Complex cognitive tasks such as language comprehension, reasoning and learning rely on our brains' ability to temporary maintain and manipulate information, that is, working memory (WM) (Baddeley, 1992). The phase coupling is fundamental neural mechanism that supports neural communication and it is therefore an apparent prospect for the underlying neural mechanism of the WM. Indeed, the role of phase coupling in memory processes has been studied extensively and the literature supports the relevance of phase coupling in memory processes (see Fell and Axmacher, 2011 for review). The majority of the studies examining the phase coupling in WM have relied on EEG data. Moreover, most of the studies have evaluated the phase coupling in sensor space, which, as discussed earlier in this review, is problematic. Here we focus on those WM studies that have examined the role of phase coupling in source space using MEG data, with the benefit of being more specific about the involved brain areas.
