A model for Social Communication And Language Evolution and Development (SCALED)

•The arcuate fasciculus connects areas for structural and pragmatic aspects of language.•The SCALED model describes five networks for language and communication.•Dorsal and ventral fronto-temporal networks implement structural language.•Dorsomedial frontal and inferior parietal networks engage in social communication.

In humans, brain connectivity implements a system for language and communication that spans from basic pre-linguistic social abilities shared with non-human primates to syntactic and pragmatic functions particular to our species. The arcuate fasciculus is a central connection in this architecture, linking regions devoted to formal aspects of language with regions involved in intentional and social communication. Here, we outline a new anatomical model of communication that incorporates previous neurofunctional accounts of language with recent advances in tractography and neuropragmatics. The model consists of five levels, from the representation of informative actions and communicative intentions, to lexical/semantic processing, syntactic analysis, and pragmatic integration. The structure of the model is hierarchical in relation to developmental and evolutionary trajectories and it may help interpreting clinico-anatomical correlation in communication disorders.