NSF Postdoctoral Fellowship in Biology FY 2013

运动过程中移动猎物探测的神经机制动物的视觉世界总是处于运动状态。直接安装在眼球上的摄像机会记录下一个模糊的永恒运动。视觉运动可以表明猎物或捕食者等行为重要对象的存在，然而每次动物转移目光或进行运动时，视觉周围也会移动。大脑如何区分由眼睛、头部或身体的运动引起的视觉运动和由环境中移动物体引起的视觉运动？为了解决这个问题，该奖学金将支持创新的虚拟现实方法的发展，该方法将与遗传技术相结合，记录幼体斑马鱼试图视觉跟踪和捕获“虚拟”猎物时大脑中特定电路元素的活动。在斑马鱼和许多其他脊椎动物中，捕捉猎物的能力依赖于一种叫做视顶盖的中脑结构；然而，关于顶盖或大脑其他地方的神经回路的身份或功能，人们知之甚少，这些神经回路的功能是检测和引导人们注意移动的猎物。虽然目前的神经记录技术要求鱼是固定的，但虚拟现实系统通过模拟鱼在自由游泳时所经历的视觉世界的运动来克服这一限制。至关重要的是，虚拟现实系统将有可能通过实验将感觉周围的变化与运动动作分离开来，从而允许对神经系统中感觉和运动处理之间的反馈机制进行精确的解剖。训练目标包括学习实现实时闭环控制器的视觉显示，并学习使用遗传方法识别和成像斑马鱼的神经元。该奖学金还将支持人类眼球追踪、虚拟现实系统的开发，该系统将用于教室或博物馆等公共场所。这种眼球追踪系统将允许学生或公众互动地调查他们的运动和他们对运动的感知之间的关系。

Neural mechanisms of mobile prey detection during locomotionThe visual world of animals is always in motion. A video camera mounted directly onto the eyeball would record a blur of perpetual movement. Visual motion can signal the presence of behaviorally important objects such as prey or predators, yet each time an animal shifts its gaze or engages in locomotion, the visual surround also moves. How does the brain distinguish between visual motion caused by movement of the eyes, head or body, versus visual motion caused by mobile objects in the environment? To tackle this question, this fellowship will support the development of innovative, virtual reality methods that will be combined with genetic techniques to record the activity of specific circuit elements in the brain of larval zebrafish while they attempt to visually track and capture "virtual" prey items. In zebrafish and many other vertebrates, the ability to capture prey is reliant on a midbrain structure called the optic tectum; however, very little is known about identity or function of neural circuits in the tectum or elsewhere in the brain that function to detect and direct attention towards mobile prey. Although current neural recording techniques require that fish be immobilized, a virtual reality system overcomes this limitation by simulating the motion of the visual world that fish would experience while freely swimming. Critically, a virtual reality system will make it possible to experimentally decouple changes in the sensory surround from motor actions, allowing for a precise dissection of feedback mechanisms between sensory and motor processing in the nervous system.Training goals include learning to implement real-time, closed-loop controllers for visual displays, and learning to use genetic methods for identifying and imaging neurons in zebrafish. This fellowship will also support the development of a human eye-tracking, virtual reality system, to be used in the classroom or in a public venue, such as a museum. This eye-tracking system will allow students or the public to interactively investigate relationships between their movement and their perception of motion.