SPATIAL SUMMATION PROPERTIES OF DIRECTIONALLY SELECTIVE MECHANISMS IN HUMAN VISION
SPATIAL SUMMATION PROPERTIES OF DIRECTIONALLY SELECTIVE MECHANISMS IN HUMAN VISION
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DOI：
10.1364/josaa.8.001330
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发表时间：
1991-08-01
影响因子：
1.9
通讯作者：
BURR, DC
中科院分区：
文献类型：
--
作者：
ANDERSON, SJ;BURR, DC
我们本文的目标是从心理物理学角度测量人类视觉中运动单位的感受野大小。为此，测量了空间频率为 0.1、1.0 和 10.0 周期每度 (c/deg) 的漂移 (8-Hz) 正弦光栅的长度和宽度空间求和函数，并具有两个阈值标准：方向辨别和简单检测。对于每个空间频率，检测漂移方向的对比敏感度随着刺激大小（长度或宽度）的增加而增加，首先迅速（斜率大于或等于 1.0），然后逐渐增加（斜率 0.29）。对于大多数刺激，检测和方向辨别对比度阈值几乎相同。然而，对于宽度严重缩减的刺激，方向辨别所需的对比度比检测所需的对比度明显更高。这些结果是用求和模型预测的，该模型结合了三维（空间-空间-时间）线性输入滤波器以及空间上和不同滤波器类型之间的概率求和。该模型的拟合给出了人类视觉中运动检测器单元的感受野长度和宽度的估计。在每个空间频率，感受野宽度和长度的估计是相似的，这表明运动检测器单元的感受野在所有空间尺度上都是长和宽的。感受野大小从 0.1 c/deg 的大约 0.12 个周期到 10.0 c/deg 的 0.52 个周期变化。
Our goal in this paper was to measure psychophysically the receptive-field size of motion units in human vision. To this aim, length and width spatial summation functions were measured for drifting (8-Hz) sinusoidal gratings of spatial frequencies 0.1, 1.0, and 10.0 cycles per degree (c/deg) with two threshold criteria: direction discrimination and simple detection. For each spatial frequency, contrast sensitivity for detection of the direction of drift increased with increasing stimulus size (length or width), at first rapidly (slope greater-than-or-equal-to 1.0) and then more gradually (slope 0.29). For most stimuli, the detection and direction-discrimination contrast thresholds were nearly the same. However, for stimuli severely curtailed in width, significantly more contrast was required for direction discrimination than for detection. These results were predicted with a summation model, which incorporated three-dimensional (space-space-time) linear input filters, and probability summation over space and among different filter types. The fit of the model gave an estimate of both the receptive-field length and width of motion-detector units in human vision. At each spatial frequency, the estimates of receptive-field width and length were similar, indicating that the receptive fields of motion-detector units are as long as they are wide at all spatial scales. Receptive-field size varied from approximately 0.12 cycle at 0.1 c/deg to 0.52 cycle at 10.0 c/deg.