The neural basis of visual snow syndrome

PROJECT SUMMARY Visual Snow Syndrome (VSS) is a poorly understood neurological condition whose primary symptom is the constant perception of flickering specks, like television static, superimposed on the visual world. VSS can be debilitating, interfering with daily life activities such as reading and driving. The cause of this condition remains unknown, and there are currently no effective treatment options. Our proposal builds on our recent discovery that a method called visual adaptation can temporarily alleviate visual snow symptoms. This exciting revelation gives us a powerful new tool for understanding the neural basis of visual snow. In this proposal, we will test the hypothesis that VSS is caused by excess spontaneous neural activity within visual brain areas. To do so, we will compare behavioral tests of visual perception using adaptation in people with VSS versus normally sighted control participants, as well as non-invasive measurements of neural activity (functional magnetic resonance imaging) and brain chemistry (magnetic resonance spectroscopy). Understanding where and how spontaneous neural activity leads to visual snow percepts will pave the way for new treatment strategies, objective tests, and biomarkers for VSS, which may in turn improve quality of life, diagnosis, and evaluation of treatment efficacy in this disorder.