For the human observer, it can be difficult to follow the motion of small objects, especially when they move against background clutter. In contrast, insects efficiently do this, as evidenced by their ability to capture prey, pursue conspecifics, or defend territories, even in highly textured surrounds. We here recorded from target selective descending neurons (TSDNs), which likely subserve these impressive behaviors. To simulate the type of optic flow that would be generated by the pursuer’s own movements through the world, we used the motion of a perspective corrected sparse dot field. We show that hoverfly TSDN responses to target motion are suppressed when such optic flow moves syn-directional to the target. Indeed, neural responses are strongly suppressed when targets move over either translational sideslip or rotational yaw. More strikingly, we show that TSDNs are facilitated by optic flow moving counterdirectional to the target, if the target moves horizontally. Furthermore, we show that a small, frontal spatial window of optic flow is enough to fully facilitate or suppress TSDN responses to target motion. We argue that such TSDN response facilitation could be beneficial in modulating corrective turns during target pursuit.

对于人类观察者来说，可能很难跟踪小物体的运动，尤其是当它们在背景杂波中移动时。相比之下，昆虫有效地做到了这一点，它们捕捉猎物、追捕同种动物或保卫领土的能力证明了这一点，即使在高度纹理化的环境中也是如此。我们在这里记录了目标选择性下降神经元 (TSDN)，这可能有助于这些令人印象深刻的行为。为了模拟追逐者自己在世界中的运动所产生的光流类型，我们使用了透视校正稀疏点场的运动。我们表明，当这种光流向目标同步移动时，hoverfly TSDN 对目标运动的响应被抑制。事实上，当目标在平移侧滑或旋转偏航上移动时，神经反应会受到强烈抑制。更引人注目的是，我们表明，如果目标水平移动，则光流与目标反向移动可以促进 TSDN。此外，我们表明，一个小的正面光流空间窗口足以完全促进或抑制 TSDN 对目标运动的响应。我们认为，这种 TSDN 响应促进可能有助于在目标追踪期间调节纠正转弯。