Dr. Simon is a pediatric cognitive neuroscientist. His research focuses on the neural basis of cognitive impairments seen in genetic disorders that produce developmental disability and psychopathology. Dr. Simon investigates how dysfunction in specific neurocognitive processing systems, such as spatial and temporal attention and cognition, can generate a range of cognitive and behavioral impairments. His goal is to develop remedial intervention programs that will minimize such disability. Dr. Simon's current projects center on studies of visuospatial and numerical cognition in children with chromosome 22q11.2 deletion syndrome, also known as DiGeorge and VeloCardioFacial syndrome. He is also engaged in similar studies of girls with Fragile Turner syndrome and also children and adults with the full range of fragile X (FMR1) gene mutations. This last project is part of the multidisciplinary NeuroTherapeutics Research Institute (http://www.ucdmc.ucdavis.edu/NTRI/), which involves numerous Neuroscience faculty, postdocs and graduate students. Besides cognitive processing analyses, Dr. Simon and his team use cutting edge neuroimaging methods, such as functional magnetic resonance imaging (fMRI), Voxel Based Morphometrics, and Diffusion Tensor Fiber Tracking in order to study the structure, function and connective patterns in the developing brain.

Publications:

Simon, T.J., Wu, Z., Avants, B., Zhang, H., Gee, J.C., Stebbins, G.T. (2008) Atypical Cortical Connectivity and Visuospatial Cognitive Impairments are Related in Children with Chromosome 22q11.2 Deletion Syndrome. Behavioral and Brain Functions, 4: 25.

Simon, T.J. (2008) A New Account of the Neurocognitive Foundations of Impairments in Space, Time and Number Processing in Children with Chromosome 22q11.2 Deletion Syndrome. Developmental Disabilities Research Reviews. 14, 52-58.

Simon, T.J., Takarae, Y., DeBoer, T.L., McDonald-McGinn, D.M., Zackai, E.H., Ross, J.L. (2008) Overlapping Numerical Cognition Impairments In Children With Chromosome 22q11.2 Deletion Or Turner Syndromes. Neuropsychologia, 46, 82-94.

DeBoer, T., Wu, Z., Lee, A., Simon, T.J. (2007) Hippocampal Volume Reduction in Children with Chromosome 22q11.2 Deletion Syndrome is Associated with Cognitive Impairment. Behavioral and Brain Functions, 23: 54.

Machado, A.M.C., Simon, T.J., Nguyen, V., McDonald-McGinn, D.M., Zackai, E.H., Gee, J.C. Corpus callosum morphology and ventricular size in chromosome 22q11.2 deletion syndrome. (2007) Brain Research. 1131, 197-210.

Bish, J.P., Pendyal, A., Ding, L., Ferrante, H., Nguyen, V., McDonald-McGinn, D.M., Zackai, E.H., & Simon, T.J. (2006) Specific cerebellar reductions in children with chromosome 22q11.2 deletion syndrome. Neuroscience Letters. 399, 245-248.

Simon, T.J., Bearden, C.E., McDonald-McGinn, D., & Zackai, E. (2005) Visuospatial and numerical cognitive deficits in children with Chromosome 22q11.2 Deletion Syndrome. Cortex, 41: 131-141.

Simon, T.J., Ding, L., Bish, J.P., McDonald-McGinn, D., Zackai, E.H., & Gee, J. (2005) Volumetric, connective and morphologic changes in the brains of children with chromosome 22q11.2 deletion syndrome: An integrative study. NeuroImage, 25: 169-180.

Simon, T.J., Bish, J.P., Bearden, C.E., Ferrante, S., Ding, L., Nguyen, V., Gee, J., McDonald-McGinn, D., Zackai, E.H., & Emanuel, B. (2005) A multi-level analysis of cognitive dysfunction and psychopathology associated with chromosome 22q11.2 deletion syndrome in children. Development and Psychopathology. 17, 753-784.

Bish, J.P., Ferrante, S., McDonald-McGinn, D., Zackai, E.H., & Simon, T.J. (2005) Maladaptive conflict monitoring as evidence for executive dysfunction in children with chromosome 22q11.2 deletion syndrome. Developmental Science, 8: 36-43.

Bish, J.P., Nguyen, V., Ding, L., Ferrante, S., & Simon, T.J. (2004) Thalamic reductions in children with chromosome 22q11.2 deletion syndrome. NeuroReport, 15, 1413-1415.

Bish, J.P., Pendyal, A., Ding, L., Ferrante, H., Nguyen, V., McDonald-McGinn, D.M., Zackai, E.H., & Simon, T.J. (2006) Specific cerebellar reductions in children with chromosome 22q11.2 deletion syndrome. Neuroscience Letters. 399, 245-248.

Bearden, C.E., Jawad, A.F., Lynch, D.R., Sokol, S., Kanes, S.J., McDonald-McGinn, D., Saitta, S., Harris, S., Moss, E.M., Wang, P.P., Zackai, E., Emanuel, B.S., & Simon, T.J. (2004) Effects of function COMT polymorphism on prefrontal cognitive function in the 22q11.2 deletion syndrome. American Journal of Psychiatry, 161, 1700-1702.

Bearden, C.E., Jawad, A.F., Lynch, D.R., Monterosso, J.R., Sokol, S., McDonald-McGinn, D., Saitta, S., Harris, S., Moss, E.M., Wang, P.P., Zackai, E., Emanuel, B.S., & Simon, T.J. (2005) Effects of COMT genotype on behavioral symptomatology in the 22q11.2 deletion syndrome. Child Neuropsychology, 11(1), 109-117.