  Standardizing terminology to describe electrophysiological events can improve
both clinical care and computational research. Sharing data enriched by such
standardized terminology can support advances in neuroscientific data
exploration, from single-subject to mega-analysis. Machine readability of
electrophysiological event annotations is essential for performing such
analyses efficiently across software tools and packages. Hierarchical Event
Descriptors (HED) provide a framework for describing events in neuroscience
experiments. HED library schemas extend the standard HED schema vocabulary to
include specialized vocabularies, such as standardized clinical terms for
electrophysiological events. The Standardized Computer-based Organized
Reporting of EEG (SCORE) defines terms for annotating EEG events, including
artifacts. This study makes SCORE machine-readable by incorporating it into a
HED library schema. We demonstrate the use of the HED-SCORE library schema to
annotate events in example EEG data stored in Brain Imaging Data Structure
(BIDS) format. Clinicians and researchers worldwide can now use the HED-SCORE
library schema to annotate and then compute on electrophysiological data
obtained from the human brain.
