Uncertainty in Pedestrian Decision-Making in Urgent Scenarios Modulates Multi-Level Neural Hierarchies from Perception to Execution

In urgent traffic scenarios, pedestrians exhibit decision-making uncertainty, significantly influencing safe interaction dynamics with automated vehicles. However, the inherent mechanisms of such decision behavior remain inadequately understood. To address this gap, we designed dynamic interactive stimulus experiments to replicate pedestrian-vehicle interactions in urgent scenarios, incorporating spatiotemporal pressure and introducing substantial penalties for decision failures. We employed multimodal data analysis, including behavioral data, electroencephalography (EEG) and eye-tracking data, to investigate the influence of urgency on uncertainty in decision-making and the underlying multi-level neural processes. Our findings demonstrate that as the urgency of the stimulus increases, humans adjust their decision objectives, resulting in an initial decrease followed by an increase in decision uncertainty when dealing with more urgent stimuli. Specifically, urgency augments top-down perceptual processes during the early perception stage. Such a mechanism implies an enhanced dependence on prior experiences for perceptual decision-making in high-urgency situations. While urgency accelerated motion preparation time during the decision-execution stage, it is noteworthy that the culmination of evidence accumulation (represented by the CPP peak) manifested later than the actual response. These results suggest that insufficient perceptual information and evidence accumulation may increase decision-making uncertainty. Our experimental study unveils a correlation between human decision-making uncertainty and scenario urgency, particularly within a defined urgency range.在紧急交通场景中，行人的决策行为存在不确定性，这将显著影响其与自动驾驶车辆的安全交互动力学特性。然而，此类决策行为的内在作用机制仍未得到充分阐释。为填补这一研究空白，我们设计了动态交互刺激实验，以复现紧急场景下的行人-车辆交互过程，实验中纳入时空压力变量，并对决策失误设置了显著惩罚机制。我们采用多模态数据分析手段，涵盖行为数据、脑电图（EEG）与眼动追踪数据，用以探究场景紧迫性对决策不确定性的影响，以及背后潜在的多层次神经加工过程。研究结果显示，随着刺激紧迫性的提升，人类会调整自身的决策目标，进而在应对愈发紧急的刺激时，决策不确定性呈现出先降低后升高的变化趋势。具体而言，在感知阶段早期，紧迫性会增强自上而下的感知加工过程。这一机制表明，在高紧迫性情境下，人类的感知决策会更依赖于先验经验。尽管紧迫性会缩短决策执行阶段的运动准备时长，但值得注意的是，证据累积的峰值（以顶中央正电位（CPP）峰表征）的出现时间晚于实际反应时刻。上述结果提示，感知信息不足与证据累积不充分可能会加剧决策不确定性。本实验研究揭示了人类决策不确定性与场景紧迫性之间的关联，尤其在特定的紧迫性区间内表现显著。