Behavioral Dynamics Between Infants With Visual Loss and Healthy Controls

Study Overview
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Brief Summary
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An individual senses the world and reflects feedbacks via independent behaviors. Such precise collaboration of the sensory and behavioral systems is fundamental to survival and evolution. When a sensory modality is altered, the behavioral system has the potential to fit in a substitute modality. However, the specific dynamics of human behaviors in response to sensory loss remain largely unknown due to the paucities of representative situations and large-scale samples. Here, the investigators focused on thousands of human infants who suffered varying degrees of visual stimuli deficiency in early stages, while their behavioral systems remained sensitive and thus retained high behavioral plasticity. Having access to this unique population provides an unprecedented opportunity to investigate the effect of diverse visual conditions on the behavioral system.

Official Title
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Comparison of the Behavioral Dynamics Between Visually Impaired Infants and Healthy Controls

Conditions
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Behavioral Dynamics, Visual Impairment

Intervention / Treatment
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* Other: Standardized video recording for behaviors


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Younger than 3 years of age Exclusion Criteria: Any brain and mental illnesses, or other known illnesses that may affect the behavioral patterns

Ages Eligible for Study
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Maximum Age: 3 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| healthy group<br>For the healthy group, the visual acuity of both eyes was in the 95% referenced range with no structural abnormalities. The referenced range could be found in the following publication: Mayer, DL., et al. Monocular acuity norms for the Teller Acuity Cards between ages one month and four years. Investigative Ophthalmology & Visual Science. 36(3):671 (1995) | Other: Standardized video recording for behaviors<br>* A standardized apparatus, scenario, and procedure was applied to record all the behavioral phenotypes with minimized background interference and stimulation. For each standardized procedure, the guardian sits in the chair, holding the infant facing the stage. Each infant is given a few minutes to adapt to the surroundings and to be calm before recording. No hints or simulations are permitted during the entire process. The recording process lasted for over 5 minutes to ensure that behavioral phenotypes could be completely recorded.<br>|
| mildly impaired group<br>The mildly impaired group was defined as a VA out of the 95% reference range in at least 1 eye, but the VA of both eyes was in the 99% referenced range with structural abnormalities. | Other: Standardized video recording for behaviors<br>* A standardized apparatus, scenario, and procedure was applied to record all the behavioral phenotypes with minimized background interference and stimulation. For each standardized procedure, the guardian sits in the chair, holding the infant facing the stage. Each infant is given a few minutes to adapt to the surroundings and to be calm before recording. No hints or simulations are permitted during the entire process. The recording process lasted for over 5 minutes to ensure that behavioral phenotypes could be completely recorded.<br>|
| severely impaired group<br>For the severely impaired group, the VA of both eyes was out of the 99% referenced range or worse than light perception with structural abnormalities. | Other: Standardized video recording for behaviors<br>* A standardized apparatus, scenario, and procedure was applied to record all the behavioral phenotypes with minimized background interference and stimulation. For each standardized procedure, the guardian sits in the chair, holding the infant facing the stage. Each infant is given a few minutes to adapt to the surroundings and to be calm before recording. No hints or simulations are permitted during the entire process. The recording process lasted for over 5 minutes to ensure that behavioral phenotypes could be completely recorded.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Behavioral dynamics | Eyeball movement (strabismus, nystagmus, and incongruous binocular movement); hand-related behaviors (eye rubbing, pressing, and poking); fixation-related behaviors (compulsive light gazing, compensatory head position, motionless fixation, and poor fixation); and eyelid reaction (frequent blinking, squint, and frown). Five experienced ophthalmologists identified the behaviors independently, and 2 professors with over 10 years of experience in pediatric ophthalmology department were consulted in cases of disagreement. | baseline |