Solomon J A, Sperling G
NASA Ames Research Center, Moffett Field, CA 94035-1000.
Vision Res. 1995 Jan;35(1):59-64. doi: 10.1016/0042-6989(94)e0077-x.
STIMULI. The 1st-order stimuli are moving sine gratings. The 2nd-order stimuli are fields of static visual texture, whose contrasts are modulated by moving sine gratings. Neither the spatial slant (orientation) nor the direction of motion of these 2nd-order (microbalanced) stimuli can be detected by a Fourier analysis; they are invisible to Reichardt and motion-energy detectors. METHOD. For these dynamic stimuli, when presented both centrally and in an annular window extending from 8 to 10 deg in eccentricity, we measured the highest spatial frequency for which discrimination between +/- 45 deg texture slants and discrimination between opposite directions of motion were each possible. RESULTS. For sufficiently low spatial frequencies, slant and direction can be discriminated in both central and peripheral vision, for both 1st- and for 2nd-order stimuli. For both 1st- and 2nd-order stimuli, at both retinal locations, slant discrimination is possible at higher spatial frequencies than direction discrimination. For both 1st- and 2nd-order stimuli, motion resolution decreases 2-3 times more rapidly with eccentricity than does texture resolution. CONCLUSIONS. (1) 1st- and 2nd-order motion scale similarly with eccentricity. (2) 1st- and 2nd-order texture scale similarly with eccentricity. (3) The central/peripheral resolution fall-off is 2-3 times greater for motion than for texture.
刺激。一级刺激是移动的正弦光栅。二级刺激是静态视觉纹理场，其对比度由移动的正弦光栅调制。这些二级（微平衡）刺激的空间倾斜（方向）和运动方向都无法通过傅里叶分析检测到；对于赖夏德探测器和运动能量探测器来说，它们是不可见的。方法。对于这些动态刺激，当在中央和从离心率8度到10度延伸的环形窗口中呈现时，我们测量了能够分别区分+/- 45度纹理倾斜和相反运动方向的最高空间频率。结果。对于足够低的空间频率，一级和二级刺激在中央和周边视觉中都可以区分倾斜和方向。对于一级和二级刺激，在两个视网膜位置，倾斜辨别在比方向辨别更高的空间频率下是可能的。对于一级和二级刺激，运动分辨率随离心率下降的速度比纹理分辨率快2至3倍。结论。（1）一级和二级运动随离心率的缩放方式相似。（2）一级和二级纹理随离心率的缩放方式相似。（3）运动的中央/周边分辨率下降比纹理大2至3倍。
