Abstract: Abstract□□The representations of the location and spatial relationship of objects have been capturing extensive attentions and disputations in spatial cognition research. Considerable evidence indicates that people select reference frames for spatial memory flexibly based on qualities such as the shape of the environment, the configuration of elements, and one’s own experience of the space. There were few researches, however, on the effect of similarity information provided by the objects themselves in the scene. In the present study, two experiments were conducted to investigate the role of similarity of objects in the environment on people’s spatial representation. 25 undergraduates (13 females, 12 males) participated in the Experiment 1, among them a female’s data was excluded for disordered eye movements. Another 24 participants (12 females and 12 males) took part in the Experiment 2. All participants were healthy and had normal (or corrected to normal) vision. In each trial, individuals were presented with a symmetrical scene to learn. The viewing perspective defined as the direction of 315° , and the axis of symmetry defined as the direction of 0°. In the learning process, participants' eye movements were tracked with the German SMI iView X Hi-SPeed Eye Tracking System (sampling rate =1250Hz, refresh rate =100Hz). Subsequently, participants used memory to finish triplet recognition task in each experiment. In the task, they were required to judge if the directional relationship in these triplets were the same as the learned scene. The correct response latencies to the targets were analyzed by ANOVA. In the first experiment with no similar objects in the scene, the participants moved their eyes to fixate on the next object more frequently along the directions aligned with the symmetric axis than along the directions aligned with their viewing direction (p=.002) and other direction (p＜.001). The partial scene recognition results showed the mean response latency to triplets including the direction of axis of symmetry was significantly shorter than those including the viewing direction (p=.041). In the second experiment with three similar objects in the scene, the participants moved their eyes to fixate on the next object still more frequently along the directions aligned with the symmetric axis than along the directions aligned with their viewing direction (p=.015) and other direction (p＜.001). They also moved their eyes to fixate on the next object more frequently among similar objects than no similar ones (p=.001). The interaction between directions and similarity is remarkable (p＜.001). Response latency results revealed that there were no differences between triplets including the direction of axis of symmetry and those including the viewing direction. However, the two-way interaction of direction and similar objects included in triplets was significant (p=.002). Further analyses confirmed that triplets with no similar objects including the direction of axis of symmetry was significantly shorter than those including the viewing direction (p=.002), while triplets with similar objects had no such differences (p=.168). Results indicate that when the layout had a symmetric axis that was different from participants’ viewing direction, the sequence of eye fixations on objects during learning and the preferred directions in partial scene recognition were both determined by the direction of the symmetric axis and the similarity of objects. In conclusion, the present study demonstrated that the similarity of objects in symmetrical scenes affects the construction of frame of reference system on people’s spatial representation.

Key words: spatial representation, spatial reference directions, layout geometry, similar objects, eye movement

摘要： 以三维场景图片为实验材料，采用眼动追踪技术，通过两个实验考察了对称场景中物体相似性对空间表征的影响。结果表明：（1）无相似物体条件下，场景本身的内在结构对空间表征有重要影响，对称轴方向可以作为空间表征参照方向；（2）存在部分相似物体条件下，物体的相似性会影响空间表征参照方向的选择，并且相似物体方向也是空间表征的参照方向之一。

关键词: 空间表征, 空间参照方向, 场景结构, 相似物体, 眼动