Hershler Orit, Hochstein Shaul
Neurobiology Department, Institute of Life Sciences and Interdisciplinary Center for Neural Computation, Hebrew University, Jerusalem 91904, Israel.
Vision Res. 2006 Sep;46(18):3028-35. doi: 10.1016/j.visres.2006.03.023. Epub 2006 May 15.
In this issue of Vision Research, VanRullen, R. (2006). On second glance: Still no high-level pop-out effect for faces. Vision Research, in press. challenges our earlier Vision Research paper, "At first sight: A high-level pop-out effect for faces" (Hershler, O., & Hochstein, S. (2005). At first sight: A high-level pop-out effect for faces. Vision Research, 45, 1707-1724). In that paper, we showed that faces pop-out from a great variety of heterogeneous distractors. This search must have been based on a holistic combination of facial features, since it could not have relied on any single low-level distinguishing feature-each of which was present in at least some of the distractors. VanRullen implies that the pop-out effect is not limited to faces, is not holistic, and is due to a low-level confound, namely that the "low-level" Fourier amplitude spectrum may differentiate between faces and other categories. We now show that he fails to substantiate all three claims. His first experiment replicates our own and shows once again that faces do indeed pop-out, while other objects, such as cars, do not. The claim regarding the non-holistic nature of face search is based on a failure to differentiate between holistic processing for face detection and for individual face identification. His central claim is that the Fourier amplitude spectrum is processed low-level and could be used for face pop-out. However, changing the amplitude spectrum may well affect high-level representations as well. For example, his demonstration uses hybrid images which are extremely fuzzy, rendering them difficult to identify. More importantly, this claim would lead to the conclusion that targets with a non-face phase spectrum and only a face amplitude spectrum would pop-out among distractors with different amplitude spectra. We demonstrate that this is, of course, not the case and that the Fourier amplitude is not the hoped for "low-level confound". Until another such "hidden" low level feature is found, we must accept that face pop out depends on a high level mechanism.
在本期《视觉研究》中，范鲁伦，R.（2006年）。再看一眼：面部仍不存在高级别的弹出效应。《视觉研究》，即将发表。对我们早期发表在《视觉研究》上的论文《乍一看：面部的高级别弹出效应》（赫什勒，O.，& 霍赫斯坦，S.（2005年）。乍一看：面部的高级别弹出效应。《视觉研究》，45，1707 - 1724）提出了挑战。在那篇论文中，我们表明面部能从各种各样的异质干扰物中弹出。这种搜索必定是基于面部特征的整体组合，因为它不可能依赖于任何单一的低级别区分特征——每个这样的特征至少在某些干扰物中也存在。范鲁伦暗示弹出效应不限于面部，不是整体性的，并且是由于一个低级别混淆因素，即“低级别”傅里叶幅度谱可能区分面部和其他类别。我们现在表明他未能证实这三个主张。他的第一个实验重复了我们的实验，再次表明面部确实会弹出，而其他物体，如汽车，则不会。关于面部搜索非整体性本质的主张是基于未能区分用于面部检测的整体处理和用于个体面部识别的整体处理。他的核心主张是傅里叶幅度谱是低级别处理的，可用于面部弹出。然而，改变幅度谱很可能也会影响高级别表征。例如，他的演示使用的混合图像极其模糊，难以识别。更重要的是，这一主张会导致这样的结论：具有非面部相位谱且只有面部幅度谱的目标会在具有不同幅度谱的干扰物中弹出。我们证明情况当然并非如此，并且傅里叶幅度不是所期望的“低级别混淆因素”。在找到另一个这样的“隐藏”低级别特征之前，我们必须接受面部弹出依赖于高级别机制。
