By Cyril Pernet, Dora Hermes, Chris Holdgraf
We are happy to announce that the Brain Imaging Data Structure (BIDS) now supports all of the major electrophysiology modalities in human neuroscience. This means that EEG, MEG, and iEEG researchers can all store their data in a BIDS-compliant manner, making these datasets more shareable, understandable, and re-usable. This post describes the BIDS standard in general and the community around it, as well as recent changes that have brought support for electrophysiology.
The Brain Imaging Data Structure: BIDS
BIDS is a standard that specifies how to organize data in different folders, how to name files and how to document metadata (i.e. information about the data). It does this using community standards and dictionaries enabling efficient communication and collaboration between data users. Details about BIDS can be found at http://bids.neuroimaging.io/.
BIDS is an initiative that arose as a specific action taken in response to deliberations of the INCF, NeuroImaging Data Sharing Task Force (NIDASH), along with the NeuroImaging Data Model. NIDM is a Semantic Web-based metadata standard that helps capture and describe experimental data, analytic workflows and statistical results that complement BIDS.
With seeds planted in January 2015, BIDS started in September after being presented at the OHBM (June) and INCF (August) annual conferences and has rapidly been taken up by our community – starting with a specification related to sharing MRI data (basic structural, functional and diffusion) submitted in December 2015 and followed by a growing number of extensions into various modalities. The analysis of a recent survey done by the Stanford Centre for reproducible neuroscience lead to a current estimate of over 65000 subjects’ data stored and/or shared using BIDS.
Building bridges with the electrophysiology communities
In 2016, MEG BIDS was published describing how to organize and share MEG data and metadata. Right after that, Cyril Pernet used the open science space during the annual OHBM meeting in Vancouver (2016) calling for an EEG-BIDS. The first draft was done the following week with the help of Robert Oostenveld during an EEGLAB workshop. Simultaneously, the iEEG community had a need to organize and share data in a standard that matches MRI, MEG and EEG data, so Dora Hermes and Chris Holdgraf developed the iEEG-BIDS extension. For almost 2 years, the two teams developed the standards, while checking with others for consistency, with some help from the MEG-BIDS team. This work culminated with two papers published in the journal Scientific Data (Holdgraf et al., 2019, Pernet et al., 2019). Concretely, this means human brain electrophysiology data sharing is fully harmonized thanks to the effort and collaborative spirit of all involved. It also means that about 2/3 of all functional imaging data can now be organized, documented and shared efficiently (with the exception of PET, NIRS, TMS and dTCS, 34.7% of publications since January 2018 according to our PubMed search).