HED schemas

Welcome to the HED (Hierarchical Event Descriptors) schemas documentation! This repository contains the official HED vocabulary schemas in multiple formats. HED is a standardized vocabulary and annotation framework designed to systematically describe events in experimental data, particularly neuroimaging and behavioral data. HED is integrated into major neuroimaging standards:

  • BIDS (Brain Imaging Data Structure)

  • NWB (Neurodata Without Borders)

Key features

  • Standard schema: Base HED vocabulary used across all domains

  • Library schemas: Specialized vocabularies for specific research areas (clinical, linguistic, etc.)

  • Multiple formats: Available in MediaWiki, XML, JSON, and TSV formats

  • Version control: Comprehensive versioning with DOIs for reproducibility

  • Open development: Community-driven schema evolution

Working with HED schemas