More evidence (this time in humans) that top-down vs bottom-up cortical processing depends on synchrony in different frequency bands, lower frequencies (beta) for top-down and higher frequencies (gamma) for bottom-up. There was cross-frequency coupling such that gamma power in auditory cortex was modulated by phase of beta in the anterior cingulate (but not the other way around).  Top-down and bottom-up processing alternattively dominated.  Thus, the brain uses both frequency- and time-multiplexing to optimize directional flow of information.

The contribution of frequency-specific activity to hierarchical information processing in the human auditory cortex.
L. Fontolan, B. Morillon, C. Liegeois-Chauvel & Anne-Lise Giraud

About the Author

The Miller Lab uses experimental and theoretical approaches to study the neural basis of the high-level cognitive functions that underlie complex goal-directed behavior.