Jingling Li, Lu Yi-Hui, Cheng Miao, Tseng Chia-Huei
Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan.
Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan.
Atten Percept Psychophys. 2017 Jul;79(5):1366-1383. doi: 10.3758/s13414-017-1308-7.
Searching for a target in a salient region should be easier than looking for one in a nonsalient region. However, we previously discovered a contradictory phenomenon in which a local target in a salient structure was more difficult to find than one in the background. The salient structure was constructed of orientation singletons aligned to each other to form a collinear structure. In the present study, we undertake to determine whether such a masking effect was a result of salience competition between a global structure and the local target. In the first 3 experiments, we increased the salience value of the local target with the hope of adding to its competitive advantage and eventually eliminating the masking effect; nevertheless, the masking effect persisted. In an additional 2 experiments, we reduced salience of the global collinear structure by altering the orientation of the background bars and the masking effect still emerged. Our salience manipulations were validated by a controlled condition in which the global structure was grouped noncollinearly. In this case, local target salience increase (e.g., onset) or global distractor salience reduction (e.g., randomized flanking orientations) effectively removed the facilitation effect of the noncollinear structure. Our data suggest that salience competition is unlikely to explain the collinear masking effect, and other mechanisms such as contour integration, border formation, or the crowding effect may be prospective candidates for further investigation.
在显著区域中寻找目标应该比在非显著区域中寻找目标更容易。然而，我们之前发现了一种矛盾的现象，即显著结构中的局部目标比背景中的局部目标更难找到。显著结构是由相互对齐以形成共线结构的方向单元素构成的。在本研究中，我们致力于确定这种掩蔽效应是否是全局结构与局部目标之间显著性竞争的结果。在前三个实验中，我们提高了局部目标的显著性值，希望增加其竞争优势并最终消除掩蔽效应；然而，掩蔽效应仍然存在。在另外两个实验中，我们通过改变背景条的方向降低了全局共线结构的显著性，但掩蔽效应仍然出现。我们的显著性操作通过一个全局结构非共线分组的对照条件得到了验证。在这种情况下，局部目标显著性的增加（例如，起始）或全局干扰物显著性的降低（例如，随机侧翼方向）有效地消除了非共线结构的促进效应。我们的数据表明，显著性竞争不太可能解释共线掩蔽效应，轮廓整合、边界形成或拥挤效应等其他机制可能是进一步研究的潜在候选因素。
