Dynamical approaches to cognitive science

Dynamical ideas are beginning to have a major impact on cognitive science, from foundational debates to daily practice. In this article, I review thre e contrasting examples of work in this area that address the lexical and gr ammatical structure of language, Piaget's classic "A-not-B' error, and acti ve categorical perception in an embodied, situated agent. From these three examples, I then attempt to articulate the major differences between dynami cal approaches and more traditional symbolic and connectionist approaches. Although the three models reviewed here vary considerable in their details, they share a focus on the unfolding trajectory of a system's state and the internal and external forces that shape this trajectory, rather than the r epresentational content of its constituent states or the underlying physica l mechanism that instantiate the dynamics. In some work, this dynamical vie wpoint is augmented with a situated and embodied perspective on cognition, forming a promising unified theoretical framework for cognitive science bro adly construed.