Summary statistics for size over space and time
Summary statistics for size over space and time
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DOI：
10.1167/14.9.22
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发表时间：
2014-01-01
影响因子：
1.8
通讯作者：
Solomon, Joshua A.
中科院分区：
文献类型：
--
作者：
Gorea, Andrei;Belkoura, Seddik;Solomon, Joshua A.
许多研究已经调查了视觉系统如何提取同时或顺序传递的刺激的集合的平均特征值。在这项研究中，我们在线性系统理论的统一框架内模拟这两个过程。本研究中使用的特定特征值是大小，我们将其定义为圆直径的对数。在每个系综内，大小取自正态分布。平均大小的歧视，测量使用一个和八个圆圈的合奏。这些圆圈同时呈现（显示时间：13-427 ms），一次一个，或一次八个（时间频率：1.2-38 Hz）。八个项目的合奏的门槛低于一个项目的合奏。当显示时间增加3，200%时，阈值减小1.3倍，而当时间频率减小3，200%时，阈值减小相同的因子。建模和模拟表明，数据与每210 ms读出三到四个项目一致。
A number of studies have investigated how the visual system extracts the average feature-value of an ensemble of simultaneously or sequentially delivered stimuli. In this study we model these two processes within the unitary framework of linear systems theory. The specific feature value used in this investigation is size, which we define as the logarithm of a circle's diameter. Within each ensemble, sizes were drawn from a normal distribution. Average size discrimination was measured using ensembles of one and eight circles. These circles were presented simultaneously (display times: 13-427 ms), one at a time, or eight at a time (temporal-frequencies: 1.2-38 Hz). Thresholds for eight-item ensembles were lower than thresholds for one-item ensembles. Thresholds decreased by a factor of 1.3 for a 3,200% increase in display time, and decreased by the same factor for a 3,200% decrease in temporal frequency. Modeling and simulations show that the data are consistent with one readout of three to four items every 210 ms.