Burr D C, Morrone M C, Ross J
Istituto di Neurofisiologia del CNR, Pisa, Italy.
Nature. 1994 Oct 6;371(6497):511-3. doi: 10.1038/371511a0.
Visual scientists have long sought to explain why the world remains stable during saccades, the ballistic eye-movements that continually displace the retinal image at fast but resolvable velocities. An early suggestion was that vision may be actively suppressed during saccades, but experimental support has been variable. Here we present evidence that saccadic suppression does occur, but that it is selective for patterns modulated in luminance at low spatial frequencies. Patterns of higher spatial frequency, and equiluminant patterns (modulated only in colour) at all spatial frequencies were not suppressed during saccades, but actually enhanced. The selectivity of the suppression suggests that it is confined to the colour-blind magnocellular stream (which provides the dominant input to motion centres and areas involved with attention), where it could dull the otherwise disturbing sense of fast low-spatial-frequency image motion. Masking studies suggest that the suppression precedes the site of contrast masking and may therefore occur early in visual processing, possibly as early as the lateral geniculate nucleus.
视觉科学家长期以来一直试图解释为什么在扫视过程中世界保持稳定，扫视是一种快速但可分辨速度的弹道式眼球运动，它不断地使视网膜图像发生位移。早期的一种观点认为，在扫视过程中视觉可能会被主动抑制，但实验支持并不一致。在这里，我们提供证据表明扫视抑制确实会发生，但它对低空间频率下亮度调制的图案具有选择性。在扫视过程中，较高空间频率的图案以及所有空间频率下的等亮度图案（仅在颜色上调制）不会被抑制，反而会增强。这种抑制的选择性表明它局限于色盲大细胞通路（该通路为运动中心和与注意力相关的区域提供主要输入），在那里它可以减轻快速低空间频率图像运动带来的干扰感。掩蔽研究表明，这种抑制先于对比度掩蔽的部位出现，因此可能在视觉处理的早期阶段发生，可能早在外侧膝状体核。
