Press Clare M, Kilner James M
Department of Psychological Sciences, Birkbeck University of London, UK.
Neuroreport. 2013 Oct 2;24(14):822-6. doi: 10.1097/WNR.0b013e328364d5fd.
When we observe object-directed actions such as grasping, we make predictive eye movements. However, eye movements are reactive when observing similar actions without objects. This reactivity may reflect a lack of attribution of intention to observed actors when they perform actions without 'goals'. Alternatively, it may simply signal that there is no cue present that has been predictive of the subsequent trajectory in the observer's experience. To test this hypothesis, the present study investigated how the time course of eye movements changes as a function of visual experience of predictable, but arbitrary, actions without objects. Participants observed a point-light display of a model performing sequential finger actions in a serial reaction time task. Eye movements became less reactive across blocks. In addition, participants who exhibited more predictive eye movements subsequently demonstrated greater learning when required either to execute, or to recognize, the sequence. No measures were influenced by whether participants had been instructed that the observed movements were human or lever generated. The present data indicate that eye movements when observing actions without objects reflect the extent to which the trajectory can be predicted through experience. The findings are discussed with reference to the implications for the mechanisms supporting perception of actions both with and without objects as well as those mediating inanimate object processing.
当我们观察诸如抓握等指向物体的动作时，我们会做出预测性眼动。然而，在观察没有物体的类似动作时，眼动是反应性的。这种反应性可能反映出当被观察的行为者在没有“目标”的情况下执行动作时，缺乏对其意图的归因。或者，这可能仅仅表明在观察者的经验中没有出现可预测后续轨迹的线索。为了验证这一假设，本研究调查了在没有物体的可预测但任意的动作的视觉经验作用下，眼动的时间进程是如何变化的。参与者在一个序列反应时任务中观察了一个模型执行连续手指动作的点光显示。在各个实验块中，眼动的反应性逐渐降低。此外，表现出更多预测性眼动的参与者随后在被要求执行或识别该序列时表现出更强的学习能力。参与者是否被告知观察到的动作是由人类还是杠杆产生的，对任何测量指标都没有影响。目前的数据表明，在观察没有物体的动作时，眼动反映了通过经验可预测轨迹的程度。我们将结合这些发现对支持有物体和无物体动作感知的机制以及介导无生命物体加工的机制的影响进行讨论。
