This book constitutes the refereed proceedings of 14th International Conference on Augmented Cognition, AC 2020, held as part of the 22nd International Conference on Human-Computer Interaction, HCII 2020, in July 2020. The conference was planned to be held in Copenhagen, Denmark, but had to change to a virtual conference mode due to the COVID-19 pandemic.From a total of 6326 submissions, a total of 1439 papers and 238 posters has been accepted for publication in the HCII 2020 proceedings.The 21 papers presented in this volume were organized in topical sections as follows: cognitive modeling, perception, emotion and interaction; electroencephalography and BCI; and AI and augmented cognition.