If you want your talk be fluent, think lazy!

In this paper we investigate an important property of coherence in discourse - the fluency. We propose a model of immediate memory and claim that it serves optimally the production of coherent discourses. From a range of possible models, this one is shown to imply minimal access costs. It is proved that put at the basis of discourse production, it yields discourses which have similar fluency patterns as those produced by humans. In the experiments fluency is measured using Centering transitions. We conclude that discourse coherence is grounded in an innate cognitive mechanism, which is driven by an economicity principle.