1 Definition 2 Functional Requirements 3 Syntax 4 Semantics

1 Definition

A Neurophysiological Signal Qualifier specifies metadata describing a Neurophysiological Signal Data instance. It does not contain signal samples; instead, it provides information about:

  • the Sub‑Type of the neurophysiological signal (e.g., EEG‑Standard‑10‑20, MEG‑Magnetometers, fNIRS‑CW, EyeTracking‑Gaze2D),
  • the Format used to encode the signal (e.g., EDF, BDF, FIF, SNIRF, EyeLink ASC), and
  • additional Attributes required to interpret the data (e.g., channel names, units, sampling rate, sensor layout).

The Neurophysiological Signal Qualifier is used in conjunction with Neurophysiological Signal Data and is aggregated by the Neurophysiological Signal Object defined in MPAI‑AIH/HSP.

The combination of Neurophysiological Signal Data and Neurophysiological Signal Qualifier is called Neurophysiological Signal Object, specified by AIH-HSP V1.0.

2 Functional Requirements

Neurophysiological Signal Qualifier satisfies all the following requirements:

1. Sub‑Type Identification: The Qualifier shall specify the neurophysiological signal sub‑type (e.g., EEG‑10‑20, MEG‑Gradiometers, fNIRS‑CW, EyeTracking‑Gaze3D).

2. Format Identification: The Qualifier shall specify the format used to encode the Neurophysiological Signal Data (e.g., EDF, BDF, FIF, SNIRF, EyeLink EDF).

3. Separation from Data: The Qualifier shall not contain intrinsic signal samples; it shall only describe the data.

4. Interpretability of Data: The Qualifier shall provide sufficient metadata (e.g., channel semantics, units, sampling rate) to interpret the associated Neurophysiological Signal Data.

5. Device and Acquisition Context: The Qualifier may include information about the acquisition device, sensor layout, and recording context.

6. Modality‑Agnostic Design: The Qualifier shall support multiple neurophysiological modalities (e.g., EEG, MEG, fNIRS, EOG, eye‑tracking).

Users needing additional entries in the Physiological Signal Qualifier or support of new Qualifiers should make a documented request to the MPAI Secretariat. Requests will be considered by the appropriate MPAI committee.

3 Syntax

https://schemas.mpai.community/TFA/V1.5/data/NeurophysiologicalSignalQualifier.json

4 Semantics

  1. SubTypes

    • EEG (Electroencephalography)
      • EEG – 10–20 system
      • EEG – 10–10 system
      • High density EEG
      • Wearable / mobile EEG
      • Evoked Potential (EP)
        • Visual Evoked Potential (VEP)
        • Auditory Evoked Potential (AEP)
        • Somatosensory Evoked Potential (SSEP)
      • Event-Related Potential (ERP)
        • P300
        • N400
        • Mismatch Negativity (MMN)
      • Wearable / mobile EEG

      MEG (Magnetoencephalography)

      • MEG – magnetometers
      • MEG – gradiometers
      • MEG – combined systems (e.g., VectorView type)

      fNIRS (Functional Near Infrared Spectroscopy)

      • Continuous wave fNIRS (CW fNIRS)
      • Frequency domain fNIRS (FD fNIRS)
      • Time domain fNIRS (TD fNIRS)

      EOG (Electrooculography – neurophysiological use)

      • Horizontal/vertical EOG
      • Blink detection EOG

      Eye tracking

      • 2D gaze tracking
      • 3D gaze tracking
      • Pupilometry (pupil size waveform)
  2. Formats
    • EEG (Electroencephalography)
      • EEG – 10–20 system
        • BDF
        • EDF
        • EDF+
        • FIF
        • HDF5
        • MFF
        • SET
        • TRC
        • WFDB
      • EEG – 10–10 system
        • BDF
        • EDF
        • EDF+
        • FIF
        • HDF5
        • MFF
        • SET
        • TRC
        • WFDB
      • High‑density EEG
        • BDF
        • EDF
        • EDF+
        • FIF
        • HDF5
        • MFF
        • SET
        • TRC
        • WFDB
      • Wearable EEG
        • Formats:
        • BDF
        • EDF
        • EDF+
        • FIF
        • HDF5
        • MFF
        • OpenSignals
        • SET
        • WFDB
      • MEG (Magnetoencephalography)
        • MEG – magnetometers
          • CON
          • DS
          • FIF
          • HDF5
          • RAW
          • WFDB
        • MEG – gradiometers
          • CON
          • DS
          • FIF
          • HDF5
          • RAW
          • WFDB
        • MEG – combined systems (e.g., VectorView)
          • CON
          • DS
          • FIF
          • HDF5
          • RAW
          • WFDB
        • fNIRS (Functional Near‑Infrared Spectroscopy)
          • Continuous‑wave fNIRS (CW‑fNIRS)
            • HDF5
            • NIRS
            • OXY3
            • OXY4
            • SNIRF
            • TSV
            • WL1
            • WL2
          • Frequency‑domain fNIRS (FD‑fNIRS)
            • HDF5
            • NIRS
            • OXY3
            • OXY4
            • SNIRF
            • TSV
            • WL1
            • WL2
          • Time‑domain fNIRS (TD‑fNIRS)
            • HDF5
            • NIRS
            • OXY3
            • OXY4
            • SNIRF
            • TSV
            • WL1
            • WL2
          • EOG (Electrooculography)
            • Horizontal/vertical EOG
              • BDF
              • EDF
              • EDF+
              • HDF5
              • MFF
              • SET
              • TRC
              • WFDB
            • Blink detection EOG
              • BDF
              • EDF
              • EDF+
              • HDF5
              • MFF
              • SET
              • TRC
              • WFDB
            • Eye‑tracking
              • 2D gaze tracking
                • ASC
                • EDF
                • HDF5
                • IDF
                • PLDATA
                • TSV
              • 3D gaze tracking
                • ASC
                • EDF
                • HDF5
                • IDF
                • PLDATA
                • TSV
              • Pupilometry
              • ASC
              • EDF
              • HDF5
              • IDF
              • PLDATA
              • TSV

  3. Attributes

    • The following additional attributes are introduced for EP/ERP interpretation:
      • StimulusType – type of stimulus (visual, auditory, somatosensory)
      • StimulusTiming – timing relative to stimulus onset
      • AveragingMethod – averaging method used
      • Latency – waveform latency
      • Amplitude – waveform amplitude