Setting

Mount mode

Tripod Mount Mode

General laboratory protocol for the use of the Eyelink Portable Duo eye-tracker to be integrated with the specific protocol defined for the experiment.

For the General Provisions on anti-covid procedures to be adopted during the sessions consult the SPP Office of Unisi)

Procedures for the use of the Eyelink Portable Duo:

Before the participant arrives

Plug in the power supplies and turn on the HOST (the experimenter's workstation) and DISPLAY (the participant's workstation with the eye-tracker installed) computers at least 5 minutes prior to the arrival of the participant.
Make sure that the eye-tracker is connected via the Ethernet cable (pink cable, in the figure shown as blue) to the computer.
In case of experiments with tripod (TRIPOD MOUNT) follow this guide for mounting the eye-tracker on the stand. The eye-tracker should be positioned approximately 52cm from the subject.
Make sure that the room has the anti-covidium protection devices and follow the procedure described in the previous point.
In case the experiment involves the use of the subject's head mount (MOUNT), make sure that it is mounted in front of the DISPLAY pc so that the subject's eyes are about 42cm from the eyelink screen, (52cm from its inner chamber) and 62cm from the screen (see figure). Follow this guide for more info and support.

When the participant arrives

Greet the participant and introduce yourself.
Ask the participant to turn off his/her cell phone and all electronic devices.
Place the subject's personal items in the table in front of the pc station.
Have the participant sign the consent form, if required by the experiment.
Explain the experiment to the participant.
Have the participant sit comfortably in the chair. Adjust the height of the chair so that the eye line is level with the top of the monitor.
Adjust the height of the chin rest and forehead rest, if necessary.
Inform the subject that during the experiment he/she should maintain a firm position and avoid body movements.
Check the distance between the eye-tracker and the subject. For head-mounted experiments: The eye of the subject should be about 45 cm away from the front of the eye-tracker (62 cm from the PC screen). For remote experiments (head free and target on the forehead): about 52 cm between target and eye-tracker.
In case of doubt you can check the setting using the Calibration Coodintate Calculator.https://www.sr-research.com/calibration-coordinate-calculator/ (set Yes for Trackable Range Check and enter the correct DISPLAY screen size).

Calibration and Validation

If the experimenter wants to track the dominant eye, determine the dominant eye.
Dim or turn off the lights (if necessary).
Open the appropriate experiment folder in the DISPLAY computer. Click on the file with the .exe extension.
Press ENTER to start the eye-tracker camera setup mode. Press ENTER again to transfer the camera image to the PC Display (the screen in front of the subject).
Press the left and right arrows (⇒, ⇐) to select the zoomed or global view of the camera.
If it appears blurry focus the camera image by turning the thumb wheel located under the eye-tracker.
Set the threshold (pupil and corneal reflection area) with the 'A' key (and adjust with the ⇑ and ⇓ keys).
Make sure that the yellow circle touches the blue circle (pupil).
Have your subject follow your finger to each corner of the screen (top left, top right, etc.). Check to see if the pupil is still detected by the camera in each corner. If the pupil is not detected in some region of the screen, adjust the threshold or position of the participant until it is.
Press 'C' to begin calibration. Tell participants to wait until the target disappears to move their eye. Maintain fixation on the target until it disappears and then look at the next target. Also, ask the participant to fixate on the WHITE DOT inside the black circle.
Press ENTER to collect the first fixation. Allow the sequence to flow. Press ENTER to accept the result, 'ESC' to repeat. If calibration was successful continue with the Validation step.
Press 'V' to start the validation, press ENTER to collect the first fixation. Let the sequence run. Press ENTER when finished.
Repeat calibration if validation is poor (i.e., redo steps 20 and 21).
Press 'O' and ENTER to start the experiment and begin recording data.

During the experiment

Check the participant's behavior in the HOST monitor. If the trace becomes sparse at any point, and if the experiment allows inter-trial recalibration, recalibrate by pressing "C" (best at a time of stasis where no stimuli are presented). If the experiment does not allow inter-trial recalibration, record the time when the trace became sparse.
Fill in the participants' table with their information.
Note if anything interesting happens during the experiment (e.g., participant appears sleepy or confused, trace quality changes, etc.).

After the experiment

Deliver compensation to the participant, if provided.
If the experiment is created as an .exe, the data should be saved automatically after the experiment.
Upload the data to.
Follow the protocol for naming the spy file for your experiment
To turn off the external computer, press EXIT SETUP >> EXIT EYELINK, and then press the switch button.

Unplug the computers and the camera from the power outlet.

SHORTCUTS:

ENTER = to start the camera setting mode.

A = to set the threshold automatically.

C = to start calibration, press ENTER to collect the first fixation.

V = to start validation, press ENTER to collect the first fixation.

O O = to start data logging.

SUPPORT AND RESOURCES:

There is an excellent video for setting up the laptop mount on this page: https://www.sr-support.com/showthread.php?tid=30.

Link to the Calibration Coodintate Calculator: <https://www.sr-research.com/calibration-coordinate-calculator

If you need you can register for the Support Forum. You can do so at no cost here: https://www.sr-support.com/member.php?action=register.

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