Folk C L, Annett S
Department of Psychology, Villanova University, PA 19085.
Percept Psychophys. 1994 Sep;56(3):277-87. doi: 10.3758/bf03209762.
Results from previous visual search studies have suggested that abrupt onsets produce involuntary shifts of attention (i.e., attentional capture), but discontinuities in simple features such as color and brightness do not (Jonides & Yantis, 1988). In the present study we tested whether feature discontinuities (i.e., "singletons") can produce attentional capture in a visual search task if defined "locally" or over a small spatial range. On each trial, a variable number of letters appeared, one of which differed from the others in color or intensity. The location of this singleton was uncorrelated with target location. Local discontinuities were created by embedding the letters in a dot texture. In Experiment 1, display size effects for singleton targets were not reduced with the addition of a background dot texture. Similar results were obtained in Experiment 2, regardless of variations in texture density. Experiment 3 confirmed that when targets are defined by a color or intensity singleton, they are detected preattentively, and that increasing texture density yields faster detection. We conclude that the spatial range over which feature discontinuities are defined may influence the guidance of spatial attention, but it has no influence on their ability to capture attention.
以往视觉搜索研究的结果表明，突然出现会引起注意力的非自愿转移（即注意力捕获），但颜色和亮度等简单特征的不连续性则不会（乔尼德斯和扬蒂斯，1988）。在本研究中，我们测试了如果特征不连续性（即“单独元素”）在“局部”或小空间范围内定义，是否能在视觉搜索任务中产生注意力捕获。在每次试验中，会出现数量可变的字母，其中一个字母在颜色或强度上与其他字母不同。这个单独元素的位置与目标位置不相关。通过将字母嵌入点状纹理中来创建局部不连续性。在实验1中，添加背景点状纹理并没有降低单独元素目标的显示大小效应。在实验2中也获得了类似的结果，无论纹理密度如何变化。实验3证实，当目标由颜色或强度单独元素定义时，它们会在预注意阶段被检测到，并且增加纹理密度会加快检测速度。我们得出结论，定义特征不连续性的空间范围可能会影响空间注意力的引导，但对其捕获注意力的能力没有影响。
