“…Unfortunately, the functional role of the second and higher-order harmonics remains elusive, and most paradigms involving harmonic responses to date uses them as a stimulus-tagging method (Andersen, Fuchs, & Muller, 2011; Andersen, Muller, & Hillyard, 2015; J. Ding, Sperling, & Srinivasan, 2006; Itthipuripat, Garcia, & Serences, 2013; Muller et al, 2006; Ordikhani-Seyedlar, Sorensen, Kjaer, Siebner, & Puthusserypady, 2014; Scherbaum, Frisch, & Dshemuchadse, 2016; Toffanin, de Jong, Johnson, & Martens, 2009), with little discussion of their specific role in brain function. Nonetheless, taken together it is possible that the basal increase in absolute alpha amplitude, while not directly affecting the induced alpha oscillatory response amplitude, might have impeded the simultaneous entrainment of neurons to fundamental and harmonic frequencies.…”