TOC.md

2 Table of contents

1 Changelog

2 Table of contents

3 Introduction

3.1 Motivation 3.2 Definitions 3.3 Compulsory, optional, and additional data and metadata 3.4 Source vs. raw vs. derived data 3.5 The Inheritance Principle 3.6 Extensions 3.7 Citing BIDS

4 File Format specification

4.1 Imaging files 4.2 Tabular files

4.2.1 Example: 4.2.2 Example:

4.3 Key/value files (dictionaries)

4.3.1 Example:

5 Participant names and other labels

6 Units

7 Directory structure

7.1 Single session example

8 Detailed file descriptions

8.1 Dataset description

8.1.1 dataset_description.json 8.1.2 README 8.1.3 CHANGES

8.2 Code 8.3 Magnetic Resonance Imaging data

8.3.1 Common metadata fields 8.3.2 Anatomy imaging data 8.3.3 Task (including resting state) imaging data

8.3.3.1 Example:

8.3.4 Diffusion imaging data

8.3.4.1 bvec example: 8.3.4.2 bval example: 8.3.4.3 JSON example:

8.3.5 Fieldmap data

8.3.5.1 Case 1: Phase difference image and at least one magnitude image 8.3.5.2 Case 2: Two phase images and two magnitude images 8.3.5.3 Case 3: A single, real fieldmap image (showing the field inhomogeneity in each voxel) 8.3.5.4 Case 4: Multiple phase encoded directions (“pepolar”)

8.4 Magnetoencephalography (MEG)

8.4.1 MEG recording data

8.4.1.1 Sidecar JSON document (*_meg.json)

8.4.2 Channels description table (*_channels.tsv) 8.4.3 Coordinate System JSON document (*_coordsystem.json) 8.4.4 Photos of the anatomical landmarks and/or head localization coils (*_photo.jpg) 8.4.5 3-D head point /electrode locations file (*_headshape.<manufacturer_specific_format>) 8.4.6 Empty-room files (sub-emptyroom)

8.5 Task events

8.5.1 Example: 8.5.2 Example: 8.5.3 Example:

8.6 Physiological and other continuous recordings

8.6.1 Example:

8.7 Behavioral experiments (with no MRI)

8.8 Scans file

8.8.1 Example:

8.9 Participant file

8.9.1 participants.tsv example:

9 Longitudinal studies with multiple sessions (visits)

9.1 Sessions file

9.1.1 Multiple sessions example:

10 Multi-site or multi-center studies

10.1 Option 1: Treat each site/center as a separate dataset. 10.2 Option 2: Combining sites/centers into one dataset

11 Appendix I: Contributors

12 Appendix II: Licenses

13 Appendix III: Hierarchical Event Descriptor (HED) Tags

13.1 Example: 13.2 Example:

14 Appendix IV: Entity table

15 Appendix V: Units

16 Appendix  VI: MEG file formats

16.1 CTF 16.2 Elekta/Neuromag 16.3 4D neuroimaging/BTi 16.4 KIT/Yokogawa 16.5 KRISS 16.6 ITAB 16.7 Aalto/MEG–MRI

17 Appendix VII: preferred names of MEG systems

18 Appendix VIII: preferred names of Coordinate systems

18.1 MEG specific Coordinate Systems 18.2 EEG specific Coordinate Systems 18.2 Template based Coordinate Systems