The space of actions - Neural circuits for transforming spatial representations into actions

我听到一个熟悉的声音，我转向它的来源，我看到一辆车接近，我远离它，我闻到一杯咖啡，我伸手去拿。所有这些日常经验最终都与我们天生的空间感有关，我们知道我们周围的东西在哪里，以及如何与它们互动。换句话说，我们能够将多感官体验绑定到一个连贯的感知中，并将其分配到一个有意义的空间框架中，以便适当地指导我们的行动。但是，这种多感官结合是如何发生的，这种连贯的心理空间框架是如何构建的，以及它最终是如何实现的，以指导行动仍然是很大程度上尚未解决的问题。近年来，我们已经开始了解动物如何编码空间信息的形式的allocentric地图，在导航的背景下。类似地，空间调谐的动作，如到达和定向，可能依赖于自我中心的周围空间地图，其神经实现在运动域中变得明显，产生适当的运动矢量。与导航空间相比，对近个人空间（"可及空间"）进行编码的神经基础以及将其实施为行动的神经机制仍远未得到表征。在这个建议中，我将评估总体假设，即这种表示是在运动域路由，并取决于运动执行。我假设大脑通过依赖于参与规划和控制三维身体运动的网络活动来构建认知和感知空间表征。用法国数学家亨利庞加莱的话来说，"定位一个物体意味着向我们自己展示到达那个物体所必须发生的运动"。因此，在最近的努力，研究知觉和认知能力的制定过程（即过程，其主要目标是指导行动），我建议，旨在测试一个动力学，电机路由理论的空间认知。我认为，实现这一目标的最有效途径是从问题的运动端开始，即从负责产生空间调谐运动的神经元群体开始，逐步向上游移动，以解开负责规划、选择和控制的电路和计算。

I hear a familiar voice and I turn towards its source, I see a car approaching and I move away from it, I smell a cup of coffee and I reach for it. All these daily experiences are ultimately linked to our innate sense of space, we know where things around us are and how to interact with them. In other words, we are able to bind multisensory experiences into a coherent percept and allocate it in a meaningful spatial frame so to appropriately direct our actions. But how this multisensory binding occurs, how such a coherent mental spatial frame is constructed and how it is finally implemented to direct actions remain largely unresolved questions.In recent years, we have begun to understand how animals encode spatial information in the form of allocentric maps, in the context of navigation. Similarly, spatially tuned actions such as reaching and orienting may rely on an egocentric map of peripersonal space, whose neural implementation becomes overt in the motor domain with the production of appropriate movement vectors. In comparison with navigational space, the neural basis of the encoding of peripersonal space ("the space within reach") as well as the neural mechanisms for its implementation into actions remain far less characterised. In this proposal I will assess the overarching hypothesis that this representation is routed in the motor domain and depends on motor execution. I hypothesise that brains construct cognitive and perceptual spatial representations by relying on the activity of networks involved in the planning and the control of three-dimensional bodily movements. In the words of Henry Poincaré, the French mathematician, "localising an object means representing to ourselves the movements that must take place to reach that object". Thus, in line with recent efforts to study perceptual and cognitive abilities as enactive processes (i.e. processes whose primary goal is to guide action), I propose and aim to test a kinetic, motor-routed theory of spatial cognition. I will argue that the most fruitful path to this goal is to start from the motor end of the problem, i.e. from the neuronal populations responsible for the generation of spatially tuned movements, and progressively move upstream to unravel circuits and computations responsible for their planning, selection and control.