Perimetry of contrast detection thresholds of moving spatial sine wave patterns. III. The target extent as a sensitivity controlling parameter.
Perimetry of contrast detection thresholds of moving spatial sine wave patterns. III. The target extent as a sensitivity controlling parameter.
复制标题
移动空间正弦波图案的对比度检测阈值的视野测量。
DOI：
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发表时间：
1978
影响因子：
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通讯作者：
S. Slappendel
中科院分区：
文献类型：
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作者：
J. Koenderink;M. A. Bouman;A. Bueno de Mesquita;S. Slappendel
对比度检测阈值移动正弦波光栅获得在中央凹和偏心率为6度，21度和50度的鼻水平子午线。目标对向从30 X 30弧分到16度X 16度。我们已经发现，对比度检测阈值严重依赖于目标场的范围。如果这个范围足够大，外围检测阈值与在中央凹处测量的阈值相当，则仅灵敏度范围被移位到较低的空间频率。我们表明，如果只是可分辨的距离在任何偏心率被视为一个标尺，和字段宽度和空间频率相应地缩放，那么时空对比度检测阈值变得相同的整个视野。它示出，一个较小的区域，测量几个刚刚可分辨的距离，必须刺激之前，连续或同时的对比度检测是可能的。如果刺激区域被放大到至少10（2）个刚好可分辨距离的直径，则检测性能提高。刚分辨距离与平均神经节间细胞距离以及皮质放大因子相关。
Contrast detection thresholds for moving sine wave gratings were obtained at the fovea and at eccentricities of 6 degrees, 21 degrees, and 50 degrees on the nasal horizontal meridian. The targets subtended from 30 X 30 minutes of arc up to 16 degrees X 16 degrees. We have found that the contrast detection thresholds depend critically on the extent of the target field. If this extent is large enough peripheral detection thresholds are on a par with those measured at the fovea, only the sensitivity range is shifted to lower spatial frequencies. We show that if the just resolvable distance at any eccentricity is taken as a yardstick, and field width and spatial frequency are scaled accordingly, then the spatio-temporal contrast detection thresholds become identical over the whole visual field. It is shown that a smaller area, measuring several just resolvable distances across, has to be stimulated before successive or simultaneous contrast detection is possible at all. Detection performance improves if the stimulated area is enlarged up to diameters of at least 10(2) just resolvable distances. The just resolvable distance correlates well with mean interganglion cell distance, and with the cortical magnification factor.