Department of Psychology, Ludwig-Maximilians-Universität München, Leopoldstr. 13, D-80802, München, Germany.
Atten Percept Psychophys. 2024 Feb;86(2):439-456. doi: 10.3758/s13414-023-02750-0. Epub 2023 Jul 5.
The present study investigated whether the integration of separate parts into a whole-object representation varies with the amount of available attentional resources. To this end, two experiments were performed, which required observers to maintain central fixation while searching in peripheral vision for a target among various distractor configurations. The target could either be a "grouped" whole-object Kanizsa figure, or an "ungrouped" configuration of identical figural parts, but which do not support object completion processes to the same extent. In the experiments, accuracies and changes in pupil size were assessed, with the latter reflecting a marker of the covert allocation of attention in the periphery. Experiment 1 revealed a performance benefit for grouped (relative to ungrouped) targets, which increased with decreasing distance from fixation. By contrast, search for ungrouped targets was comparably poor in accuracy without revealing any eccentricity-dependent variation. Moreover, measures of pupillary dilation mirrored this eccentricity-dependent advantage in localizing grouped targets. Next, in Experiment 2, an additional attention-demanding foveal task was introduced in order to further reduce the availability of attentional resources for the peripheral detection task. This additional task hampered performance overall, alongside with corresponding pupil size changes. However, there was still a substantial benefit for grouped over ungrouped targets in both the behavioral and the pupillometric data. This shows that perceptual grouping scales with the allocation of attention even when only residual attentional resources are available to trigger the representation of a complete (target) object, thus illustrating that object completion operates in the "near absence" of attention.
本研究旨在探讨将不同部分整合成整体对象表示的过程是否会随可利用注意资源的数量而变化。为此，进行了两项实验，要求观察者在中央注视的同时，在外周视觉中搜索目标，同时目标周围有各种干扰配置。目标可以是一个“分组”的整体 Kanizsa 图形，也可以是相同图形部分的“未分组”配置，但不能同等程度地支持对象完成过程。在实验中，评估了准确性和瞳孔大小的变化，后者反映了注意力在周边区域的隐性分配的标志。实验 1 表明，对于分组（相对于未分组）的目标，表现有优势，并且随着与注视点的距离减小而增加。相比之下，未分组目标的搜索在准确性上同样较差，没有显示出任何与离焦相关的变化。此外，瞳孔扩张的测量结果反映了在定位分组目标时这种与离焦相关的优势。接下来，在实验 2 中，引入了一个额外的需要注意力的中央任务，以进一步减少外周检测任务中可利用的注意力资源。这个额外的任务整体上阻碍了表现，同时伴随着瞳孔大小的相应变化。然而，在行为和瞳孔测量数据中，分组目标仍然比未分组目标有显著优势。这表明，即使只有剩余的注意力资源可用于触发完整（目标）对象的表示，感知分组也会随着注意力的分配而变化，从而表明对象完成在“几乎没有”注意力的情况下运作。
