Saccadic Suppression Is Embedded Within Extended Oscillatory Modulation of Sensitivity.
Alessandro Benedetto1,2, Maria Concetta Morrone3,4,5
1Department of Neuroscience, Psychology, Pharmacology and Child Health, University of Florence, 50135 Florence, Italy.
Summary
Eye movements, called saccades, reduce vision temporarily. This study reveals that visual sensitivity oscillates rhythmically before and after saccades, potentially aligning eye movements with vision suppression for stability.
Area of Science:
- Neuroscience
- Vision Science
- Perception
Background:
- Action and perception are linked, with saccadic suppression reducing visibility during eye movements to maintain visual stability.
- The precise timing mechanisms synchronizing saccadic suppression with saccade onset remain unclear.
Purpose of the Study:
- To investigate how saccades influence contrast discrimination sensitivity over an extended period before and after execution.
- To explore the relationship between saccadic preparation and oscillations in visual sensitivity.
Main Methods:
- Human subjects performed horizontal saccades between targets.
- A Gabor patch was briefly presented at random intervals, and subjects detected its location.
- Contrast discrimination sensitivity was measured across a time window exceeding 1 second before and after saccade onset.
Main Results:
- Significant saccadic suppression occurred between -50 and 50 ms relative to saccade onset.
- This suppression was embedded within delta-range (∼3 Hz) oscillations in contrast sensitivity.
- These oscillations began approximately 1 second before saccade execution and persisted for up to 1 second after.
Conclusions:
- Saccadic preparation and visual sensitivity oscillations are coupled systems.
- This coupling may play a crucial role in temporally aligning saccade initiation with visual suppression for enhanced stability.
