According to one account – the internal orienting hypothesis – the DMN is activated during a variety of conditions involving internally-oriented attention [18], [26]. The DMN is not only active during rest and retrieval, but also during other internally-oriented task conditions, including thinking about the past and the future [27], [28], self-referential processing [29], and visual imagery [30]. At the same time, the DMN shows deactivation during demanding tasks requiring externally-oriented, rather than internal, attention [3]. Extrapolating these findings to memory, the internal orienting account holds that during successful retrieval, the DMN shows enhanced activity due to the orienting of attention to internalized mnemonic representations. In contrast, during successful encoding of study items, which is strongly dependent on externally-oriented attention [31], the DMN should show deactivation due to the efficient suppression of internally-oriented thoughts [3]. Despite the plausibility of this account in relation to memory, the role of internal attention in memory-related DMN activations has never been tested.
