EyeLink Device¶

Available on macOS

Description¶

Digital interface to an EyeLink eye tracker. Tested with the EyeLink 1000/1000 Plus and EyeLink II trackers, but may be compatible with additional devices.

If the tracker is run in binocular mode, eye_x, eye_y, and eye_z give the midpoint of the shortest connecting line that is orthogonal to both gaze vectors; otherwise, these values will be empty. All other output parameters are specified and described in the EyeLink 1000 User Manual. If an eye tracker packet contains no data for a parameter, EyeLink’s MISSING_DATA value (-32768) is written to the corresponding variable.

Calibration

In order to perform a tracker-driven calibration, validation, or drift correction, you must arrange for the drawing of a fixation target on MWorks’ stimulus display at locations and times controlled by the tracker. This is accomplished via the parameters cal_target_x, cal_target_y, and cal_target_visible, as demonstrated in the following example:

// cal_target_x and cal_target_y receive the location of the
// fixation target

var cal_target_x = 0
var cal_target_y = 0

circle cal_target (
    color = 1,0,0
    x_size = 1
    x_position = cal_target_x
    y_position = cal_target_y
    )

// cal_target_visible receives the signal to show or hide
// the fixation target.  Attached actions draw or remove
// the target as appropriate.

var cal_target_visible (false) {
    choose {
        when (cal_target_visible) {
            queue_stimulus (cal_target)
            update_display ()
        }
        otherwise {
            clear_display ()
        }
    }
}

// All three variable names must be provided as parameters
// in the device declaration

iodevice/eyelink eyelink (
    ...
    cal_target_x = cal_target_x
    cal_target_y = cal_target_y
    cal_target_visible = cal_target_visible
    ...
    )

To initiate a calibration, validation, or drift correction, use the EyeLink Tracker Setup action:

eyelink_tracker_setup (
    device = eyelink
    calibration_type = HV13
    )

Signature¶

iodevice/eyelink

Required Parameters¶

tracker_ip¶

Example:: 100.1.1.1

The tracker’s IP address

data_interval¶

Example:: 1ms

Data polling interval. Should not be too short, but faster than tracker’s sampling rate.

Optional Parameters¶

tracking_dist¶

Example:: 1024

Tracking range in eye tracker units. (The default value should be 1024.)

Required to compute eye_x, eye_y, and eye_z.

eye_rx¶

Variable in which to store right eye screen gaze x

eye_ry¶

Variable in which to store right eye screen gaze y

eye_lx¶

Variable in which to store left eye screen gaze x

eye_ly¶

Variable in which to store left eye screen gaze y

eye_x¶

Variable in which to store computed eye_x (described above)

eye_y¶

Variable in which to store computed eye_y (described above)

eye_z¶

Variable in which to store computed eye_z (described above)

href_rx¶

Variable in which to store right eye headref x

href_ry¶

Variable in which to store right eye headref y

href_lx¶

Variable in which to store left eye headref x

href_ly¶

Variable in which to store left eye headref y

pupil_rx¶

Variable in which to store right eye pupil x

pupil_ry¶

Variable in which to store right eye pupil y

pupil_lx¶

Variable in which to store left eye pupil x

pupil_ly¶

Variable in which to store left eye pupil y

pupil_size_r¶

Variable in which to store right pupil size or area

pupil_size_l¶

Variable in which to store left pupil size or area

blink_r¶

Variable in which to store right eye blink state (true when blinking, false otherwise)

blink_l¶

Variable in which to store left eye blink state (true when blinking, false otherwise)

saccade_r¶

Variable in which to store right eye saccade state (true when in saccade, false otherwise)

saccade_l¶

Variable in which to store left eye saccade state (true when in saccade, false otherwise)

fixation_r¶

Variable in which to store right eye fixation state (true when fixating, false otherwise)

fixation_l¶

Variable in which to store left eye fixation state (true when fixating, false otherwise)

cal_target_x¶

Variable in which to store calibration target x coordinate

cal_target_y¶

Variable in which to store calibration target y coordinate

cal_target_visible¶

Variable in which to store calibration target visibility state (true when the target should be visible, false when it should be hidden)

eye_time¶

Variable in which to store time of sample (on EyeLink clock)

display¶

Name of the display on which to perform tracker-driven calibration. If omitted, the default display (if available) will be used.

autostart¶

Default:: NO

If YES, the device will start I/O automatically (as if by an implicit Start IO Device action) when the experiment starts running.

Note: Device I/O will always stop automatically when the experiment stops running, irrespective of this setting.

alt¶

Alternative device to use if this one fails to initialize (e.g. because the required hardware is not available). If #allowAltFailover is set to 0 or false, this parameter is ignored.

Placement¶

Allowed at top level:	Yes
Allowed parent:	Folder