Linander Nellie, Dacke Marie, Baird Emily
Lund Vision Group, Department of Biology, Lund University, Lund SE-22362, Sweden
Lund Vision Group, Department of Biology, Lund University, Lund SE-22362, Sweden.
J Exp Biol. 2015 Apr;218(Pt 7):1051-9. doi: 10.1242/jeb.107409. Epub 2015 Feb 5.
When flying through narrow spaces, insects control their position by balancing the magnitude of apparent image motion (optic flow) experienced in each eye and their speed by holding this value about a desired set point. Previously, it has been shown that when bumblebees encounter sudden changes in the proximity to nearby surfaces - as indicated by a change in the magnitude of optic flow on each side of the visual field - they adjust their flight speed well before the change, suggesting that they measure optic flow for speed control at low visual angles in the frontal visual field. Here, we investigated the effect that sudden changes in the magnitude of translational optic flow have on both position and speed control in bumblebees if these changes are asymmetrical; that is, if they occur only on one side of the visual field. Our results reveal that the visual region over which bumblebees respond to optic flow cues for flight control is not dictated by a set viewing angle. Instead, bumblebees appear to use the maximum magnitude of translational optic flow experienced in the frontal visual field. This strategy ensures that bumblebees use the translational optic flow generated by the nearest obstacles - that is, those with which they have the highest risk of colliding - to control flight.
在狭窄空间飞行时，昆虫通过平衡每只眼睛所经历的表观图像运动（光流）的大小来控制自身位置，并通过将该值保持在所需设定点附近来控制飞行速度。此前研究表明，当大黄蜂遇到与附近表面距离的突然变化时——这可通过视野两侧光流大小的变化来指示——它们会在变化之前就调整飞行速度，这表明它们在正面视野的低视角下测量光流以控制速度。在此，我们研究了如果平移光流大小的突然变化不对称，即在视野的一侧发生时，对大黄蜂位置和速度控制的影响。我们的结果表明，大黄蜂对用于飞行控制的光流线索做出反应的视觉区域并非由固定视角决定。相反，大黄蜂似乎利用正面视野中所经历的平移光流的最大大小。这种策略确保大黄蜂利用最近障碍物产生的平移光流——即那些它们碰撞风险最高的障碍物——来控制飞行。
