Abstract
This thesis gets into the main question of Categorial Change in Perception and proposes a Dynamical approach that relies on the Catastrophes Theory and the model of the CUSP. In this work, we claim that perceptive categories are attractors in a non linear dynamics system. If we state right, we must find out several specific phenomenon theoretically linked to a phase transition in the moment of a categorial change. We bear witness for Hysteresis, which is yet widely documented in perception. Besides and in addition, we also look for divergence and critical slowing down phenomena. Along seven experimentations, we put those hypotheses to the test and achieve to attest for the occurrence of the three predicted phenomena over the categorial change. Not only results show that hysteresis, divergence and critical slowing down occur together during a categorial change but also they are quantitatively related as predicted by the catastrophe model of the cusp. More widely, we conclude, that perceptual categories might be regarded as strongly related to attractors and that survey and modeling of changes in perception shall include inevitable dynamics considerations henceforth.