Expansion of visual space after saccadic eye movements

Area of Science:

• Neuroscience
• Visual Perception
• Human Motor Control

Background:

• Accurate spatial perception is crucial for navigation and interaction.
• Saccades, rapid eye movements, can alter visual perception.
• Previous research noted horizontal mislocalization after saccades, but 2D effects are less understood.

Purpose of the Study:

• To investigate the two-dimensional spatial mislocalization of visual targets following saccades.
• To characterize the pattern and influencing factors of this mislocalization.
• To differentiate saccadic mislocalization from non-veridical motion perception.

Main Methods:

• Human participants performed saccades in the absence of visual references.
• Visual targets were briefly presented post-saccade.
• Participants reported the perceived 2D location of the targets.
• Analysis focused on horizontal and vertical mislocalization components.

Main Results:

• A consistent horizontal mislocalization occurred opposite to the saccade direction.
• Mislocalization magnitude increased with target distance from the saccade trajectory and contraversive visual field.
• A 2D expansion of visual space was observed, originating from a point shifted in the saccade direction.
• Spatial mislocalization was distinct from non-veridical motion perception.

Conclusions:

• Visual spatial processing during saccades involves topographic neural interactions between saccade execution and visual input.
• The observed 2D expansion suggests a systematic distortion of perceived space post-saccade.
• Saccadic spatial mislocalization and motion perception are independent phenomena.