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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
The "diagonal effect": a systematic error in oblique antisaccades
John D Koehn1, Elizabeth Roy, Jason J S Barton
1Human Vision and Eye Movement Laboratory, University of British Columbia, Vancouver, Canada.
Journal of Neurophysiology
|May 24, 2008
Summary
Antisaccades, or voluntary eye movements to the opposite side of a visual target, show a systematic directional error. Oblique antisaccades deviate toward diagonal meridians, suggesting a common spatial bias in perception.
Area of Science:
- Neuroscience
- Ophthalmology
- Cognitive Psychology
Background:
- Antisaccades exhibit greater variability and hypometria compared to prosaccades.
- Previous research focused on antisaccade amplitude errors, not directional accuracy.
Purpose of the Study:
- To investigate systematic directional errors in human antisaccades.
- To determine if antisaccades deviate towards specific meridians.
Main Methods:
- Human subjects performed prosaccades and antisaccades to various target locations.
- Experiments varied the number and arrangement of target locations per block.
- Analysis focused on saccadic trajectory deviations.
Main Results:
- Oblique antisaccades systematically deviated towards the 45-degree diagonal meridians.
- Prosaccades did not show this diagonal deviation.
- The effect persisted across different experimental designs and was not due to range effects.
Conclusions:
- A consistent directional bias exists in antisaccade performance.
- This diagonal effect in antisaccades may stem from perceptual mechanisms.
- The findings suggest a shared spatial bias in processing uncertain spatial information across different tasks.
