AUTHOR=Mulder Eric , Sieber Arne , Schagatay Erika TITLE=Corrigendum: Using Underwater Pulse Oximetry in Freediving to Extreme Depths to Study Risk of Hypoxic Blackout and Diving Response Phases JOURNAL=Frontiers in Physiology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.700804 DOI=10.3389/fphys.2021.700804 ISSN=1664-042X