What role, if any, do neuronal oscillations play in shaping computation and communication in large-scale brain networks? There is increasing interest in this question for several reasons. First, electrical brain activity is now commonly recorded at a variety of different scales, each of which exhibits oscillatory activity correlated with functional activation. Recordings from these different spatial scales include not only spikes from single neurons but also measures of synchronized population activity such as the local field potential (LFP) – recorded from penetrating microelectrodes and reflecting the activity of several tens of thousands of nerve cells – to the subdural electrocorticogram (ECoG) – recorded from clinical macroelectrodes and reflecting activity of several million cells – to the noninvasive electro- and magneto-encephalogram (EEG/MEG) at the largest scales, reflecting the simultaneous activity of multiple cortical areas [1]. Despite the wide range of population sizes generating each type of signal, decades of research have revealed distinct frequency bands common across different signal types that exhibit characteristic changes in response to sensory, motor, and cognitive events [2–4].
