Understanding Visual Confusion Using Stereoscopic Displays

Study Overview
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Brief Summary
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In this research study we want to test how people understand a visual scene when the same image is presented to both the eyes, but portions of these images are altered in terms of contrast, depth or in some cases motion.

Official Title
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Monocular Visual Confusion for Field Expansion

Conditions
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Diplopia, Binocular Vision Suppression, Binocular; Fusion, With Defective Stereopsis, Monocular Diplopia

Intervention / Treatment
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* Behavioral: Binocular visual confusion (unilateral opaque)
* Behavioral: Unilateral monocular visual confusion (unilateral see-through)
* Behavioral: Bilateral monocular visual confusion (bilateral see-through)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Better than 20/40 visual acuity in the worse eye No restrictions of the peripheral visual field: (at least 60 degrees vertically and 40 degrees horizontally) At least 14 years of age (no upper age limit) Able to give voluntary, informed consent Able to understand English Binocular vision parameters within normal limits (Stereopsis ≤ 100 arc sec on any stereo test) Exclusion criteria: Patients with any physical or mental disabilities, including cognitive dysfunction, balance problems, or other deficits that could impair their ability to respond to the stimuli presented in this study will be excluded Being unable to complete sessions lasting 2-3 hours

Ages Eligible for Study
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Minimum Age: 14 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: All participants in the group will see all three interventions (peripheral targets in three visual confusion conditions) in a randomized order. In this study design, each participant will serve as their own control, and the order of the interventions will be randomized to account for potential carryover or ordering effects. There will be no comparison or control group. The outcome will be compared through a within-subject analysis.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Visual confusion<br>Participants viewed peripheral targets in three different visual confusion conditions (three interventions): binocular visual confusion (unilateral opaque target), unilateral monocular visual confusion (unilateral see-through target), and bilateral monocular visual confusion (bilateral see-through target). Each intervention was presented twice in a randomized order, resulting in a total of six trials. During each trial, a peripheral target was presented in front of a forward-moving background for one minute. Participants were instructed to hold down the controller button while the target was visible and release it when a third or more of the target disappeared. After each trial, participants could take a brief break before the next trial in a different visual confusion condition was presented in a randomized order. | Behavioral: Binocular visual confusion (unilateral opaque)<br>* The peripheral target was a horizontally drifting grating measuring 10° by 10°, with a spatial frequency of 1 cycle per degree and a temporal frequency of 3 Hz, and located at 10° above the fixation. For the binocular visual confusion condition, the non-transparent (opaque) peripheral target will be displayed on only one eye (unilateral opaque display).<br>Behavioral: Unilateral monocular visual confusion (unilateral see-through)<br>* The peripheral target was a horizontally drifting grating measuring 10° by 10°, with a spatial frequency of 1 cycle per degree and a temporal frequency of 3 Hz, and located at 10° above the fixation. For the unilateral monocular visual confusion condition, the half-transparent peripheral target will be displayed on only one eye (unilateral see-through display).<br>Behavioral: Bilateral monocular visual confusion (bilateral see-through)<br>* The peripheral target was a horizontally drifting grating measuring 10° by 10°, with a spatial frequency of 1 cycle per degree and a temporal frequency of 3 Hz, and located at 10° above the fixation. For bilateral monocular visual confusion condition, the half-transparent peripheral target will be displayed on both eyes (bilateral see-through display).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Total Viewing Time That Peripheral Target is Perceived | (Total time the peripheral target in the visual confusion condition was visible) / (total viewing time (=1 min)) | Approximately 1-2 sessions to finish total 6 trials, up to 2 hours for each session, any time within the 4month study period | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Visual confusion, Rivalry, Head mounted display, Stereoscopic displays, Binocular vision