Eye Movements in Visual Search

Study Overview
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Brief Summary
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Using a noninvasive eye tracker, the investigators will measure how participants move their eyes to objects arrayed on a computer screen. Participants will be asked to find one element among many.

Detailed Description
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The investigators measure how quickly and how accurately participants can move their eyes from a central fixation point to a target object arrayed with one or more distractor objects. A noninvasive eye tracker will be used to measure their eye movements. Participants may also be asked to make a decision about a feature of the target they have selected with a key press. Difficulty of the search for the target object and difficulty of the decision about a feature of the target object will be manipulated.

Official Title
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Eye Movement Studies of Visual Search

Conditions
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Healthy

Intervention / Treatment
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* Behavioral: Target and Stimulus


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Sona System users (open to the public) Exclusion Criteria: participants that fail the Ishihara color vision screening test participants with acuity worse than 20/20 with or without correction children under 18 adults over 50

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

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: Participants are asked to view an array of objects on a computer screen equipped with a noninvasive eye tracker. They are asked to search for a target object among one or more distractor objects and may be asked to respond to a feature of the target object with a key press that was selected via a gaze shift.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Within Subjects Experimental Design<br>All participants are tested in all conditions. | Behavioral: Target and Stimulus<br>* The investigators manipulate the difficulty of search for the target object by manipulating the number of distractor objects and/or the similarity between the target and distractors. The investigators manipulate the difficulty of the decision about a feature by manipulating the similarity of the feature to a criterion. The investigators manipulate the timing of when the decision feature appears on the object relative to the onset of the array and/or the onset of the saccade away from fixation in a gaze-contingent manner.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Eye Tracking Data | Saccade Events, Fixation Events, Pupil Size | During 1-2 hour experimental session | 
| Response Data | Response Time, Error Rate | During 1-2 hour experimental session | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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eye tracker, visual perception