对威胁刺激的碰撞时间估计

对靠近运动刺激的碰撞时间(time-to-collision, TTC)估计具有重要的进化意义。为了解释个体如何进行TTC估计, 研究者提出了结构主义理论、生态光学理论和tau理论等, 也考察了影响TTC估计的部分因素。近年的研究通过比较个体对威胁刺激和非威胁刺激的TTC估计, 考察了刺激的情绪相关属性对TTC估计的影响。结果表明, 相比于自然非威胁刺激(如兔子等图片), 个体会低估自然威胁刺激(如蛇等图片)的TTC, 但这种TTC的低估在社会威胁刺激(如愤怒面孔图片)上有时很小甚至不显著。个体低估TTC可能存在三种原因：(1)个体对威胁刺激具有特异性反应; (2)威胁刺激具有较高的情绪唤醒度; (3)个体对威胁刺激具有心理距离更近和运动速度更快的知觉偏差。未来研究可以进一步考察在社会威胁刺激上表现出的TTC低估效应不稳定的原因; 探索威胁刺激TTC估计中的自主生理反应和神经机制; 采用虚拟现实技术进行威胁刺激TTC估计的研究; 在实验设计中考虑性别和人格特质等个体因素的影响。

Estimating the time-to-collision with a threatening object

Estimating the time-to-collision (TTC) of approaching objects is crucial for organism survival. Researchers have proposed the constructivist approaches, the ecological optics theory and the tau hypothesis to explain how humans estimate TTC and which factors may affect the estimation. Recently, a few studies examined how the emotional content of stimuli impacts TTC estimation, by comparing TTC judgements between threatening and nonthreatening stimuli. Their findings suggest that natural threatening stimuli (e.g., images of snakes) lead to underestimation of TTC compared to natural nonthreatening stimuli (e.g., images of rabbits). However, other findings suggest that TTC underestimation of social threatening stimuli (e.g. pictures of angry faces) is smaller or absent. Underestimated TTC of threatening stimuli may be due to 1) a specific response to threatening stimuli, 2) high emotional arousal of threatening stimuli, and 3) a perceptual bias causing threatening stimuli to appear closer and move faster than typical. We suggest that future studies should (1) further investigate the reasons why TTC underestimation of social threatening stimuli is smaller or absent, (2) explore the autonomic physiological response patterns and neural correlates of TTC estimation of threatening stimuli, (3) examine TTC estimation of threatening stimuli in virtual reality (VR) environments, and (4) experimentally test the effects of individual differences (e.g., gender and personality traits) on TTC estimation.