Eyetracking (eye)

Following the guidelines from BEP020, we propose the following additional requirements for eyetracking data.

Modality specific data SHOULD be split into modality specific files carrying the modality-label. Modality label for eyetracking data is eye<#> as shown in the example below

physio/
├─ sub-01_ses-1_task-TaskName_recording-eye1_physio.json
├─ sub-01_ses-1_task-TaskName_recording-eye2_physio.json
├─ sub-01_ses-1_task-TaskName_recording-eye1_physio.tsv
├─ sub-01_ses-1_task-TaskName_recording-eye2_physio.tsv

For facilitating automated data processing, we REQUIRE “eye1” to correspond to the “left” eye, and “eye2” to correspond to the “right” eye.

Eyetracking Physiological Data

TSV file: <matches>_recording-eye1_physio.tsv

pupil_size  x-coordinate    y-coordinate
4.43498         515.3       257.1
4.43851         587.5       247.2
4.43910         586.2       247.9
4.43851         584.5       248.9
4.44028         583.5       248.9
4.44264         583.3       249.2
4.44499         583.7       248.9
4.44558         584.2       248.5

In case of compressed tabular files (like `.tsv.gz`) column names MUST NOT be included.

JSON sidecar: <matches>_recording-eye1_physio.json - Must include metadata as specified in BEP020.

Example of JSON sidecar:

{
"Columns": [
    "pupil_size",
    "x_coordinate",
    "y_coordinate"
],
"Manufacturer": "SR-Research",
"ManufacturersModelName": "EYELINK II CL v4.56 Aug 18 2010",
"RecordedEye": "left",
"StartTime": 0,
"SampleCoordinateSystem": "gaze-on-screen",
"SamplingFrequency": 500,
"pupil_size": {
    "Description": "Pupil diameter",
    "Units": "mm"
},
"x_coordinate": {
    "LongName": "Gaze position (x)",
    "Description": "Gaze position x-coordinate of the recorded eye",
    "Units": "pixel"
},
"y_coordinate": {
    "LongName": "Gaze position (y)",
    "Description": "Gaze position y-coordinate of the recorded eye",
    "Units": "pixel"
},
"BestEye": "l",
"PupilFitMethod": "ellipse",
"GazeRange": {
    "xmin": 0,
    "ymin": 0,
    "xmax": 1023,
    "ymax": 767
},
"RecordingDuration": 597.102
}

Eyetracking Events

The eyetracking “physioevents” file contains information about physiological events detected by the eyetracker during the session.

Files: - <matches>_physioevents.tsv - <matches>_physioevents.json