Why does oral fluency predict silent reading comprehension? Neurocognitive markers of implicit meter as a potential mediator - PROJECT SUMMARY Oral reading fluency predicts silent reading comprehension in developing readers, but the underlying neurocognitive mechanisms of this relationship are unknown. It is critical to understand these mechanisms, as the relationship between fluency and comprehension supports the inclusion of fluency in national literacy policy; fluency instruction to improve comprehension however, cannot be optimized if the mechanistic pathway linking these faculties is unclear. Moreover, understanding the mechanistic pathway between fluency and comprehension in typical reading development can provide neurocognitive targets for remediation in struggling readers, including children diagnosed with dyslexia. Oral reading prosody, a component of oral reading fluency, has recently been shown to carry a unique portion of the fluency to comprehension relationship, that is separable from the contributions of automatic decoding. We propose that meter, a component of prosody concerning the organization of stress, plays a key role in this process. Our overarching hypothesis is that maturation of oral reading prosody coincides with maturing fluency of “inner voice” auditory imagery (i.e., implicit prosody) during silent reading, leading to improved comprehension. We predict that developing readers with improved oral reading meter will have improved implicit representation of metric structure at the neural level (Aim 1), and improved application of implicit metric structure during silent reading (Aim 2), in a manner that improves silent reading comprehension (Aim 3). We will test our hypothesis by measuring oral reading meter, neural implicit metric representation, and realization of implicit metric structure in eye movements during silent reading in children between the ages of 6 and 10 years old, a developmental epoch within which oral prosody and silent reading undergo significant maturation. We will model how the adult-likeness of implicit metric representation and realization mediate the relationship between oral reading meter and standardized measures of silent reading comprehension, covarying for automatic decoding and phonological awareness. This work will provide clear insight into the mechanisms relating oral reading fluency to silent reading comprehension, which will inform national educational policy and provide mechanistic targets for remediation training in struggling readers. Moreover, this work will provide our team of undergraduate researchers training in using human electrophysiology and behavior to interrogate the neurocognitive underpinnings of complex behavioral development, providing footing for a competitive future in academia, clinical practice, or biomedical industry.