Visual crowding is a phenomenon in which the perception of a peripheral target depends on nearby, task-irrelevant flankers. The exact nature of this dependency is controversial (Whitney & Levi 2011). Phenomenologically, some flanker features appear to be confused, or substituted, with target features. One current debate (akin to early- vs. late-selection debates in attention) centers around whether substitution occurs for entire objects, for basic features, or something in between. Results have been mixed: in letter stimuli, observers sometimes appear to swap the target with entire flankers (van den Berg et al. 2012), to preferably swap with similar flankers, or to report letters not present in the display (Freeman et al. 2012). In feature conjunction stimuli, observers appear to swap unbound features (P?μder & Wagemans 2007), whereas in stimuli of intermediate complexity observers appear to lose location information after binding simple features (Greenwood et al. 2012). We ask whether a high-dimensional pooling model can predict these seemingly disparate results. In this model (Balas et al 2009), the visual system measures a texture descriptor (Portilla & Simoncelli 2000) in each local pooling region. We test whether the ambiguities and confusions inherent in this representation can account for diverse substitution phenomena. To do this, we synthesize new images ("mongrels") which share the same texture descriptor as the original stimuli. We find that the model explains seemingly contradictory results. In mongrels of "complex" letter stimuli, we observe swapping of flankers with targets, preferred generation of similar flankers, and synthesis of absent letters. Mongrels of simple feature conjunction stimuli show illusory conjunctions, supporting observations of non-binding of features. Mongrels of arrays of crosses (Greenwood et al. 2012), typically reproduce arrays of crosses, in line with apparent low-level "binding" in crowding of these stimuli. Thus, our high-dimensional pooling model can reconcile disparate crowding accounts.
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机译：视觉拥挤是一种现象，其中对周围目标的感知取决于附近的，与任务无关的侧翼。这种依赖关系的确切性质是有争议的（Whitney＆Levi 2011）。现象学上，一些侧翼特征似乎与目标特征相混淆或替代。当前的一场辩论（类似于对早期选择与后期选择的关注）围绕着是整个对象，基本特征还是介于两者之间的替代发生。结果好坏参半：在字母刺激中，观察者有时似乎会与整个侧翼交换目标（van den Berg等人，2012），最好与相似的侧翼交换目标，或者报告显示屏中不存在的字母（Freeman等。 2012）。在特征连带刺激中，观察者似乎会交换未绑定的特征（Püder＆Wagemans 2007），而在中等复杂度的刺激中，观察者似乎在绑定简单特征后会丢失位置信息（Greenwood等人，2012）。我们问一个高维合并模型是否可以预测这些看似完全不同的结果。在该模型中（Balas等人，2009年），视觉系统在每个局部池化区域中测量纹理描述符（Portilla和Simoncelli 2000）。我们测试了此表示形式中固有的歧义和混淆是否可以解释各种替代现象。为此，我们合成了新图像（“杂物”），这些图像与原始刺激共享相同的纹理描述符。我们发现该模型解释了看似矛盾的结果。在“复杂”字母刺激的杂种动物中，我们观察到侧翼与靶标的交换，相似侧翼的优先生成以及缺失字母的合成。简单特征连词刺激的杂种动物显示出虚幻的连词，从而支持了对未绑定特征的观察。十字架阵列的杂种动物（Greenwood等人，2012）通常复制十字架阵列，与这些刺激物拥挤时明显的低水平“结合”相一致。因此，我们的高维合并模型可以协调不同的拥挤帐户。
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