1. University of Oklahoma Health Sciences Center, Department of Communication Sciences and Disorders and Department of Neurology, Oklahoma City, Okla and the Veterans Affairs Medical Center, Oklahoma City, Okla,
2. University of Oklahoma Health Sciences Center, Department of Communication Sciences and Disorders, Oklahoma City, Okla
3. University of Oklahoma Health Sciences Center, Department of Communication Sciences and Disorders and Department of Neurology, Oklahoma City, Okla and the Veterans Affairs Medical Center, Oklahoma City, Okla