Becker Stefanie I, Grubert Anna, Horstmann Gernot, Ansorge Ulrich
The University of Queensland, Brisbane, Australia.
Durham University, United Kingdom.
Cognition. 2023 Jul;236:105420. doi: 10.1016/j.cognition.2023.105420. Epub 2023 Mar 9.
Previous research has identified three mechanisms that guide visual attention: bottom-up feature contrasts, top-down tuning, and the trial history (e.g., priming effects). However, only few studies have simultaneously examined all three mechanisms. Hence, it is currently unclear how they interact or which mechanisms dominate over others. With respect to local feature contrasts, it has been claimed that a pop-out target can only be selected immediately in dense displays when the target has a high local feature contrast, but not when the displays are sparse, which leads to an inverse set-size effect. The present study critically evaluated this view by systematically varying local feature contrasts (i.e., set size), top-down knowledge, and the trial history in pop-out search. We used eye tracking to distinguish between early selection and later identification-related processes. The results revealed that early visual selection was mainly dominated by top-down knowledge and the trial history: When attention was biased to the target feature, either by valid pre-cueing (top-down) or automatic priming, the target could be localised immediately, regardless of display density. Bottom-up feature contrasts only modulated selection when the target was unknown and attention was biased to the non-targets. We also replicated the often-reported finding of reliable feature contrast effects in the mean RTs, but showed that these were due to later, target identification processes (e.g., in the target dwell times). Thus, contrary to the prevalent view, bottom-up feature contrasts in dense displays do not seem to directly guide attention, but only facilitate nontarget rejection, probably by facilitating nontarget grouping.
自下而上的特征对比、自上而下的调整以及试验历史（例如，启动效应）。然而，只有少数研究同时考察了这三种机制。因此，目前尚不清楚它们是如何相互作用的，也不清楚哪种机制比其他机制更具主导性。关于局部特征对比，有人认为，只有当目标具有高局部特征对比时，才能在密集显示中立即选择弹出式目标，而在稀疏显示中则不能，这就导致了一种反向集大小效应。本研究通过系统地改变弹出式搜索中的局部特征对比（即集大小）、自上而下的知识和试验历史，对这一观点进行了批判性评估。我们使用眼动追踪来区分早期选择和后期与识别相关的过程。结果表明，早期视觉选择主要由自上而下的知识和试验历史主导：当注意力通过有效的预提示（自上而下）或自动启动偏向目标特征时，无论显示密度如何，目标都能立即被定位。只有当目标未知且注意力偏向非目标时，自下而上的特征对比才会调节选择。我们还在平均反应时中重复了经常报道的数据，发现可靠的特征对比效应，但表明这些效应是由于后期的目标识别过程（例如，在目标停留时间）。因此，与普遍观点相反，密集显示中的自下而上的特征对比似乎并不直接引导注意力，而只是通过促进非目标分组来促进非目标排除。
