In this thesis, we assessed the tight relations between motor and sensory processes used to determine the areas of space in which a direct action is possible. We thus focused on the eprception of the reachability of an object, i.e. on the cerebral processes which allow to decide if an object could be reached or not by moving the arm. To do so, we made the hypothesis that theses judgments require to take into account functional motor and body knowledge, in addition to the visual information extracted from the environment. More specifically, we proposed that these judgments rely on a prediction of the consequences of a potential motor act toward the object, thus on the feasibility of the action at a given moment. Our studies discarded the hypothesis of the role of the effort associated to actions on the perception of reachable space. However, the critical role of predicting the sensorimotor consequences of an action has been showed, by demonstrating the strong relation between on the one hand the correspondence between visual distance and movement amplitude, and on the other hand the distance at which the reachability limit is perceived. Sensorimotor anticipation processes have also been showed in spatial perception involving dynamical targets, showing the spatio-temporal aspect of the involved mechanisms. Finally, our last study showed the influence of body representations and of their plasticity on the perception of peripersonal space, highlighting the implication of the body in action in perceptual judgments
