Watson D G, Humphreys G W
Cognitive Science Research Centre, School of Psychology, University of Birmigham, Edgbaston, England.
Percept Psychophys. 1995 Jul;57(5):583-97. doi: 10.3758/bf03213264.
In five experiments, we investigated the power of targets defined by the onset or offset of one of an object's parts (contour onsets and offsets) either to guide or to capture visual attention. In Experiment 1, search for a single contour onset target was compared with search for a single contour offset target against a static background of distractors; no difference was found between the efficiency with which each could be detected. In Experiment 2, onsets and offsets were compared for automatic attention capture, when both occurred simultaneously. Unlike in previous studies, the effects of overall luminance change, new-object creation, and number of onset and offset items were controlled. It was found that contour onset and offset items captured attention equally well. However, display size effects on both target types were also apparent. Such effects may have been due to competition for selection between multiple onset and offset stimuli. In Experiments 3 and 4, single onset and offset stimuli were presented simultaneously and pitted directly against one another among a background of static distractors. In Experiment 3, we examined "guided search," for a target that was formed either from an onset or from an offset among static items. In Experiment 4, the onsets and offsets were uncorrelated with the target location. Similar results occurred in both experiments: target onsets and offsets were detected more efficiently than static stimuli which needed serial search; there remained effects of display size on performance; but there was still no advantage for onsets. In Experiment 5, we examined automatic attention capture by single onset and offset stimuli presented individually among static distractors. Again, there was no advantage for onset over offset targets and a display size effect was also present. These results suggest that, both in isolation and in competition, onsets that do not form new objects neither guide nor gain automatic attention more efficiently than offsets. In addition, in contrast to previous studies in which onsets formed new objects, contour onsets and offsets did not reliably capture attention automatically.
在五项实验中，我们研究了由物体某一部分的起始或结束（轮廓起始和结束）所定义的目标引导或捕获视觉注意力的能力。在实验1中，将搜索单个轮廓起始目标与在干扰物的静态背景下搜索单个轮廓结束目标进行了比较；在检测效率上未发现二者有差异。在实验2中，当起始和结束同时出现时，比较了它们对注意力的自动捕获情况。与之前的研究不同，整体亮度变化、新物体创建以及起始和结束项目数量的影响都得到了控制。结果发现，轮廓起始和结束项目捕获注意力的效果同样好。然而，显示大小对两种目标类型的影响也很明显。这种影响可能是由于多个起始和结束刺激之间的选择竞争所致。在实验3和实验4中，单个起始和结束刺激同时呈现，并在静态干扰物背景中直接相互竞争。在实验3中，我们研究了“引导搜索”，即搜索由静态项目中的起始或结束形成的目标。在实验4中，起始和结束与目标位置不相关。两个实验都出现了类似的结果：目标起始和结束比需要串行搜索的静态刺激检测效率更高；显示大小对性能仍有影响；但起始仍没有优势。在实验5中，我们研究了在静态干扰物中单独呈现的单个起始和结束刺激对注意力的自动捕获情况。同样，起始目标相对于结束目标没有优势，并且显示大小效应也存在。这些结果表明，无论是单独出现还是相互竞争，不形成新物体的起始在引导或自动捕获注意力方面并不比结束更有效。此外，与之前起始形成新物体的研究不同，轮廓起始和结束并不能可靠地自动捕获注意力。
