Actively Recruiting
Study of Visual Perception Phenomena: Phosphene Mapping Induced by TMS and Its Relationship With Eye Movements
Led by Skolkovo Institute of Science and Technology · Updated on 2025-08-07
50
Participants Needed
1
Research Sites
65 weeks
Total Duration
On this page
Sponsors
S
Skolkovo Institute of Science and Technology
Lead Sponsor
I
I.M. Sechenov First Moscow State Medical University
Collaborating Sponsor
AI-Summary
What this Trial Is About
The purpose of this basic science study is to better understand human visual perception. Phosphenes are flashes of light that can be induced using Transcranial Magnetic Stimulation (TMS). The location of these phosphenes is known to change with eye movements, but the exact influence of these movements is not fully understood. The main questions this study aims to answer are: How does stimulating specific areas of the visual cortex relate to where a person perceives a phosphene? How do eye movements affect the accuracy of mapping these sensations? The study will enroll three groups of adults (aged 18-65): patients with Visual Snow Syndrome, color-blind participants, and healthy volunteers. During the experiment, participants will receive single-pulse TMS to their visual cortex. Simultaneously, their eye movements will be monitored with an eye-tracker, and their brain activity will be recorded with EEG. Participants will be asked to report the location of the perceived light flashes. This will help create a map of the brain areas responsible for visual sensations and clarify how eye movements influence this process.
CONDITIONS
Official Title
Study of Visual Perception Phenomena: Phosphene Mapping Induced by TMS and Its Relationship With Eye Movements
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Adults aged 18 to 65 years
- Patients with Visual Snow Syndrome confirmed by International Classification of Headache Disorders, 3rd edition (ICHD-3) criteria
- Presence of persistent dynamic tiny dots ("visual snow") across the entire visual field
- At least one additional visual symptom: palinopsia, photophobia, nyctalopia, or blurred vision
- Patients with symptoms appearing after SARS-CoV-2 illness may be included
- Color-blind participants must have a formal diagnosis confirmed by specific ophthalmologic tests (e.g., Ishihara, Rabkin, Justova, Stilling polychromatic plates, Farnsworth-Munsell test)
- Healthy controls must have no active or past neurological, psychiatric, or ophthalmological disorders
You will not qualify if you...
- Use of psychotropic drugs
- Contraindications to Transcranial Magnetic Stimulation (TMS), including history of epilepsy, seizures, or metallic implants in the head
- Pregnancy
- For Visual Snow Syndrome patients: any organic abnormalities in eyes or visual system found in standard eye exam
- Presence of comorbid psychiatric disorders or other medical conditions (e.g., migraine with aura) explaining symptoms
- For color-blind participants: any non-congenital color blindness
- Presence of visual impairments affecting perception (e.g., cataracts, glaucoma, macular degeneration)
- Presence of neurological or psychiatric diseases such as schizophrenia, epilepsy, or mood disorders that could affect results
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Trial Site Locations
Total: 1 location
1
Skolkovo Institute of Science and Technology (Skoltech)
Moscow, Russia
Actively Recruiting
Research Team
A
Akinshin R.
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NON_RANDOMIZED
Model
PARALLEL
Primary Purpose
BASIC_SCIENCE
Number of Arms
3
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here