“…It is possible that higher performances could be achieved by exploring the discriminative power of further sleep specific neuronal phenomena: Quantifying the presence of K-complex waves (Colrain, 2005;Loomis et al, 1938), sleep spindles (Andrillon et al, 2011;Contreras and Steriade, 1996), bursts of high-frequency gamma oscillations (Ayoub et al, 2012;Dalal et al, 2010;Le Van Quyen et al, 2010;Valderrama et al, 2012;Worrell et al, 2012), monofractal and multifractal properties of the human sleep EEG (Weiss et al, 2009(Weiss et al, , 2011Zorick and Mandelkern, 2013) and including them in the proposed DSVM method could potentially lead to an even better classification. The detection of some of these phenomena might be enhanced by recent methodological developments (Ahmed et al, 2009;Babadi et al, 2012;Chaibi et al, 2012Chaibi et al, , 2013Chaibi et al, , 2014Jaleel et al, 2014;Nonclercq et al, 2013;O'Reilly and Nielsen, 2014a,b;Warby et al, 2014;Worrell et al, 2012). Furthermore, features such as cross-frequency interactions, longrange coupling among distant electrodes and long-range temporal correlations may also provide efficient novel markers for distinct sleep stages.…”