Luther Lisa, Horschig Jörn M, van Peer Jacobien M, Roelofs Karin, Jensen Ole, Hagenaars Muriel A
Behavioural Science Institute (BSI), Radboud University, Nijmegen, Netherlands.
Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands.
Front Hum Neurosci. 2023 Jan 18;16:868549. doi: 10.3389/fnhum.2022.868549. eCollection 2022.
Emotional cues draw attention, thereby enabling enhanced processing. Electrophysiological brain research in humans suggests that increased gamma band activity and decreased alpha band activity over posterior brain areas is associated with the allocation of attention. However, emotional events can alternate quickly, like rapidly changing news items and it remains unknown whether the modulation of brain oscillations happens in a stimulus induced manner, changing with each individual stimulus, or whether the events lead to prolonged, state-like changes. To investigate this, we measured the electroencephalogram (EEG) during a passive viewing task ( = 32) while emotional pictures International Affective Picture System (IAPS) were presented in blocks containing either and or and pictures. As predicted, we found decreased alpha and increased gamma power over posterior areas in response to compared to pictures (and also compared to pictures for gamma power). When testing the pictures of the unpleasant and pleasant block against each other, we found no significant difference, which speaks to a stimulus induced effect of alpha and gamma power rather than a state effect. In addition, the inter-trial interval (ITI) between the pictures did not differ between the unpleasant and pleasant block either, corroborating this conclusion. Since emotional pictures can at the same time elicit a freezing-like response and we were interested in whether this freezing-like response co-occurs with enhanced attention, we also collected postural sway data. However, within this EEG-setup, postural analyses indicated no stimulus-related effects nor a correlation with EEG-data. We interpret the alpha and gamma band results as reflecting event-related attention toward unpleasant compared to pleasant (and neutral) pictures and discuss this finding in light of previous EEG research and in combination with behavioral research on threat-induced reductions in body sway (freezing-like response).
情绪线索会吸引注意力，从而促进信息的强化处理。针对人类的脑电生理学研究表明，大脑后区伽马波段活动增强而阿尔法波段活动减弱与注意力分配有关。然而，情绪事件变化迅速，犹如快速更迭的新闻条目，目前尚不清楚大脑振荡的调制是以刺激诱导的方式发生，随每个单独刺激而变化，还是这些事件会导致长时间的、类似状态的变化。为了探究这一问题，我们在一项被动观看任务（n = 32）中测量了脑电图（EEG），期间以组块形式呈现国际情感图片系统（IAPS）中的情绪图片，每组块包含令人不愉快和令人愉快的图片，或者令人不愉快和中性的图片。正如预期的那样，我们发现与令人愉快的图片相比（对于伽马功率，也与中性图片相比），观看令人不愉快的图片时大脑后区阿尔法功率降低，伽马功率增加。当比较令人不愉快组块和令人愉快组块中的令人不愉快图片时，我们未发现显著差异，这表明阿尔法和伽马功率的变化是由刺激诱导的，而非状态效应。此外，令人不愉快组块和令人愉快组块中图片之间的试次间隔（ITI）也没有差异，这进一步证实了这一结论。由于情绪图片同时可能引发类似僵住的反应，并且我们想了解这种类似僵住的反应是否与注意力增强同时出现，我们还收集了姿势摇摆数据。然而，在此EEG设置下，姿势分析表明没有与刺激相关的效应，也未发现与EEG数据的相关性。我们将阿尔法和伽马波段的结果解释为反映了与事件相关的、对令人不愉快图片（与令人愉快和中性图片相比）的注意力，并根据先前的EEG研究以及结合关于威胁诱导身体摇摆减少（类似僵住的反应）的行为研究来讨论这一发现。
