Introduction to the Proceedings of the 8th International Conference on Spatial Cognition: Cognition and Action in a Plurality of Spaces (ICSC 2021) : Publication of this supplement was funded by the 8th International Conference on Spatial Cognition: Cognition and Action in a Plurality of Spaces (ICSC 2021). All contents were reviewed and approved by the experts of the ICSC 2021 Scientific Committee, which held full responsibility for the selection and acceptance of abstracts and papers September 13-17, 2021