One of the central questions in cognitive science is to understand how conceptual knowledge is represented in the human mind. The classical answer to this question is the assumption of a separate semantic module in which knowledge is stored through abstract symbolic representations. The semantic module is separate from other systems, such as modules for perception and action. In the last twenty years, an alternative approach, known as embodied or grounded cognition, has been developed and intensively studied, starting from the assumption that conceptual knowledge is in constant interaction with perception and action, and that conceptual knowledge is grounded in them through the mechanism of perceptual simulation. The aim of this paper is to review different theoretical perspectives on embodied cognition and to evaluate them. The theory of perceptual symbol systems, the model of the immersed experiencer and the indexical hypothesis are presented in detail, as well as empirical findings that support or refute these models. Then, critiques of embodied cognition related to the understanding of abstract concepts are presented, as well as responses to these critiques. The idea of degrees or continuum of embodiment is also considered. Finally, directions for future research are outlined, to try to shed light on the question of what exactly is the role of embodiment in the representation of knowledge.
