Robots communicating with fish: Investigating the role of electric signals and locomotor displays following episodes of mutual attention in weakly electric fish

生活在社会群体中的动物必须相互作用，才能呆在一起，集体行动。一个基本的生物学问题是，哪些规则管理着社会互动，并导致群体成员协调他们的行动并做出共同决定。在鱼群中，个体通过不同的感觉渠道交换信息，例如通过视觉或机械感觉侧线系统。在以前的研究中，我们已经表明，变态弱电鱼几乎完全依赖于它们的电感觉通道来实现群体一致性和鱼群的形成。个体通过发射和感知电信号来定位和接近群体内的同种生物，甚至完全接受人造的、没有身体的信号源作为交流伙伴。除了发出特定于环境的信号模式外，浅水鱼还经常通过相互同步它们的信号来参与互动电信号的发作。然而，目前还不知道哪些信号实际上是通过这个渠道交换的，这些信号意味着什么，以及它们在其他鱼类身上引发了哪些行为。在这个项目中，我们想通过开发一种仿生电动鱼类机器人作为群体中的交流伙伴，来研究支持弱电鱼类群中社会互动的基本过程。通过设计一个完全交互的机器人，它在电气和运动两个方面都在闭环中运行，我们将完全控制我们注入社会系统的线索。我们的主要目标之一是理解为什么两个群体成员在接近对方时经常同步他们的信号。我们将测试这样一种假设，即这种行为是一种策略，以应对群体中的另一个个体，并引起“社会关注”--即两种动物打开一条专属的沟通渠道，通过电子同步之后的行为来交换信息。通过在群体中引入一个完全互动的机器人，它能够建立和维持鱼和机器人之间的相互同步情节，我们将调查随后的运动和/或电互动对鱼的行为的影响。机器人的行为将基于对所有鱼类群体的同步后行为的分析，以找出在两条鱼同步期间和之后立即发生了什么，以及哪些动作可以将信息传递给另一个个体。通过在个体和群体级别提取行为属性，我们将评估完全交互的机器人行为和缺乏电或运动交互部分的行为之间的差异。机器人改变单个鱼和整个鱼群行为的有效性将通过使用现代统计方法来量化个体之间的信息传输来进行评估。

Animals that live in social groups must interact in order to stay together and move collectively. A fundamental biological question is which rules govern social interactions and cause group members to coordinate their movements and come to joint decisions. In fish shoals, individuals exchange information through different sensory channels, e.g. through vision or the mechanosensory lateral line system. In previous studies, we have shown that mormyrid weakly electric fish rely almost exclusively on their electro-sensory modality for group coherence and shoal formation. Individuals emit and perceive electric signals to localize and approach conspecifics within the group, and even fully accept an artificial, bodiless signal source as communication partner. Besides emitting context-specific signal patterns, shoaling mormyrids frequently engage in episodes of interactive electric signalling by synchronizing their signals to each other. However, it is not yet known which signals are actually exchanged via this channel, what these signals mean and which behaviour they evoke in other fish.In this project, we want to investigate the basic processes that support social interactions in shoals of weakly electric fish by developing a biomimetic electric fish robot that serves as communication partner in a group. By designing a fully interactive robot, which operates in closed-loop both electrically and locomotory, we will have full control over the cues we inject into the social system.One of our main goals is to understand why two group members often synchronize their signals when they approach each other. We will test the hypothesis that this behaviour is a strategy to address another individual in the group and to provoke "social attention" - i.e., a means for two animals to open an exclusive communication channel through which information can be exchanged, expressed by the behaviour that follows the electrical synchronization.By introducing a fully interactive robot into the group, which is able to establish and sustain mutual synchronization episodes between fish and robot, we will investigate the effect of ensuing locomotor and/or electrical interactions on the behaviour of the fish. The robot’s behaviour will be based on an analysis of post-sync behaviours in all-fish groups in order to find out what happens during and immediately after two fish have synchronized, and which actions can transmit information to another individual. By extracting behavioural properties at the level of the individual and the group, we will assess differences between fully interactive robot behaviours and behaviours that lack either the electrical or the locomotor interactive component, respectively. The robot’s effectiveness to alter the behaviour of single fish and the whole group will be assessed by employing modern statistical methods to quantify information transfer between individuals.