Retinotopically defined primary visual cortex in Williams syndrome.

ABSTRACT: Williams syndrome, caused by a hemizygous microdeletion on chromosome 7q11.23, is characterized by severe impairment in visuospatial construction. To examine potential contributions of early visual processing to this cognitive problem, we functionally mapped the size and neuroanatomical variability of primary visual cortex (V1) in high-functioning adults with Williams syndrome and age- and IQ-matched control participants from the general population by using fMRI-based retinotopic mapping and cortical surface models generated from high-resolution structural MRI. Visual stimulation, consisting of rotating hemicircles and expanding rings, was used to retinotopically define early visual processing areas. V1 boundaries based on computed phase and field sign maps were used to calculate the funct

SUBMITTER: Olsen RK 

PROVIDER: S-EPMC2724925 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature