Variations in crowding, saccadic precision, and spatial localization reveal the shared topology of spatial vision
Variations in crowding, saccadic precision, and spatial localization reveal the shared topology of spatial vision
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DOI：
10.1073/pnas.1615504114
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发表时间：
2017-04-25
影响因子：
11.1
通讯作者：
Cavanagh, Patrick
中科院分区：
文献类型：
--
作者：
Greenwood, John A.;Szinte, Martin;Cavanagh, Patrick
视觉敏感度在视野中以几种特征方式变化。例如，周边（相对于中央凹）视觉的灵敏度急剧下降，并且在上（相对于下）视野中通常更差。这些变化可以影响从敏锐度和拥挤（杂乱对物体识别的有害影响）到扫视眼球运动的精确度的过程。在这里，我们研究这些变化是否可以归因于视觉系统内的一个共同的来源。我们首先比较了拥挤区的大小与使用定向时钟目标和两个相邻的侧翼元素的扫视精度。我们报告说，眼跳精度和拥挤的目标报告不同的特质在整个视野中的所有参与者的任务之间具有很强的相关性。然而，无论是组水平和试验的试验分析显示解离，排除了一个共同的代表性的两个过程。因此，我们比较拥挤的空间定位的两个措施：兰道尔特-C间隙分辨率和三点平分。在这里，我们观察到类似的特质的变化与强烈的参与者之间的相关性，尽管相当精细的精度。分层回归分析进一步表明，空间精度的变化占拥挤的变化，包括拥挤和扫视之间的相关性。总之，我们表明，拥挤，空间定位和扫视精度显示出明确的解离，独立的空间表征的指示，但在空间拓扑共享特质的变化。我们认为，这些拓扑特质是在视觉系统的早期建立的，并在整个后期阶段继承，以影响一系列更高级别的表示。
Visual sensitivity varies across the visual field in several characteristic ways. For example, sensitivity declines sharply in peripheral (vs. foveal) vision and is typically worse in the upper (vs. lower) visual field. These variations can affect processes ranging from acuity and crowding (the deleterious effect of clutter on object recognition) to the precision of saccadic eye movements. Here we examine whether these variations can be attributed to a common source within the visual system. We first compared the size of crowding zones with the precision of saccades using an oriented clock target and two adjacent flanker elements. We report that both saccade precision and crowded-target reports vary idiosyncratically across the visual field with a strong correlation across tasks for all participants. Nevertheless, both group-level and trial-by-trial analyses reveal dissociations that exclude a common representation for the two processes. We therefore compared crowding with two measures of spatial localization: Landolt-C gap resolution and three-dot bisection. Here we observe similar idiosyncratic variations with strong interparticipant correlations across tasks despite considerably finer precision. Hierarchical regression analyses further show that variations in spatial precision account for much of the variation in crowding, including the correlation between crowding and saccades. Altogether, we demonstrate that crowding, spatial localization, and saccadic precision show clear dissociations, indicative of independent spatial representations, whilst nonetheless sharing idiosyncratic variations in spatial topology. We propose that these topological idiosyncrasies are established early in the visual system and inherited throughout later stages to affect a range of higher-level representations.