visual snow syndrome visual snow, visual snow syndrome, visual adaptation
Conditions
Interventions
Each participant is instructed to complete a psychophysical task developed by a program called Psychopy on the computer, and their performance data are collected during the task. The total duration of
s reported visual snow characteristics.
Then, participants were asked to press a button as soon as their visual snow reappears at the side where the noise adapter had been presented. The features of e
Experimental Behavioral
Visual adaptaion
Sponsors
None listed
Eligibility
Sex/Gender
All
Age
18 Years to 60 Years
Inclusion criteria
Inclusion criteria: 1. Age more than 18 years old 2. Diagnosed as visual snow syndrome. 2.1. Having experienced visual snow continually for at least the last 3 months 2.2. Presence of at least 2 additional visual symptoms of the following categories 2.2.1. Palinopsia 2.2.2. Enhanced entopic phenomena 2.2.3. Photophobia 2.2.4. Nyctalopia 2.3. Symptoms are not the consistent with the typical migraine aura. 2.4. Symptoms are not better explained by another disorder.
Exclusion criteria
Exclusion criteria: 1. Using of hallucinogenic/dissociative substances within 12 months prior to the onset of visual snow or within 12 months of the beginning of the study. 2. Having secondary causes of visual snow syndrome 2.1. Having underlying disease of ophthalmological condition 2.2. Having underlying disease of brain pathology
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The specificity of visual snow adaptation to reported spatial frequency, motion speed and contrast. after completing the task Quantitative visual snow features will be summarized (mean and SD or median and IQR), and Spearman correlation will assess links with features showing maximal adaptation. | — |
Secondary
| Measure | Time frame |
|---|---|
| visual snow adaptation duration after completing the task The duration of symptom relief was measured as the length of time participants' visual snow symptoms decreased or disappeared after watching the noise adapter. | — |
Countries
Thailand
Contacts
Public ContactNITHIT SINGTOKUM
Department of physiology, Faculty of medicine, Chulalongkorn University
Outcome results
None listed