Liesefeld Heinrich René, Moran Rani, Usher Marius, Müller Hermann J, Zehetleitner Michael
Department of Psychology, Ludwig- Maximilians-Universität München.
School of Psychological Sciences, Tel-Aviv University.
J Exp Psychol Hum Percept Perform. 2016 Jun;42(6):821-36. doi: 10.1037/xhp0000156. Epub 2016 Jan 4.
Searching for an object among distracting objects is a common daily task. These searches differ in efficiency. Some are so difficult that each object must be inspected in turn, whereas others are so easy that the target object directly catches the observer's eye. In 4 experiments, the difficulty of searching for an orientation-defined target was parametrically manipulated between blocks of trials via the target-distractor orientation contrast. We observed a smooth transition from inefficient to efficient search with increasing orientation contrast. When contrast was high, search slopes were flat (indicating pop-out); when contrast was low, slopes were steep (indicating serial search). At the transition from inefficient to efficient search, search slopes were flat for target-present trials and steep for target-absent trials within the same orientation-contrast block-suggesting that participants adapted their behavior on target-absent trials to the most difficult, rather than the average, target-present trials of each block. Furthermore, even when search slopes were flat, indicative of pop-out, search continued to become faster with increasing contrast. These observations provide several new constraints for models of visual search and indicate that differences between search tasks that were traditionally considered qualitative in nature might actually be due to purely quantitative differences in target discriminability. (PsycINFO Database Record
在干扰物体中寻找目标物体是一项常见的日常任务。这些搜索在效率上存在差异。有些搜索非常困难，以至于必须逐个检查每个物体，而另一些则非常容易，以至于目标物体能直接吸引观察者的目光。在4项实验中，通过目标与干扰物的方向对比度，在不同的试验组块之间对寻找方向定义目标的难度进行了参数化操作。我们观察到，随着方向对比度的增加，搜索从低效到高效呈现出平滑的转变。当对比度高时，搜索斜率平缓（表明弹出式搜索）；当对比度低时，斜率陡峭（表明系列搜索）。在从低效搜索到高效搜索的转变过程中，在同一方向对比度组块内，目标存在试验的搜索斜率平缓，而目标缺失试验的搜索斜率陡峭——这表明参与者在目标缺失试验中将其行为调整为适应每个组块中最困难的目标存在试验，而非平均难度的目标存在试验。此外，即使搜索斜率平缓，表明是弹出式搜索，随着对比度增加，搜索速度仍会继续加快。这些观察结果为视觉搜索模型提供了几个新的限制条件，并表明传统上被认为本质上是定性的搜索任务之间的差异，实际上可能仅仅是由于目标可辨别性的纯粹定量差异所致。（《心理学文摘数据库记录》 ）
