This research is an integral and synergistic part of the Program Project: Williams Syndrome: Bridging Cognition, Brain and Genes to link higher cognitive functions with their underlying neurobiological basis and genetic foundations. The goal of this subproject is to characterize the electrophysiological phenotypes of sensory and cognitive processing in individuals with Williams Syndrome (WS) and to link variability in the expression of these phenotypes to variability in brain structure and function (Project III), neurocognitive (Project V), and genetic profiles (Project I). To this end, event-related potentials (ERPs) will be recorded using a high-density ERP system to examine the timing and topography of brain activity linked to 1) differential activation of the dorsal and ventral visual streams, 2) the effects of emotion on processing facial expressions and verbal declarative memory systems, 3) Studies of genetic variability and brain function: atypical deletions and parent of origin. Using similar paradigms across projects behavioral, fMRI and ERP data will be used to develop a cross-disciplinary characterization of the WS phenotype for sensory, cognitive and social emotional processes. Links between abnormal brain function and genetic profiles (Project I) will be conducted by characterizing patterns of activity typical of individuals with WMS with a full deletion and comparing these patterns with ERPs from individuals with different genetic profiles such as atypical deletions or parent of origin of the deletion for WS. The first two years of this project have revealed a number of surprising findings including abnormal patterns of brain activity to visual stimuli in both the magno/dorsal and parvo/ventral pathways. These data in collaboration with fMRI data may help elucidate the underlying mechanisms for atypical patterns of brain organization observed for higher cognitive functions such as langauge and face processing. Other prelimiary findings in collaboration with Project I suggest that atypical language and face processing may be related to parent of origin and interactions with the expression of specific genes. Relation to public health: this research offers promise in furthering our understanding of neurocognitive development in individuals with a specific medical condition, WS, that together with neurophysiological, neuroimaging, genetic, cellular, and molecular studies from other projects, will help us bridge an understanding of cognition and gene within the greater human population. [unreadable] [unreadable] [unreadable]