Path Integration in Fiddler Crabs: Its Interaction with Stabilizing Reflexes and Co-Evolution with Social Behavior

大多数动物，包括人类，都有能力通过一种被称为路径整合的过程，知道自己相对于起点的当前位置。从本质上讲，它们把它们在向外旅行中所做的所有动作加起来（或整合），将计算结果存储在内存中，并使用它返回到起点。本项目旨在分析目前未知的路径整合的感觉和运动机制，以及这一过程如何与其他两种相互交织的行为相关联：1)维持身体和感知稳定性的反射（例如前庭反射），以及2)空间依赖的社会行为。招潮蟹是研究路径整合机制的理想系统，因为通过路径整合，它们与家园形成了最严格的空间关系。直到最近，招蟹才被认为只对自己的洞穴形成强烈的依恋，但新的证据表明，一些物种同时记住几个洞穴的位置。这种空间记忆的差异与该属的两种主要交配系统相对应，最近的实验表明，来自每个系统的物种具有根本不同的路径整合机制，包括不同的眼睛和身体稳定反射。空间定向机制似乎与交配系统的变化共同进化，产生空间导航能力，使物种独特地适应其社会和生态环境。这项研究将为空间认知和社会行为的相互依存演变提供独特的综合理解。这项研究的结果将回答空间认知和空间定向的基本概念，这将广泛影响任务导向机器的工程。关于空间导航如何演变成不同程度的任务依赖复杂性的结果具有实际应用的潜力，特别是对于机器人的设计，其反射性补偿干扰的能力已完全纳入其执行路径整合的能力。该项目将通过“学生研究成就与奖学金项目”（STARS）和“女性参与科学与工程项目”（WISE）培训在科学领域未被充分代表的少数族裔的研究生和本科生。

Most animals, including humans, have the ability to know their current location relative to a starting point through a process called path integration. Essentially, they add up (or integrate) all of the movements they make on their outward journey, store this calculation in memory, and use it to return to their starting point. This project aims to dissect the currently unknown sensory and motor mechanisms of path integration and how this process works in relation to two other behaviors with which it is critically intertwined: 1) reflexes that maintain physical and perceptual stability (e.g., the vestibuloocular reflex), and 2) spatially dependent social behavior. Fiddler crabs are an ideal system for studying the mechanisms underlying path integration, since through path integration they form the strictest spatial relationship with home of any animal. Until recently fiddler crabs were thought only to form a strong attachment to their own burrow, but new evidence shows some species remember the locations of several burrows simultaneously. This disparity in spatial memory corresponds with the two major mating systems in the genus, and recent experiments suggest that species from each system have fundamentally different path integration mechanisms that incorporate eye- and body-stabilizing reflexes differently. Spatial orientation mechanisms appear to have co-evolved with changes in mating systems to produce spatial navigation abilities that uniquely adapt a species for its social and ecological contexts. This research will provide a uniquely integrative understanding of the interdependent evolution of spatial cognition and social behavior. The results from this research will answer fundamental concepts in spatial cognition and spatial orientation that will broadly impact the engineering of task-oriented machines. Results on how spatial navigation has evolved to varying degrees of task-dependent complexity have the potential to be materially applied, particularly for the design of robots whose ability to reflexively compensate for disturbances is fully incorporated into their ability to perform path integration. The project will train graduate students, and undergraduate students from minorities underrepresented in the sciences through the Student Achievement in Research and Scholarship (STARS) and Women in Science and Engineering (WISE) programs.