Effects of Vergence Eye Movement Planning on Size Perception and Early Visual Processing

Area of Science:

• Neuroscience
• Visual Perception
• Oculomotor Function

Background:

• Object perception relies on oculomotor and non-oculomotor depth cues.
• Previous research focused on proprioception's effect on distance and size perception.
• The influence of vergence eye movement commands on visual processing remains unclear.

Purpose of the Study:

• To investigate if the oculomotor command of vergence eye movement influences visual processing.
• To examine the effect of vergence eye movement planning on size perception and early visual evoked potentials.

Main Methods:

• Participants fixated on a near light, then diverged their eyes to view a stimulus on a far screen.
• Stimuli were presented during the preparation stage of divergence eye movements.
• Visual evoked component C1 was analyzed for amplitude and latency variations.

Main Results:

• Stimuli were perceived as larger and less sensitive to size variations in the divergence condition.
• The C1 component showed similar amplitudes for different stimulus sizes during divergence.
• Vergence eye movement planning impacted early visual processing and size perception.

Conclusions:

• Vergence eye movement commands significantly affect early visual processing.
• Motor commands, specifically vergence planning, influence sensory processing and size perception.
• This study provides evidence for the interplay between oculomotor commands and visual perception.