Interareal oscillatory synchronization in top-down neocortical processing

- Top-down processing in the neocortex supports important cognitive functions.
- Top-down neocortical influences are carried by interareal beta-frequency synchrony.
- Large-scale distributed networks may be the source of top-down neocortical influence.
- Top-down beta-frequency synchrony may convey behavioral context to sensory cortex.

Top-down processing in the neocortex underlies important cognitive functions such as predictive coding and attentional set. We review evidence indicating that top-down neocortical processes are carried by interareal synchrony, particularly in the beta frequency band. We hypothesize that top-down neocortical signals in the beta band convey behavioral context to low-level sensory neurons. We further speculate that large-scale distributed networks, self-organized at the highest hierarchical levels, are the source of top-down signals in the neocortex.