Kunar Melina A, Humphreys Glyn W
Brigham and Women's Hospital, Cambridge, Massachusetts, USA.
Mem Cognit. 2006 Apr;34(3):459-74. doi: 10.3758/bf03193571.
Visual search in a conjunction task can be facilitated if half the distractor items are previewed prior to the other half of the distractors and the target item. Here, we investigate the nature of this preview by using a top-up procedure, which presents an initial preview followed by a secondary preview after a period of time (the offset period). In Experiment 1, we demonstrate that increasing the time of the offset period decreases search efficiency. If the offset period is increased to 2 sec, the previewed items are searched to a greater extent than when the offset period is 450 msec. This holds even when the old items remain in the same positions across presentations and when they differ in color from new search stimuli. However, when the offset intervals are reduced, the preview can be discounted from search even when the old items change locations between exposures (Experiment 2) and when they are not distinguished from search displays by their color (Experiment 3). The last result occurs only as long as the preview items can be grouped in terms of form. When the preview stimuli are heterogeneous, they are no longer discounted from search if their locations change across the offset period (Experiment 4). We interpret the data in terms of object-based priming, which enables the repeated form of the old distractors to be filtered more easily from search.
如果在另一半干扰项和目标项之前预先呈现一半干扰项，那么在联合任务中的视觉搜索就能得到促进。在此，我们通过使用一种补充程序来研究这种预览的本质，该程序先呈现初始预览，一段时间（偏移期）后再呈现二次预览。在实验1中，我们证明增加偏移期的时间会降低搜索效率。如果将偏移期增加到2秒，与偏移期为450毫秒时相比，对预先呈现的项目的搜索范围会更大。即使旧项目在各次呈现中保持相同位置，并且它们与新的搜索刺激颜色不同，情况也是如此。然而，当偏移间隔缩短时，即使旧项目在各次呈现之间改变位置（实验-2）以及它们在颜色上与搜索显示无差异（实验-3），预览也可能在搜索中被忽略。只要预览项目能按形式分组，最后这个结果就会出现。当预览刺激是异质的时，如果它们的位置在偏移期内发生变化，它们就不再在搜索中被忽略（实验-4）。我们根据基于对象的启动来解释这些数据，这使得旧干扰项的重复形式能更容易地从搜索中被过滤掉。
