Skip to content

Physiological and other continuous recordings



Optional: Yes

For the template directory name, <datatype> can correspond to any data recording modality, for example func, anat, dwi, meg, eeg, ieeg, or beh.

In the template file names, the <matches> part corresponds to task file name before the suffix. For example for the file sub-control01_task-nback_run-1_bold.nii.gz, <matches> would correspond to sub-control01_task-nback_run-1.

The recording-<label> entity can be used to distinguish between several recording files. For example sub-01_task-bart_recording-eyetracking_physio.tsv.gz to contain the eyetracking data in a certain sampling frequency, and sub-01_task-bart_recording-breathing_physio.tsv.gz to contain respiratory measurements in a different sampling frequency.

Physiological recordings (including eyetracking) SHOULD use the _physio suffix, and signals related to the stimulus SHOULD use _stim suffix.

Physiological recordings such as cardiac and respiratory signals and other continuous measures (such as parameters of a film or audio stimuli) can be specified using two files: a gzip compressed TSV file with data (without header line) and a JSON for storing the following metadata fields:

Note that when supplying a *_<physio|stim>.tsv.gz file, an accompanying *_<physio|stim>.json MUST be supplied as well.

Key name Requirement level Data type Description
SamplingFrequency REQUIRED number Sampling frequency in Hz of all columns in the file.
StartTime REQUIRED number Start time in seconds in relation to the start of acquisition of the first data sample in the corresponding neural dataset (negative values are allowed).
Columns REQUIRED array of strings Names of columns in file.

Additional metadata may be included as in any TSV file to specify, for example, the units of the recorded time series. Please note that, in contrast to other TSV files in BIDS, the TSV files specified for phsyiological and other continuous recordings do not include a header line. Instead the name of columns are specified in the JSON file. This is to improve compatibility with existing software (for example, FSL, PNM) as well as to make support for other file formats possible in the future.

Example *_physio.tsv.gz:


(after decompression)

34    110    0
44    112    0
23    100    1

Example *_physio.json:

   "SamplingFrequency": 100.0,
   "StartTime": -22.345,
   "Columns": ["cardiac", "respiratory", "trigger"],
   "cardiac": {
       "Units": "mV"

Recommendations for specific use cases

To store pulse or breathing measurements, or the scanner trigger signal, the following naming conventions SHOULD be used for the column names:

Column name Description
cardiac continuous pulse measurement
respiratory continuous breathing measurement
trigger continuous measurement of the scanner trigger signal

For any other data to be specified in columns, the column names can be chosen as deemed appropriate by the researcher.

Recordings with different sampling frequencies and/or starting times should be stored in separate files.

If the same continuous recording has been used for all subjects (for example in the case where they all watched the same movie), one file MAY be used and placed in the root directory. For example, task-movie_stim.tsv.gz

For motion parameters acquired from MRI scanner side motion correction, the _physio suffix SHOULD be used.

For multi-echo data, a given physio.tsv file is applicable to all echos of a particular run. For example: