Statistical Learning as a Novel Intervention for Cortical Blindness

This project aims to develop a novel visual training paradigm for use in visually-intact participants and those sufferings from stroke-induced visual impairments. Our task design is built upon theories of statistical learning to reduce the overall training burden while still producing profound improvements to visual abilities. Efficacy will be first established in visually-intact controls before testing in stroke survivors to assess the feasibility of this form of learning in the damaged visual system.

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Key information

Conditions

Stroke, Ischemic Blindness Brain Diseases Cardiovascular Diseases Central Nervous System Diseases Cerebrovascular Disorders Eye Diseases Hemianopia, Homonymous Hemianopsia Hemorrhagic Stroke Ischemic Stroke Nervous System Diseases Neurologic Manifestations Occipital Lobe Infarct Pathological Conditions, Signs and Symptoms Quadrantanopia Sensation Disorders Signs and Symptoms Stroke Stroke Hemorrhagic Vascular Diseases Vision Disorders Vision Loss Partial Visual Field Defect, Peripheral

Age range

21 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Rochester Medical Center

Rochester, New York, 14642, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Cortically Blind participants

Inclusion criteria

Between 21 and 75 years of age
Residents of the United States or Canada
Have successfully completed previous enrollment in Dr. Huxlin study (IRB #5966 or #75)
Exhibit unilateral stroke or stroke-like damage to primary visual cortex or its immediate afferent white matter sustained within the specified age range of 21 - 75 years (verified by MRI and/or CT scans)
Reliable visual field defects in both eyes (homonymous defects) as measured by Humphrey visual fields. This deficit must be large enough to enclose a 5-deg diameter visual stimulus.
Able to fixate on visual targets reliably for 1000ms within 1-deg of visual angle.
Willing, able, and competent to provide their own informed consent
Normal cognitive abilities and be able to understand written and oral instructions in English

Exclusion criteria

Past or present ocular disease interfering with visual acuity
Best corrected visual acuity (BCVA) worse than 20/40 in either eye
Sustained documented or suspected damage to the dorsal Lateral Geniculate Nucleus
Presence of diffuse whole brain degenerative processes
History of traumatic brain injury
Any other brain damage deemed by study staff to potentially interfere with training ability or outcome measures
Documented history of drug/alcohol abuse
Currently taking neuroactive medications which would impact training, as determined by PI
Cognitive or seizure disorders
One-sided attentional neglect
Those who lack the competence or are otherwise unable to perform the visual training exercises as directed.

Control participants

Inclusion criteria

Between 21 and 75 years of age
No history of neurological disorder.
Competent and responsible, as determined by the screening interview

Exclusion criteria

Any damage to the visual system
Those who are suffering from an active disease process involving their nervous system.
Presence of cognitive or seizure disorders
Best corrected visual acuity worse than 20/40 in either eye
Presence of visual field loss from ocular disease or disorder

Treatment and study plan

Vision Training and Learning Task

Device

Participants will be seated at a computer, and will be shown a random-noise visual stimulus drifting in one of eight directions. Participants will be instructed to indicate the direction of motion they perceive using a Sony Access Controller or a computer keyboard. Sound cues during stimulus presentation will also be used to ensure participants are aware of stimulus onset during the training task.

After several repetitions of this visual training, a second set of visual cues will be presented to evaluate participant's learning of the program. Responses will be provided in the same manner by input from the controller or the keyboard.

Primary outcomes

Explicit Learning - Response Time

Time frame: Baseline

Reaction time (ms) when performing motion discriminations for the final stimulus of a statistically-linked triplet will be compared against reaction times for stimuli with identical motion directions, presented with alternative placement within a triplet. Comparisons will be made only for correct responses in the final 20% of overall testing session trials.
Implicit Learning - Triplet Familiarity

Time frame: Baseline

Participant familiarity with statistically-linked triplets of motion will be assessed via a two-interval, forced-choice task. Familiarity will be measured as a percentage of comparisons in which the more prevalent triplet is selected as more familiar. Familiarity of high-probability, low-probability, and null-probability triplets will be compared following training.

Sponsors and collaborators

Lead sponsor

University of Rochester

Other

Registry information

Important dates

Study start: 2024
Primary completion: 2027
Study completion: 2027
First posted: Aug 29, 2024
Registry last updated: Jan 30, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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