Oscillatory synchrony in the brain has been shown to undergo significant changes during visual processing (e.g., Eckhorn et al.,
1988; Gray, Konig, Engel, & Singer,
1989) and during various tasks (Jensen, Kaiser, & Lachaux,
2007). Neuronal synchrony has been proposed to play a role in mediating contextual interactions among local stimulus attributes (Eckhorn,
1994; Singer,
1999; Tallon-Baudry & Bertrand,
1999) and in selective attentional processing (M. Bauer, Oostenveld, Peeters, & Fries,
2006; Gruber, Muller, Keil, & Elbert,
1999; Womelsdorf & Fries,
2007). Mechanistically, local synchrony among neuronal populations may enhance the impact of signals on downstream targets through more effective summation at postsynaptic neurons (Salinas & Sejnowski,
2001). The role of selective
phase synchronization between neuronal populations involved in stimulus processing has initially been emphasized in the original “binding-by-synchrony” hypothesis (Singer,
1999) but also more recently by Fries (
2005) to selectively strengthen the effective connectivity between different neuronal populations. Computational studies have demonstrated that oscillatory dynamics can modulate network responses to inputs (Borgers, Epstein, & Kopell,
2008; Zeitler, Fries, & Gielen,
2008) and can, in principle, accurately and selectively control the gain of signal flow between networks (Akam & Kullmann,
2010).