“…The historical evolution of QEEG will be explored with emphasis on significant steps its development. The following will be highlighted: 1) Early steps in quantification that pave the way, including normative equations (John et al, 1980), source localization (Pascual-Marqui, Esslen, Kochi, & Lehman, 2002), and Default Mode Network (Buckner, AndrewsHanna, & Schacter, 2008); 2) QEEG treatment predictive biomarkers, including cognitive decline (Jelic et al, 2000;Prichep et al, 2006) and OCD (Dohrmann, Stengler, Jahn, & Olbrich, 2017); 3) QEEG as a surrogate for advanced neuroimaging, including TBI (Hanley et al, 2017) and chronic pain (Prichep et al, 2017). Impact of the "perfect storm" represented by advances over the last decade in technology, signal processing, and machine learning classification methodologies will be discussed in this context.…”