Brain oscillations are salient features of active neural networks, with specific frequency rhythms correlated to sensory perception and cognitive performance, including conscious awareness, memory, and stimulus processing [Llinas and Ribary, 1993; Klimesch et al., 1997, 2001; Basar et al., 2001a]. These electrophysiological markers are highly heritable [van Beijsterveldt and Boomsma, 1994; van Beijsterveldt et al., 1996] and are modulated by neurotransmitters and signal transduction factors, qualities that make them advantageous as intermediate phenotypes or endophenotypes that are less complex, quantitative, and more proximate to gene function than traditional cognitive measures and clinical diagnoses that are more influenced by individual and familial environmental factors [Tsuang and Faraone, 2000; Begleiter and Porjesz, 2006].
