HED — Hierarchical Event Descriptors
Overview
HED (Hierarchical Event Descriptors) is a structured annotation system for describing experimental events in neuroscience data. It provides a hierarchical, machine-readable vocabulary allowing researchers to annotate what happened during a recording in a standardised way that supports automated analysis and cross-dataset comparison. HED is integrated into BIDS event files and endorsed by INCF. The clinical EEG terminology SCORE (Standardized Computer-based Organized Reporting of EEG) has been encoded as a HED library schema, extending HED annotation to seizure and clinical EEG events.
Adoption
A large-scale example of HED is the Healthy Brain Network EEG release produced by the Child Mind Institute, a multi-release BIDS dataset of EEG from thousands of children and adolescents with full HED event annotation, hosted on OpenNeuro and NEMAR.
Connections
- endorsedBy: INCF
- implements: SCORE (the HED-SCORE library schema encodes SCORE clinical EEG terminology as a HED library schema)
- relatedTo: BIDS (HED event annotations integrated into BIDS event files)
- relatedTo: NWB (HED annotations supported for NWB event data)
Resources
- https://www.hedtags.org
- https://github.com/hed-standard (GitHub organisation)
- https://hed-specification.readthedocs.io (HED specification documentation)
- https://doi.org/10.1038/s41597-021-00988-0 (Robbins et al. 2021, Scientific Data)