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theses

Reading is a critical skill, with lack of reading proficiency related to poor outcomes including poverty, unemployment, and incarceration rates. Poor reading skill can occur for multiple reasons. Research on the brain basis of reading problems typically focuses on issues with letter-sound mappings, but much less work has been done on the equally critical issues of what kinds of feedback are most effective for learning these mappings; and what other kinds of challenges, including environmental ones, can disrupt this process. In particular, stressors prevalent in low-income urban communities, such as exposure to violence, affect neural activity, thereby interfering with the cognitive processes involved in learning. Despite the prevalence of violence in urban communities and coinciding low literacy rates, research assessing the neural effects of violence, and examining specific reading interventions targeted at these neural differences, is quite limited. The first goal of the following research was to determine what makes for effective orthography-phonology (spelling-sound) training. Novel letter strings are trained with Elaborative Feedback, which we expected to promote cognitive processing by pairing content-specific information with an affective component. In Study 1, novel letter strings trained with Elaborative Feedback, compared to feedback containing only content-specific information (Content Feedback) and to that containing only affective information (Positive Feedback), resulted in the highest performance accuracy. This Elaborative Feedback condition was also associated with activation in the ventromedial prefrontal cortex (vmPFC), implicated in reward-processing, as well as neural regions implicated in orthography-phonology mapping, such as the posterior middle and superior temporal and supramarginal gyri. Therefore this study revealed both which type of feedback was most effective for learning novel word forms, and the neural mechanisms behind its effectiveness. The second goal was to enhance the effectiveness of orthography-phonology training specifically for individuals exposed to urban stressors. Study 2 revealed differential resting state functional connectivity (rsFc) by childhood exposure to violence among neural regions implicated in both the affective and cognitive components of feedback processing. Individuals exposed to high levels of violence in childhood had decreased rsFc between the vmPFC and the amygdala, as well as the right dlPFC and other neural regions implicated in working memory, such as the intraparietal sulcus (IPS). Study 3 tested whether exposure to violence during childhood and reading ability moderate the effectiveness of feedback type. Individuals with high reading ability and who were exposed to increasing levels of violence during childhood benefited more from EF. This research provides cognitive neuroscientific evidence that could ultimately inform the integration of affective with cognitive skills in urban schools, possibly helping to improve performance and close the achievement gap.

ETD_8971

Ph.D.

Includes bibliographical references

by Samantha Rachael Mattheiss

doi:10.7282/T3JM2F1V

ETD doctoral

The author owns the copyright to this work.