2-DIMENSIONAL SPATIAL AND SPATIAL-FREQUENCY SELECTIVITY OF MOTION-SENSITIVE MECHANISMS IN HUMAN VISION
2-DIMENSIONAL SPATIAL AND SPATIAL-FREQUENCY SELECTIVITY OF MOTION-SENSITIVE MECHANISMS IN HUMAN VISION
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DOI：
10.1364/josaa.8.001340
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发表时间：
1991-08-01
影响因子：
1.9
通讯作者：
MORRONE, MC
中科院分区：
文献类型：
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作者：
ANDERSON, SJ;BURR, DC;MORRONE, MC
在存在空间频率和方向都变化的掩模的情况下，测量用于检测漂移（8-Hz）垂直光栅[空间频率为0.1、1.0和10.0周期/度（c/deg）]的运动方向的阈值。 使用具有不同时间特性的掩模。 掩蔽的特异性也测量了空间频率为3.0 c/deg的固定测试光栅。 经过适当的缩放和变换后，掩蔽数据给出了人类视觉中皮层探测器单元的二维空间频率调谐表面的估计。 在小信号线性和零相位的假设下，对调谐表面进行逆傅立叶变换，以指示检测器单元的心理物理感受野的大小和结构。 漂移测试光栅和抖动（随机相位）掩模光栅得到的结果表明，运动检测器感受野的大小（在周期）随着空间频率的增加，但在所有的空间尺度，有一个长宽比为1。 这些结果与J. Opt. Soc. Am. A 8，1330（1991）。 使用相同的抖动掩模刺激和静止测试光栅，我们证实了Daugman [Vision Res.24，891（1984）]和Harvey和多安[J. Opt. Soc. Am. A7，116（1990）]，运动无关性单位具有长形的感受野，其长宽比接近1.8。 我们的结论是，在人类视觉中的运动依赖性和非依赖性机制的感受野是根本不同的。 讨论了运动单元的取向选择性通过其运动方向的选择性而变得尖锐的可能性。
Thresholds for detecting the direction of motion of drifting (8-Hz) vertical gratings [of spatial frequencies 0.1, 1.0, and 10.0 cycles per degree (c/deg)] were measured in the presence of masks that varied in both spatial frequency and orientation. Masks with different temporal properties were used. The specificity of masking was also measured for a stationary test grating of spatial frequency 3.0 c/deg. After suitable scaling and transformation, the masking data gave an estimate of the two-dimensional spatial-frequency tuning surface of cortical detector units in human vision. With the assumption of small-signal linearity and zero phase, the tuning surfaces were inverse Fourier transformed to give an indication of the size and structure of the psychophysical receptive fields of detector units. The results obtained with drifting test gratings and jittering (random phase) mask gratings indicate that motion-detector receptive fields increase in size (in cycles) with increasing spatial frequency but, at all spatial scales, have a length-width ratio of 1. These results are in close agreement with the summation results reported in J. Opt. Soc. Am. A 8, 1330 (1991). Using the same jittering mask stimuli and stationary test gratings, we confirm reports by Daugman [Vision Res. 24, 891 (1984)] and Harvey and Doan [J. Opt. Soc. Am. A 7, 116 (1990)] that motion-independent units have elongated receptive fields with a length-width ratio near 1.8. We conclude that the receptive fields of motion-dependent and -independent mechanisms in human vision are fundamentally different. The possibility that the orientation selectivity of a motion unit is sharpened by its selectivity for direction of motion is discussed.