MAD saccade: statistically robust saccade threshold estimation via the median absolute deviation.
Benjamin Voloh1, Marcus R Watson2, Seth König1
1Vanderbilt University Nashville, USA.
Journal of Eye Movement Research
|April 8, 2021
Summary
Robust median absolute deviation (MAD) improves saccade detection in gaze analysis. This method enhances accuracy by reducing false positives and negatives, especially in noisy data.
Area of Science:
- Ophthalmology
- Neuroscience
- Computer Science
Background:
- Saccade detection is essential for analyzing eye-tracking data.
- Current velocity/acceleration threshold methods are sensitive to outliers, impacting accuracy.
- Existing methods can be influenced by the saccade signal itself.
Purpose of the Study:
- To introduce a robust method for saccade detection using median absolute deviation (MAD).
- To improve the accuracy and reliability of automatic saccade detection algorithms.
- To address the limitations of traditional threshold-based methods in gaze analysis.
Main Methods:
- Modified an existing saccade detection algorithm (Nyström et al.).
- Incorporated the median absolute deviation (MAD) as a robust dispersion estimator.
- Evaluated performance using both simulated and human eye-tracking data.
Main Results:
- The modified algorithm demonstrated significant improvements in saccade detection.
- Observed an increase in true positives and a decrease in false negatives.
- Performance gains were particularly notable under higher levels of data noise.
Conclusions:
- Robust estimators like MAD offer a superior alternative for saccade detection.
- The proposed method enhances the reliability of gaze data analysis.
- Robust estimators are easily implementable in other automatic gaze classification algorithms.
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