Open challenges in understanding development and evolution of speech forms: The roles of embodied self-organization, motivation and active exploration

This article discusses open scientific challenges for understanding development and evolution of speech forms, as a commentary to Moulin-Frier, Diard, Schwartz and Bessiere, 2015. Based on the analysis of mathematical models of the origins of speech forms, with a focus on their assumptions, we study the fundamental question of how speech can be formed out of non-speech, at both developmental and evolutionary scales. In particular, we emphasize the importance of embodied self-organization, as well as the role of mechanisms of motivation and active curiosity-driven exploration in speech formation. Finally, we discuss an evolutionary-developmental perspective of the origins of speech. (C) 2015 Elsevier Ltd. All rights reserved.