Eye tracker - natmegsweden/NatMEG_Wiki GitHub Wiki

Eye-tracker

For details on how to set-up Eye-tracker consult the User manual which is also available in the locker behind the MSR-cabinet.

Equipment required

  • The screen
  • Eye-tracker

You will also need some lines of code in your Presentation scripts to initiate the eye-tracker, start calibration procedure and start recording.

Before measurement

  1. Put screen in correct position (see Screen and projector)
  2. Start eye-tracker software by pressing the letter t on the keyboard, then press enter

! If you do not see a terminal on the eye-tracking PC when you turn on the screen

  • Check that the screen setting of the Stimulation PC is not set in dual screen mode and that the correct input channel is selected
  • Check that the eye-tracking computer is turned on. The computer is found at the bottom of the stimulation cabinet

! To start eye-tracker in simulation mode type t -x and press enter

  1. Make sure you have the right configuration for your needs and that the corneal reflection (CR) and pupil thresholds are set.
  2. Adjust eye-tracker by moving the arm or by tilting the screen a bit.
  3. Make sure MISC-channels 1-6 are activated in Acquisition settings. This is where ET-data is stored.

Calibration and validation

When participant is seated in the MSR, calibrate the system then validate your calibration.

During measurement

  1. Monitor eye-positions

! As participants tend to sink down a bit during recordings eye-tracking may be lost if not chair is raised properly ! If using the table, make sure pads or participant's hands are not blocking the eye-tracker

  1. Check calibration

After measurement

  1. Turn off eye-tracking software
  2. Remove eye-tracker and put back in box

Eye-tracking data is saved accordingly:

  • MISC001 = X Left
  • MISC002 = Y Left
  • MISC003 = Pupil Left
  • MISC004 = X Right
  • MISC005 = Y Right
  • MISC006 = Pupil Right

Issues

The eye-tracking program is beeping and blinking

The eye-tracker has been disconnected from the cables in the MSR. Reconnect the eye-tracker or close the eye-tracking program.

Eyes look blurry and the pupils are not detected.

Check that the participant's hands or paddings are not blocking the camera.