Knöll Jonas, Binda Paola, Morrone M Concetta, Bremmer Frank
Department of Physics, Philipps-Universität Marburg, Germany.
J Vis. 2011 Dec 16;11(14):15. doi: 10.1167/11.14.15.
Sensitivity to luminance contrast is reduced just before and during saccades (saccadic suppression), whereas sensitivity to color contrast is unimpaired peri-saccadically and enhanced post-saccadically. The exact spatiotemporal map of these perceptual effects is as yet unknown. Here, we measured detection thresholds for briefly flashed Gaussian blobs modulated in either luminance or chromatic contrast, displayed at a range of eccentricities. Sensitivity to luminance contrast was reduced peri-saccadically by a scaling factor, which was almost constant across retinal space. Saccadic suppression followed a similar time course across all tested eccentricities and was maximal shortly after the saccade onset. Sensitivity to chromatic contrast was enhanced post-saccadically at all tested locations. The enhancement was not specifically linked to the execution of saccades, as it was also observed following a displacement of retinal images comparable to that caused by a saccade. We conclude that luminance and chromatic contrast sensitivities are subject to distinct modulations at the time of saccades, resulting from independent neural processes.
在扫视之前和扫视期间，对亮度对比度的敏感度会降低（扫视抑制），而对颜色对比度的敏感度在扫视前后不受影响，并且在扫视后会增强。这些感知效应的确切时空图谱尚不清楚。在这里，我们测量了在一系列离心率下显示的、以亮度或颜色对比度调制的短暂闪烁高斯斑点的检测阈值。对亮度对比度的敏感度在扫视前后按比例因子降低，该比例因子在整个视网膜空间几乎恒定。扫视抑制在所有测试的离心率下遵循相似的时间进程，并且在扫视开始后不久达到最大值。在所有测试位置，扫视后对颜色对比度的敏感度都会增强。这种增强与扫视的执行没有特定联系，因为在视网膜图像发生与扫视引起的位移相当的位移后也观察到了这种增强。我们得出结论，亮度和颜色对比度敏感度在扫视时受到不同的调制，这是由独立的神经过程导致的。
