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Updated: Jun 18, 2026
Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity
Published on: March 18, 2019
Microsaccades and preparatory set: a comparison between delayed and immediate, exogenous and endogenous pro- and
Frouke Hermens1, Johannes M Zanker, Robin Walker
1Department of Psychology, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK. frouke.hermens@gmail.com
Abstract:
When we fixate an object, our eyes are not entirely still, but undergo small displacements such as microsaccades. Here, we investigate whether these microsaccades are sensitive to the preparatory processes involved in programming a saccade. We show that the frequency of microsaccades depends in a specific manner on the intention where to move the eyes (towards a target location or away from it), when to move (immediately after the onset of the target or after a delay), and what type of cue is followed (a peripheral onset or a centrally presented symbolic cue). In particular, in the preparatory interval before and early after target onset, more microsaccades were found when a delayed saccade towards a peripheral target was prepared than when a saccade away was programmed. However, no such difference in the frequency of microsaccades was observed when saccades were initiated immediately after the onset of the target or when the saccades were programmed on the basis of a centrally presented arrow cue. The results are discussed in the context of the neural correlates of response preparation, known as preparatory set.
Insights
Eye movements, specifically microsaccades, are influenced by how we prepare to look at targets. Their frequency changes based on movement direction, timing, and cue type, revealing insights into preparatory set.
Area of Science:
- Neuroscience
- Ophthalmology
- Cognitive Psychology
Background:
- During visual fixation, eyes exhibit small, involuntary movements called microsaccades.
- Microsaccades may reflect underlying neural processes related to eye movement control.
Purpose of the Study:
- To investigate if microsaccade frequency is modulated by the preparatory processes involved in programming saccades.
- To determine how saccade intention (direction, timing, cue type) affects microsaccade generation.
Main Methods:
- Participants performed eye movement tasks involving saccade programming.
- Microsaccade frequency was analyzed in relation to different preparatory conditions.
- Variations in target location, cue type (peripheral onset vs. central arrow), and timing (immediate vs. delayed saccade) were manipulated.
Main Results:
- Microsaccade frequency was higher during preparation for delayed saccades towards a peripheral target compared to saccades away.
- This difference was not observed for immediate saccades or saccades guided by a central symbolic cue.
- The findings suggest a specific sensitivity of microsaccades to preparatory set variations.
Conclusions:
- Microsaccade frequency is sensitive to the specific nature of saccade preparation.
- These results provide insights into the neural mechanisms of response preparation and preparatory set.
- Microsaccades may serve as a measurable indicator of cognitive control during motor preparation.
