Structural Priming in Aphasia: A State-of-the-Art Review and Future Directions.

Background & Aims: Decades of research on structural priming - speakers' tacit reuse of previously encountered syntactic structures in subsequent production and comprehension of sentences - has made substantial contributions to theories of syntactic representations, processing, and language learning and acquisition. There is growing interest in the application of structural priming to assess and facilitate language processing and learning in clinical populations. Yet, little research has explored structural priming in aphasia. The purpose of this paper is to provide a state-of-the art review of structural priming studies in aphasia and provide future research directions with an eye towards using structural priming for aphasia rehabilitation. Main contribution: Structural priming occurs not only in laboratory settings, but also in everyday speech, across many simple to complex grammatical structures, different languages, and throughout the lifespan. Importantly, a body of literature suggests that structural priming may reflect processes of implicit learning, strengthening the language user's ability to map messages and sentence structures. With respect to aphasia, existing studies have discovered that priming can help persons with aphasia (PWA) produce and comprehend more complex sentences that are otherwise difficult to produce or comprehend on their own. Additionally, priming effects transfer across production and comprehension modalities, and create long-lasting, cumulative improvements of sentence processing in PWA. Conclusions: The review of the literature suggests that structural priming can be used to assess PWA's ability to access various syntactic structures but also to intervene sentence production deficits in PWA. Future research is recommended to systematically investigate functions of structural priming for widespread recovery of aphasia beyond increasing syntactic complexity, to delineate essential tenants of structural priming intervention at both person and treatment levels, and to examine its use for cross-linguistic treatment of bi/multi-lingual aphasia.