Overview

EyeTrackerAnalyzer is a MATLAB toolbox dedicated to analyzing eye-tracking data saved in EDF files (as outputted by SR Research Eyelink). The toolbox can be interfaced via an API (Application Programming Interface - A bundle of MATLAB functions that constitute EyeTrackerAnalyzer's operations), or via a MATLAB GUI (Graphical User Interface). With EyeTrackerAnalyzer you can extract from the eye-tracking data the following elements:

• Saccades - Rapid eye movements. The saccades are extracted using an adapted version of Enbgert & Kliegl's (2003) algorithm for microsaccade detection. The toolbox detects the saccades and extracts the following variables for each one:

• Onset
• Duration
• Amplitude
• Direction
• Velocity

• Fixations - Defined as segments of valid eye samples that are not part of a saccade or a blink. Calculated variables per fixation:

• Onset
• Duration
• Position

• Pupil size- As reported directly by the eye-tracker.

• Blinks - Can be extracted directly as reported by the eye tracker or based on pupil size data.

The toolbox additionally allows for visual inspection of detection quality and manual overriding of detected saccades in order to correct for misses and false alarms.

EyeTrackerAnalyzer outputs all results into a .mat struct file, arranged by condition (according to triggers) and trials (segments), while additionally generating several figures (per condition and aggregated across conditions):

• Saccadic rate - the probability for a saccade onset as a function of time
• Average saccade amplitude per direction (polar plot)
• Saccades number per direction (rose plot)
• Main sequence - saccade amplitude as a function of saccade velocity