Brain oscillatory correlates of working memory constraints.

It has been claimed that the coordination of neuronal oscillations differing in frequency is relevant for cognition. However, the validity of this claim has scarcely been investigated. Recent studies revealed that cross-frequency phase coupling and modulations of alpha-power dissociate between retention of relevant and suppression of irrelevant information in visual working memory (WM). We summarize these important results, and discuss possible implications for understanding the neural mechanisms of WM constraints.