I would like to follow the Nature article https://www.nature.com/articles/d41586-018-06694-6 about voltage imaging of brains, about use of GEVI - Genetically Encoded Voltage Indicators. But I am having hard time using Google search - it does not give any recent (2018, 2019) articles about human brain research, about more high level conclusions from the results from the lower level animals.
Where and how should I search for articles about voltage imaging of human brains? I am specifically interested in human brains, i.e. in cognitive processes.