Authors: Sophie De Beukelaer, Antonia Klein and Christoph J. Schankin
Abstract
Neurobehavioral signatures, such as cortical hyperexcitability, thalamo-cortical dysrhythmia, and pulvinar dysfunction, appear to drive the persistent visual misperceptions in Visual Snow Syndrome (VSS). We propose that heightened perceptual uncertaintyand impaired metacognitive monitoring perpetuate these disturbances and formalize these processes within different frameworks (predictive coding, signal detection theory, and attentional control).
By clarifying these mechanisms, we aim to inform targeted interventions that could address this currently untreatable condition.
Introduction
Patients with Visual Snow Syndrome (VSS) experience a persistent, static-like flickering across the entire visual field, often referred to as “visual snow”, alongside additional disturbances such as enhanced entoptic phenomena (e.g., floaters), palinopsia, photophobia, and nyctalopia. These symptoms occur without detectable structural lesions to the visual system [1–4].
Despite clear diagnostic criteria (ICHD-3), the pathophysiological mechanisms of VSS remain poorly understood, and no effective treatment options are available [5]. We propose that perceptual uncertainty, an inability to reliably distinguish relevant signals from sensory noise, underlies the visual misperceptions in VSS. Moreover, we hypothesize that impaired metacognition, disrupted self-monitoring, and confidence assessment may contribute to the chronification of these symptoms.
When perceptual processing fails to correct noisy inputs, patients can experience ongoing misinterpretations and a persistent sense of visual overload.
By first describing the neural underpinnings that produce perceptual uncertainty in VSS, applying these formal models, and finally showing how metacognitive dysfunction may perpetuate symptoms, we hope to offer a comprehensive hypothetical perspective on VSS.
We conclude by discussing potential clinical implications, including how training metacognitive abilities might alleviate the disorder’s hallmark misperceptions.
