Abstract：
Biological motion perception plays a critical role in various decisions in daily life. Failure to decide accordingly in such a perceptual task could have life-threatening consequences. Neurophysiology and computational modeling studies suggest two processes mediating perceptual decision-making. One of these signals is associated with the accumulation of sensory evidence and the other with response selection. Recent EEG studies with humans have introduced an event-related potential called Centroparietal Positive Potential (CPP) as a neural marker aligned with the sensory evidence accumulation while effectively distinguishing it from motor-related lateralized readiness potential (LRP). The present study aims to investigate the neural mechanisms of biological motion perception in the framework of perceptual decision-making, which has been overlooked before. More specifically, we examine whether CPP would track the coherence of the biological motion stimuli and could be distinguished from the LRP signal. We recorded EEG from human participants while they performed a direction discrimination task of a point-light walker stimulus embedded in various levels of noise. Our behavioral findings revealed shorter reaction times and reduced miss rates as the coherence of the stimuli increased. In addition, CPP tracked the coherence of the biological motion stimuli with a tendency to reach a common level during the response, albeit with a later onset than the previously reported results in random-dot motion paradigms. Furthermore, CPP was distinguished from the LRP signal based on its temporal profile. Overall, our results suggest that the mechanisms underlying perceptual decision-making generalize to more complex and socially significant stimuli like biological motion.
摘要：
生物运动感知在日常生活中的各种决策中起着至关重要的作用。在这样的感知任务中未能做出相应的决定可能会危及生命。神经生理学和计算建模研究提出了两个介导感知决策的过程。这些信号中的一个与感官证据的积累有关，另一个与反应选择有关。最近对人类的EEG研究引入了一种与事件相关的电位，称为中心顶叶正电位（CPP），作为与感觉证据积累相一致的神经标记，同时有效地将其与运动相关的侧向准备电位（LRP）区分开。本研究旨在研究知觉决策框架下生物运动知觉的神经机制,以前被忽视了。更具体地说,我们检查了CPP是否会跟踪生物运动刺激的相干性，并且是否可以与LRP信号区分开。我们记录了人类参与者的EEG，同时他们执行了嵌入各种噪声水平的点灯助行器刺激的方向识别任务。我们的行为发现显示，随着刺激的连贯性增加，反应时间更短，漏检率降低。此外,CPP跟踪生物运动刺激的连贯性，在反应过程中倾向于达到共同水平，尽管发病时间比以前报道的随机点运动范式的结果晚。此外，基于其时间分布将CPP与LRP信号区分开。总的来说,我们的结果表明,感知决策的潜在机制可以推广到更复杂和具有社会意义的刺激,如生物运动.
