Crowding is directed to the fovea and preserves only feature contrast.
Crowding is directed to the fovea and preserves only feature contrast.
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DOI：
10.1167/7.2.8
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发表时间：
2007-03
影响因子：
1.8
通讯作者：
Y. Petrov;Ariella V. Popple
中科院分区：
文献类型：
--
作者：
Y. Petrov;Ariella V. Popple
关于拥挤的大量文献为这种现象提供了相当简单的解释，例如位置不确定性或特征池，但缺乏令人信服的证据来支持这些解释。在某种程度上，这是因为拥挤研究中使用的刺激通常是字母或其他复杂的形状，这使得很难确定到底丢失了什么样的信息。在我们的实验中，我们要求观察者同时识别三个水平对齐的Gabor目标的倾斜（左或右）。目标在外围呈6度角，它们的大小和间隔被选择为引起强烈的拥挤。丢失的信息的位置或方向的个别成员的Gabor三元组并不能解释我们的结果。相反，拥挤似乎是一种特殊形式的集体信息损失。首先，最外面的目标比其他目标拥挤得少，这排除了基于简单汇集的解释，并表明拥挤具有明显的中央凹方向性。第二，所有观察者所表现出的混乱的特定模式表明，他们所能获得的唯一可靠信息是方位对比，也就是倾斜度发生变化的地点的数量（以及在较小程度上的位置）。因此，拥挤似乎只是备用的最显着的周边信息，这支持了拥挤是由注意力解决的局限性。
The abundant literature on crowding offers fairly simple explanations for the phenomenon, such as position uncertainty or feature pooling, but convincing evidence to support these explanations is lacking. In part, this is because the stimuli used for crowding studies are usually letters or other complex shapes, which makes it hard to determine exactly what kind of information is lost. In our experiment, we asked observers to identify simultaneously the slants (left or right) of three horizontally aligned Gabor targets. The targets were presented at 6 degrees in the periphery, and their size and separation were chosen to incur strong crowding. The loss of information about the position or orientation of individual members of the Gabor triads does not explain our results. Instead, crowding appears to be a particular form of collective information loss. Firstly, the outmost target was crowded much less than the other targets, which rules out explanations based on simple pooling and shows that crowding has a pronounced foveal directionality. Secondly, the specific pattern of confusion shown by all the observers indicates that the only reliable information available to them was orientation contrast, that is, the number (and, to a lesser degree, the location) of sites where slant changed. Thus, crowding appears to spare only the most salient peripheral information, which supports the hypothesis that crowding is caused by limitations of attentional resolution.