This book constitutes the refereed proceedings of 17th International Conference, AC 2023, held as part of the 25th International Conference, HCI International 2023, which was held virtually in Copenhagen, Denmark in July 2023. The total of 1578 papers and 396 posters included in the HCII 2023 proceedings was carefully reviewed and selected from 7472 submissions. The AC 2023 conference focuses on topics related to Brain-Computer Interfaces and neurotechnology; neuroergonomics, physiological measurements, and human performance; evolving theory and practice of AC; Augmented and Virtual Reality for AC; as well as understanding human cognition and performance in IT security.