An observational study in Vision Loss Partial, Vision; Loss, Both Eyes and Hemianopia, Homonymous, sponsored by University of Rochester. Withdrawn. Open to participants aged 21 Years to 75 Years. Per ClinicalTrials.gov, last updated 2024-10-08.
Sponsored by University of Rochester · Observational
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.
63 studies on the registry are indexed under Hemianopsia; 24 are open to participants now.
Browse Hemianopsia studies →University of Rochester is the lead sponsor of 729 studies on the registry; 116 are open to participants now.
Of its 56 completed or terminated interventional studies of FDA-regulated products, 44 (79%) have results posted.
Compared within Hemianopsia, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Blindness. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Subjects will all be individuals who have sustained partial vision loss after an occipital lobe stroke.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Orientation discrimination threshold
Assessment of Static Orientation Discrimination. For each subject, the investigators will measure the ability to correctly identify the orientation of non-moving visual stimuli that vary in degree of angle tilt to the right or left of vertical. The investigators will measure the degree of angle tilt that can be reliably detected at a 72-75% correct level of performance. Tilt difference from vertical will vary between 80° (maximum) and 0.1° (minimum) based on subject performance and an adaptive staircase that will change tilt magnitude depending on subject performance, increasing the tilt (making the task easier) for each incorrect answers and decreasing tilt (making the task harder) after a number of correct answers in a row.
Time frame: Baseline
Perceptual Confidence in Orientation Discrimination
Assessment of Metacognition (i.e., perceptual confidence) in Orientation Discrimination. For each subject, the investigators will measure their confidence in identifying an object's tilt to the right or left of vertical. A running tally of 'response points' will be collected during the orientation testing. Points will be awarded for each response on a scale, with the highest points awarded for "correct discrimination \& high confidence", intermediate points awarded for "correct discrimination \& low confidence", followed by "incorrect discrimination \& low confidence" and with points subtracted for "incorrect discrimination \& high confidence". Total points will be recorded for each test, with the patient asked to accumulate the highest number of points they can during the task.
Time frame: Baseline
No study locations are listed for this record.
Start is estimated for Dec 2025; primary completion for Sep 2028, 33 months later.
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This study is withdrawn, as verified in Oct 2024. You cannot join it, but the record below documents what was studied.
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