EyeLink II Training Session Copyright of SR Research Ltd., Eye Link II System Introduction and Basic Training Session SR Research Ltd. Mississauga - Ottawa, Canada

EyeLink II Training Session Copyright of SR Research Ltd., Agenda n Functional System Overview n System Architecture n Eye Tracking Experiment Process n Software Architecture n EyeLink EDF Data/Data Viewer n EyeLink Gaze Overlay n EyeLink Support

EyeLink II Training Session Copyright of SR Research Ltd., Binocular / Monocular 250 / 500Hz Corneal Reflection vs. Pupil Only Head tracking / Head-free Recording Real-time Data Access Windows API and Experiment Builder Functional System overview

EyeLink II Training Session Copyright of SR Research Ltd., EyeLink II High Speed Eye Tracking System EyeLink II Key Features High Speed – Binocular Recording at sampling rate of 250 or 500Hz. Exceptional Resolution <0.01°, and low noise <0.01° RMS. Accurate - Average gaze position error <0.5°. 2 Modes of Operation - Pupil-Only or Pupil-Corneal. Headband assembly is lightweight robust and ergonomic. Compatible with most eyeglasses and contact lenses. Easy Set-up, Calibration, and Validation. Real-time operator feedback. Online analysis of data into saccades, fixations, and blinks. Powerful Application Programming Interface (API). Compatible with EyeLink I applications.

EyeLink II Training Session Copyright of SR Research Ltd., System System architecture Host PC  Data flow / integration  Display PC

EyeLink II Training Session Copyright of SR Research Ltd., Host Application n Runs on ROM DOS environment n Performs image analysis, eye event parsing, and data recording functions n Allows the system operator to view real-time gaze position overlaid on a static display representation while data recording is being performed n Allows preference selection, camera setup, calibration, and recording functions n Facilitates for the selection of 5 different calibration types (3pt - 13pt)

EyeLink II Training Session Copyright of SR Research Ltd., Display API n Integrates calibration, gaze position collection, head position compensation, and saccade and fixation analysis into one step n Gaze position is overlaid on experiment graphics in real time, allowing validation of calibration accuracy before recording and monitoring of data quality during data collection n Perform drift correction at any time n Time stamped experiment event messaging; Dedicated Ethernet connection between Host and Display so no data is lost n Allows the user to focus on stimulus presentation and data analysis

EyeLink II Training Session Copyright of SR Research Ltd., Pre-Experiment activities Participant setup Calibration Validation Running the experiment Drift correction Trials Blocks Recording and Data Acquisition Data analysis Eye Tracking experiment process

EyeLink II Training Session Copyright of SR Research Ltd., Pre-Experimental Activities n EyeLink II is provided with several system configuration (.ini) files, which are designed to help the Experimenter control the tracker. n Before starting recording eye movements, it is critical to properly set-up the eyes and head cameras, and to calibrated/validate the subject. n A poor system set-up will result in a low data accuracy. n One of the most useful screens is called Set Options. Often it is overlooked.

EyeLink II Training Session Copyright of SR Research Ltd., Pre-Experimental Activities

EyeLink II Training Session Copyright of SR Research Ltd.,

EyeLink II Training Session Copyright of SR Research Ltd., Participant Setup - Headband The Headband placement becomes a smooth and fast procedure with practise: learn on yourself and test on colleagues before running an experiment. It should take less than 2 days of practise.

EyeLink II Training Session Copyright of SR Research Ltd., Participant Setup - Eye Cameras

EyeLink II Training Session Copyright of SR Research Ltd., Participant Setup - Head Camera Please, adjust the monitor or participants height till you reach this result

EyeLink II Training Session Copyright of SR Research Ltd., Optimal Too FarToo Close Camera too HighCamera too Low Pupil too HighPupil too Low Participant Setup - Optimal Eye View

EyeLink II Training Session Copyright of SR Research Ltd., Participant Setup - Eye in Focus Not focusedFocused

EyeLink II Training Session Copyright of SR Research Ltd., The pupil threshold can be adjusted automatically, through the Auto-threshold command, or manually, through the up/down arrow. A threshold too low will result in shadows (fig.1), while a threshold too high will result in a noisy signal (fig. 2). Fig. 1 Fig. 2 Participant Setup - Eye Threshold

EyeLink II Training Session Copyright of SR Research Ltd., Calibration Experiment Setup

EyeLink II Training Session Copyright of SR Research Ltd., Experiment Setup Calibration Good poor

EyeLink II Training Session Copyright of SR Research Ltd., Experiment Setup Validation

EyeLink II Training Session Copyright of SR Research Ltd., Experiment Setup Validation GoodPoor

EyeLink II Training Session Copyright of SR Research Ltd., Trials: Smallest unit or presentation of a display Try to perform a drift correction for each trial Blocks: Many trials make up a block. Try to arrange a short break between blocks and check whether re-calibration is necessary. Data Recording Data Analysis – Selective filtering based on application Running Experiment

EyeLink II Training Session Copyright of SR Research Ltd., Running Experiment Drift correction

EyeLink II Training Session Copyright of SR Research Ltd., Running Experiment Avoiding Large Drifts Headband slippage Make sure that headband is not placed too far forward Suspend the cable from above the subject or clip it to the back of the subject's collar Head or Body Movements Sit still and avoid major head/body movements Use chin-rest Supply a comfortable, stable chair Pupil Occlusion Check the positions and alignments of the camera and subjects' eye positions

EyeLink II Training Session Copyright of SR Research Ltd., EyeLink Recording Data EDF File Use EDF2ASC converter to get ASC file Use EyeLink Data Viewer for analysis What’s recorded? Samples Events Messages Buttons Saccades Fixations Blinks

EyeLink II Training Session Copyright of SR Research Ltd., MSG TRIALID PIX1 Normal START RIGHTEVENTS PUPILAREA EVENTSGAZERIGHTTRACKINGPFILTER2 SFIX R MSG DISPLAY ON MSG SYNCTIME 3 BUTTON EFIX R SSACC R ESACC R SFIX R MSG TIMEOUT EFIX R END EVENTRES MSG TRIAL_RESULT 0 MSG TRIAL OK EyeLink Recording Data ASC File structure

EyeLink II Training Session Copyright of SR Research Ltd., EyeLink Recording Data (Please read chapter 4 of the user manual) Samples: System time, x, y and pupil size With additional velocity, resolution, and CR status

EyeLink II Training Session Copyright of SR Research Ltd., EyeLink Recording Data Saccades: SSACC: eye, start time ESACC: eye, start and end times, duration, start x/y, end x/y, saccade size, and additionally peak velocity, resolution SSACC L SSACC R ESACC L ESACC R (Please read chapter 4 of the user manual)

EyeLink II Training Session Copyright of SR Research Ltd., EyeLink Recording Data Fixations: SFIX: eye, start time EFIX: eye, start and end times, duration, average x/y, pupil size, and additionally, resolution SFIX L SFIX R EFIX R EFIX L (Please read chapter 4 of the user manual)

EyeLink II Training Session Copyright of SR Research Ltd., Data Viewer

EyeLink II Training Session Copyright of SR Research Ltd., Data Viewer n Three different viewing modes n Spatial, Temporal and Gaze Cursor Playback n Output detailed reports n Fixation, Saccade, Interest Area, or Trial n Export Data Views as JPG images n Import multiple recording files into one viewing session n Supports EyeLink I, II, 1000/2k, and Remote EDF files n Fully integrated with API

EyeLink II Training Session Copyright of SR Research Ltd., Data Viewer

EyeLink II Training Session Copyright of SR Research Ltd., Data Viewer n Generate detailed Fixation, Saccade, Interest Area and Trial reports for further analysis

EyeLink II Training Session Copyright of SR Research Ltd., Data Viewer n Create ‘Interest Periods’ to analyze data within a specified period of time n Define ‘Reaction Time Definitions’ for automatic trial by trial reaction time calculation Monitoring eye data over time

EyeLink II Training Session Copyright of SR Research Ltd., For more detailed information on our products and services, visit our website on or Send us an or call toll free (North America Only) EyeLink Support

EyeLink II Training Session Copyright of SR Research Ltd., EyeLink Support

EyeLink II Training Session Copyright of SR Research Ltd., We will take a short break. Then it’s your turn to get eyetracking!