Oscillatory coupling reveals the dynamic reorganization of networks processing reward, maintaining working memory and controlling attention

摘要

It is unclear how the brain dynamically forms and reforms different large-scale networks underlying specific cognitive operations across different phases of a given task. Here we show that when subjects were given the opportunity to earn a large reward, theta and beta oscillations over prefrontal regions formed a distributed network defined by the coupling of these distinct frequencies. Next, we found that as subjects maintained a representation of a target object in visual working memory, theta and alpha oscillations across frontoparietal areas formed a network distinct from that related to processing reward. Then, as the subjects searched for a target object in complex visual scenes, theta and alpha oscillations across frontotemporal areas formed a third spatially distinct network related to the deployment of visual attention and perceptual analysis of the search array. We found that our measures of network synchronization strength were robust trial-by-trial predictors of upcoming network formation and behavioral response speed and success. These findings are consistent with the hypothesis that oscillatory synchrony is the mechanism for providing fast dynamic regulation of active brain networks, and suggest a functional role for inter-regional cross-frequency interactions in the human brain.