Project Summary While the vast majority of children correct speech production errors by age 8, a select group of children show persistent misarticulation beyond this age, despite attempts at traditional speech therapy. This condition is termed variously as “resistant” or “residual” speech sound disorder (RSSD), and typically affects production of articulatorily complex sounds such as “r” (/r/). Children with RSSD may experience long-term negative consequences in academic, literacy, and social-emotional domains. In order to effectively implement intervention strategies specifically targeted to children with RSSD, a more thorough understanding of the neural underpinning of these differences in speech processing and production is needed. Recently, investigators have reported that children with RSSD significantly improve their articulation errors when additional intervention tools, such as ultrasound biofeedback, are implemented in their therapy program. We propose to retrospectively investigate tongue movement trajectories and neural activation patterns underlying speech production in typical children vs. children with residual speech sound disorder (RSSD) before and after an ultrasound biofeedback speech therapy program. In this proposal, our long-term goal is to elucidate the interaction of the phonological and speech motor systems in RSSD children in relation to therapy outcomes. Based on prior findings, we predict that: (1) children with RSSD will exhibit greater activation than controls in the phonological and speech motor networks during the SRT during an initial assessment; (2) activation patterns for speech produced under fMRI will reflect performance accuracy on the non-word repetition task, and (3) children who show more success in therapy will show increased tongue movement and more normalized neural activation during speech production. We plan to objectively test our hypotheses by analyzing phonological and speech motor network activation patterns of children with RSSD pre-and post-treatment, in comparison to normally speaking children. We will also investigate the relationship between tongue movement, neural activation patterns, and therapy outcomes. The outcomes of this F31 project will provide further knowledge about the interaction between phonological and motor networks for speech production in children who fail to acquire all the sounds of their language. The training for this Fellowship will be conducted at the University of Cincinnati and the Imaging Research Center at Cincinnati Children's Hospital Medical Center. The proposed plan will provide opportunities to work closely with experienced investigators to investigate the neural mechanisms for speech and the use of fMRI as a tool to study these mechanisms in a more detailed, thorough manner. These are skills that I will be able to apply to future treatment projects in my career.