Specialization for different memory dimensions in brain activity evoked by cued recollection

Abstract

Cued recollection involves the retrieval of different features of the encoded event. Previous research has shown that the recollection of complex events jointly recruits the Default Mode and the Frontoparietal Control networks, but the degree to which activity within these networks varies as a function of the particular memory dimension (e.g., the “when-what-where” information) remains largely unknown. In the present functional Magnetic Resonance Imaging (fMRI) study, human participants retrieved specific information about a previously encoded TV show to assess the veracity of detailed sentences along four memory dimensions (i.e., object and character details, spatial layouts, temporal sequences, verbal dialogues). A common activity for all dimensions was observed in a left-lateralized network of regions that largely overlaps with the Frontoparietal Control Network (FPCN), including the lateral prefrontal, lateral superior parietal, and lateral temporal cortex. Instead, a larger degree of specialization for different memory dimensions was observed within the Default Mode Network (DMN), particularly in its posterior nodes. Dimension-related specificity in both networks was associated with memory performance across subjects. Finally, a clear leftward asymmetry was observed in the DMN for all dimensions except for the temporal one, whereas the FPCN showed a bilateral activation across dimensions. The present results generally support the view that specific memory information is processed by a mosaic of regions within large portions of the associative cortex involved in higher-order mnemonic functions.