Eyer Peak is an unofficial designation for a perceived sharp, temporary spike in the visual representation of eye tracking data. It typically occurs when an eye tracker loses contact with the pupil or when the pupil is momentarily obscured (e.g., by an eyelid partially closing during a blink). These peaks manifest as extreme values in metrics such as gaze position (x, y coordinates), gaze velocity, or pupil diameter.
Unlike genuine saccades or fixations, Eyer Peaks are artifacts of the data collection process rather than reflecting actual eye movements. They are characterized by their suddenness, short duration, and extreme amplitude. These peaks can significantly distort data analysis if not properly identified and handled.
Causes of Eyer Peaks can include:
- Blink Artifacts: Partial or complete eyelid closures momentarily obscuring the pupil.
- Data Loss: Temporary loss of the eye tracker's connection to the pupil.
- Glint Interference: Reflections of infrared light from glasses or other surfaces interfering with pupil detection.
- Head Movement: Significant head movements causing temporary tracking issues.
- Environmental Factors: Changes in lighting conditions or other environmental factors affecting pupil detection.
Strategies for mitigating the impact of Eyer Peaks on data analysis include:
- Data Smoothing: Applying smoothing algorithms to reduce the influence of outlier data points.
- Outlier Removal: Implementing algorithms to identify and remove data points that fall outside acceptable ranges.
- Blink Detection and Removal: Identifying and removing data segments corresponding to blinks.
- Data Interpolation: Replacing missing or corrupted data points with estimated values based on surrounding data.
- Proper Calibration: Ensuring accurate and stable calibration of the eye tracker.
Careful identification and handling of Eyer Peaks are crucial for obtaining accurate and reliable results from eye tracking studies. Ignoring these artifacts can lead to erroneous conclusions about visual behavior.