Microsaccades counteract perceptual filling-in

Area of Science:

• Neuroscience
• Visual Perception
• Ophthalmology

Background:

• Artificial scotomas fade during visual fixation due to perceptual filling-in by dynamic noise.
• This filling-in effect is not explained by low-level adaptation, unlike classical Troxler fading.
• Microsaccades were previously shown to counteract Troxler fading and maintain first-order visual visibility.

Purpose of the Study:

• To determine if microsaccades counteract the perceptual filling-in of artificial scotomas.
• To investigate if microsaccades drive second-order visual visibility during fixation.
• To explore the role of microsaccades in higher perceptual processes beyond low-level adaptation.

Main Methods:

• Subjects fixated on artificial scotomas presented on a dynamic noise background.
• Participants reported scotoma visibility via button presses.
• Simultaneous high-precision video recording of eye movements, specifically microsaccades, was performed.

Main Results:

• Increased microsaccade production correlated with counteracting perceptual filling-in.
• Higher microsaccade activity drove the visibility of the artificial scotoma.
• Decreased microsaccade activity allowed perceptual filling-in to occur.

Conclusions:

• Microsaccades counteract perceptual filling-in of artificial scotomas during fixation.
• Microsaccades contribute to maintaining second-order visual visibility.
• Microsaccades play a role in higher perceptual processes, not just low-level adaptation.