McKendrick A M, Johnson C A
Discoveries in Sight Laboratory, Devers Eye Institute, Legacy Clinical Research and Technology Center, Portland, Oregon 97208-3950, USA.
J Opt Soc Am A Opt Image Sci Vis. 2000 Oct;17(10):1703-12. doi: 10.1364/josaa.17.001703.
We investigated whether resolution is sampling limited for stimuli optimized for detection by magnocellular mechanisms. We measured peripheral (15 degrees and 30 degrees) spatial detection and resolution thresholds using 50% and 90% contrast flicker-defined gratings (25 Hz) and 90% contrast counterphasing sinusoidal gratings (25 Hz). Direction-discrimination performance for 90% contrast counterphasing sinusoidal gratings (25 Hz) was measured foveally. Our results indicate that resolution of rapidly counterphasing stimuli is sampling limited in peripheral vision but is consistent with limiting of performance by parvocellular mechanisms. Also, undersampling may not be necessary to account for motion reversals observed with gratings that both drift and flicker.
我们研究了对于由大细胞机制优化用于检测的刺激，分辨率是否受采样限制。我们使用50%和90%对比度的闪烁定义光栅（25赫兹）以及90%对比度的反相正弦光栅（25赫兹）测量了周边（15度和30度）空间检测和分辨率阈值。在中央凹测量了90%对比度的反相正弦光栅（25赫兹）的方向辨别性能。我们的结果表明，快速反相刺激的分辨率在周边视觉中受采样限制，但与小细胞机制对性能的限制一致。此外，对于既有漂移又有闪烁的光栅所观察到的运动反转，可能无需欠采样来解释。
