Beyond behavior: a neurocognitive agenda for investigating the neural underpinnings of successful high-technology augmentative and alternative communication in adults.

Purpose: Research has shown that augmentative and alternative communication (AAC) has the potential to function not only as a compensatory communicative strategy, but also as a tool to facilitate language recovery for people with aphasia. However, much work remains in order to understand the brain changes associated with AAC-driven recovery. The purpose of this article is to highlight the need for neurological research on high-technology AAC use, and to advance that research agenda by proposing the Transformation of Representation Across Neurocognitive Systems for Concept to External Navigation and Display (TRANSCEND) framework, a testable model of language production for people with aphasia who use AAC. We also argue for fNIRS as a promising neuroimaging tool that offers the advantage of allowing ecologically valid AAC use during experimental tasks. Conclusion: The TRANSCEND framework, a dual-route neurological model that begins with concept retrieval and leads to either verbal or AAC output, provides a foundation for future research that teases apart the neural underpinnings of motor, speech, and language aspects of AAC use.