Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary.
Pázmány Péter Catholic University, Budapest, Hungary.
Exp Brain Res. 2023 Apr;241(4):1001-1008. doi: 10.1007/s00221-023-06573-1. Epub 2023 Mar 2.
The detection of unattended visual changes is investigated by the visual mismatch negativity (vMMN) component of event-related potentials (ERPs). The vMMN is measured as the difference between the ERPs to infrequent (deviant) and frequent (standard) stimuli irrelevant to the ongoing task. In the present study, we used human faces expressing different emotions as deviants and standards. In such studies, participants perform various tasks, so their attention is diverted from the vMMN-related stimuli. If such tasks vary in their attentional demand, they might influence the outcome of vMMN studies. In this study, we compared four kinds of frequently used tasks: (1) a tracking task that demanded continuous performance, (2) a detection task where the target stimuli appeared at any time, (3) a detection task where target stimuli appeared only in the inter-stimulus intervals, and (4) a task where target stimuli were members of the stimulus sequence. This fourth task elicited robust vMMN, while in the other three tasks, deviant stimuli elicited moderate posterior negativity (vMMN). We concluded that the ongoing task had a marked influence on vMMN; thus, it is important to consider this effect in vMMN studies.
事件相关电位（ERP）中的视觉失匹配负波（vMMN）成分可用于检测无人值守的视觉变化。vMMN 是通过比较与当前任务不相关的稀有（偏离）和常见（标准）刺激的 ERP 得出的差异。在本研究中，我们使用表达不同情绪的人脸作为偏离和标准刺激。在这样的研究中，参与者执行各种任务，因此他们的注意力会从与 vMMN 相关的刺激上转移。如果这些任务的注意力需求不同，它们可能会影响 vMMN 研究的结果。在这项研究中，我们比较了四种常用的任务：（1）需要持续执行的跟踪任务，（2）目标刺激随时出现的检测任务，（3）目标刺激仅在刺激间隔出现的检测任务，以及（4）目标刺激是刺激序列成员的任务。第四个任务引起了强烈的 vMMN，而在其他三个任务中，偏离刺激引起了中度的后向负波（vMMN）。我们得出结论，正在进行的任务对 vMMN 有显著影响；因此，在 vMMN 研究中考虑这种影响很重要。
