Neuroscience Group, University of Antioquia UdeA, Medellín, Colombia.
GISAME, Facultad Nacional de Salud Pública, Universidad de Antioquia UdeA Medellín, Medellín, Colombia.
PLoS One. 2021 Apr 2;16(4):e0249407. doi: 10.1371/journal.pone.0249407. eCollection 2021.
Threatening stimuli seem to capture attention more swiftly than neutral stimuli. This attention bias has been observed under different experimental conditions and with different types of stimuli. It remains unclear whether this adaptive behaviour reflects the function of automatic or controlled attention mechanisms. Additionally, the spatiotemporal dynamics of its neural correlates are largely unknown. The present study investigates these issues using an Emotional Flanker Task synchronized with EEG recordings. A group of 32 healthy participants saw response-relevant images (emotional scenes from IAPS or line drawings of objects) flanked by response-irrelevant distracters (i.e., emotional scenes flanked by line drawings or vice versa). We assessed behavioural and ERP responses drawn from four task conditions (Threat-Central, Neutral-Central, Threat-Peripheral, and Neutral-Peripheral) and subjected these responses to repeated-measures ANOVA models. When presented as response-relevant targets, threatening images attracted faster and more accurate responses. They did not affect response accuracy to targets when presented as response-irrelevant flankers. However, response times were significantly slower when threatening images flanked objects than when neutral images were shown as flankers. This result replicated the well-known Emotional Flanker Effect. Behavioural responses to response-relevant threatening targets were accompanied by significant modulations of ERP activity across all time-windows and regions of interest and displayed some meaningful correlations. The Emotional Flanker Effect was accompanied by a modulation over parietal and central-parietal regions within a time-window between 550-690ms. Such a modulation suggests that the attentional disruption to targets caused by response-irrelevant threatening flankers appears to reflect less neural resources available, which are seemingly drawn away by distracting threatening flankers. The observed spatiotemporal dynamics seem to concur with understanding of the important adaptive role attributed to threat-related attention bias.
威胁性刺激似乎比中性刺激更快地吸引注意力。这种注意力偏向在不同的实验条件下和不同类型的刺激下都有观察到。目前尚不清楚这种适应性行为是反映了自动注意力机制还是受控注意力机制的功能。此外，其神经相关物的时空动态在很大程度上尚不清楚。本研究使用与 EEG 记录同步的情绪侧翼任务来研究这些问题。一组 32 名健康参与者观看了与反应相关的图像（来自 IAPS 的情绪场景或物体的线条图），这些图像被与反应无关的干扰物（即情绪场景被线条图包围或反之亦然）所包围。我们评估了来自四个任务条件（威胁中心、中性中心、威胁外围和中性外围）的行为和 ERP 反应，并对这些反应进行了重复测量 ANOVA 模型分析。当作为与反应相关的目标呈现时，威胁性图像会吸引更快和更准确的反应。当作为与反应无关的侧翼呈现时，它们不会影响对目标的反应准确性。然而，当威胁性图像包围物体时，反应时间明显比中性图像作为侧翼时慢。这一结果复制了著名的情绪侧翼效应。对与反应相关的威胁性目标的行为反应伴随着 ERP 活动在所有时间窗口和感兴趣区域的显著调制，并显示出一些有意义的相关性。情绪侧翼效应伴随着在 550-690ms 之间的时间窗口中，顶叶和中央顶叶区域的调制。这种调制表明，对与反应无关的威胁性侧翼的注意力干扰似乎反映了可用的神经资源较少，这些资源似乎被分心的威胁性侧翼吸引走了。观察到的时空动态似乎与对与威胁相关的注意力偏向赋予的重要适应作用的理解一致。
