Bionics Institute, Victoria, Australia.
Medical Bionics Department, University of Melbourne, Victoria, Australia.
Trends Hear. 2024 Jan-Dec;28:23312165241258056. doi: 10.1177/23312165241258056.
This study investigated the morphology of the functional near-infrared spectroscopy (fNIRS) response to speech sounds measured from 16 sleeping infants and how it changes with repeated stimulus presentation. We observed a positive peak followed by a wide negative trough, with the latter being most evident in early epochs. We argue that the overall response morphology captures the effects of two simultaneous, but independent, response mechanisms that are both activated at the stimulus onset: one being the obligatory response to a sound stimulus by the auditory system, and the other being a neural suppression effect induced by the arousal system. Because the two effects behave differently with repeated epochs, it is possible to mathematically separate them and use fNIRS to study factors that affect the development and activation of the arousal system in infants. The results also imply that standard fNIRS analysis techniques need to be adjusted to take into account the possibilities of multiple simultaneous brain systems being activated and that the response to a stimulus is not necessarily stationary.
本研究调查了从 16 名睡眠婴儿中测量到的功能近红外光谱 (fNIRS) 对语音反应的形态，以及这种反应如何随重复刺激呈现而变化。我们观察到一个正峰，后面跟着一个宽的负谷，后者在早期阶段最为明显。我们认为，整体反应形态捕捉到了两个同时发生但独立的反应机制的影响，这两个机制在刺激开始时都被激活：一个是听觉系统对声音刺激的强制性反应，另一个是由觉醒系统引起的神经抑制效应。由于这两种效应在重复的时期表现不同，因此可以通过数学方法将它们分开，并使用 fNIRS 来研究影响婴儿觉醒系统发育和激活的因素。结果还表明，标准的 fNIRS 分析技术需要进行调整，以考虑到多个同时激活的大脑系统的可能性，并且对刺激的反应不一定是静止的。
