In line with the hippocampal coupling hypothesis, HF showed an exception to the DMN encoding/retrieval flip pattern. Although large portions of both left and right HF were identified by as part of the DMN by the resting state analysis, this region showed a different activation pattern. Rather than an encoding/retrieval flip and regardless of encoding orientation (Int-Enc/Ext-Enc), increased activity in HF was not only associated with successful retrieval, but also with successful encoding. This finding further substantiates overwhelming evidence indicating a critical role of HF in both encoding and retrieval [38], [39], [40]. This is the first study to clearly show that HF was activated together with the other DMN regions - as indentified independently on the basis of resting-state data - during retrieval, but not during encoding. These findings raise some important questions regarding the precise link between HF and the DMN.
