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Behavioral experiments (with no neural recordings)

Example datasets

Datasets containing behavioral data can be found in the BIDS examples repository and can be used as helpful guidance when curating new datasets.

Template:

Legend:
  • For more information about filename elements (for example, entities, suffixes, extensions), follow the links embedded in the filename template.

  • Filename entities or directories between square brackets (for example, [_ses-<label>]) are OPTIONAL.

  • Some entities may only allow specific values, in which case those values are listed in <>, separated by |.

  • _<suffix> means that there are several (>6) valid suffixes for this filename pattern.

  • .<extension> means that there are several (>6) valid extensions for this file type.

  • [.gz] means that both the unzipped and gzipped versions of the extension are valid.

In addition to logs from behavioral experiments performed alongside imaging data acquisitions, one MAY also include data from experiments performed with no neural recordings. The results of those experiments MAY be stored in the beh directory using the same formats for event timing (_events.tsv), metadata (_events.json), physiological (_physio.tsv.gz, _physio.json) and other continuous recordings (_stim.tsv.gz, _stim.json) as for tasks performed during MRI, electrophysiological or other neural recordings. Additionally, events files that do not include the mandatory onset and duration columns MAY be included, but MUST be labeled _beh.tsv rather than _events.tsv.

The following OPTIONAL columns are pre-defined for behavioral data files:

Column name Requirement Level Data type Description
trial_type OPTIONAL string Primary categorisation of each trial to identify them as instances of the experimental conditions. For example: for a response inhibition task, it could take on values go and no-go to refer to response initiation and response inhibition experimental conditions.
response_time OPTIONAL number Response time measured in seconds. A negative response time can be used to represent preemptive responses and n/a denotes a missed response.
HED OPTIONAL string Hierarchical Event Descriptor (HED) Tag. See the HED Appendix for details.
stim_file OPTIONAL string Represents the location of the stimulus file (such as an image, video, or audio file) presented at the given onset time. There are no restrictions on the file formats of the stimuli files, but they should be stored in the /stimuli directory (under the root directory of the dataset; with OPTIONAL subdirectories). The values under the stim_file column correspond to a path relative to /stimuli. For example images/cat03.jpg will be translated to /stimuli/images/cat03.jpg.
Additional Columns OPTIONAL n/a Additional columns are allowed.

Sidecar JSON (*_beh.json)

In addition to the metadata that is either:

  • RECOMMENDED for sidecar JSON files for tabular data, or

  • REQUIRED for some data that can be found in the beh directory (for example SamplingFrequency and StartTime for *_<physio|stim>.tsv.gz files),

it is RECOMMENDED to add the following metadata to the JSON files of this directory.

Task information

Key name Requirement Level Data type Description
TaskName RECOMMENDED string Name of the task. No two tasks should have the same name. The task label included in the filename is derived from this "TaskName" field by removing all non-alphanumeric characters (that is, all except those matching [0-9a-zA-Z]). For example "TaskName" "faces n-back" or "head nodding" will correspond to task labels facesnback and headnodding, respectively.
Instructions RECOMMENDED string Text of the instructions given to participants before the recording.
TaskDescription RECOMMENDED string Longer description of the task.
CogAtlasID RECOMMENDED string URI of the corresponding Cognitive Atlas Task term.
CogPOID RECOMMENDED string URI of the corresponding CogPO term.

Institution information

Key name Requirement Level Data type Description
InstitutionName RECOMMENDED string The name of the institution in charge of the equipment that produced the measurements.
InstitutionAddress RECOMMENDED string The address of the institution in charge of the equipment that produced the measurements.
InstitutionalDepartmentName RECOMMENDED string The department in the institution in charge of the equipment that produced the measurements.

Example _beh.tsv

trial   response    response_time   stim_file
congruent   red 1.435   images/word-red_color-red.jpg
incongruent red 1.739   images/word-red_color-blue.jpg

In the accompanying JSON sidecar, the trial column might be documented as follows:

{
   "TaskName": "Stroop",
   "trial": {
      "LongName": "Trial name",
      "Description": "Indicator of the type of trial",
      "Levels": {
         "congruent": "Word and font color match.",
         "incongruent": "Word and font color do not match."
      }
   }
}