Systems and methods detect a multicomponent brain-based bio-signal in non-brain internal body tissues and cavities of a patient, such as the mouth and nostrils. Sub-component signals are filtered from the multi-component signal to isolate occurrences of physiological activities that correspond to the sub-component signals, such as eye movement, heart function, respiration, and body movement. Based on detections of certain body activities from the sub-component signals, the control of or display of a body monitoring device is influenced by such detections.
