Eye Movement Behaviour and Pupil Size in Natural Outdoor and Indoor Scenes

Study Overview
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Brief Summary
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In this study, the researchers will be using eye tracking and detailed lighting measurements to understand how different types of indoor and outdoor lighting affect the eye movements and pupil sizes of our participants. Participants will be paired up and undergo six eye tracking sessions, split across two appointments. Each appointment will involve viewing either indoor or outdoor scenes, and before each session, participants will spend time adapting to the lighting conditions. Overall, each participant will spend 24 minutes being tracked, and the entire study will take about 2-3 hours to complete. The investigators expect differences in eye movements and pupil size between indoor and outdoor scenes.

Official Title
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Characterization of Eye Movement Behaviour and Pupil Size Through Eye-tracking in Natural Outdoor and Indoor Scenes

Conditions
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Light Sensitivity

Intervention / Treatment
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* Other: Indoor vs. outdoor scenes


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: No previous eye-surgeries or ocular impairments like anisometropia, amblyopia, strabism, cataract, watery eyes or hanging eye lids Normal or corrected-to-normal visual acuity (+3dpt. to -5dpt.) Normal colour vision Normal binocular vision Exclusion Criteria: Any use of medications or drugs that influence photosensitivity or the ability to concentrate Excessive alcohol and/or drug use Presence of psychiatric disorders Poor sleep quality Diagnosed with epilepsy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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 will be exposed to the same environmental conditions (same indoor and outdoor scenes for the same duration) and the captured eye-movement data of every participant will be of the same type. Participants will be exposed to different orders of scene sequences.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Eye-tracking, pupillometry and scene rating indoors & outdoors<br> | Other: Indoor vs. outdoor scenes<br>* Light conditions in indoor (artificial light) and outdoor (daylight) settings<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Saccade frequency - Indoor scene 1 | Number per second [n/s] | Baseline | 
| Saccade frequency - Indoor scene 2 | Number per second [n/s] | Baseline | 
| Saccade frequency - Indoor scene 3 | Number per second [n/s] | Baseline | 
| Saccade frequency - Outdoor scene 1 | Number per second [n/s] | Baseline | 
| Saccade frequency - Outdoor scene 2 | Number per second [n/s] | Baseline | 
| Saccade frequency - Outdoor scene 3 | Number per second [n/s] | Baseline | 
| Saccade amplitude - Indoor scene 1 | Mean angular distance traveled [°] | Baseline | 
| Saccade amplitude - Indoor scene 2 | Mean angular distance traveled [°] | Baseline | 
| Saccade amplitude - Indoor scene 3 | Mean angular distance traveled [°] | Baseline | 
| Saccade amplitude - Outdoor scene 1 | Mean angular distance traveled [°] | Baseline | 
| Saccade amplitude - Outdoor scene 2 | Mean angular distance traveled [°] | Baseline | 
| Saccade amplitude - Outdoor scene 3 | Mean angular distance traveled [°] | Baseline | 
| Saccade velocity - Indoor scene 1 | Mean peak velocity [°/s] | Baseline | 
| Saccade velocity - Indoor scene 2 | Mean peak velocity [°/s] | Baseline | 
| Saccade velocity - Indoor scene 3 | Mean peak velocity [°/s] | Baseline | 
| Saccade velocity - Outdoor scene 1 | Mean peak velocity [°/s] | Baseline | 
| Saccade velocity - Outdoor scene 2 | Mean peak velocity [°/s] | Baseline | 
| Saccade velocity - Outdoor scene 3 | Mean peak velocity [°/s] | Baseline | 
| Fixation duration - Indoor scene 1 | Mean fixation duration [s] | Baseline | 
| Fixation duration - Indoor scene 2 | Mean fixation duration [s] | Baseline | 
| Fixation duration - Indoor scene 3 | Mean fixation duration [s] | Baseline | 
| Fixation duration - Outdoor scene 1 | Mean fixation duration [s] | Baseline | 
| Fixation duration - Outdoor scene 2 | Mean fixation duration [s] | Baseline | 
| Fixation duration - Outdoor scene 3 | Mean fixation duration [s] | Baseline | 
| Fixation frequency - Indoor scene 1 | Number per minute [n/min] | Baseline | 
| Fixation frequency - Indoor scene 2 | Number per minute [n/min] | Baseline | 
| Fixation frequency - Indoor scene 3 | Number per minute [n/min] | Baseline | 
| Fixation frequency - Outdoor scene 1 | Number per minute [n/min] | Baseline | 
| Fixation frequency - Outdoor scene 2 | Number per minute [n/min] | Baseline | 
| Fixation frequency - Outdoor scene 3 | Number per minute [n/min] | Baseline | 
| Pupil size - Indoor scene 1 | Mean pupil size [mm] | Baseline | 
| Pupil size - Indoor scene 2 | Mean pupil size [mm] | Baseline | 
| Pupil size - Indoor scene 3 | Mean pupil size [mm] | Baseline | 
| Pupil size - Outdoor scene 1 | Mean pupil size [mm] | Baseline | 
| Pupil size - Outdoor scene 2 | Mean pupil size [mm] | Baseline | 
| Pupil size - Outdoor scene 3 | Mean pupil size [mm] | Baseline | 
| Melanopic irradiance - Indoor scene 1 | Irradiance [W/(sqm*nm)] | Baseline | 
| Melanopic irradiance - Indoor scene 2 | Irradiance [W/(sqm*nm)] | Baseline | 
| Melanopic irradiance - Indoor scene 3 | Irradiance [W/(sqm*nm)] | Baseline | 
| Melanopic irradiance - Outdoor scene 1 | Irradiance [W/(sqm*nm)] | Baseline | 
| Melanopic irradiance - Outdoor scene 2 | Irradiance [W/(sqm*nm)] | Baseline | 
| Melanopic irradiance - Outdoor scene 3 | Irradiance [W/(sqm*nm)] | Baseline | 
| Photopic illuminance - Indoor scene 1 | Illuminance [lux] | Baseline | 
| Photopic illuminance - Indoor scene 2 | Illuminance [lux] | Baseline | 
| Photopic illuminance - Indoor scene 3 | Illuminance [lux] | Baseline | 
| Photopic illuminance - Outdoor scene 1 | Illuminance [lux] | Baseline | 
| Photopic illuminance - Outdoor scene 2 | Illuminance [lux] | Baseline | 
| Photopic illuminance - Outdoor scene 3 | Illuminance [lux] | Baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjective scene ratings - Indoor scene 1 | Unabbreviated scale titles (1)., min. and max, values (2.), score assessment (3.): 1. How beautiful is this scene to you? 2. 1 = not beautiful at all; 10 = extremely beautiful 3. No better or worse outcome 1. How would you rate the brightness of this scene? 2. 1 = dimly lit room; 10 = bright sunny day 3. No better or worse outcome 1. How visually comfortable did you find this scene? 2. 1 = No discomfort; 10 = Very uncomfortable 3. No better or worse outcome 1. How would you rate the complexity of the scene (e.g. colour contrasts, different object identities, moving objects)? 2. 1 = very simple; 10 = Very complex 3. No better or worse outcome 1. How sleepy do you currently feel 2. 1 = Extremely alert; 10 = Extremely sleep, can't keep awake 3. Lower score is better | Baseline | 
| Subjective scene ratings - Indoor scene 2 | Unabbreviated scale titles (1)., min. and max, values (2.), score assessment (3.): 1. How beautiful is this scene to you? 2. 1 = not beautiful at all; 10 = extremely beautiful 3. No better or worse outcome 1. How would you rate the brightness of this scene? 2. 1 = dimly lit room; 10 = bright sunny day 3. No better or worse outcome 1. How visually comfortable did you find this scene? 2. 1 = No discomfort; 10 = Very uncomfortable 3. No better or worse outcome 1. How would you rate the complexity of the scene (e.g. colour contrasts, different object identities, moving objects)? 2. 1 = very simple; 10 = Very complex 3. No better or worse outcome 1. How sleepy do you currently feel 2. 1 = Extremely alert; 10 = Extremely sleep, can't keep awake 3. Lower score is better | Baseline | 
| Subjective scene ratings - Indoor scene 3 | Unabbreviated scale titles (1)., min. and max, values (2.), score assessment (3.): 1. How beautiful is this scene to you? 2. 1 = not beautiful at all; 10 = extremely beautiful 3. No better or worse outcome 1. How would you rate the brightness of this scene? 2. 1 = dimly lit room; 10 = bright sunny day 3. No better or worse outcome 1. How visually comfortable did you find this scene? 2. 1 = No discomfort; 10 = Very uncomfortable 3. No better or worse outcome 1. How would you rate the complexity of the scene (e.g. colour contrasts, different object identities, moving objects)? 2. 1 = very simple; 10 = Very complex 3. No better or worse outcome 1. How sleepy do you currently feel 2. 1 = Extremely alert; 10 = Extremely sleep, can't keep awake 3. Lower score is better | Baseline | 
| Subjective scene ratings - Outdoor scene 1 | Unabbreviated scale titles (1)., min. and max, values (2.), score assessment (3.): 1. How beautiful is this scene to you? 2. 1 = not beautiful at all; 10 = extremely beautiful 3. No better or worse outcome 1. How would you rate the brightness of this scene? 2. 1 = dimly lit room; 10 = bright sunny day 3. No better or worse outcome 1. How visually comfortable did you find this scene? 2. 1 = No discomfort; 10 = Very uncomfortable 3. No better or worse outcome 1. How would you rate the complexity of the scene (e.g. colour contrasts, different object identities, moving objects)? 2. 1 = very simple; 10 = Very complex 3. No better or worse outcome 1. How sleepy do you currently feel 2. 1 = Extremely alert; 10 = Extremely sleep, can't keep awake 3. Lower score is better | Baseline | 
| Subjective scene ratings - Outdoor scene 2 | Unabbreviated scale titles (1)., min. and max, values (2.), score assessment (3.): 1. How beautiful is this scene to you? 2. 1 = not beautiful at all; 10 = extremely beautiful 3. No better or worse outcome 1. How would you rate the brightness of this scene? 2. 1 = dimly lit room; 10 = bright sunny day 3. No better or worse outcome 1. How visually comfortable did you find this scene? 2. 1 = No discomfort; 10 = Very uncomfortable 3. No better or worse outcome 1. How would you rate the complexity of the scene (e.g. colour contrasts, different object identities, moving objects)? 2. 1 = very simple; 10 = Very complex 3. No better or worse outcome 1. How sleepy do you currently feel 2. 1 = Extremely alert; 10 = Extremely sleep, can't keep awake 3. Lower score is better | Baseline | 
| Subjective scene ratings - Outdoor scene 3 | Unabbreviated scale titles (1)., min. and max, values (2.), score assessment (3.): 1. How beautiful is this scene to you? 2. 1 = not beautiful at all; 10 = extremely beautiful 3. No better or worse outcome 1. How would you rate the brightness of this scene? 2. 1 = dimly lit room; 10 = bright sunny day 3. No better or worse outcome 1. How visually comfortable did you find this scene? 2. 1 = No discomfort; 10 = Very uncomfortable 3. No better or worse outcome 1. How would you rate the complexity of the scene (e.g. colour contrasts, different object identities, moving objects)? 2. 1 = very simple; 10 = Very complex 3. No better or worse outcome 1. How sleepy do you currently feel 2. 1 = Extremely alert; 10 = Extremely sleep, can't keep awake 3. Lower score is better | Baseline | 
| Geographical scene location - Indoor scene 1 | Longitude and latitude [°] | Baseline | 
| Geographical scene location - Indoor scene 2 | Longitude and latitude [°] | Baseline | 
| Geographical scene location - Indoor scene 3 | Longitude and latitude [°] | Baseline | 
| Geographical scene location - Outdoor scene 1 | Longitude and latitude [°] | Baseline | 
| Geographical scene location - Outdoor scene 2 | Longitude and latitude [°] | Baseline | 
| Geographical scene location - Outdoor scene 3 | Longitude and latitude [°] | Baseline | 
| Ambient temperature - Indoor scene 1 | Temperature [°C] | Baseline | 
| Ambient temperature - Indoor scene 2 | Temperature [°C] | Baseline | 
| Ambient temperature - Indoor scene 3 | Temperature [°C] | Baseline | 
| Ambient temperature - Outdoor scene 1 | Temperature [°C] | Baseline | 
| Ambient temperature - Outdoor scene 2 | Temperature [°C] | Baseline | 
| Ambient temperature - Outdoor scene 3 | Temperature [°C] | Baseline |