Proactive action preparation: Seeing action preparation as a continuous and proactive process

In this paper, we aim to elucidate the processes that occur during action preparation from both a conceptual and a computational point of view. We rst introduce the traditional, serial model of goaldirected action and discuss from a computational viewpoint its subprocesses occurring during the two phases of covert action preparation and overt motor control. Then, we discuss recent evidence indicating that these sub-processes are highly intertwined at representational and neural levels, which undermines the validity of the serial model and points instead to a parallel model of action speci cation and selection. Within the parallel view, we analyze the case of delayed choice, arguing that action preparation can be proactive, and preparatory processes can take place even before decisions are made. Speci cally, we discuss how prior knowledge and prospective abilities can be used to maximize utility even before deciding what to do. To support our view, we present a computational implementation of (an approximated version of) proactive action preparation, showing its advantages in a simulated tennis-like scenario.