Dipartimento di Ingegneria dell'Informazione, University of Pisa, 56122 Pisa, Italy.
Research Center "E. Piaggio", University of Pisa, 56122 Pisa, Italy.
Sensors (Basel). 2024 Aug 4;24(15):5053. doi: 10.3390/s24155053.
The orienting reaction (OR) towards a new stimulus is subject to habituation, i.e., progressively attenuates with stimulus repetition. The skin conductance responses (SCRs) are known to represent a reliable measure of OR at the peripheral level. Yet, it is still a matter of debate which of the P3 subcomponents is the most likely to represent the central counterpart of the OR. The aim of the present work was to study habituation, recovery, and dishabituation phenomena intrinsic to a two-stimulus auditory oddball paradigm, one of the most-used paradigms both in research and clinic, by simultaneously recording SCRs and P3 in twenty healthy volunteers. Our findings show that the target stimulus was capable of triggering a more marked OR, as indexed by both SCRs and P3, compared to the standard stimulus, that could be due to its affective saliency and relevance for task completion; the application of temporal principal components analysis (PCA) to the P3 complex allowed us to identify several subcomponents including both early and late P3a (eP3a; lP3a), P3b, novelty P3 (nP3), and both a positive and a negative Slow Wave (+SW; -SW). Particularly, lP3a and P3b subcomponents showed a similar behavior to that observed for SCRs , suggesting them as central counterparts of OR. Finally, the P3 evoked by the first standard stimulus after the target showed a significant dishabituation phenomenon which could represent a sign of the local stimulus change. However, it did not reach a sufficient level to trigger an SCR/OR since it did not represent a salient event in the context of the task.
朝向新刺激的定向反应（OR）会习惯化，即随着刺激重复而逐渐减弱。皮肤电反应（SCR）被认为是 OR 在周围水平的可靠测量指标。然而，哪种 P3 子成分最有可能代表 OR 的中枢对应物，仍然存在争议。本工作的目的是通过同时记录 20 名健康志愿者的 SCR 和 P3，研究两刺激听觉Oddball 范式固有的习惯化、恢复和去习惯化现象，该范式是研究和临床中最常用的范式之一。我们的研究结果表明，与标准刺激相比，目标刺激能够引发更明显的 OR，这可以通过 SCR 和 P3 来衡量，这可能是由于其情感显著性和对任务完成的相关性；对 P3 复合体应用时间主成分分析（PCA）允许我们识别出几个子成分，包括早期和晚期 P3a（eP3a；lP3a）、P3b、新颖 P3（nP3）以及正和负慢波（+SW；-SW）。特别是，lP3a 和 P3b 子成分表现出与 SCR 观察到的相似行为，这表明它们是 OR 的中枢对应物。最后，在目标刺激后的第一个标准刺激引起的 P3 表现出明显的去习惯化现象，这可能是局部刺激变化的迹象。然而，它没有达到触发 SCR/OR 的足够水平，因为它在任务背景下不是一个显著的事件。
