Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095-7239, USA.
Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095-7239, USA.
Curr Biol. 2017 Oct 9;27(19):2901-2914.e2. doi: 10.1016/j.cub.2017.08.035. Epub 2017 Sep 21.
Like many visually active animals, including humans, flies generate both smooth and rapid saccadic movements to stabilize their gaze. How rapid body saccades and smooth movement interact for simultaneous object pursuit and gaze stabilization is not understood. We directly observed these interactions in magnetically tethered Drosophila free to rotate about the yaw axis. A moving bar elicited sustained bouts of saccades following the bar, with surprisingly little smooth movement. By contrast, a moving panorama elicited robust smooth movement interspersed with occasional optomotor saccades. The amplitude, angular velocity, and torque transients of bar-fixation saccades were finely tuned to the speed of bar motion and were triggered by a threshold in the temporal integral of the bar error angle rather than its absolute retinal position error. Optomotor saccades were tuned to the dynamics of panoramic image motion and were triggered by a threshold in the integral of velocity over time. A hybrid control model based on integrated motion cues simulates saccade trigger and dynamics. We propose a novel algorithm for tuning fixation saccades in flies.
和许多视觉活跃的动物一样，包括人类，苍蝇会产生平滑和快速的扫视运动，以稳定他们的注视。目前尚不清楚快速的身体扫视运动和平滑运动如何相互作用，以实现同时进行的目标追踪和注视稳定。我们在自由旋转的磁约束果蝇中直接观察到了这些相互作用。一个移动的棒会引发一连串的扫视运动，这些运动紧随棒的运动，而平滑运动却很少。相比之下，一个移动的全景图会引发强大的平滑运动，偶尔会出现光流性扫视运动。棒固定扫视运动的幅度、角速度和转矩瞬变被精细地调整到棒运动的速度，并由棒误差角的时间积分的阈值而不是其绝对视网膜位置误差触发。光流性扫视运动则根据全景图像运动的动力学进行调整，并由速度随时间的积分的阈值触发。基于综合运动线索的混合控制模型模拟了扫视运动的触发和动力学。我们提出了一种新的算法，用于调整果蝇的固定扫视运动。
