认知与发展心理学研究室知识库

知觉客体间的因果关系称为因果知觉（causal perception）。因果知觉可以帮助人们理解自然规律并与环境进行有效交互。经典客体碰撞研究认为因果知觉是一种自动化的自下而上的加工过程，另一些研究则表明注意可能参与调解因果知觉。在日常生活中，往往多个事件同时发生，而且人们对事件的发生通常也没有预期因果，因此日常生活中人们往往是在多任务条件的分散注意状态下进行因果判断。因此，本论文聚焦于研究第二任务对因果知觉的影响，在更有生态效度的条件下探究因果知觉的机制。
根据因果知觉领域和注意分散对时间知觉影响的研究结果，我们假设，被试在做因果判断任务时，如果有第二任务占用注意资源，则会增加被试知觉到因果关系的比例。为了验证上述假设，我们在有时间间隔的因果知觉碰撞范式的基础上，加入数字判断作为第二任务，考察第二任务对因果知觉的影响。
研究1探讨干扰刺激、第二任务判断对因果知觉的影响，结果发现：1）仅在两球接触时在外周视野呈现干扰刺激或仅作简单第二任务判断不足以影响因果知觉；2）对干扰刺激做第二任务判断会增加因果判断的比例，我们将其称为因果知觉的第二任务效应。
研究2探讨第二任务刺激出现的时间对因果知觉的影响，结果发现：1）第二任务刺激出现的时间接近因果事件关键时间点（碰撞时）时，因果知觉的第二任务效应更大；2）第二任务刺激出现的时间在因果事件关键时间点前比在后，该效应更大。
研究3探讨第二任务刺激出现的位置对因果知觉的影响，结果发现：第二任务刺激和因果判断刺激出现位置的距离较远时，因果知觉的第二任务效应更大。
本研究首次通过多个实验发现了稳定的因果知觉的第二任务效应，即无关的第二任务会增加知觉到的因果关系。时钟模型的注意闸门理论给我们一种可能的解释：第二任务减少了投入在因果事件上的注意力，时间知觉的闸门变窄，进而减少了节拍器频率的记录和累计器的计数，缩短了因果事件的主观时间间隔，因而增加了因果感觉。

Besides the basic physical properties, our visual system also has the ability to perceive the causal interaction between objects. This causal perception ability is critical for us to understand the rules of nature and therefore interact with it effectively. Some researchers suggest that causal perception is an automatic bottom-up process, others suggest that attention can affect causal perception. Causal judgments with attention distraction are typical in everyday life, because people usually have no expectation for the causal events. Can attention distraction affect causal perception? How? Answers to these questions help to understand the characteristics of causal perception, and help people better interact with environment, but so far we didn’t find a direct answer in literatures.
Study of the following areas may indirectly help to find the answer. Studies in causal perception area find that continuity in time perception is one of the most important factors that affect causal perception. The more continuous, the more perceived causality. Using dual task paradigm, studies in time perception find that a distractive secondary task shortens perceived time duration. Therefore, we hypothesize that if a distractive secondary task occurs when participants are doing a causal judgment task, it will increase perceived causality. To test this, we add a digital judgment task as a secondary task to Michotte’s launching task.
Study 1 investigates whether distractive stimulus and a secondary task affects causal perception. We found that: mere appearance of distractive stimulus isn’t sufficient to influence causal perception. Performing a concurrent secondary task biased the participants toward perceiving more causality. This effect is named as secondary task effect of causal perception.
Study 2 investigates whether the onset of the secondary task stimulus makes a difference, and we found that: the effect is bigger when the secondary task stimulus appears near the contact time (key point of the causal event). The effect is bigger when it appears before the contact time than after.
Study 3 investigates whether the location of the secondary task stimulus makes an influence, and we found that: the effect is smaller when the secondary task stimulus appears near the causal task stimulus than away from it.
Overall, in this study we found a steady effect of secondary task on causal perception, i.e. performing a concurrent secondary task can bias the visual system toward perceiving the test event as causal launching. According to attentional gate model of time perception, the secondary task reduced participates’ attention resources on causal perception task, therefore narrowed the attentional gate of time perception, hense increased the perceived time continuity of the causal events, and then increased the perceived causal launching.