Tichenor Seth E, Walsh Bridget, Gerwin Katelyn L, Tian Fenghua
Duquesne University, Speech-Language Pathology, Pittsburgh, Pennsylvania, United States.
Michigan State University, Communicative Sciences and Disorders, East Lansing, Michigan, United States.
Neurophotonics. 2022 Jan;9(1):015003. doi: 10.1117/1.NPh.9.1.015003. Epub 2022 Feb 18.
Hemodynamic responses (HRs) are typically averaged across experimental sessions based on the assumption that brain activation is consistent over multiple trials. This may not be a safe assumption, especially in pediatric populations, due to unaccounted effects of inattention, fatigue, or habituation. The purpose of this study was to quantify the consistency of the HR over speech and language brain regions during speech production in typically developing school-aged children. Brain activity over speech and language regions of interest (ROIs) was recorded with functional near-infrared spectroscopy during a picture description paradigm with 37 children (aged 7 to 12 years). We divided the 30 experimental trials, each 5 s long, into three segments of 10 trials each corresponding with early (trials 1 to 10), middle (trials 11 to 20), and late (trials 21 to 30) trials. We then compared oxygenated (HbO) and deoxygenated (HbR) hemoglobin concentrations averaged across each 10 trial segment to overall concentrations averaged across all 30 trials. We also compared differential hemoglobin (HbD) across ROIs. HbO and HbR averaged across all experimental trials most strongly correlated with HbO and HbR from early trials. HbD values from channels over most speech and language regions did not appreciably change throughout the experimental session. The exception was HbD values from channels over the dorsal inferior frontal gyrus (dIFG). This region showed significantly higher activation over the left hemisphere during the first segment of the experiment. Our findings suggest that brain activity from speech and language ROIs was relatively consistent over the experimental session. The exception was increased activation of left dIFG during earlier experimental trials. We suggest that researchers critically evaluate the consistency of HRs from different brain regions to determine the reliability of HRs recorded during experimental sessions. This step is instrumental in ensuring that uncontrolled effects do not mask patterns of task-related activation.
血流动力学反应（HRs）通常是在多个实验环节中进行平均计算的，其依据的假设是大脑激活在多次试验中保持一致。然而，这可能并非一个可靠的假设，尤其是在儿科人群中，因为存在注意力不集中、疲劳或习惯化等未被考虑的影响因素。本研究的目的是量化在典型发育的学龄儿童言语产生过程中，言语和语言脑区HR的一致性。在一个图片描述范式中，使用功能近红外光谱技术记录了37名儿童（7至12岁）言语和语言感兴趣区域（ROIs）的大脑活动。我们将30次时长均为5秒的实验试验分为三个部分，每个部分10次试验，分别对应早期（试验1至10）、中期（试验11至20）和晚期（试验21至30）试验。然后，我们将每个10次试验部分的平均氧合血红蛋白（HbO）和脱氧血红蛋白（HbR）浓度与所有30次试验的总体平均浓度进行比较。我们还比较了不同ROIs之间的差异血红蛋白（HbD）。所有实验试验的平均HbO和HbR与早期试验的HbO和HbR相关性最强。在大多数言语和语言区域的通道中，HbD值在整个实验过程中没有明显变化。唯一的例外是背侧额下回（dIFG）通道的HbD值。在实验的第一部分，该区域左半球的激活明显更高。我们的研究结果表明，在整个实验过程中，言语和语言ROIs的大脑活动相对一致。唯一的例外是在早期实验试验中左dIFG的激活增加。我们建议研究人员严格评估不同脑区HR的一致性，以确定实验过程中记录的HR的可靠性。这一步骤对于确保未控制的影响因素不会掩盖与任务相关的激活模式至关重要。
