In the situation of pandemic with people being ill, contagious, or suffering from long-term effects, touchless human computer interfaces, and especially brain computer interfaces (BCI), could provide humans with safe communication technologies as well as user-centric systems for rehabilitation. Hence, this work studies at first the representation of electroencephalogram (EEG) signals in a data space which is appropriate for an efficient data processing and a user-friendly interpretation. Then, we propose 3D data visualizations mapping the human brain activity into that data space. The developed representations have been successfully tested within a BCI framework through 3D data visualizations the user can see and interact with in real time.