Mechanisms of Visual Restoration After Occipital Stroke

Inclusion Criteria

• •Cortically Blind Subjects (n=50)
• •Inclusion:
• •Subjects between 21 and 80 years of age
• •Subjects must be residents of the United States or Canada
• •Subjects must exhibit unilateral stroke or stroke-like damage to primary visual cortex or its immediate afferent white matter sustained within the specified age range of 21 - 80 years (verified by MRI and/or CT scans)
• •Subjects with reliable visual field defects in both eyes (homonymous defects) as measured by Humphrey, MAIA, Goldmann, and/or equivalent perimetry. This deficit must be large enough to enclose a 5-deg diameter visual stimulus.
• •Subjects must be able to fixate on visual targets reliably for 1000ms, with jitter over less than 1-deg of visual angle.
• •o Note: This will be initially assessed by review of visual field reports as supplied by subjects during the screening process. However, we will be unable to fully assess their fixation ability until they start the psychophysics testing in our lab. If at that time we discover that they are unable to maintain adequate fixation, they will be withdrawn from the study.
• •Subjects must be willing, able, and competent to provide their own informed consent
• •Subjects must have their own home computer (desktop or laptop) and reliable internet access
• +18 more criteria