Saarinen J
Department of Psychology, University of Helsinki, Finland.
Perception. 1994;23(2):237-43. doi: 10.1068/p230237.
The observer looked for a target pattern differing from distractors in orientation at one spatial scale only (either at a global or at a local scale) and ignored the other. The stimulus patterns in the search array were vertical or horizontal bars consisting of four oblique line segments sharing the same orientation (45 degrees or 135 degrees). In the search at the global scale, the target and distractors differed from each other in the bar orientation, but not in the orientation of the line segments, which was random. In the search at the local scale, the observer had to use the line orientation for discriminating the target and distractors (the bar orientation was random). The results showed that even though the search was parallel at both scales (ie the search time did not increase with an increasing number of distractors), target detection at the local scale required considerably more time than at the global scale. This latter finding is in agreement with the phenomenon of 'global precedence'.
观察者仅在一个空间尺度（全局或局部尺度）上寻找与干扰物方向不同的目标图案，而忽略另一个尺度。搜索阵列中的刺激图案是由四个具有相同方向（45度或135度）的倾斜线段组成的垂直或水平条。在全局尺度搜索中，目标和干扰物在条的方向上彼此不同，但在线段的方向上没有差异，线段方向是随机的。在局部尺度搜索中，观察者必须使用线段方向来区分目标和干扰物（条的方向是随机的）。结果表明，尽管在两个尺度上搜索都是平行的（即搜索时间不会随着干扰物数量的增加而增加），但局部尺度上的目标检测比全局尺度上需要更多的时间。后一个发现与“全局优先”现象一致。
