The purpose of this study is to explore the functional and physiological effects associated with the use of High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM), as supplemental care, for symptoms of neurological, cardiovascular, and neuropsychological disorders. This is a non-randomized, open label, and unblinded before-and-after trial, evaluating the effect of HIRREM on an objective, physiological common denominator (heart rate variability, HRV), across a variety of relevant conditions, as well as changes in clinical symptoms inventories, to generate hypotheses and pilot data for investigation in future proposals.