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Updated: Jul 5, 2026
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Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity
Published on: March 18, 2019
Blind saccades: an asynchrony between seeing and looking
Claudio de'Sperati1, Gabriel Baud-Bovy
1Visuomotor Functions Laboratory, University Vita-Salute San Raffaele, 20132 Milan, Italy. desperati.claudio@hsr.it
Summary
Saccades, or rapid eye movements, can be influenced by visual motion before perception is complete. This study reveals distinct phases in eye movement control, showing how action and perception may operate asynchronously.
Area of Science:
- Neuroscience
- Cognitive Science
- Ophthalmology
Background:
- Saccades, crucial for visual exploration, are typically assumed to follow perceptual processing.
- The precise timing and relationship between saccade generation and visual perception remain incompletely understood.
- Motion-induced illusions provide a tool to probe the dynamics of visual processing and motor responses.
Purpose of the Study:
- To investigate the temporal dynamics of saccadic eye movements in relation to visual perception.
- To determine how visual motion influences saccade accuracy at different time latencies.
- To elucidate the asynchronous nature of visual perception and action (looking).
Main Methods:
- Utilized a motion-induced illusion of position to manipulate perceived target location.
- Analyzed saccade latency and direction in normal observers under varying visual motion conditions.
- Reconstructed the temporal coding of saccadic direction based on observed latencies.
Main Results:
- Saccades with latencies < 100 ms were predictive; 100-250 ms were target-guided.
- Saccades with latencies > 250 ms were increasingly biased by motion, reflecting perceptual illusions.
- A dissociation between action (saccade) and perception (localization) was observed.
Conclusions:
- Seeing and looking are based on asynchronous neural processes with potentially independent thresholds.
- Saccade metrics reflect the evolution of visual signals from predictive to perceptual states.
- Saccades initiated during an intermediate visuomotor state can bypass perceptual misinterpretations.
