Atypical functional organization in the brains of adult male dyslexics was investigated through the divided visual field (DVF) paradigm. By intentional manipulation, equal levels of overall performance between groups were obtained, which made clearer interpretation of the results possible. Both dyslexic and control subjects appeared to have left hemisphere specialization for nonsense words. Dyslexics exhibited no asymmetry for face recognition indicating bilateral representation of this function in their brains, while control subjects exhibited the expected left visual field advantage. The results are considered both as group means and as frequency data. The results provide modest support tor the hypothesis that dyslexics have atypical functional organization. / Thesis / Master of Arts (MA)

The default network (DN), and specifically its sub-networks default network A (DN A) and default network B (DN B), has been strongly implicated in social cognition. This study examined its role in predicting social behavior, and also differences that may exist across diagnostic groups that may explain discrepancies in social cognition and behavior. One of the popular methods of study is functional connectivity, or analyzing correlated activity in the brain. Autism Spectrum Disorder (ASD) is a disorder characterized by social impairment and abnormal social behavior. To date, much of the functional connectivity research in ASD has focused on global connectivity, or specific but large areas of the brain. This study adds to the body of that research in attempting to understand both global functional connectivity and the functional connectivity of specific networks (DN A and DN B) that are involved in social cognition and thus implicated in ASD. A sample of 75 individuals with ASD, 85 neurotypical individuals, and 505 individuals with varying other diagnoses was examined to determine the role of global functional connectivity and the role of DN A and DN B in social cognition by the predictive ability of brain features to determine behavioral outcomes. This analysis also aimed to determine if there are group differences in these same brain features. The features we examined included functional connectivity, or the comparison of timeseries of regions of interest, network surface area, and network similarity. This study found that there was no discernible difference across diagnostic group in global or network-specific functional connectivity for DN A. The majority of features for DN B did not differ across diagnostic group, but there was one connection that was significantly different between the autism group and the others. There was no global predictive ability of functional connectivity and brain topology for social cognition measures, nor was there predictive ability for DN A features. DN B features, however, were predictive of social cognition in the autism group, but not in the control group or the other diagnostic groups examined. This study adds to the current body of research by supporting findings already reported by others, and by adding new findings about the role of DN B in social cognition in autism.