## **Annotating the timeline of neuroimaging time series data using Hierarchical Event Descriptors (HED)** ##
**Scott Makeig**, University of California San Diego
**Relevant work:** Robbins et al. (2021) [HED NeuroImage paper][1] and the Robbins et al. (2021) [NeuroInfomatics paper][2].
**Software/program requirements:** An extensive set of tutorials and examples are contained [here][3] including [this Quickstart][4] information mentioned in the talk. The HED GitHub page is [here][5]. The example in the talk uses the HED online tools, which can be found [here][6]. The source code for CTagger is [here][7] and the documentation for CTagger is [here][8]. The code for fitlins is [here][9].
**Datasets:** Example HED datasets are [here][10]
**Modalities:** M/EEG, fMRI
**Abstract:**
For historical reasons, accepted standards for annotating a complete and detailed answer to the question, What happened during the recording?,' have remained minimal. Unfortunately, timeline event annotations in currently archived time series neuroimaging datasets are insufficient for supporting detailed, advanced and/or cross-study large-scale data analysis. The Hierarchical Event Descriptors (HED) system, first proposed in 2013, was accepted into all the BIDS modality standards in 2019. Recently, new (3rd-generation) HED specification, schema, and software tools have been released by our HED Working Group. We will demonstrate working examples of annotating EEG/MEG an IMRI datasets using HED, and will illustrate uses of the resulting HED annotations in data search, extraction, and analysis.
[1]: https://doi.org/10.1016/j.neuroimage.2021.118766
[2]: https://link.springer.com/article/10.1007/s12021-021-09537-4
[3]: https://hed-examples.readthedocs.io/en/latest/
[4]: https://hed-examples.readthedocs.io/en/latest/HedAnnotationQuickstart.html
[5]: https://github.com/hed-standard
[6]: https://hedtools.ucsd.edu/hed
[7]: https://github.com/hed-standard/CTagger/
[8]: https://ctagger.readthedocs.io/_/downloads/en/latest/pdf/
[9]: https://github.com/poldracklab/fitlins
[10]: https://github.com/hed-standard/hed-examples
