“…Recently, correction schemes have been proposed in order to recover some assumed properties of the phase variables (Kralemann et al, 2007(Kralemann et al, , 2008Revzen and Guckenheimer, 2008). Measures for the strength of interactions can then be derived by exploiting phase differences either statistically (Lachaux et al, 1999;Mormann et al, 2000;Kalitzin et al, 2002;Canolty et al, 2006;Chavez et al, 2006a;Schelter et al, 2006Schelter et al, , 2007Stam et al, 2007b) or via information-theoretical approaches (Tass et al, 1998), and the direction of interactions can be quantified with a phase modeling approach Smirnov and Bezruchko, 2003;Cimponeriu et al, 2003;Paluš and Stefanovska, 2003;Smirnov and Andrzejak, 2005;Bahraminasab et al, 2008;Smirnov and Bezruchko, 2009).…”