Visual search and attentional alignment in 3D space are potentially modulated by information in unattended depth planes. The number of relevant and irrelevant items as well as their spatial relations may be regarded as factors which contribute to such effects. On a behavioral level, it might be different whether multiple distractors are presented in front of or behind target items. However, several studies revealed that attention cannot be restricted to a single depth plane. To further investigate this issue, two experiments were conducted. In the first experiment, participants searched for (multiple) targets in one depth plane, while non-target items (distractors) were simultaneously presented in this or another depth plane. In the second experiment, an additional spatial cue was presented with different validities to highlight the target position. Search durations were generally shorter when the search array contained two additional targets and were markedly longer when three distractors were displayed. The latter effect was most pronounced when a single target and three distractors coincided in the same depth plane and this effect persisted even when the target position was validly cued. The study reveals that the depth relation of target and distractor stimuli was more important than the absolute distance between these objects. Furthermore, the present findings suggest that within an attended depth plane, irrelevant information elicits strong interference. In sum, this study provides further evidence that allocation of attention is a flexible process which may be modulated by a variety of perceptual and cognitive factors.

3D 空间中的视觉搜索和注意力对准可能会受到无人值守深度平面中信息的调节。相关和不相关项目的数量以及它们的空间关系可以被视为促成这种效果的因素。在行为层面上，多个干扰项出现在目标项目之前还是之后可能会有所不同。然而，一些研究表明，注意力不能仅限于单一深度平面。为了进一步研究这个问题，进行了两个实验。在第一个实验中，参与者在一个深度平面中搜索（多个）目标，同时在这个或另一个深度平面中呈现非目标项目（干扰物）。在第二个实验中，提出了具有不同有效性的附加空间线索来突出目标位置。当搜索阵列包含两个额外目标时，搜索持续时间通常较短，而当显示三个干扰物时，搜索持续时间明显较长。当单个目标和三个干扰物在同一深度平面内重合时，后一种效果最为明显，并且即使目标位置得到有效提示，这种效果仍然存在。研究表明，目标刺激和干扰刺激的深度关系比这些物体之间的绝对距离更重要。此外，目前的研究结果表明，在有人关注的深度平面内，不相关的信息会引起强烈的干扰。总之，这项研究提供了进一步的证据，表明注意力分配是一个灵活的过程，可能受到各种感知和认知因素的调节。