Dr. Renaud Bastien: The role of perception in models of movement
Title: The role of perception in models of movement, by Dr. Renaud Bastien, Max Planck Institute
Abstract: Classical phenomenological models of collective behavior often take a "birds-eye perspective," assuming that individuals have access to social information that is not directly available (e.g., the behavior of individuals outside of their field of view). Despite the explanatory success of those models, it is now thought that a better understanding needs to incorporate of the perception of the individual, i.e., how internal and external information are acquired and processed. In particular, vision has appeared to be a central feature to gather external information and influence the collective organization of the group. In this talk, I will show how models can be constructed from the perception of an individual and how virtual reality can be used to infer the relationship between the structure of the group and the individual perception of the animals.
Starting with research on plants tropism, I will first discuss the design of models relating perception and movements. From this framework, a simple model can be constructed that relate directly to the visual field of each individual and the dynamics observed at the scale of the group. It is then possible to discuss how visual features can be combined to create basic interaction between individuals, as well as the existence of internal representations of space and others. To complement this theoretical approach, I participated in the developped of virtual reality techniques with animals. A single fish, usually zebrafish larvae, is tracked inside a bowl as it swims. After accounting for fish’s location and perspective, interactive images are projected on the sides of the bowl, allowing us to modify and control what each fish perceives in its field of view. I will discuss the conditions under which an interaction between a real fish and a virtual conspecific can be considered as equivalent to social interaction between two real fish. This opens the way to link multiple VR systems together where animals can share the same virtual environment. Finally, I will present how the flexibility of the system can be harnessed to get insights into collective dynamics and decision-making.