Eye and Brain Mapping Laboratory (iBMLab), Department of Psychology, University of Fribourg, Fribourg 1700, Switzerland.
Soc Cogn Affect Neurosci. 2024 Jan 10;19(1). doi: 10.1093/scan/nsad076.
When asked to categorize faces according to 'race', people typically categorize other-race faces faster than faces belonging to their own race. This 'Other Race Categorization Advantage' is thought to reflect enhanced sensitivity to early visual signals characteristic of other-race faces, and can manifest within 200 ms of face presentation. However, recent research has highlighted the importance of signal intensity in this effect, where visual-degradation of the face images significantly enhances the effect and exposes a behavioural threshold at very low levels of visual quality where other-race visual signals are able to be perceived while same-race signals are not. The current study investigated the effect of signal intensity in race categorization processes in the brain through electroencephalography and in accuracy/reaction times. While replicating the previously observed enhancement of the other-race categorization advantage, we also found enhanced sensitivity to other-race faces in early P1 peaks, as well as later N170 and N250 peaks. These effects, however, related to the varying levels of signal intensity in the face stimuli, suggesting that race categorization may involve different types of perceptual and neural processes rather than one discrete process. The speed at which race is perceived depends on the intensity of the face signal.
当被要求根据“种族”对人脸进行分类时，人们通常会比自己种族的人脸更快地对其他种族的人脸进行分类。这种“异族分类优势”被认为反映了对其他种族面孔特征的早期视觉信号的敏感性增强，并且可以在面孔呈现后的 200 毫秒内表现出来。然而，最近的研究强调了信号强度在这种效应中的重要性，其中对面部图像的视觉降级显著增强了效应，并在非常低的视觉质量水平上暴露了行为阈值，在这种水平下，可以感知到异族视觉信号，而不能感知到同族信号。本研究通过脑电图和准确性/反应时间来研究信号强度对面孔分类过程中大脑种族分类的影响。在复制先前观察到的异族分类优势增强的同时，我们还发现了早期 P1 峰值对异族面孔的敏感性增强，以及后来的 N170 和 N250 峰值。然而，这些效应与面部刺激中信号强度的不同水平有关，这表明种族分类可能涉及不同类型的感知和神经过程，而不是一个离散的过程。种族被感知的速度取决于面部信号的强度。
