The effects of mental synchronization can be achieved by deep learning and big data analysis based on EEG data. However, this natural phenomenon can also be observed through other experiments. UCLA’s experiment is about the automatic synchronization of metronomes.
Also a research has been going on at Princeton University for years, The Global Consciousness Project, that has shown a synchronous effect between relevant events affecting the population and random number generators of IT devices.
UCLA – Synchronization of metronomes: video
Princeton – The Global Consciousness Project: website