Events (Super-BIDS)

The events modality in PRISM enforces a “Super-BIDS” standard. While standard BIDS allows for minimal event files, PRISM requires detailed provenance about the stimulus presentation software to ensure reproducibility.

File Name Structure

Event files MUST follow the standard BIDS naming convention:

sub-<label>[_ses-<label>]_task-<label>[_run-<index>]_events.tsv

Sidecar JSON (*_events.json)

PRISM enforces strict requirements on the JSON sidecar associated with the events file.

StimulusPresentation Object

This object is MANDATORY in PRISM (though optional in standard BIDS). It describes the software and hardware used to present stimuli.

Key	Requirement	Type	Description
OperatingSystem	REQUIRED	string	The operating system used (e.g., "Windows 10", "macOS 12.4").
SoftwareName	REQUIRED	string	The name of the presentation software (e.g., "PsychoPy", "Presentation").
SoftwareVersion	RECOMMENDED	string	The specific version used (e.g., "2023.1.0").
SoftwareRRID	RECOMMENDED	string	Research Resource Identifier (e.g., "SCR_006571").
Code	OPTIONAL	string	URL to the experiment code repository.

Column Definitions

Standard BIDS column definitions are supported and validated.

Key	Description
onset	Description of the onset column.
duration	Description of the duration column.
trial_type	Description of the trial_type column.

Example Sidecar

{
  "StimulusPresentation": {
    "OperatingSystem": "macOS 14.0",
    "SoftwareName": "PsychoPy",
    "SoftwareVersion": "2023.2.3",
    "SoftwareRRID": "SCR_006571",
    "Code": "https://github.com/lab/experiment-repo"
  },
  "trial_type": {
    "LongName": "Event category",
    "Description": "Category of the presented stimulus",
    "Levels": {
      "face": "Face image",
      "house": "House image"
    }
  }
}