Computational Neuroscience, Brandenburg University of Technology Cottbus-Senftenberg, Universitätsplatz 1, 01968, Senftenberg, Germany.
Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg, Germany.
Sci Rep. 2021 Apr 19;11(1):8445. doi: 10.1038/s41598-021-87835-2.
The optokinetic reflex is a closed-loop gaze-stabilizing ocular motor reaction that minimizes residual retinal image slip during vestibulo-ocular reflexes. In experimental isolation, the reflex is usually activated by motion of an achromatic large-field visual background with strong influence of radiance contrast on visual motion estimation and behavioral performance. The presence of color in natural environments, however, suggests that chromatic cues of visual scenes provide additional parameters for image motion detection. Here, we employed Xenopus laevis tadpoles to study the influence of color cues on the performance of the optokinetic reflex and multi-unit optic nerve discharge during motion of a large-field visual scene. Even though the amplitude of the optokinetic reflex decreases with smaller radiance contrast, considerable residual eye movements persist at the 'point of equiluminance' of the colored stimuli. Given the color motion preferences of individual optic nerve fibers, the underlying computation potentially originates in retinal circuits. Differential retinal ganglion cell projections and associated ocular motor signal transformation might further reinforce the color dependency in conceptual correspondence with head/body optomotor signaling. Optokinetic reflex performance under natural light conditions is accordingly influenced by radiance contrast as well as by the color composition of the moving visual scene.
视动反射是一种闭环眼球稳定运动反应，可在前庭眼反射期间将视网膜残留像移最小化。在实验隔离的情况下，该反射通常通过具有强亮度对比度对视觉运动估计和行为表现影响的大视野无彩色视觉背景的运动来激活。然而，由于自然环境中存在颜色，因此视觉场景的色觉线索为图像运动检测提供了其他参数。在这里，我们使用非洲爪蟾蝌蚪来研究在大视野视觉场景运动期间，颜色线索对光运动反射和多单位视神经放电性能的影响。即使光运动反射的幅度随着亮度对比度的减小而减小，但在彩色刺激的“等辉点”处仍存在相当大的残余眼球运动。鉴于单个视神经纤维的颜色运动偏好，潜在的计算可能起源于视网膜回路。视网膜神经节细胞的差异投射以及相关的眼球运动信号转换可能会进一步加强与头部/身体运动信号的概念对应中的颜色依赖性。因此，自然光条件下的光运动反射性能受到亮度对比度以及运动视觉场景的颜色组成的影响。
