应用浅层组织血液动力学伪影去除方法。
