National Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China.
Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom.
Elife. 2017 Sep 5;6:e26117. doi: 10.7554/eLife.26117.
Small fly eyes should not see fine image details. Because flies exhibit saccadic visual behaviors and their compound eyes have relatively few ommatidia (sampling points), their photoreceptors would be expected to generate blurry and coarse retinal images of the world. Here we demonstrate that see the world far better than predicted from the classic theories. By using electrophysiological, optical and behavioral assays, we found that R1-R6 photoreceptors' encoding capacity is maximized to fast high-contrast bursts, which resemble their light input during saccadic behaviors. Whilst , R1-R6s resolve moving objects at saccadic speeds beyond the predicted motion-blur-limit. Our results show how refractory phototransduction and rapid photomechanical photoreceptor contractions jointly sharpen retinal images of moving objects , enabling hyperacute vision, and explain how such microsaccadic information sampling exceeds the compound eyes' optical limits. These discoveries elucidate how acuity depends upon photoreceptor function and eye movements.
小蝇眼不应看到精细的图像细节。因为蝇类表现出扫视视觉行为，并且它们的复眼相对较少小眼（采样点），它们的光感受器应该会产生模糊和粗糙的世界视网膜图像。在这里，我们证明了它们看到的世界远比经典理论预测的要好。通过使用电生理、光学和行为测定法，我们发现 R1-R6 光感受器的编码能力最大限度地适应于快速高对比度的爆发，这类似于它们在扫视行为期间的光输入。虽然如此，R1-R6 可以在扫视速度超过预测的运动模糊极限的情况下分辨移动的物体。我们的结果表明，光感受性的不应期和快速的光机械光感受器收缩如何共同锐化移动物体的视网膜图像，从而实现超敏视觉，并解释了这种微扫视信息采样如何超过复眼的光学限制。这些发现阐明了视力如何取决于光感受器的功能和眼球运动。
