Janelia Research Campus, Howard Hughes Medical Institute; 19700 Helix Drive, Ashburn, Virginia 20147, USA.
University of Arizona, Department of Neuroscience, 1040 E. 4th Street, Tucson, Arizona 85721, USA.
Nature. 2015 Jan 15;517(7534):333-8. doi: 10.1038/nature14045. Epub 2014 Dec 10.
Sensorimotor control in vertebrates relies on internal models. When extending an arm to reach for an object, the brain uses predictive models of both limb dynamics and target properties. Whether invertebrates use such models remains unclear. Here we examine to what extent prey interception by dragonflies (Plathemis lydia), a behaviour analogous to targeted reaching, requires internal models. By simultaneously tracking the position and orientation of a dragonfly's head and body during flight, we provide evidence that interception steering is driven by forward and inverse models of dragonfly body dynamics and by models of prey motion. Predictive rotations of the dragonfly's head continuously track the prey's angular position. The head-body angles established by prey tracking appear to guide systematic rotations of the dragonfly's body to align it with the prey's flight path. Model-driven control thus underlies the bulk of interception steering manoeuvres, while vision is used for reactions to unexpected prey movements. These findings illuminate the computational sophistication with which insects construct behaviour.
脊椎动物的感觉运动控制依赖于内部模型。当手臂伸展去够物体时，大脑会使用对肢体动力学和目标属性的预测模型。目前尚不清楚无脊椎动物是否使用这种模型。本文中，我们研究了蜻蜓（Plathemis lydia）捕食猎物的行为（类似于目标性抓取）在多大程度上需要内部模型。我们通过在飞行过程中同时跟踪蜻蜓头部和身体的位置和方向，提供了证据表明，拦截转向是由蜻蜓身体动力学的前向和逆向模型以及猎物运动模型驱动的。对蜻蜓头部的预测性旋转持续跟踪猎物的角度位置。通过猎物跟踪建立的头-身角度似乎引导着蜻蜓身体的系统旋转，使它与猎物的飞行路径对齐。因此，模型驱动的控制是拦截转向操作的基础，而视觉则用于对意外猎物运动的反应。这些发现揭示了昆虫构建行为的计算复杂性。
