Institute of Brain and Psychological Sciences, Sichuan Normal University, Chengdu, 610068, People's Republic of China.
Research Center of Brain and Cognitive Neuroscience, Liaoning Normal University, Dalian, People's Republic of China.
Sci Rep. 2021 Sep 2;11(1):17574. doi: 10.1038/s41598-021-97039-3.
Previous studies have shown that humans have a left spatial attention bias in cognition and behaviour. However, whether there exists a leftward perception bias of gaze direction has not been investigated. To address this gap, we conducted three behavioural experiments using a forced-choice gaze direction judgment task. The point of subjective equality (PSE) was employed to measure whether there was a leftward perception bias of gaze direction, and if there was, whether this bias was modulated by face emotion. The results of experiment 1 showed that the PSE of fearful faces was significantly positive as compared to zero and this effect was not found in angry, happy, and neutral faces, indicating that participants were more likely to judge the gaze direction of fearful faces as directed to their left-side space, namely a leftward perception bias. With the response keys counterbalanced between participants, experiment 2a replicated the findings in experiment 1. To further investigate whether the gaze direction perception variation was contributed by emotional or low-level features of faces, experiment 2b and 3 used inverted faces and inverted eyes, respectively. The results revealed similar leftward perception biases of gaze direction in all types of faces, indicating that gaze direction perception was biased by emotional information in faces rather than low-level facial features. Overall, our study demonstrates that there a fear-specific leftward perception bias in processing gaze direction. These findings shed new light on the cerebral lateralization in humans.
先前的研究表明，人类在认知和行为上存在左空间注意偏向。然而，人们是否存在左向注视方向知觉偏向尚未得到研究。为了解决这一差距，我们使用强制选择注视方向判断任务进行了三项行为实验。主观相等点（PSE）用于测量是否存在注视方向的左向知觉偏向，如果存在，这种偏向是否受到面部情绪的调节。实验 1 的结果表明，与零相比，恐惧面孔的 PSE 明显为正，而在愤怒、快乐和中性面孔中没有发现这种效应，这表明参与者更有可能判断恐惧面孔的注视方向指向他们的左侧空间，即存在左向知觉偏向。在参与者之间平衡反应键后，实验 2a 复制了实验 1 的发现。为了进一步探究注视方向知觉变化是否是由面部的情绪或低水平特征引起的，实验 2b 和 3 分别使用了倒置的面孔和倒置的眼睛。结果表明，在所有类型的面孔中都存在类似的注视方向左向知觉偏向，这表明注视方向知觉受到面部情绪信息的影响，而不是低水平的面部特征。总的来说，我们的研究表明，在处理注视方向时存在特定于恐惧的左向知觉偏向。这些发现为人类大脑的偏侧化提供了新的视角。
