Understanding Visual Processing After Occipital Stroke
Stopped: Study was never officially approved by IRB and never open to enrollment. Submission withdrawn due to lack of funding.
0Started 2025-12
Plain-language summary
The purpose of this study is to investigate how visual orientation discrimination and metacognition (i.e., perceptual confidence) are affected by occipital stroke that causes hemianopia and quadrantanopia in adults. This research will provide insight as to how the residual visual system, which not directly damaged by the occipital stroke, processes orientation (assayed in terms of orientation discrimination) and metacognition (by measuring perceptual confidence for orientation discrimination). These measures will be used to refine computational models that attempt to explain how the brain copes with loss of primary visual cortex (V1) as a result of stroke. This knowledge is essential to devise more effective visual rehabilitation therapies for patients suffering from occipital strokes.
Who can participate
Age range
21 Years – 75 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Residents of the United States or Canada
* MRI and/or CT scans showing unilateral stroke or stroke-like damage to primary visual cortex or its immediate afferent white matter sustained 1-year or more prior to enrollment
* Reliable visual field defects in both eyes as measured by Humphrey, Macular Integrity Assessment (MAIA), Goldmann, and/or equivalent perimetry. This deficit must be large enough to enclose a 5-deg diameter visual stimulus.
* Ability to fixate on visual targets reliably for 1000ms (as demonstrated by visual fields, and verified in study participation)
* Willing, able, and competent to provide informed consent
* Cognitively able to understand and respond to written and oral instructions in English
Exclusion Criteria:
* Past or present ocular disease interfering with visual acuity
* Corrected vision worse than 20/40 in either eye
* Presence of damage to the dorsal Lateral Geniculate Nucleus
* Diffuse, whole brain degenerative processes
* Brain damage deemed by study staff to potentially interfere with testing ability or outcome measures
* Documented history of traumatic brain injury
* Documented history of drug/alcohol abuse
* Current use neuroactive
* Cognitive or seizure disorders
* Subjects with one-sided attentional neglect
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Orientation discrimination threshold
Timeframe: Baseline
2
Perceptual Confidence in Orientation Discrimination