视觉表象扫描中的视角大小效应

The effect of visual angle on visual image scanning

采用视觉表象的几何距离扫描任务，通过两个实验首次揭示了视觉表象扫描中的视角大小效应。实验一采用3 (视角：2.7°，5.5°和8.2°) × 3 (扫描距离：0.0cm、0.4cm和0.8cm) 组内实验设计，探讨了视角大小这种表象前加工因素是否影响心理扫描的问题；实验二采用8 (视角：2.7°，4.1°，5.5°，6.9°，8.2°，9.6°，12.3°和17.1°) × 2 (扫描距离：0.4cm和0.8cm) 组内实验设计，探讨了视角大小如何影响心理扫描加工过程的问题。结果表明：（1）在视觉表象扫描中，扫描时间会受到表象对应刺激的视角大小影响，即使扫描的几何距离相等，不同视角大小条件下的扫描时间仍存在显著差异；（2）在4°到10°这个视角范围内心理扫描的时间显著短于这个范围之外的扫描时间，6.5°左右是视觉表象扫描的最佳视角。视角大小效应有别于心理扫描的大小效应和距离效应，为Kosslyn的表象计算理论增加了新的内容，具有重要的理论意义。同时它对仪表、图形设计以及棋牌游戏等工作和生活实践具有一定的应用价值。

It was revealed that visual angle existed in visual image， and mental image influenced image operation. Kosslyn mentioned size effect in his image calculation theory， but didn’t think about how external factors might act on the internal visual image processing. Most research on mental image didn’t regard visual angle as a factor. Whether actual visual angles of objects influence image operation was explored in the present research.MethodTwo experiments were used to investigate the effects of visual angle on visual image scanning with the task of scanning the Euclidean distance on mental image. In Experiment 1， 3(visual angle: 2.7°， 5.5°and 8.2°)×3(scanning distance: 0.0cm， 0.4cm and 0.8cm) within-subject factorial design was taken to examine whether visual angle influence image scanning. Experiment 2 investigated how visual angle influence image scanning process with a 8 (visual angle: 2.7°， 4.1°， 5.5°，6.9°， 8.2°， 9.6°， 12.3°and 17.1°)×2 ( scanning distance: 0.4cm and 0.8 cm ) within-subject factorial design.ResultsThe findings indicated that: (1) visual angle of stimulus did influence the scanning time of visual image， even though the scanning Euclidean distances were the same; (2) When the visual angle was in the range from 4°to 10°， scanning time was significantly shorter than that of visual angle outside this range， the shortest scanning time was found on 6.5°.ConclusionsThe present research dispelled the interferences of the category distance， and verified the distance effect in visual image. The size effect of visual angle was different from size effect of mental scan and distance effect. The present findings have significant theoretical values. They add to Kosslyn’s image calculation theory. The findings have important practical implications as well. For it can be applied to the design of panel， illustration， game， interface， screen， and other instruments both in work and daily life.