Visual Snow Is Susceptible to the Motion Aftereffect

Area of Science:

• Neuroscience
• Visual Perception
• Ophthalmology

Background:

• Visual snow syndrome (VSS) is characterized by persistent visual static.
• The underlying neural mechanisms of VSS remain largely unknown.
• Current treatments for VSS are limited.

Purpose of the Study:

• To investigate if spontaneous neural activity causing visual snow reaches motion-selective areas.
• To test the hypothesis that visual snow originates early in the visual pathway.
• To utilize the motion aftereffect (MAE) to probe VSS neural mechanisms.

Main Methods:

• Eleven participants with VSS and 12 controls adapted to moving gratings.
• Participants reported the perceived motion of their visual snow after adaptation.
• The duration of adapting stimuli was varied to assess MAE strength.

Main Results:

• Most VSS participants (10/11) perceived their visual snow moving in the opposite direction of adapting stimuli.
• The duration of the motion aftereffect showed a linear relationship with adapter duration on a log-log axis.
• Participants with VSS exhibited a typical MAE to external visual stimuli in control conditions.

Conclusions:

• Visual snow is influenced by the motion aftereffect, indicating it involves motion-selective neurons, potentially including area V5/MT.
• The findings suggest that neural activity generating visual snow propagates through the visual system.
• Identifying the neural origins of visual snow could pave the way for targeted therapeutic interventions.