Brain activity is distributed over the 3-dimensional volume and evolves in time. Mapping spatio-temporal distribution of brain activation with high spatial resolution and high temporal resolution is of great importance for understanding the brain and aiding in the clinical diagnosis and management of brain disorders. Electrophysiological source imaging (ESI) from noninvasively recorded high density electroencephalogram (EEG) has played a significant role in advancing our ability to image brain function and dysfunction. We will discuss principles and current state of EEG-based ESI in localizing and imaging human brain activity with applications to imaging epileptic networks. I will also discuss our recent progress in noninvasive brain-computer interface, for controlling of a drone or robotic arm from noninvasive EEG signals using a motor imagery paradigm. Our work in a group of human subjects further demonstrate the enhanced capability in subjects with meditation/yoga training, compared with controls.