Project Summary Implicit Structural Priming as a Treatment Component in Aphasia Impaired message-to-structure mapping is at the heart of communication deficits in persons with aphasia (PWA), resulting in impaired sentence production and comprehension. As of yet, the few treatment options available for the mapping deficits involve explicit metacognitive training of sentence production, yielding variable generalization and maintenance effects. Therefore, there remains a critical need to identify interventions that successfully improve mapping abilities in PWA. This project introduces implicit structural priming as a novel facilitator for language recovery in aphasia. Structural priming, a tendency to repeat or better process a current sentence because of its structural similarity to a previously experienced (“prime”) sentence, has been ubiquitously observed across decades of psycholinguistic research and viewed as a powerful tool to study the processes of implicit language learning. Preliminary studies reported in this application suggest that structural priming can be applied to PWA and might produce positive, enduring language recovery in PWA. The planned studies seek to test the hypothesis that implicit structural priming alters the central syntactic system in PWA, creating lasting and generalized improvements in both language production and comprehension. Aim 1 will determine the extent to which different manipulations of structural priming conditions modulate immediate and long-term improvement in sentence production. We integrate multiple theories of language learning and apply them to make predictions about the trajectory of priming-induced syntactic learning in PWA. In Aim 2, using a set of eyetracking sentence comprehension tasks, we investigate whether the effects of structural priming in production generalize to off-line (accuracy) and on-line (eye fixations) sentence comprehension and determine what learning conditions result in greater cross- modality generalization. In Aim 3, we develop and establish Phase I efficacy data of an implicit structural priming treatment, incorporating the crucial learning conditions supporting maximal retention from Aims 1 and 2. The outcomes of this work will lead to identification of a model of language (re-)learning in aphasia and the development of a novel treatment that capitalizes on the benefits of the implicit learning mechanisms underlying structural priming.